Separations

16 pages, 5693 KiB

Open AccessArticle

Separation of Metal and Cathode Materials from Waste Lithium Iron Phosphate Battery by Electrostatic Process

by Huabing Zhu, Yuxuan Bai, Lei Zu, Haijun Bi and Jian Wen

Separations 2023, 10(3), 220; https://doi.org/10.3390/separations10030220 - 22 Mar 2023

Cited by 4 | Viewed by 2168

The improper disposal of retired lithium batteries will cause environmental pollution and a waste of resources. In this study, a waste lithium iron phosphate battery was used as a raw material, and cathode and metal materials in the battery were separated and recovered [...] Read more.

The improper disposal of retired lithium batteries will cause environmental pollution and a waste of resources. In this study, a waste lithium iron phosphate battery was used as a raw material, and cathode and metal materials in the battery were separated and recovered by mechanical crushing and electrostatic separation technology. The effects on material electrostatic separation of separation parameters such as the crushing particle size, the voltage of the static electrode, and the rotating speed of the grounding rotor were all studied combined with trajectory simulation and separation experiments. The results show that the crushing particle size of the material has the most significant impact on the separation effect, and the material separation effect primarily occurs in the range of 0.2–2.0 mm particle sizes. When the voltage of the static electrode is 30 kV, the rotating speed of the grounded rotor is 60 r/min, and the particle size is 0.4–0.8 mm, and the recovery rates for aluminum, copper, and lithium iron phosphate reach 93.2%, 91.1%, and 97.1%, respectively. In the recovery process for waste lithium batteries, using electrostatic separation technology instead of high-temperature roasting or chemical leaching can effectively improve the separation efficiency and reduce secondary pollution. Full article

(This article belongs to the Special Issue Advances in Materials for Separations: Energy and Environment)

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12 pages, 5601 KiB

Open AccessArticle

ZIF-8 Assisted Polyacrylamide Functionalized Silica Core-Shell Stationary Phase for Hydrophilic Interaction Liquid Chromatography

by Tong Zhang, Yijing Li, Xiaofeng Lu, Yong Guo, Licheng Wang and Xiaojing Liang

Separations 2023, 10(3), 219; https://doi.org/10.3390/separations10030219 - 22 Mar 2023

Viewed by 1268

Abstract

A novel ZIF-8 assisted polyacrylamide functionalized silica polar stationary phase was prepared by a facile method of adding ZIF-8 nanoparticles and silica into polyacrylamide (PAM) aqueous solution, and then stirring the mixture until the solution was evaporated absolutely with the help of mechanical [...] Read more.

A novel ZIF-8 assisted polyacrylamide functionalized silica polar stationary phase was prepared by a facile method of adding ZIF-8 nanoparticles and silica into polyacrylamide (PAM) aqueous solution, and then stirring the mixture until the solution was evaporated absolutely with the help of mechanical agitator. Interestingly, the prepared stationary phase (PAM-Sil@ZIF-8/PAM) showed favorable hydrophilicity, as demonstrated by good separation performance and strong retention ability toward several types of polar compounds, such as amino acids, saccharides, and alkaloids. In addition, PAM-Sil@ZIF-8(50 mg)/PAM showed better separation performance compared with amino-modified silica and Sil/PAM stationary phase due to the addition of ZIF-8. Furthermore, it was demonstrated that the addition of ZIF-8 improved the specific surface area and provided extra interaction sites for the stationary phase and analytes, which is beneficial for the separation of samples. In addition, the column efficiency can reach 7861.9 plates/m for colchicine. Moreover, it exhibited good stability and reproducibility under our operation conditions. In short, a novel stationary phase, which can be used for hydrophilic interaction liquid chromatography, was obtained and proved that the separation performance of polymer modifying silica stationary phase can be greatly improved by the addition of MOF nanoparticles. Full article

(This article belongs to the Section Chromatographic Separations)

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15 pages, 11418 KiB

Open AccessArticle

Isolation and In Vitro Stability Studies of Edible Plant-Seed Derived (Raphani Semen) Nanoparticles

by Jiahui An and Yi Zhu

Separations 2023, 10(3), 218; https://doi.org/10.3390/separations10030218 - 21 Mar 2023

Viewed by 1658

Abstract

(1) Background: Edible plant-derived nanoparticles contain large amounts of endogenous substances and can be used as carriers for disease treatment. However, the extraction rate and purity are not high. Raphani Semen, the dried seed of the Raphanus sativus L., has been used as [...] Read more.

(1) Background: Edible plant-derived nanoparticles contain large amounts of endogenous substances and can be used as carriers for disease treatment. However, the extraction rate and purity are not high. Raphani Semen, the dried seed of the Raphanus sativus L., has been used as food and medicine for clinical treatment and health care for many years. (2) Methods: This study began with the extraction of edible Raphani Semen-derived nanoparticles (ERDNs) by ultracentrifugation (UC). Then a new method was proposed for ERDNs to be extracted by polyethylene glycol (PEG) and purified by size exclusion chromatography (SEC), followed by SDS-PAGE for identified proteins. The stability of ERDNs was also verified in three digestion simulations. (3) Results: The PEG offered higher yields of 1.14–2.31 mg/g than UC. Transmission electron microscopy showed both UC and PEG with cup-shaped nanoparticles of around 200 nm. The SEC-purified ERDNs contained a range of proteins smaller than 70 kDa. The size stability of ERDNs in digestion solutions demonstrated their ability to withstand extreme conditions, confirming their potential as a nano drug delivery platform. (4) Conclusions: In conclusion, the data suggest that PEG+SEC could isolate ERDNs with high efficiency, providing a reference for the separation of other seed nanoparticles. Full article

(This article belongs to the Section Purification Technology)

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19 pages, 686 KiB

Open AccessReview

Mycotoxins in Seafood: Occurrence, Recent Development of Analytical Techniques and Future Challenges

by Slim Smaoui, Teresa D’Amore, Sofia Agriopoulou and Amin Mousavi Khaneghah

Separations 2023, 10(3), 217; https://doi.org/10.3390/separations10030217 - 20 Mar 2023

Cited by 3 | Viewed by 2340

Abstract

The co-occurrence of mycotoxigenic fungi and mycotoxins in aquatic food commodities has recently become a source of severe worldwide food insecurity since these toxicants may damage human health. The consumption of aquatic food itself represents a relatively novel and non-negligible source of mycotoxins. [...] Read more.

The co-occurrence of mycotoxigenic fungi and mycotoxins in aquatic food commodities has recently become a source of severe worldwide food insecurity since these toxicants may damage human health. The consumption of aquatic food itself represents a relatively novel and non-negligible source of mycotoxins. Mycotoxins in seafood lead to important human genotoxins, carcinogens, and immunosuppressors. Consequently, it is crucial to quantify and characterize these contaminants in aquatic food products subject to extensive consumption and develop new regulations. The present paper provides an overview of recent advancements in liquid chromatography and mass spectrometry and the coupling of these techniques for identifying and characterizing mycotoxins in various fresh, comestible, and treated marine products. The disposable data display that a multiplicity of fungal species and further mycotoxins have been detected in seafood, comprising aflatoxins, ochratoxins, fumonisins, deoxynivalenol, zearalenone, and trichothecenes. In addition, a wider and up-to-date overview of global occurrence surveys of mycotoxin occurrence in seafood in 2017–2022 is explored. In this regard, the predominant occurrence of enniatins has been documented in seafood products. Likewise, special attention has been given to current EU seafood legal and existing national regulations of mycotoxins in seafood. In this way, rigorous national and international guidelines are needed for palpable and effective measures in the future. Nevertheless, controlling mycotoxins in aquatic foods is an ambitious aim for scientists and industry stakeholders to ensure sustainable global food safety. Full article

(This article belongs to the Section Forensics/Toxins)

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10 pages, 1025 KiB

Open AccessArticle

Study on Separation of Rhenium, a Surrogate Element of Fissiogenic Technetium, from Aqueous Matrices Using Ion-Selective Extraction Chromatographic Resins

by M. Ferdous Alam, Zinnat A. Begum, Yoshiaki Furusho, Hyoe Takata and Ismail M. M. Rahman

Separations 2023, 10(3), 216; https://doi.org/10.3390/separations10030216 - 20 Mar 2023

Cited by 1 | Viewed by 1321

Abstract

Long-lived fissiogenic technetium, ⁹⁹Tc (half-life, 2.11 × 10⁵ yrs), is a byproduct of the ²³⁵U and ²³⁹Pu fission in nuclear reactors and is a major component in nuclear waste. Hence, the monitoring of ⁹⁹Tc activity in the environmental [...] Read more.

Long-lived fissiogenic technetium, ⁹⁹Tc (half-life, 2.11 × 10⁵ yrs), is a byproduct of the ²³⁵U and ²³⁹Pu fission in nuclear reactors and is a major component in nuclear waste. Hence, the monitoring of ⁹⁹Tc activity in the environmental samples is essential. Techniques used to measure ⁹⁹Tc in environmental samples include radiometric and non-radiometric approaches. Inductively coupled plasma mass spectrometry (ICP-MS) has some advantages among the methods due to its high sample throughput, better selectivity, and commercial availability. Rhenium (Re) is often used as the non-isotopic tracer during ⁹⁹Tc measurement by ICP-MS. From this perspective, studying the separation behavior of Re from the aqueous matrix can provide helpful insight regarding the ecological monitoring of ⁹⁹Tc. In the current work, three extraction chromatographic resins (ECRs), MetaSEP AnaLig Tc-01, MetaSEP AnaLig Tc-02, and Eichrom TRU, have been used to separate Re from the aqueous matrix. Operating variables, such as solution pH, choice of eluent and eluent concentration, matrix cation effect, and retention capacity, have been studied to optimize the separation protocol. The extraction and recovery behavior of Re was used to interpret the selectivity behavior of the ECRs. The Re separation factor at optimized operating conditions comparing with Mo and Ru (interfering elements during the measurement by ICP-MS) for Meta SEP AnaLig Tc-01, Meta SEP AnaLig Tc-02, and Eichrom TRU resin, respectively, are SF_Re/Mo~32, 16.51, and ∞ (metal not retained at all), while SF_Re/Ru~∞, 3.25, 5437. In terms of selectivity and retention capacity, MetaSEP AnaLig Tc-01 is the better choice for selective separation of Re, and, assumably so, also Tc, from the aqueous matrices. Full article

(This article belongs to the Section Environmental Separations)

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12 pages, 302 KiB

Open AccessArticle

LC-MS/MS and GC-MS Analysis for the Identification of Bioactive Metabolites Responsible for the Antioxidant and Antibacterial Activities of Lygodium microphyllum (Cav.) R. Br.

by Wuen Yew Teoh, Yoong Soon Yong, Faizan Naeem Razali, Sarah Stephenie, Muhammad Dawood Shah, Jen Kit Tan, Charles Gnanaraj and Norhaizan Mohd Esa

Separations 2023, 10(3), 215; https://doi.org/10.3390/separations10030215 - 20 Mar 2023

Cited by 5 | Viewed by 3487

Abstract

Natural products serve as a valuable source of antioxidants with potential health benefits for various conditions. Lygodium microphyllum (Cav.) R. Br., also known as Old World climbing fern, is an invasive climbing fern native to Southeast Asia, Africa, South America, Australia, and Melanesia. [...] Read more.

Natural products serve as a valuable source of antioxidants with potential health benefits for various conditions. Lygodium microphyllum (Cav.) R. Br., also known as Old World climbing fern, is an invasive climbing fern native to Southeast Asia, Africa, South America, Australia, and Melanesia. It has been reported to possess interesting pharmacological properties including hepatoprotective and anti-inflammatory mechanisms. This study analyzed the potential bioactive metabolites that contribute to the antioxidant and antimicrobial effects of L. microphyllum (LM) by profiling the crude extract using high-resolution LC-MS/MS and GC-MS systems. Several classes of compounds such as phenolics, flavonoids, terpenoids, steroids, macrolides, vitamins, lipids, and other hydrocarbons were found in the crude extract of LM through non-targeted analysis. A total of 74 compounds were detected in LC-MS/MS, whereas a total of nine compounds were identified in GC-MS. Out of the 74 compounds detected in LC-MS/MS, 34 compounds, primarily quercetin, kaempferol, trifolin, pyroglutamic acid, arachidonic acid, and rutin were reported with antioxidant, antimicrobial, anti-inflammatory, and hepatoprotective activities. The presence of phenolic and flavonoid compounds with reported bioactivities in the crude extract of LM evidence its pharmacological properties. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

16 pages, 1841 KiB

Open AccessArticle

Isolation and Purification of Single Gold Nanoclusters by Alternate Pumping Chromatography

by Malvina Supper, Virginia Birner, Lukas Gromotka, Wolfgang Peukert and Malte Kaspereit

Separations 2023, 10(3), 214; https://doi.org/10.3390/separations10030214 - 18 Mar 2023

Viewed by 1309

Abstract

Alternate pumping chromatography is applied to obtain atomically precise glutathione-stabilized gold nanoclusters in high purity from synthesized mixtures. On the basis of anion exchange chromatography, the feasibility of isolating a single cluster, Au

_{10}

GSH

_{10}

, as well as two different clusters [...] Read more.

Alternate pumping chromatography is applied to obtain atomically precise glutathione-stabilized gold nanoclusters in high purity from synthesized mixtures. On the basis of anion exchange chromatography, the feasibility of isolating a single cluster, Au

_{10}

GSH

_{10}

, as well as two different clusters simultaneously (Au

_{25}

GSH

_{18}

and Au

_{29}

GSH

_{20}

) is demonstrated. In addition, Au

_{18}

GSH

_{14}

, which is present only in trace amounts, is successfully enriched. A simple design procedure is proposed that allows using columns with different retention behavior. Successful experiments with large injection amounts confirm the potential of the concept for preparative-scale productions of high-quality nanoparticulate products. Full article

(This article belongs to the Topic Advances in Chemistry and Chemical Engineering)

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17 pages, 5879 KiB

Open AccessArticle

Mechanism of Separation of Contaminants from Activated Carbon by Closed Cycle Temperature Swing Desorption

by Tianzhe Shi, Ning Qiang, Tao Liu, Jiao He, Haichao Miao, Zhaohai Li, Yiqi Cao, Shumin Chen and Xianbin Shi

Separations 2023, 10(3), 213; https://doi.org/10.3390/separations10030213 - 18 Mar 2023

Cited by 1 | Viewed by 1379

Abstract

In this paper, the mechanism of separation of volatile organic compounds (VOCs) from activated carbon adsorption beds during closed cycle temperature swing desorption was studied. Toluene gas at different concentrations was used as the gas for closed cycle temperature swing desorption to regenerate [...] Read more.

In this paper, the mechanism of separation of volatile organic compounds (VOCs) from activated carbon adsorption beds during closed cycle temperature swing desorption was studied. Toluene gas at different concentrations was used as the gas for closed cycle temperature swing desorption to regenerate activated carbon beds saturated with toluene. This research advances our understanding of the separation of contaminants from activated carbon and the mechanism of the process by which waste gas with a background concentration desorbs activated carbon in hot gas with a background concentration, establishing a technological foundation for the closed cycle temperature swing desorption process of activated carbon. When the background concentration was 2 g/m³, the average desorption rates of unit activated carbon at 10 cm in 40 min and 60 min were the largest, at 0.0099 and 0.0067 g/ (g•min), respectively. The fit of the Bangham desorption rate equation was the best. When the background concentration of toluene was 2 g/m³ and the filling length of the activated carbon layer was 10 cm, the desorption rate constant was the highest, at 0.0152 min⁻¹. Full article

(This article belongs to the Section Environmental Separations)

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17 pages, 3415 KiB

Open AccessArticle

Biomass-Based Silica/Calcium Carbonate Nanocomposites for the Adsorptive Removal of Escherichia coli from Aqueous Suspensions

by Ibrahim Birma Bwatanglang, Samuel T. Magili, Faruq Mohammad, Hamad A. Al-Lohedan and Ahmed A. Soleiman

Separations 2023, 10(3), 212; https://doi.org/10.3390/separations10030212 - 18 Mar 2023

Cited by 2 | Viewed by 1378

Abstract

The present study deals with the adsorptive removal of Escherichia coli (E. coli) by making use of chitosan-silica/calcium carbonate (CS-SiO₂/CaCO₃) nanocomposites (NCs) where it was synthesized using the waste eggshells and rice husks occurred by natural sources. [...] Read more.

The present study deals with the adsorptive removal of Escherichia coli (E. coli) by making use of chitosan-silica/calcium carbonate (CS-SiO₂/CaCO₃) nanocomposites (NCs) where it was synthesized using the waste eggshells and rice husks occurred by natural sources. The bioadsorbent CS-SiO₂/CaCO₃ NCs were synthesized by incorporating eggshell-CaCO₃ nanoparticles (NPs) and rice husk-SiO₂ NPs in chitosan NPs solution. The adsorbents were characterized using HRTEM, BET, DLS, and TGA. The characterization of NCs revealed the formation of adsorbents in the range of 10–50 nm and some structural changes to the spectra of adsorbents before and after the adsorption of E. coli was revealed by the FTIR analysis. Moreover, the adsorption efficiency of E. coli over the adsorbents after 35 min of incubation was about 80% for CS-SiO₂/CaCO₃ NCs. Further, the kinetics of adsorption studies were observed to be well-fitted to the Langmuir isotherm model with an adsorption capacity of 3.18 × 10¹ (CFU E. coil per gram of CS-SiO₂/CaCO₃). From the analysis, the synthesized bioadsorbent demonstrated the potential for ameliorating the inherent risk of pathogens in water. Full article

(This article belongs to the Special Issue Advanced Techniques in the Separation Processes and Development of Novel Adsorbents)

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12 pages, 3646 KiB

Open AccessArticle

Effect of Functional Groups on Protein Adsorption Performance of Membrane Adsorbers

by Lifang Zhang, Jialin Yang, Yiqing Yan and Weidong Zhang

Separations 2023, 10(3), 211; https://doi.org/10.3390/separations10030211 - 18 Mar 2023

Viewed by 1239

Abstract

Functional groups on support membranes are important for the preparation of high-performance membrane adsorbers (MAs). In this work, the effects of different functional groups on support membranes on the adsorption performance of MAs were studied through surface modifications such as alkali treatment, oxidation [...] Read more.

Functional groups on support membranes are important for the preparation of high-performance membrane adsorbers (MAs). In this work, the effects of different functional groups on support membranes on the adsorption performance of MAs were studied through surface modifications such as alkali treatment, oxidation treatment and polydopamine (PDA) deposition. Our experiment results indicate that chemical bonds are prone to form between C-F on PVDF membrane and amine groups on PEI, which serves to improve the protein adsorption capacity. Furthermore, PDA deposition has the potential to enhance protein adsorption capacity. Introducing a PDA layer on a support membrane with uniform pore size distribution shows potential to improve protein adsorption capacity. Full article

(This article belongs to the Section Materials in Separation Science)

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19 pages, 12001 KiB

Open AccessArticle

Moringa oleifera L. Screening: SFE-CO₂ Optimisation and Chemical Composition of Seed, Leaf, and Root Extracts as Potential Cosmetic Ingredients

by Júlia C. Kessler, Yaidelin A. Manrique, Isabel M. Martins, Alírio E. Rodrigues, Maria Filomena Barreiro and Madalena M. Dias

Separations 2023, 10(3), 210; https://doi.org/10.3390/separations10030210 - 17 Mar 2023

Viewed by 1380

Abstract

Moringa oleifera L. tree (Mo) has emerged as a rich alternative source of bioactive compounds to design cosmetic formulations. Supercritical carbon dioxide fluid extraction (SFE-CO₂) was successfully applied on the screening of Mo seed, leaf, and root extracts. The extraction yield [...] Read more.

Moringa oleifera L. tree (Mo) has emerged as a rich alternative source of bioactive compounds to design cosmetic formulations. Supercritical carbon dioxide fluid extraction (SFE-CO₂) was successfully applied on the screening of Mo seed, leaf, and root extracts. The extraction yield was evaluated by response surface methodology (RSM), for pressure and temperature ranges of 117–273 bar and 41–60 °C, respectively, using a design of experiments (DOE). The pressure significantly affected the results (

α = 0.05

), with the highest extraction efficiency obtained at conditions above 195 bar. The extracts’ composition, evaluated by gas chromatography-mass spectrometer (GC-MS), revealed an increasing correlation between the pressure, total extract solubility, and mass of extract at a constant temperature, due to the higher extraction yield. Seed extracts presented more than 80% of oleic acid in relative composition (8.04 mg_compound∙g_plantpart⁻¹). Leaf extracts performed well for the obtainment of linolenic acid (>20%; 3.10 mg∙g⁻¹), nonacosane (>22%; 0.46 mg∙g⁻¹), and α-tocopherol (>20%; 0.21 mg∙g⁻¹). Mo root resulted in higher relative composition for sterol molecules, despite its very low affinity with CO₂. The most promising bioactive compounds, oleic acid and α-tocopherol, were more abundant when operating at 250 bar at 45 °C and 195 bar at 55 °C, for Mo seed and leaf SFE-CO₂ extracts, respectively. Full article

(This article belongs to the Topic New Trends on Separation and Extraction of Bioactive Compounds and Respective Applications)

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15 pages, 1120 KiB

Open AccessArticle

Flavonol-Glycoside and Rare Triterpenoid Derivatives Isolated from Leaves of Combretum glutinosum Perr. Ex Dc. with In Vitro Cytotoxic Activity

by Sherouk Hussein Sweilam, Maha B. O. Ebrahim, Mehnaz Kamal, El-Sayed Khafagy, Ashraf N. Abdalla, Mohamed E. Elzubier and Ehssan H. Moglad

Separations 2023, 10(3), 209; https://doi.org/10.3390/separations10030209 - 17 Mar 2023

Cited by 1 | Viewed by 1611

Abstract

Combretaceae plants are used traditionally by many cultures, especially in Sudanese patients for the treatment of diverse ailments such as anti-inflammatory, antimicrobial, antitumor, and antioxidant disorders. Of these plants, the genus Combretum are traditional medicinal plants. Thus, they are formed from the non-polar [...] Read more.

Combretaceae plants are used traditionally by many cultures, especially in Sudanese patients for the treatment of diverse ailments such as anti-inflammatory, antimicrobial, antitumor, and antioxidant disorders. Of these plants, the genus Combretum are traditional medicinal plants. Thus, they are formed from the non-polar or polar extracts of many isolated phytochemicals. Of these necessities, the use of Combretum extracts for their medicinal properties can be found in the earliest of myths and traditions used to document the plants’ ability to treat diseases. Combretum glutinosum Perr. Ex Dc. is a common shrub native to the African continent, especially Sudan. Currently, there are no published data regarding its cytotoxic activity. Additionally, there are few chemical and biological reports of C. glutinosum. Therefore, the current study aimed to isolate the chemical bioactive compounds (1–6) from the ethyl acetate (EtOAc) extract of C. glutinosum. A new flavonoid compound, namely, glutosinumoside (4), was afforded, and five known compounds were obtained: three oleanane-glycosides (1–3) and two phenolic acids (5,6). The structures of the six compounds were determined by spectroscopic analysis, including one- and two-dimensional (1D and 2D) NMR, mass spectrometry, and chromatographic analysis. Moreover, an in vitro cytotoxic evaluation of the successive extracts and the bioactive EtOAc fractions of C. glutinosum against MCF7 (breast), HT29 (colon), HepG2 (liver), and MRC5 (normal lung) cell lines was performed. The isolated compounds showed comparable cytotoxic activities with the crude EtOH extract and doxorubicin against the tested cell lines. Compounds (1) and (6) exhibited the highest cytotoxicity against MCF7 (1.37 ± 0.21 and 1.48 ± 0.34 µg/mL, respectively) and HepG2 (3.30 ± 0.02 and 2.10 ± 0.22 µg/mL, respectively) in the MTT assay. In addition, compounds (1) and (3) demonstrated a significant upregulation of cancer’s two important hallmarks (caspase 3 and bax genes) by inducing apoptosis and perturbing the MCF7 cell cycle. Full article

(This article belongs to the Special Issue Extraction, Purification and Structure Elucidation of Active Natural Compounds)

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16 pages, 2265 KiB

Open AccessArticle

Concurrent Optimization of Ultrasonic-Assisted Extraction of Total Phenolic Compounds and In Vitro Anticancer and Antioxidant Potential of Pulicaria schimperi (Aerial Parts) Using Response Surface Methodology

by Perwez Alam, Omer I. Fantoukh, Mohammed Asaker, Omer M. Almarfadi, Ali Akhtar, Gadah A. Al-Hamoud, Mohammed F. Hawwal and Ali S. Alqahtani

Separations 2023, 10(3), 208; https://doi.org/10.3390/separations10030208 - 17 Mar 2023

Viewed by 1285

Abstract

This study aimed to maximize the dependent variables [total phenolic content (TPC), antioxidant (DPPH and ABTS), and anticancer activities (against HepG2 and MCF-7 cells)] from P. schimperi aerial parts by optimizing three independent variables (extraction temperature, extraction time, and liquid-to-solid ratio) of ultrasound-assisted [...] Read more.

This study aimed to maximize the dependent variables [total phenolic content (TPC), antioxidant (DPPH and ABTS), and anticancer activities (against HepG2 and MCF-7 cells)] from P. schimperi aerial parts by optimizing three independent variables (extraction temperature, extraction time, and liquid-to-solid ratio) of ultrasound-assisted extraction (UAE) using the Box–Behnken design (BBD) of response surface methodology (RSM). For each of the dependent variables, the projected quadratic models were found to be very significant (p < 0.001). The extraction temperature and extraction time had a significant impact on the TPC extraction, antioxidant, and anticancer properties (p < 0.05). The best conditions were identified as an extraction temperature of 54.4 °C, extraction time of 48 min, and liquid-to-solid ratios of 20.72 mL/g for the simultaneous extraction of the TPC, antioxidant, and anticancer properties of P. schimperi. The experimental results and the expected values agreed under these circumstances. Regarding the high extraction effectiveness and antioxidant and anticancer effects at comparably low extraction temperature and duration, UAE demonstrated considerable benefits over conventional solvent extraction (CSE). This improved UAE approach has shown a potential use for effective polyphenolic antioxidant extraction from P. schimperi aerial parts in the nutraceutical sectors. Full article

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25 pages, 1692 KiB

Open AccessReview

The Role of Selective Flavonoids on Triple-Negative Breast Cancer: An Update

by Pooja Chinnikrishnan, Ibrahim Abdel Aziz Ibrahim, Abdullah R. Alzahrani, Naiyer Shahzad, Prathibha Sivaprakasam and Ashok Kumar Pandurangan

Separations 2023, 10(3), 207; https://doi.org/10.3390/separations10030207 - 16 Mar 2023

Cited by 1 | Viewed by 3119

Abstract

Among the many types of breast cancer (BC), Triple-Negative Breast Cancer (TNBC) is the most alarming. It lacks receptors for the three main biomarkers: estrogen, progesterone, and human epidermal growth factor, hence the name TNBC. This makes its treatment a challenge. Surgical procedures [...] Read more.

Among the many types of breast cancer (BC), Triple-Negative Breast Cancer (TNBC) is the most alarming. It lacks receptors for the three main biomarkers: estrogen, progesterone, and human epidermal growth factor, hence the name TNBC. This makes its treatment a challenge. Surgical procedures and chemotherapy, performed either alone or in combination, seem to be the primary therapeutic possibilities; however, they are accompanied by severe complications. Currently, the formulation of drugs using natural products has been playing an important role in the pharmaceutical industries, owing to the drugs’ increased efficacies and significantly lessened side effects. Hence, treating TNBC with chemotherapeutic drugs developed using natural products such as flavonoids in the near future is much warranted. Flavonoids are metabolic compounds largely present in all plants, vegetables, and fruits, such as blueberries, onions, (which are widely used to make red wine,) chocolates, etc. Flavonoids are known to have enormous health benefits, such as anticancer, antiviral, anti-inflammatory, and antiallergic properties. They are known to arrest the cell cycle of the tumor cells and induces apoptosis by modulating Bcl-2, Bax, and Caspase activity. They show a considerable effect on cell proliferation and viability and angiogenesis. Various studies were performed at both the biochemical and molecular levels. The importance of flavonoids in cancer treatment and its methods of extraction and purification to date have been reported as individual publications. However, this review article explains the potentiality of flavonoids against TNBC in the preclinical levels and also emphasizes their molecular mechanism of action, along with a brief introduction to its methods of extraction, isolation, and purification in general, emphasizing the fact that its quantum of yield if enhanced and its possible synergistic effects with existing chemotherapeutics may pave the way for better anticancer agents of natural origin and significantly lessened side-effects. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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12 pages, 3687 KiB

Open AccessArticle

Efficient Oxidative Desulfurization of High-Sulfur Diesel via Peroxide Oxidation Using Citric, Pimelic, and α-Ketoglutaric Acids

by Barham Sharif Ahmed, Luqman Omar Hamasalih, Kosar Hikmat Hama Aziz, Yousif M. Salih, Fryad S. Mustafa and Khalid Mohammad Omer

Separations 2023, 10(3), 206; https://doi.org/10.3390/separations10030206 - 15 Mar 2023

Cited by 4 | Viewed by 2260

Abstract

The widespread use of diesel fuel for transportation, industry, and electricity generation causes several environmental issues via an increase in the amount of sulfur compound emissions. Commercial diesel fuel must be free of sulfur-containing compounds since they can cause several environmental problems. Considering [...] Read more.

The widespread use of diesel fuel for transportation, industry, and electricity generation causes several environmental issues via an increase in the amount of sulfur compound emissions. Commercial diesel fuel must be free of sulfur-containing compounds since they can cause several environmental problems. Considering the currently available processes to eliminate sulfur compounds, oxidative desulfurization (ODS) is one of the effective means for this purpose. This work presented a simple, low cost, and efficient ODS system of high-sulfur diesel fuels using peroxide oxidation with the aid of citric, pimelic, and α-ketoglutaric acids. The aim of the study was to investigate the potential of these acids as hydrogen peroxide (H₂O₂) activators for ODS and to optimize the reaction conditions for maximum sulfur removal. The results showed that citric, pimelic, and α-ketoglutaric acids were effective catalysts for the desulfurization of high-sulfur diesel with an initial sulfur content of 2568 mg L⁻¹, achieving a sulfur removal efficiency of up to 95%. The optimized reaction conditions were found to be 0.6 g of carboxylic acid dosage and 10 mL of H₂O₂ at 95 °C. The desulfurization efficiency of the real diesel sample (2568 mg L⁻¹) was shown to be 27, 34, and 84.57%, using citric acid, α-ketoglutaric acid, and pimelic acid after 1h, respectively. The effectiveness of the oxidation process was characterized by gas chromatographic pulsed flame photometric detector (GC-PFPD) and Fourier-transform infrared spectroscopy (FTIR) techniques. The experimental results demonstrated that the developed system exhibited high efficiency for desulfurization of real high-sulfur diesel fuels that could be a good alternative for commercial application with a promising desulfurization efficiency. Full article

(This article belongs to the Section Purification Technology)

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20 pages, 3214 KiB

Open AccessReview

Review of Artificial Nacre for Oil–Water Separation

by Apriliana Cahya Khayrani, Nonni Soraya Sambudi, Hans Wijaya, Yose Fachmi Buys, Fitri Ayu Radini, Norwahyu Jusoh, Norashikin Ahmad Kamal and Hazwani Suhaimi

Separations 2023, 10(3), 205; https://doi.org/10.3390/separations10030205 - 15 Mar 2023

Cited by 1 | Viewed by 2254

Abstract

Due to their extraordinary prospective uses, particularly in the areas of oil–water separation, underwater superoleophobic materials have gained increasing attention. Thus, artificial nacre has become an attractive candidate for oil–water separation due to its superhydrophilicity and underwater superoleophobicity properties. Synthesized artificial nacre has [...] Read more.

Due to their extraordinary prospective uses, particularly in the areas of oil–water separation, underwater superoleophobic materials have gained increasing attention. Thus, artificial nacre has become an attractive candidate for oil–water separation due to its superhydrophilicity and underwater superoleophobicity properties. Synthesized artificial nacre has successfully achieved a high mechanical strength that is close to or even surpasses the mechanical strength of natural nacre. This can be attributed to suitable synthesis methods, the selection of inorganic fillers and polymer matrices, and the enhancement of the mechanical properties through cross-linking, covalent group modification, or mineralization. The utilization of nacre-inspired composite membranes for emerging applications, i.e., is oily wastewater treatment, is highlighted in this review. The membranes show that full separation of oil and water can be achieved, which enables their applications in seawater environments. The self-cleaning mechanism’s basic functioning and antifouling tips are also concluded in this review. Full article

(This article belongs to the Special Issue Removal of Emerging Pollutants and Environmental Analysis)

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12 pages, 2051 KiB

Open AccessArticle

Self-Declared and Measured Prevalence of Glucocorticoid Use in Polish Athletes

by Andrzej Pokrywka, Daria Berezovska, Sylwia Lewandowska-Pachecka, Jarosław Krzywański, Michał Rynkowski, Mariola Wicka, Dorota Kwiatkowska and Raphael Faiss

Separations 2023, 10(3), 204; https://doi.org/10.3390/separations10030204 - 15 Mar 2023

Viewed by 1524

Abstract

Glucocorticoids (GCs) are included in the list of prohibited substances and methods in sport published annually by the World Anti-Doping Agency (WADA). In its 2022 update, the WADA list prohibits all injectable routes of administration of GCs for use during in-competition periods. Previously, [...] Read more.

Glucocorticoids (GCs) are included in the list of prohibited substances and methods in sport published annually by the World Anti-Doping Agency (WADA). In its 2022 update, the WADA list prohibits all injectable routes of administration of GCs for use during in-competition periods. Previously, GCs were prohibited in-competition when administered by oral, intravenous, intramuscular, or rectal routes, but local injections (in addition to topical applications) were allowed. This study first investigated the prevalence of GC use by athletes in Poland, declared in 2130 doping control forms, and the related 2130 urine samples analysed at the Polish Anti-Doping Laboratory. Second, the validity of the analytical methodology to detect GCs was evaluated with the updated WADA requirement for substance-specific minimum reporting levels and considering the proposed washout periods. Despite the new regulation in place, the use of 30 different GC preparations were declared in a total of 162 occurrences (8% of the tests) with therapeutic purposes. Laboratory analyses resulted in the presence of GCs in 16 occurrences with only two samples with a concentration triggering an adverse analytical finding. Our study allowed us to confirm that the applied methodology for the determination of GCs in urine samples (ultra-high-performance liquid chromatography–tandem mass spectrometry) remains fully valid after the latter regulation change while the challenge to assess the timing and administration route for GCs persists. Full article

(This article belongs to the Topic Application of Analytical Chemistry in Exercise Physiology and Pharmacology)

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11 pages, 1556 KiB

Open AccessArticle

Rapid Simultaneous Determination of 11 Synthetic Cannabinoids in Urine by Liquid Chromatography-Triple Quadrupole Mass Spectrometry

by Jianbing Wu, Fan Zhang, Xing Ke, Wei Jia, Xuzhi Wan, Lange Zhang, Yilei Fan and Jing Zhou

Separations 2023, 10(3), 203; https://doi.org/10.3390/separations10030203 - 14 Mar 2023

Cited by 2 | Viewed by 1623

Abstract

Synthetic cannabinoids are a series of synthetic substances that mimic the effects of natural cannabinoids and produce a much stronger toxicity than natural cannabinoids, and they have become the most abused family of new psychoactive substances. A solid-phase extraction–liquid chromatography–triple quadrupole/linear ion trap [...] Read more.

Synthetic cannabinoids are a series of synthetic substances that mimic the effects of natural cannabinoids and produce a much stronger toxicity than natural cannabinoids, and they have become the most abused family of new psychoactive substances. A solid-phase extraction–liquid chromatography–triple quadrupole/linear ion trap mass spectrometry method has been developed to determine 11 synthetic cannabinoids in rat urine. Oasis HLB cartridge was selected to simultaneously extract synthetic cannabinoids for pretreatment. The effects of the loading solution and elution reagent volume on the recovery were investigated. The optimized acetonitrile proportion and elution reagent volume were determined by both high recovery and low solvent consumption. The results showed that the linear coefficients of determination of 11 types of synthetic cannabinoids ranged from 0.993 to 0.999, the limit of quantitation ranged from 0.01 to 0.1 ng/mL, and the spiked recoveries ranged from 69.90% to 118.39%. The research presented here provides a validated liquid chromatography tandem mass spectrometry method to accurately identify and quantitate synthetic cannabinoid metabolites in urine samples. Full article

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15 pages, 1865 KiB

Open AccessEditor’s ChoiceArticle

Development and Validation of a Confirmatory Method for the Determination of 12 Coccidiostat Residues in Eggs and Muscle by Means of Liquid Chromatography Coupled to Hybrid High Resolution Mass Spectrometry

by Federica Castellani, Matteo Ricci, Maria Novella Colagrande, Giampiero Scortichini and Giorgio Saluti

Separations 2023, 10(3), 202; https://doi.org/10.3390/separations10030202 - 14 Mar 2023

Cited by 5 | Viewed by 1646

Abstract

A confirmatory, highly selective multi-residue method based on liquid chromatography coupled to hybrid high resolution mass spectrometry (LC-Q-Orbitrap) was developed and validated for the determination of 12 regulated coccidiostats in eggs and muscle. Particularly, ionophore antibiotics (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) [...] Read more.

A confirmatory, highly selective multi-residue method based on liquid chromatography coupled to hybrid high resolution mass spectrometry (LC-Q-Orbitrap) was developed and validated for the determination of 12 regulated coccidiostats in eggs and muscle. Particularly, ionophore antibiotics (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) and synthetic coccidiostats (diclazuril, halofuginone, nicarbazin as 4,4′-dinitrocarbanilide fraction, robenidine and toltrazuril as toltrazuril-sulphone) were included in the method. The sample preparation consisted in the extraction of the analytes from the matrix with acetonitrile, followed by a clean-up step with Oasis^® PRiME HLB SPE and a defatting procedure with n-hexane. Validation was successfully performed according to Commission Implementing Regulation (EU) 2021/808, starting from 1 µg kg⁻¹. The procedure was verified through the analysis of a certified reference material (CRM) and the occurrence of the residues was assessed in the context of the Italian National Residue Control Plan (NRCP). Full article

(This article belongs to the Special Issue Novel Applications of Separation Technology)

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15 pages, 1548 KiB

Open AccessArticle

Uncertainty of Postmortem Time Estimation Based on Potassium Ion Determination in Vitreous Humor Using Potentiometric Ion-Selective Electrode and Microwave-Induced Plasma with Optical Emission Spectrometry Methods

by Sonia Zięba, Marek Wiergowski, Bartłomiej Michał Cieślik, Jacek Sein Anand and Marta Krzyżanowska

Separations 2023, 10(3), 201; https://doi.org/10.3390/separations10030201 - 14 Mar 2023

Cited by 1 | Viewed by 1567

Abstract

There is a need for a reliable and independent evaluation and confirmation of the postmortem interval (PMI) based on objective factors other than only postmortem changes or temperature measurements. Estimating the PMI by examining the concentration of potassium ions in the vitreous humor [...] Read more.

There is a need for a reliable and independent evaluation and confirmation of the postmortem interval (PMI) based on objective factors other than only postmortem changes or temperature measurements. Estimating the PMI by examining the concentration of potassium ions in the vitreous humor (VH) has a tradition in forensic toxicology dating back to the mid-20th century. So far, the methods for determining the presence of potassium ions have not been characterized in terms of the measurement uncertainty of types A and B, which directly affect the estimation of time of death uncertainty. The study evaluated the uncertainty of the determination of potassium ion concentrations using potentiometric ion-selective electrode (ISE) and microwave-induced plasma with optical emission spectrometry (MIP-OES) methods. In addition, the influence of the estimated measurement uncertainty on the results of the analysis of potassium ions in the VH was investigated. The estimated values of the expanded uncertainty determined by the type A experimental method indicate lower uncertainty in the determination of potassium ion concentration in the case of MIP-OES than ISE; that is, for concentrations of 2, 10, and 25 mg/L of potassium ions, the expanded uncertainties by MIP-OES were 1.2%, 2.2%, and 2.5% and the uncertainties by ISE were 12.2%, 6.1%, and 3.1%, respectively. Similarly, in the case of estimating the uncertainty of type B, the MIP-OES method compared to ISE was characterized by almost two times lower expanded uncertainty; that is, for MIP-OES, it was 2.53%, and for ISE, it was 4.75%. Both methods of uncertainty estimation, types A and B, can be used interchangeably, as they provide comparable results. Full article

(This article belongs to the Section Forensics/Toxins)

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18 pages, 4078 KiB

Open AccessArticle

Effective Removal of Methylene Blue by Mn₃O₄/NiO Nanocomposite under Visible Light

by Komal Majeed, Jaweria Ambreen, Saeed Ahmed Khan, Saz Muhammad, Aqeel Ahmed Shah, Muhammad Ali Bhatti, Syeda Sitwat Batool, Muhammad Farooq, Syed Nizam Uddin Shah Bukhari, Ali Dad Chandio, Sadaf Jamal Gilani and May Nasser Bin Jumah

Separations 2023, 10(3), 200; https://doi.org/10.3390/separations10030200 - 14 Mar 2023

Cited by 4 | Viewed by 2038

Abstract

Wastewater treatment is indispensable as wastewater can lead to adverse health effects and deteriorate the quality of life on earth. Photocatalysis is a facile methodology to address this issue. In this study, nanocomposites (NCs) of manganese oxide (Mn₃O₄) and [...] Read more.

Wastewater treatment is indispensable as wastewater can lead to adverse health effects and deteriorate the quality of life on earth. Photocatalysis is a facile methodology to address this issue. In this study, nanocomposites (NCs) of manganese oxide (Mn₃O₄) and nickel oxide (NiO) were synthesized in different weight ratios via the solid-state reaction route. Structural properties, optical properties, surface morphology, and functional group analysis of the synthesized nanomaterials were conducted using X-ray diffraction (XRD), UV– Vis spectroscopy, scanning electron microscopy (SEM) along with energy-dispersive X-ray (EDX) analysis, and Fourier-transform infrared (FTIR) spectroscopy, respectively. The bandgap of the nanocomposite decreases significantly from 2.35 eV for the Mn₃O₄ NPs to 1.65 eV for the Mn₃O₄/NiO nanocomposite (NC). Moreover, adsorption studies followed by the photocatalytic performance of the Mn₃O₄/NiO NCs were evaluated to determine the removal of methylene blue (MB) dye from wastewater. The photocatalytic performance of the nanocomposite enhances as the ratio of Mn₃O₄ in the composite increases from one weight percentage to three weight percentage. The photocatalytic degradation efficiency was calculated to be 95%. The results show that the synthesized NCs could play an important role in photocatalytic wastewater purification and environmental remediation. Full article

(This article belongs to the Special Issue Extraction and Analysis of Emerging Environmental Pollutants)

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11 pages, 969 KiB

Open AccessArticle

A Validated HPLC-RID Method for Quantification and Optimization of Total Sugars: Fructose, Glucose, Sucrose, and Lactose in Eggless Mayonnaise

by Mrityunjay Tiwari, Sandesh Mhatre, Tejas Vyas, Arohi Bapna and Govindarajan Raghavan

Separations 2023, 10(3), 199; https://doi.org/10.3390/separations10030199 - 14 Mar 2023

Cited by 2 | Viewed by 7763

Abstract

Mayonnaise is an oil-in-water emulsion containing 70–80% finely dispersed droplets of oil in a continuous phase of water. Since mayonnaise has a sour and acidic taste, its sugar profile is barely noticed and thus often disregarded. However, today, there are various variants of [...] Read more.

Mayonnaise is an oil-in-water emulsion containing 70–80% finely dispersed droplets of oil in a continuous phase of water. Since mayonnaise has a sour and acidic taste, its sugar profile is barely noticed and thus often disregarded. However, today, there are various variants of mayonnaise available on the market; hence, it is crucial to understand their mono- and disaccharide profile, in order to determine the precise total sugar composition. The traditional methods of sugar analysis available, such as titration, can only quantify sucrose and are unable to differentiate between mono- and disaccharides. The aim of this study was to develop and validate a method for the quantification of total sugars, including fructose, glucose, sucrose, and lactose, in eggless mayonnaise, using a high performance liquid chromatography refractive index detector (HPLC-RID). Sugars were separated on an amino column with an oven temperature of 35 °C, using an isocratic solvent system consisting of a 75:25 v/v mixture of acetonitrile and HPLC water, at a 0.9 mL/min flow rate with RID. Method validation was performed for the linearity, specificity, precision, accuracy, LOD, LOQ, and robustness. A linearity for total sugars, with a regression coefficient of 0.9998, was obtained within the range of 0.05024 to 10.048 mg/mL. The relative standard deviation was less than 2.0% for the intra-day and inter-day precision. The accuracy was found to be 96.78–108.88% using a three-level recovery method. The LOD and LOQ were also found to be suitable. The samples used in this study contained 0.24–10.32% total sugars. The sucrose value obtained matched the label claim of the products and no significant differences were observed between results in a paired sample t-test. This showed the applicability of the proposed method for analyzing the sugar profile in a finished product. Routine analysis of total sugars in eggless mayonnaise and similar finished products can thus be performed using this technique, which was found to be simple, rapid, and reproducible. Full article

(This article belongs to the Special Issue Development of Highly Efficient Separation-Based Analytical Methods for Food Integrity Assurance)

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12 pages, 1852 KiB

Open AccessArticle

Comparative GC Analysis, Bronchodilator Effect and the Detailed Mechanism of Their Main Component—Cinnamaldehyde of Three Cinnamon Species

by Najeeb Ur Rehman, Faisal F. Albaqami, Mohammad Ayman A. Salkini, Noureldin M. Farahat, Hatim H. Alharbi, Saad M. Almuqrin, Maged S. Abdel-Kader and Asmaa E. Sherif

Separations 2023, 10(3), 198; https://doi.org/10.3390/separations10030198 - 13 Mar 2023

Cited by 1 | Viewed by 1799

Abstract

Cinnamon is one of the most commonly used spices worldwide. In some Arab countries, cinnamon is used with other ingredients to relieve bronchospasm and treatment of airways-related disorders. In the current study, GC, GC-MS and tracheal relaxant effect comparison were performed using the [...] Read more.

Cinnamon is one of the most commonly used spices worldwide. In some Arab countries, cinnamon is used with other ingredients to relieve bronchospasm and treatment of airways-related disorders. In the current study, GC, GC-MS and tracheal relaxant effect comparison were performed using the three available types in Saudi Arabia, Cinnamomum verum (Ceylon cinnamon), C. cassia (Chinese cinnamon) and C. loureiroi (Vietnamese cinnamon). The essential oil of C. verum was the most potent in the relaxation of guinea pig isolated tracheal muscles against carbachol (CCh, 1 uM)-evoked bronchospasm at the concentration range from 0.03 to 3 mg/mL followed by C. bureiroi at 0.03 to 5 mg/mL; whereas, C. cassia was the least potent oil. Cinnamaldehyde (1), isolated as the main component of the three oils induced complete relaxation of low K⁺ (25 mM)-evoked contractions, with mild effect on the contractions evoked by high K⁺ (80 mM). Pre-incubation of the tracheal tissues with glibenclamide (10 μM) significantly opposed the relaxation of low K⁺ by cinnamaldehyde. The standard drug, cromakalim also inserted glibenclamide-sensitive inhibition of low K⁺ without relaxing high K⁺. These results indicate that cinnamaldehyde acts predominantly by ATP-specific K⁺ channel opening followed by weak Ca⁺⁺ antagonistic effects. The obtained results justify the medicinal value of cinnamon oil in respiratory disorders. Full article

(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)

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34 pages, 2021 KiB

Open AccessReview

Biochar as a Green Sorbent for Remediation of Polluted Soils and Associated Toxicity Risks: A Critical Review

by Ghulam Murtaza, Zeeshan Ahmed, Sayed M. Eldin, Iftikhar Ali, Muhammad Usman, Rashid Iqbal, Muhammad Rizwan, Usama K. Abdel-Hameed, Asif Ali Haider and Akash Tariq

Separations 2023, 10(3), 197; https://doi.org/10.3390/separations10030197 - 13 Mar 2023

Cited by 17 | Viewed by 4625

Abstract

Soil contamination with organic contaminants and various heavy metals has become a global environmental concern. Biochar application for the remediation of polluted soils may render a novel solution to soil contamination issues. However, the complexity of the decontaminating mechanisms and the real environment [...] Read more.

Soil contamination with organic contaminants and various heavy metals has become a global environmental concern. Biochar application for the remediation of polluted soils may render a novel solution to soil contamination issues. However, the complexity of the decontaminating mechanisms and the real environment significantly influences the preparation and large-scale application of biochar for soil ramification. This review paper highlights the utilization of biochar in immobilizing and eliminating the heavy metals and organic pollutants from contaminated soils and factors affecting the remediation efficacy of biochar. Furthermore, the risks related to biochar application in unpolluted agricultural soils are also debated. Biochar production conditions (pyrolysis temperature, feedstock type, and residence time) and the application rate greatly influence the biochar performance in remediating the contaminated soils. Biochars prepared at high temperatures (800 °C) contained more porosity and specific surface area, thus offering more adsorption potential. The redox and electrostatic adsorption contributed more to the adsorption of oxyanions, whereas ion exchange, complexation, and precipitation were mainly involved in the adsorption of cations. Volatile organic compounds (VOCs), dioxins, and polycyclic aromatic hydrocarbons (PAHs) produced during biochar pyrolysis induce negative impacts on soil alga, microbes, and plants. A careful selection of unpolluted feedstock and its compatibility with carbonization technology having suitable operating conditions is essential to avoid these impurities. It would help to prepare a specific biochar with desired features to target a particular pollutant at a specific site. This review provided explicit knowledge for developing a cost-effective, environment-friendly specific biochar, which could be used to decontaminate targeted polluted soils at a large scale. Furthermore, future study directions are also described to ensure a sustainable and safe application of biochar as a soil improver for the reclamation of polluted soils. Full article

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32 pages, 3193 KiB

Open AccessEditor’s ChoiceReview

Application of Hydrogen-Bonded Organic Frameworks in Environmental Remediation: Recent Advances and Future Trends

by Yu Zhang, Mengfei Tian, Zahid Majeed, Yuxin Xie, Kaili Zheng, Zidan Luo, Chunying Li and Chunjian Zhao

Separations 2023, 10(3), 196; https://doi.org/10.3390/separations10030196 - 13 Mar 2023

Cited by 6 | Viewed by 3331

Abstract

The hydrogen-bonded organic frameworks (HOFs) are a class of porous materials with crystalline frame structures, which are self-assembled from organic structures by hydrogen bonding in non-covalent bonds π-π packing and van der Waals force interaction. HOFs are widely used in environmental remediation due [...] Read more.

The hydrogen-bonded organic frameworks (HOFs) are a class of porous materials with crystalline frame structures, which are self-assembled from organic structures by hydrogen bonding in non-covalent bonds π-π packing and van der Waals force interaction. HOFs are widely used in environmental remediation due to their high specific surface area, ordered pore structure, pore modifiability, and post-synthesis adjustability of various physical and chemical forms. This work summarizes some rules for constructing stable HOFs and the synthesis of HOF-based materials (synthesis of HOFs, metallized HOFs, and HOF-derived materials). In addition, the applications of HOF-based materials in the field of environmental remediation are introduced, including adsorption and separation (NH₃, CO₂/CH₄ and CO₂/N₂, C₂H₂/C₂H_e and C_eH₆, C₂H₂/CO₂, Xe/Kr, etc.), heavy metal and radioactive metal adsorption, organic dye and pesticide adsorption, energy conversion (producing H₂ and CO₂ reduced to CO), organic dye degradation and pollutant sensing (metal ion, aniline, antibiotic, explosive steam, etc.). Finally, the current challenges and further studies of HOFs (such as functional modification, molecular simulation, application extension as remediation of contaminated soil, and cost assessment) are discussed. It is hoped that this work will help develop widespread applications for HOFs in removing a variety of pollutants from the environment. Full article

(This article belongs to the Special Issue Applications of Porous Materials in Adsorption)

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19 pages, 6815 KiB

Open AccessArticle

Study on the Removal of Chloride Ions in an Acidic Solution of Zinc Smelting by Green Method

by Zhiwen Xiao, Jing Li, Guang Fu, Xinpei Li, Likun Gu, Chaobo Zhang, Te Zhang, Weibo Yin, Dianchuan Liu and Junchang Liu

Separations 2023, 10(3), 195; https://doi.org/10.3390/separations10030195 - 13 Mar 2023

Cited by 1 | Viewed by 1710

Abstract

In the process of zinc smelting, when the chloride ion concentration exceeds 100 mg/L, it continuously corrodes the electrode plate and affects the stability of the electrodeposition process. Therefore, the chloride concentration must be reduced below 100 mg/L. Compared with other methods used [...] Read more.

In the process of zinc smelting, when the chloride ion concentration exceeds 100 mg/L, it continuously corrodes the electrode plate and affects the stability of the electrodeposition process. Therefore, the chloride concentration must be reduced below 100 mg/L. Compared with other methods used to control the reactions of Cu(II), the use of the copper slag produced in zinc smelting without other additives does not cause reverse dissolution; to reduce the cost, turn the waste into treasure, and protect the environment, research was carried out on chloride removal by the copper slag via a synergistic valence control process. In this study, the influencing factors, such as the amount of copper slag, the reaction time, and reaction temperature, were systematically investigated. The results showed that the optimum dechlorination conditions were as follows: the copper: copper(II): chloride molar ratio was 6:5:1, the reaction time was 60 min, and the reaction temperature was 20 °C. The chloride ion concentration was decreased from 1.6 g/L to 0.05 g/L, the dechlorination efficiency was 96.875%, and the residual chloride ion concentration was less than 100 mg/L, which provides a basis for industrial use. Full article

(This article belongs to the Special Issue Advanced Methods for Recovery of Valuable Metals from Waste)

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8 pages, 1102 KiB

Open AccessCommunication

Conceptual Design of a Compact Water Purification Unit Using Reed Bed Filtration

by Elias Farah, Maria Khalil, Manuella Richa and Chantal Abou Harb

Separations 2023, 10(3), 194; https://doi.org/10.3390/separations10030194 - 12 Mar 2023

Viewed by 2617

Abstract

One of the most widespread global challenges is the insufficient provision of potable water, which affects individuals across diverse geographical regions. It is anticipated that issues related to water scarcity and quality will escalate in tandem with the expanding human population and the [...] Read more.

One of the most widespread global challenges is the insufficient provision of potable water, which affects individuals across diverse geographical regions. It is anticipated that issues related to water scarcity and quality will escalate in tandem with the expanding human population and the rapid pace of global development. Water sources are massively polluted hence, not safe for drinking nor irrigation. As a consequence, it is very important to have a water purification treatment plant to provide good water quality. Given the pressing need to ensure universal access to safe and clean drinking water, this investigation aims to engineer a compact and space-efficient apparatus that can expeditiously produce purified water. The proposed system seeks to optimize water purification performance while minimizing spatial requirements and operational duration. Its size is minimized by combining the three processes: coagulation, flocculation, and clarification together in one tank. Following to the aforementioned reservoir, an integrated natural system is employed to reduce the usage of chemicals and establish an ecologically sustainable platform. A hydraulic study is conducted to obtain the dimensioning of the several units which can be later scaled according to the flowrate. The latter was assumed in this study to be 2 L/s, then the compact unit can serve up to 800 persons by scaling the model and adjusting it. Full article

(This article belongs to the Topic Sustainable Water Purification Technologies for Multiple Applications)

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13 pages, 4543 KiB

Open AccessArticle

Recovery of Carbon and Cryolite from Spent Carbon Anode Slag Using a Grinding Flotation Process Based on Mineralogical Characteristics

by Jiawei Zheng, Song Wang, Xuexia Wang, Muhammad Bilal, Zhiming Zhang, Sijie Yang, Changkai Jing, Guangqian Xu and Chao Ni

Separations 2023, 10(3), 193; https://doi.org/10.3390/separations10030193 - 12 Mar 2023

Cited by 2 | Viewed by 1666

Abstract

The aluminum electrolysis industry continually and unavoidably produces hazardous solid waste in the form of carbon anode slag. Carbon anode slag poses a serious environmental pollution risk, and it must be disposed of in a harmless manner. On the other hand, it contains [...] Read more.

The aluminum electrolysis industry continually and unavoidably produces hazardous solid waste in the form of carbon anode slag. Carbon anode slag poses a serious environmental pollution risk, and it must be disposed of in a harmless manner. On the other hand, it contains a few valuable resources, as well. In order for the aluminum electrolysis industry to develop in an environmentally friendly and high-quality manner, the harmless disposal of carbon anode slag and its resourceful utilization are of considerable importance. The selective comminution of carbon and cryolite particles in carbon anode slag can be effectively achieved with grinding pretreatment. However, the optimization study of grinding process parameters has yet to be investigated. Therefore, firstly, the mineralogical characteristics and existing mode of carbon anode slag from the perspective of mineralogical properties are analyzed in this study. Then, the effects of grinding time, grinding concentration, and steel ball diameter on the particle size of the ground product (γ_{−0.074 mm}) are investigated using response surface analysis. The results showed that the effect of grinding time was the most significant, followed by grinding concentration and steel ball diameter. In addition, the performance of the multi-stage flotation process for separating the −0.074 mm ground product was analyzed. Cryolite with a purity of 93.12% and a carbon product with an ash content of 10.67% could be simultaneously obtained through multi-stage flotation. It should be pointed out that the deep dissociation and efficient recovery of fine undissociated particles still need to be further explored. Full article

(This article belongs to the Special Issue Separation, Beneficiation, and Purification of Carbonaceous Minerals and Materials)

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14 pages, 2018 KiB

Open AccessArticle

Experimental and Computational Evaluation of 1,2,4-Triazolium-Based Ionic Liquids for Carbon Dioxide Capture

by Sulafa Abdalmageed Saadaldeen Mohammed, Wan Zaireen Nisa Yahya, Mohamad Azmi Bustam and Md Golam Kibria

Separations 2023, 10(3), 192; https://doi.org/10.3390/separations10030192 - 10 Mar 2023

Cited by 6 | Viewed by 1679

Abstract

Utilization of ionic liquids (ILs) for carbon dioxide (CO₂) capture is continuously growing, and further understanding of the factors that influence its solubility (notably for new ILs) is crucial. Herein, CO₂ absorption of two 1,2,4-triazolium-based ILs was compared with imidazolium-based [...] Read more.

Utilization of ionic liquids (ILs) for carbon dioxide (CO₂) capture is continuously growing, and further understanding of the factors that influence its solubility (notably for new ILs) is crucial. Herein, CO₂ absorption of two 1,2,4-triazolium-based ILs was compared with imidazolium-based Ils of different anions, namely bis(trifluoromethylsulfonyl)imide, tetrafluoroborate, and glycinate. The CO₂ absorption capacity was determined using an isochoric saturation method and compared with predicted solubility employing COnductor-like Screening Model for Real Solvents (COSMO-RS). To gain an understanding of the effects of cations and anions of the ILs on the CO₂ solubility, the molecular orbitals energy levels were calculated using TURBOMOLE. Triazolium-based ILs exhibit higher absorption capacity when compared to imidazolium-based ILs for the same anions. The results also showed that the anions’ energy levels are more determinant towards solubility than the cations’ energy levels, which can be explained by the higher tendency of CO₂ to accept electrons than to donate them. Full article

(This article belongs to the Special Issue Application of Ionic Liquids in Separation Science)

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18 pages, 4876 KiB

Open AccessEditor’s ChoiceArticle

Deep Eutectic Solvent-Based Microwave-Assisted Extraction for the Extraction of Seven Main Flavonoids from Ribes mandshuricum (Maxim.) Kom. Leaves

by Wei Wang, Si-Qiu Xiao, Ling-Yu Li and Qing-Yan Gai

Separations 2023, 10(3), 191; https://doi.org/10.3390/separations10030191 - 10 Mar 2023

Cited by 5 | Viewed by 1546

Abstract

Flavonoids exhibit many biological properties, so it is very important to find an efficient and green method to extract them from plant materials. In this paper, DES-MAE (deep eutectic solvent-based microwave-assisted extraction) technique was developed to extract the seven major active flavonoids from [...] Read more.

Flavonoids exhibit many biological properties, so it is very important to find an efficient and green method to extract them from plant materials. In this paper, DES-MAE (deep eutectic solvent-based microwave-assisted extraction) technique was developed to extract the seven major active flavonoids from Ribes mandshuricum leaves, namely, trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol. After the completion of the extraction process, macroporous adsorption resin was used for the purification of seven flavonoids. The BBD (Box–Behnken design) method combined with RSM (response surface methodology) was applied to acquire the optimal operating conditions of DES-MAE. The optimal parameters were: temperature: 54 °C, time: 10 min, extraction solvent: choline chloride/lactic acid with a 1:2 mass ratio, water content: 25%, and liquid/solid ratio: 27 mL/g. The yields of the seven target flavonoids were 4.78, 2.57, 1.25, 1.15, 0.34, 0.32, and 0.093 mg/g DW (dry weight), respectively. The direct purification of trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol in DES-MAE solution was achieved by using macroporous resin X-5. The recoveries were 87.02%, 81.37%, 79.64%, 87.13%, 97.36%, 88.08%, and 99.39%, respectively. The results showed that DES-MAE followed by MRCC (macroporous resin column chromatography) represents a promising approach to extracting and separating active components from plants. Full article

(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)

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