Next Article in Journal
Assessment of Systemic Toxicity, Genotoxicity, and Early Phase Hepatocarcinogenicity of Iron (III)-Tannic Acid Nanoparticles in Rats
Next Article in Special Issue
The Use of H2 in Catalytic Bromate Reduction by Nanoscale Heterogeneous Catalysts
Previous Article in Journal
Oxidation of Supported Nickel Nanoparticles at Low Exposure to O2: Charging Effects and Selective Surface Activity
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Editorial

Nano Geochemistry

1
Friedrich Schiller University Jena, Institute of Geosciences, Applied Geology, 07749 Jena, Germany
2
Civil and Environmental Engineering, Nazarbayev University, Nur-Sultan 010000, Kazakhstan
3
Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
*
Author to whom correspondence should be addressed.
Nanomaterials 2022, 12(7), 1039; https://doi.org/10.3390/nano12071039
Submission received: 9 March 2022 / Revised: 14 March 2022 / Accepted: 18 March 2022 / Published: 22 March 2022
It is our great pleasure to briefly introduce our motivation to collect scientific contributions for this Special Issue, entitled “Nano Geochemistry”. The geophysical and chemical dynamics at the solid–water interface, ultimately, control the transport properties of natural and engineered colloids/nanoparticles via, e.g., mineral dissolution/precipitation reactions and the variation in nano- to microscale surface roughness [1,2]. The nanoparticles present can significantly influence the mobility of strongly sorbing organic and/or inorganic contaminants in groundwater systems, frequently used as a drinking-water resource [3]. In addition, wetting/drying cycles in the vadose zone have attracted interest, concerning the mobility of organic nanoparticles/colloids [4], and the nanoparticle composition and element redox state can significantly change, especially in karst systems, due to seasonal variations [5]. More pronounced changes, due to extreme weather events, potentially triggered by climate change, have been observed [6]. The generation of these nanoparticles based on the nucleation and growth theory (classical or non-classical crystallization pathway) for the formation of nanoparticles in natural systems is still a matter of debate. It could be shown, e.g., for magnetite, that the nanoparticle formation in natural systems proceeds through rapid agglomeration of nanometric primary particles. In contrast to the nucleation of other minerals, no intermediate bulk phase is involved [7]. Nucleation and nanoparticle formation, associated with surfaces, are also key aspects of the formation of, e.g., Au ore deposits and hydrothermal vents [2,8], also referred to as the field of nanogeology [8].
Biomineralization is another field of active research, especially the study of magnetotactic bacteria (MTB), which attracts great interest. Due to their nano-sized magnetosomes (MS), which are biomineral crystals of either magnetite (Fe3O4) or greigite (Fe3S4), with a size range of 30–120 nm, the removal of heavy metals from wastewater, via an external magnetic field, might be very promising [9]. However, detailed investigations on, e.g., the economic suitability and cost-effective magnetic separator for metal recovery, amongst other things, are needed.
The shortage of freshwater, due to surface and groundwater contamination, is still creating a need for novel and sustainable water purification technologies in the global environmental technology market [10]. Diverse environmental technologies, such as adsorption and ion exchange, reverse osmosis, electro-catalysis, and biological redox processes, have all been developed, showing disadvantages to date. Thus, the market and environmental engineers have been looking for effective, promising water purification technologies, to satisfy novel operational, technological, and economic needs, with higher removal efficiency and selectivity. Nanomaterials bring a new hope towards efficient water purification, due to their high surface area and reactivity. In addition, advanced remediation strategies, using nano zero-valent iron (nZVI) or modified core-shell type functionalized nanoparticles, are available to decontaminate groundwater resources, under the prevailing geochemical conditions of the natural systems [11,12].
Extensive geochemical knowledge on the speciation of targeted contaminants in the environment can aid in the further fine-tuning of nanoadsorbents, leading to high selectivity and removal efficiency [13].
Among various nanoadsorbents, redox-sensitive nanoparticles (RSNPs) and composites can feature electron transfer on their surface, resulting in the redox transformation of contaminants. Direct electron gain by heavy metal ions and other contaminants can result in their reductive co-precipitation, while free radical generation in aqueous solutions can result in the degradation of organic contaminants [14,15]. nZVI and its composites are among the extensively explored RSNPs, for the remediation of contaminated soil and groundwater, and have brought about the revolution of remediation technologies [16], leading to the breakthrough of advanced water purification technologies, with diverse nanomaterials and their redox catalysis [17]. Extensive studies on the nanomaterial applications and natural and anthropogenic nano-catalysis have been carried out to remove heavy metals [18], organic chemicals [19,20], and radionuclides [21], effectively and selectively in the contaminated soil and groundwater plumes.
Direct application of these RSNPs is challenging due to their instantaneous oxidation; therefore, researchers are continuously exploring various methods for the preservation of RSNPs, such as encapsulation in polymers, use of supporting surfaces, like clays and carbon-based materials, antioxidant capping, etc., to prevent agglomeration and preserve their redox activity [11,12,22,23]. Moreover, anthropogenically influenced soils and water bodies may hold multiple contaminant loads. Therefore, the simultaneous removal or stabilization of multiple pollutants, with advanced redox-sensitive nanocomposites, is at the forefront of current scientific focus [14,23].
In industrial processes, e.g., the global cement industry, different raw materials, called supplementary cementitious materials (SCMs), are considered to replace part of the clinker in cement, which is discussed as one of the most successful strategies to reduce CO2 emissions globally [24]. Clays (montmorillonite, illite, kaolinite), nanoscale in nature, are the only material available in the quantities needed to meet the SCM demand, especially in those countries where a growth in demand for cement is forecast [24]. However, early cement hydration and rheology are key aspects [25,26], and future research directions need the mechanistic understanding of the SGM reaction pathways and the new design of appropriate superplasticizers. The mechanistic process understanding of nanomaterials is a prerequisite for the reliable prediction of the long-term behavior of the chemical compounds in the natural and engineered environment. Due to the advancement of high-energy X-ray beam spectroscopy (XAF and XANES) and supercomputing systems with molecular dynamic and DFT simulations, the reaction mechanisms of environmental contaminants on the surface of natural and anthropogenic nanomaterials could be more conveniently observed and identified, and the prediction of their molecular behaviors would provide more credible information on the nanomaterial applications for the successful remediation of contaminated underground environments [18,27].

Author Contributions

T.S., W.L. and G.K.D. did the writing together jointly—review and editing. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

Not applicable.

Acknowledgments

We would like to thank all authors and reviewers who have contributed to this Special Issue.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Liang, Y.; Zhou, J.; Dong, Y.; Klumpp, E.; Šimůnek, J.; Bradford, S.A. Evidence for the critical role of nanoscale surface roughness on the retention and release of silver nanoparticles in porous media. Environ. Pollut. 2020, 258, 113803. [Google Scholar] [CrossRef] [Green Version]
  2. Sharma, V.K.; Filip, J.; Zboril, R.; Varma, R.S. Natural inorganic nanoparticles—Formation, fate, and toxicity in the environment. Chem. Soc. Rev. 2015, 44, 8410–8423. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  3. Schäfer, T.; Huber, F.; Seher, H.; Missana, T.; Alonso, U.; Kumke, M.; Eidner, S.; Claret, F.; Enzmann, F. Nanoparticles and their influence on radionuclide mobility in deep geological formations. Appl. Geochem. 2012, 27, 390–403. [Google Scholar] [CrossRef]
  4. Liao, J.; Hu, C.; Li, X.; Ruan, J. Drying increases organic colloidal mobilization in the karst vadose zone: Evidence from a 15-year cave-monitoring study. Hydrol. Process. 2021, 35, e14163. [Google Scholar] [CrossRef]
  5. Einsiedl, F.; Mayer, B.; Schäfer, T. Evidence for Incorporation of H2S in Groundwater Fulvic Acids from Stable Isotope Ratios and Sulfur K-edge X-ray Absorption Near Edge Structure Spectroscopy. Environ. Sci. Technol. 2008, 42, 2439–2444. [Google Scholar] [CrossRef] [PubMed]
  6. Cholet, C.; Steinmann, M.; Charlier, J.B.; Denimal, S. Characterizing fluxes of trace metals related to dissolved and suspended matter during a storm event: Application to a karst aquifer using trace metals and rare earth elements as provenance indicators. Hydrogeol. J. 2019, 27, 305–319. [Google Scholar] [CrossRef]
  7. Baumgartner, J.; Dey, A.; Bomans, P.H.H.; Le Coadou, C.; Fratzl, P.; Sommerdijk, N.A.J.M.; Faivre, D. Nucleation and growth of magnetite from solution. Nat. Mater. 2013, 12, 310–314. [Google Scholar] [CrossRef]
  8. Ju, Y.W.; Huang, C.; Sun, Y.; Zou, C.N.; He, H.P.; Wan, Q.; Wang, X.Q.; Lu, X.C.; Lu, S.F.; Wu, J.G.; et al. Nanogeology in China: A review. China Geol. 2018, 1, 286–303. [Google Scholar] [CrossRef]
  9. Ali, I.; Peng, C.; Khan, Z.M.; Naz, I.; Sultan, M. An overview of heavy metal removal from wastewater using magnetotactic bacteria. J. Chem. Technol. Biotechnol. 2018, 93, 2817–2832. [Google Scholar] [CrossRef]
  10. Centi, G.; Perathoner, S. Remediation of water contamination using catalytic technologies. Appl. Catal. B Environ. 2003, 41, 15–29. [Google Scholar] [CrossRef]
  11. Stefaniuk, M.; Oleszczuk, P.; Ok, Y.S. Review on nano zero-valent iron (nZVI): From synthesis to environmental applications. Chem. Eng. J. 2016, 287, 618–632. [Google Scholar] [CrossRef]
  12. Raval, N.P.; Kumar, M. Geogenic arsenic removal through core-shell based functionalized nanoparticles: Groundwater in-situ treatment perspective in the post-COVID anthropocene. J. Hazard. Mater. 2021, 402, 123466. [Google Scholar] [CrossRef] [PubMed]
  13. Khandelwal, N.; Darbha, G.K. A decade of exploring MXenes as aquatic cleaners: Covering a broad range of contaminants, current challenges and future trends. Chemosphere 2021, 279, 130587. [Google Scholar] [CrossRef] [PubMed]
  14. Khandelwal, N.; Tiwari, E.; Singh, N.; Darbha, G.K. Heterogeneously Porous Multiadsorbent Clay-Biochar Surface to Support Redox-Sensitive Nanoparticles: Applications of Novel Clay-Biochar-Nanoscale Zerovalent Iron Nanotrident (C-BC-nZVI) in Continuous Water Filtration. ACS EST Water 2021, 1, 641–652. [Google Scholar] [CrossRef]
  15. Khandelwal, N.; Tiwari, E.; Singh, N.; Marsac, R.; Schafer, T.; Monikh, F.A.; Darbha, G.K. Impact of long-term storage of various redox-sensitive supported nanocomposites on their application in removal of dyes from wastewater: Mechanisms delineation through spectroscopic investigations. J. Hazard. Mater. 2021, 401, 123375. [Google Scholar] [CrossRef]
  16. Kumar, M.A.; Bae, S.; Han, S.; Chang, Y.; Lee, W. Reductive dechlorination of trichloroethylene by polyvinylpyrrolidone stabilized nanoscale zero-valent iron particles with Ni. J. Hazard. Mater. 2017, 340, 399–406. [Google Scholar] [CrossRef] [PubMed]
  17. Hamid, S.; Kumar, M.A.; Han, J.-I.; Kim, H.; Lee, W. Nitrate reduction on the surface of bimetallic catalysts supported by nano-crystalline beta-zeolite (NBeta). Green Chem. 2017, 19, 853–866. [Google Scholar] [CrossRef]
  18. Bae, S.; Sihn, Y.; Kyung, D.; Yoon, S.; Eom, T.; Kaplan, U.; Kim, H.; Schäfer, T.; Han, S.; Lee, W. Molecular Identification of Cr(VI) Removal Mechanism on Vivianite Surface. Environ. Sci. Technol. 2018, 52, 10647–10656. [Google Scholar] [CrossRef]
  19. Gong, J.; Lee, C.-S.; Kim, E.-J.; Kim, J.-H.; Lee, W.; Chang, Y.-S. Self-Generation of Reactive Oxygen Species on Crystalline AgBiO3 for the Oxidative Remediation of Organic Pollutants. ACS Appl. Mater. Interfaces 2017, 9, 28426–28432. [Google Scholar] [CrossRef]
  20. Prabhu, S.M.; Khan, A.; Hasmath Farzana, M.; Hwang, G.C.; Lee, W.; Lee, G. Synthesis and characterization of graphene oxide-doped nano-hydroxyapatite and its adsorption performance of toxic diazo dyes from aqueous solution. J. Mol. Liq. 2018, 269, 746–754. [Google Scholar] [CrossRef]
  21. Sihn, Y.H.; Byun, J.; Patel, H.A.; Lee, W.; Yavuz, C.T. Rapid extraction of uranium ions from seawater using novel porous polymeric adsorbents. RSC Adv. 2016, 6, 45968–45976. [Google Scholar] [CrossRef]
  22. Khandelwal, N.; Behera, M.P.; Rajak, J.K.; Darbha, G.K. Biochar-nZVI nanocomposite: Optimization of grain size and Fe-0 loading, application and removal mechanism of anionic metal species from soft water, hard water and groundwater. Clean Technol. Environ. 2020, 22, 1015–1024. [Google Scholar] [CrossRef]
  23. Khandelwal, N.; Darbha, G.K. Combined antioxidant capped and surface supported redox-sensitive nanoparticles for continuous elimination of multi-metallic species. Chem. Commun. 2021, 57, 7280–7283. [Google Scholar] [CrossRef]
  24. Scrivener, K.; Martirena, F.; Bishnoi, S.; Maity, S. Calcined clay limestone cements (LC3). Cem. Concr. Res. 2018, 114, 49–56. [Google Scholar] [CrossRef]
  25. Link, J.; Sowoidnich, T.; Pfitzner, C.; Gil-Diaz, T.; Heberling, F.; Lützenkirchen, J.; Schäfer, T.; Ludwig, H.-M.; Haist, M. The Influences of Cement Hydration and Temperature on the Thixotropy of Cement Paste. Materials 2020, 13, 1853. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  26. Bogner, A.; Link, J.; Baum, M.; Mahlbacher, M.; Gil-Diaz, T.; Lützenkirchen, J.; Sowoidnich, T.; Heberling, F.; Schäfer, T.; Ludwig, H.M.; et al. Early hydration and microstructure formation of Portland cement paste studied by oscillation rheology, isothermal calorimetry, 1H NMR relaxometry, conductance and SAXS. Cem. Concr. Res. 2020, 130, 105977. [Google Scholar] [CrossRef]
  27. Bae, S.; Yoon, S.; Kaplan, U.; Kim, H.; Han, S.; Lee, W. Effect of groundwater ions (Ca2+, Na+, and HCO3) on removal of hexavalent chromium by Fe(II)-phosphate mineral. J. Hazard. Mater. 2020, 398, 122948. [Google Scholar] [CrossRef] [PubMed]
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Schäfer, T.; Lee, W.; Darbha, G.K. Nano Geochemistry. Nanomaterials 2022, 12, 1039. https://doi.org/10.3390/nano12071039

AMA Style

Schäfer T, Lee W, Darbha GK. Nano Geochemistry. Nanomaterials. 2022; 12(7):1039. https://doi.org/10.3390/nano12071039

Chicago/Turabian Style

Schäfer, Thorsten, Woojin Lee, and Gopala Krishna Darbha. 2022. "Nano Geochemistry" Nanomaterials 12, no. 7: 1039. https://doi.org/10.3390/nano12071039

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop