Sustainability

Editorial

2 pages, 194 KiB

Open AccessEditorial

Editorial for the Special Issue on the Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City

by Zhitong Yao, Wei Qi and José Luiz Francisco Alves

Sustainability 2023, 15(1), 826; https://doi.org/10.3390/su15010826 - 03 Jan 2023

Cited by 1 | Viewed by 1238

Abstract

Cities around the world are expanding rapidly, taking up vast resources (e [...] Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

Research

Jump to: Editorial, Review

19 pages, 10079 KiB

Open AccessArticle

Chitosan/Silica Nanocomposite Preparation from Shrimp Shell and Its Adsorption Performance for Methylene Blue

by Tao Zhong, Meisheng Xia, Zhitong Yao and Chenhua Han

Sustainability 2023, 15(1), 47; https://doi.org/10.3390/su15010047 - 20 Dec 2022

Cited by 4 | Viewed by 1505

Abstract

In this study, novel chitosan/silica composites with different mass ratios were prepared by in-situ hydrolysis using chitosan (from shrimp shell) as a carrier, triblock copolymer (P123) as the structure-directing agent, and ethyl orthosilicate as a silicon source. These nanocomposites were characterized by different [...] Read more.

In this study, novel chitosan/silica composites with different mass ratios were prepared by in-situ hydrolysis using chitosan (from shrimp shell) as a carrier, triblock copolymer (P123) as the structure-directing agent, and ethyl orthosilicate as a silicon source. These nanocomposites were characterized by different techniques, including the FT-IR, XRD, TGA, SEM, TEM and N₂ adsorption–desorption. The results indicated that the morphology and properties of composites changed with the introduction of silica. When the CS/TEOS mass ratio was 0.0775, the CS−2/SiO₂ composite displayed a coral-like three-dimensional porous structure with specific surface area of 640.37 m²/g and average pore size of 1.869 nm. The adsorption properties for methylene blue (MB) were investigated as well and the CS−2/SiO₂ showed better adsorption performance. The removal rate for MB reached 94.01% with absorbents dosage of 6 g/L, initial concentration of 40 mg/L, initial pH value of 7, temperature of 35 °C, and adsorption time of 40 min. The adsorption process well fitted the Langmuir isothermal model and quasi-second-order adsorption kinetics model. The maximum adsorption capacity for MB was 13.966 mg/g based on Langmuir fitting. The surface functional groups of the composites can play an important role in the adsorption. The adsorption mechanism of CS−2/SiO₂ on MB involved electrostatic interaction, hydrogen bonding and functional group complexation. In addition, the prepared chitosan/silica composites showed good reusability at six cycles, making them a promising material in the application of removing dyeing wastewater. Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

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16 pages, 597 KiB

Open AccessArticle

The Practical Experience of “Zero Waste City” Construction in Foshan City Condenses the Chinese Solution to the Sustainable Development Goals

by Tianyu Qin, Lingling She, Zhaolong Wang, Luosong Chen, Wanyi Xu, Gaoming Jiang and Zhe Zhang

Sustainability 2022, 14(19), 12118; https://doi.org/10.3390/su141912118 - 25 Sep 2022

Cited by 6 | Viewed by 1992

Abstract

“Zero Waste City” (ZWC) is an urban development model that minimizes the environmental impact of solid waste at the city level and is a specific practice of the Sustainable Development Goals (SDGs). This paper aims to summarize the key points for realizing the [...] Read more.

“Zero Waste City” (ZWC) is an urban development model that minimizes the environmental impact of solid waste at the city level and is a specific practice of the Sustainable Development Goals (SDGs). This paper aims to summarize the key points for realizing the construction of ZWC and the SDGs and make suggestions for promoting the construction of ZWC and forming a Chinese solution for the SDGs. It takes Foshan City, one of the second batch of ZWC pilot projects, as a case study, analyzes the relationship between the construction of ZWC and sustainable urban development from the relevance of the ZWC index system in Foshan City and the SDGs, and analyzes the foundation and problems of its ZWC construction in adjusting the industrial structure and improving the protection system. We find that the concept of the ZWC index system in Foshan City and the SDGs are consistent in the objectives of solid waste, resource utilization, management, sustainability, and multi-stakeholder partnerships. The construction of ZWC in Foshan City is built through two intertwined paths by (1) adjusting the industrial structure of solid waste generation areas such as industrial waste, domestic waste, agricultural solid waste, and hazardous waste and promoting the refinement of the whole industrial chain in these fields and (2) improving the institutional, technical, market, regulatory and other protection systems in the solid waste generation fields. This paper condenses the construction of ZWC in Foshan as a Chinese solution for SDGs, providing a practical example of sustainable transformation for other manufacturing cities, with implications for both China and other manufacturing-oriented cities. Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

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17 pages, 2251 KiB

Open AccessArticle

Research on Greenhouse Gas Emission Characteristics and Emission Mitigation Potential of Municipal Solid Waste Treatment in Beijing

by Ying Li, Sumei Zhang and Chao Liu

Sustainability 2022, 14(14), 8398; https://doi.org/10.3390/su14148398 - 08 Jul 2022

Cited by 11 | Viewed by 1865

Abstract

Greenhouse gas (GHG) emissions are a significant cause of climate change, and municipal solid waste (MSW) is an important source of GHG emissions. In this study, GHG emissions from MSW treatment in Beijing during 2006–2019 were accounted, basing on the Intergovernmental Panel on [...] Read more.

Greenhouse gas (GHG) emissions are a significant cause of climate change, and municipal solid waste (MSW) is an important source of GHG emissions. In this study, GHG emissions from MSW treatment in Beijing during 2006–2019 were accounted, basing on the Intergovernmental Panel on Climate Change (IPCC) inventory model; the influencing factors affecting GHG emissions were analyzed by the logarithmic mean Divisia index (LMDI) model combined with the extended Kaya identity, and the GHG mitigation potential were explored based on different MSW management policy contexts. The results showed that the GHG emissions from MSW treatment in Beijing increased from 3.62 Mt CO₂e in 2006 to 6.57 Mt CO₂e in 2019, with an average annual growth rate (AAGR) of 4.68%, of which 89.34–99.36% was CH₄. Moreover, the driving factors of GHG emissions from MSW treatment were, in descending order: economic output (EO), GHG emission intensity (EI), population size (P), and urbanization rate (U). The inhibiting factors were, in descending order: MSW treatment pattern (TP) and MSW treatment intensity (TI). Furthermore, compared with the BAU (business–as–usual) scenario, the GHG mitigation potential of the MSW classification and the population control scenario were 35.79% and 0.51%, respectively, by 2030. Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

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15 pages, 2304 KiB

Open AccessArticle

The Effects of Portland and Sulphoaluminate Cements Solidification/Stabilization on Semi-Dynamic Leaching of Heavy Metal from Contaminated Sediment

by Yan Sun, Daofang Zhang, Hong Tao and Yang Yang

Sustainability 2022, 14(9), 5681; https://doi.org/10.3390/su14095681 - 08 May 2022

Cited by 5 | Viewed by 1802

Abstract

Cement-based solidification/stabilization technology is widely applied in the treatment of heavy metals in river sediment because it is an effective treatment, with the advantages of saving time and being economically and environmentally friendly. In this study, the heavy metal polluted sediment in Shanghai [...] Read more.

Cement-based solidification/stabilization technology is widely applied in the treatment of heavy metals in river sediment because it is an effective treatment, with the advantages of saving time and being economically and environmentally friendly. In this study, the heavy metal polluted sediment in Shanghai Fuxing Island Canal was used as the raw material, the cement solidified form was prepared by adding 10% Portland cement or sulphoaluminate cement, and semi-dynamic leaching tests were carried out on the solidified forms. In this study, we compare two types of cements as metal conditioners and curing agents aiming to determine the more economical and effective way to utilize river sediments. The results showed that the compressive strength of Portland cement solidified form (PSF) increased with an increase in curing time, which could reach 0.75 MPa after 28 days and met the requirements of general subgrade engineering. The compressive strength of sulphoaluminate cement solidified form (SSF) reached 0.35 MPa after curing for 1 day, however, it decreased later. The semi-dynamic leaching test results showed that the mobility of Cu and Cd in the cement solidified form was low, and the migration mechanism of heavy metals was mainly diffusion. The mobility of heavy metals in the PSF was lower than in the SSF, thus, the PSF had a better solidification effect and was more suitable for treating heavy metal-contaminated sediment. Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

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10 pages, 4355 KiB

Open AccessArticle

Optimization of Solidification and Stabilization Efficiency of Heavy Metal Contaminated Sediment Based on Response Surface Methodology

by Yang Yang, Moting Li, Yan Sun, Huimin Gao, Lingchen Mao, He Zhang and Hong Tao

Sustainability 2022, 14(6), 3306; https://doi.org/10.3390/su14063306 - 11 Mar 2022

Cited by 4 | Viewed by 1720

Abstract

Solidification and stabilization (S/S) by agents and stabilizers is an effective way to treat heavy metal-contaminated sediments. Optimization of curing condition is crucial to minimize the consumption of reagents on the base of effective S/S. In this work, the synergistic effects of cement [...] Read more.

Solidification and stabilization (S/S) by agents and stabilizers is an effective way to treat heavy metal-contaminated sediments. Optimization of curing condition is crucial to minimize the consumption of reagents on the base of effective S/S. In this work, the synergistic effects of cement and stabilizer on mechanical strength and leaching toxicity of contaminated sediments were investigated, and the S/S conditions were optimized using response surface methodology. On the basis of a single-factor test, multi-factor experiments were conducted to fit the relationship between the S/S effect of contaminated sediments and the amount of cement and stabilizer. The mechanism of stabilization was investigated by the results from the revised BCR method. The results indicate that the optimal curing conditions were 44.29% of cement content with 2.05% of trimercapto-s-triazine trisodium salt (TMT). After 28 days of curing, the compressive strength reached 2.07 MPa and the leaching concentrations of Cd, Cu, and Pb were 0.094 mg/L, 0.031 mg/L, and 0.173 mg/L, respectively, which met the requirement of in-situ resource recycling standard. The stability of heavy metals was significantly improved as a result of the removal of acid extractable fraction (15.58~69.92%) and an increase in the residual fraction (18.27~49.07%). Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

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Review

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18 pages, 1224 KiB

Open AccessReview

Resource Recycling with the Aim of Achieving Zero-Waste Manufacturing

by Omojola Awogbemi, Daramy Vandi Von Kallon and Kazeem Aderemi Bello

Sustainability 2022, 14(8), 4503; https://doi.org/10.3390/su14084503 - 10 Apr 2022

Cited by 17 | Viewed by 5902

Abstract

The management of the huge amounts of waste generated from domestic and industrial activities has continued to be a source of concern for humanity globally because of its impact on the ecosystem and human health. Millions of tons of such used materials, substances, [...] Read more.

The management of the huge amounts of waste generated from domestic and industrial activities has continued to be a source of concern for humanity globally because of its impact on the ecosystem and human health. Millions of tons of such used materials, substances, and products are therefore discarded, rejected, and abandoned, because they have no further usefulness or application. Additionally, owing to the dearth of affordable materials for various applications, the environmental impact of waste, and the high cost of procuring virgin materials, there have been intensive efforts directed towards achieving the reduction, minimization, and eradication of waste in human activities. The current review investigates zero-waste (ZW) manufacturing and the various techniques for achieving zero waste by means of resource recycling. The benefits and challenges of applying innovative technologies and waste recycling techniques in order to achieve ZW are investigated. Techniques for the conversion of waste glass, paper, metals, textiles, plastic, tire, and wastewater into various products are highlighted, along with their applications. Although waste conversion and recycling have several drawbacks, the benefits of ZW to the economy, community, and environment are numerous and cannot be overlooked. More investigations are desirable in order to unravel more innovative manufacturing techniques and innovative technologies for attaining ZW with the aim of pollution mitigation, waste reduction, cost-effective resource recovery, energy security, and environmental sustainability. Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

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19 pages, 2580 KiB

Open AccessReview

A State-of-the-Art Review of Radioactive Decontamination Technologies: Facing the Upcoming Wave of Decommissioning and Dismantling of Nuclear Facilities

by Shengyong Liu, Yingyong He, Honghu Xie, Yongjun Ge, Yishan Lin, Zhitong Yao, Meiqing Jin, Jie Liu, Xinyang Chen, Yuhang Sun and Binhui Wang

Sustainability 2022, 14(7), 4021; https://doi.org/10.3390/su14074021 - 29 Mar 2022

Cited by 22 | Viewed by 4106

Abstract

The average share of nuclear energy in electricity production is expected to increase under the background of the global pursuit towards carbon neutrality. Conjugating with its rapid development, the wave of decommissioning and dismantling (D&D) of nuclear facilities is coming. The surface decontamination [...] Read more.

The average share of nuclear energy in electricity production is expected to increase under the background of the global pursuit towards carbon neutrality. Conjugating with its rapid development, the wave of decommissioning and dismantling (D&D) of nuclear facilities is coming. The surface decontamination is a prerequisite to D&D, which will make it easier and reduce the volume of radioactive wastes. However, there are no comprehensive studies on the decontamination methods, which is not helpful for the sustainable development of nuclear energy and environment protection. Therefore, in this work, the current status and future trends of global energy and nuclear energy are first analyzed. Then, various decontamination approaches are comparatively studied, including cleaning mechanisms, application subjects, and intrinsic advantages and disadvantages. Finally, the criteria and factors for selecting a decontamination process, the challenges, and future studies are directed. Among the mechanical methods, laser-based cleaning is high-speed, having automation ability, and thus is promising, although it creates a dust and airborne contaminant hazard. In further studies, factors such as selecting a proper laser facility, optimizing operating parameters, and designing a high-efficiency dust collection system could be studied. Regarding the chemical method, chemical gels are good for decontaminating complex shapes and vertical and overhead surfaces. In addition, they can enhance other decon agents’ efficiency by improving contact time. However, the formulation of colloidal gels is complex and no gel type is useful for all contaminants. Therefore, novel and versatile gels need be developed to enlarge their application field. Combining various decontamination methods will often have better results and thus a reasonable and effective combination of these decontamination methods has become the main direction. Full article

(This article belongs to the Special Issue The Environmentally Friendly Management and Treatment of Solid Waste to Approach Zero Waste City)

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