International Journal of Environmental Research and Public Health

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12 pages, 2369 KiB

Open AccessArticle

Solvent Extraction for Separation of Indonesian Oil Sands

by Wenlong Cui, Qingqing Zhu, Chenze Zhao, Weiyou Zhou and Cheli Wang

Int. J. Environ. Res. Public Health 2023, 20(5), 4527; https://doi.org/10.3390/ijerph20054527 - 3 Mar 2023

Cited by 2 | Viewed by 1995

Abstract

Based on the examination of the basic properties, the solvent extraction process (SEP) was applied with high efficiency in the extraction of bitumen from Indonesian oil sands. To separate the oil sands, different organic solvents were first screened, and the extraction effects were [...] Read more.

Based on the examination of the basic properties, the solvent extraction process (SEP) was applied with high efficiency in the extraction of bitumen from Indonesian oil sands. To separate the oil sands, different organic solvents were first screened, and the extraction effects were analyzed to select a suitable solvent. Then, the effects of operating conditions on the extraction rate of bitumen were investigated. Finally, the compositions and structures of the bitumen obtained under suitable conditions were analyzed. The results showed that the Indonesian oil sands were oil-wet oil sands with a bitumen content of 24.93%, containing a large number of asphaltenes and resins with high polarity and complex structures. The separation performance was affected by different organic solvents and operating conditions. It was shown that the closer the structure and polarity of the selected solvent is to the solute, the better the extraction effect. The extraction rate of bitumen reached 18.55% when toluene was used as the extraction solvent under the operating conditions of V (solvent):m (oil sands) 3:1, temperature 40 °C, stirring velocity 300 r/min, time 30 min. The method could also be applied to the separation of other oil-wet oil sands. The compositions and structures of bitumen can guide the separation and comprehensive use of industrial oil sands. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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11 pages, 2878 KiB

Open AccessArticle

Impact of Different Lignin Sources on Nitrogen−Doped Porous Carbon toward the Electrocatalytic Oxygen Reduction Reaction

by Zheng Li, Yuwei Feng, Xia Qu, Yantao Yang, Lili Dong, Tingzhou Lei and Suxia Ren

Int. J. Environ. Res. Public Health 2023, 20(5), 4383; https://doi.org/10.3390/ijerph20054383 - 1 Mar 2023

Cited by 1 | Viewed by 1888

Abstract

Lignin is an ideal carbon source material, and lignin−based carbon materials have been widely used in electrochemical energy storage, catalysis, and other fields. To investigate the effects of different lignin sources on the performance of electrocatalytic oxygen reduction, different lignin−based nitrogen−doped porous carbon [...] Read more.

Lignin is an ideal carbon source material, and lignin−based carbon materials have been widely used in electrochemical energy storage, catalysis, and other fields. To investigate the effects of different lignin sources on the performance of electrocatalytic oxygen reduction, different lignin−based nitrogen−doped porous carbon catalysts were prepared using enzymolytic lignin (EL), alkaline lignin (AL) and dealkaline lignin (DL) as carbon sources and melamine as a nitrogen source. The surface functional groups and thermal degradation properties of the three lignin samples were characterized, and the specific surface area, pore distribution, crystal structure, defect degree, N content, and configuration of the prepared carbon−based catalysts were also analyzed. The electrocatalytic results showed that the electrocatalytic oxygen reduction performance of the three lignin−based carbon catalysts was different, and the catalytic performance of N−DLC was poor, while the electrocatalytic performance of N−ELC was similar to that of N−ALC, both of which were excellent. The half−wave potential (E_1/2) of N−ELC was 0.82 V, reaching more than 95% of the catalytic performance of commercial Pt/C (E_1/2 = 0.86 V) and proving that EL can be used as an excellent carbon−based electrocatalyst material, similar to AL. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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12 pages, 4080 KiB

Open AccessArticle

Investigation of Catalytic Co-Pyrolysis Characteristics and Synergistic Effect of Oily Sludge and Walnut Shell

by Qinghong Li, Huan Yang, Ping Chen, Wenxue Jiang, Fei Chen, Xiaorong Yu and Gaoshen Su

Int. J. Environ. Res. Public Health 2023, 20(4), 2841; https://doi.org/10.3390/ijerph20042841 - 6 Feb 2023

Cited by 5 | Viewed by 2067

Abstract

The co-pyrolysis of oily sludge and walnut shell is a reliable method for solid waste treatment and waste recycling. In this paper, a thermogravimetric analysis was used to study the thermodynamics and synergy effect of oily sludge (OS) and walnut shell (WS) at [...] Read more.

The co-pyrolysis of oily sludge and walnut shell is a reliable method for solid waste treatment and waste recycling. In this paper, a thermogravimetric analysis was used to study the thermodynamics and synergy effect of oily sludge (OS) and walnut shell (WS) at four heating rates (10, 20, 30, and 40 °C/min) in the temperature range from 50–850 °C. Two model-free methods (FWO and KAS) were used to calculate the activation energy. The results showed that the heating rate had no significant effect on the pyrolysis process. The addition of walnut shell improved the pyrolysis process of the samples. Mixture 1OS3WS had a synergy effect, while other blends showed an inhibitory effect. The synergy effect of co-pyrolysis was strongest when the mass ratio of oily sludge was 25%. The activation energy of the Zn-ZSM-5/25 catalyst was the lowest, and the residual substances were the least, indicating that the Zn-ZSM-5/25 was beneficial to the co-pyrolysis of oily sludge and walnut shell. The analysis of catalytic pyrolysis products by Py-GC/MS found that co-pyrolysis was beneficial to the generation of aromatic hydrocarbons. This study provided a method for the resource utilization of hazardous waste and biomass waste, which was conducive to the production of aromatic chemicals with added value while reducing environmental pollution. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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13 pages, 1837 KiB

Open AccessArticle

Concentration Characteristics and Correlations with Other Pollutants of Atmospheric Particulate Matter as Affected by Relevant Policies

by Hong Song, Yuhang Dong, Jiayu Yang, Xin Zhang, Xingxin Nie and Yuesheng Fan

Int. J. Environ. Res. Public Health 2023, 20(2), 1051; https://doi.org/10.3390/ijerph20021051 - 6 Jan 2023

Cited by 11 | Viewed by 2005

Abstract

With the increase in global environmental pollution, it is important to understand the concentration characteristics and correlations with other pollutants of atmospheric particulate matter as affected by relevant policies. The data presented in this paper were obtained at monitoring stations in Xi’an, China, [...] Read more.

With the increase in global environmental pollution, it is important to understand the concentration characteristics and correlations with other pollutants of atmospheric particulate matter as affected by relevant policies. The data presented in this paper were obtained at monitoring stations in Xi’an, China, in the years from 2016 to 2020, and the spatial distribution characteristics of the mass and quantity concentrations of particulate matter in the atmosphere, as well as its correlation with other pollutants, were analyzed in depth. The results showed that the annual average concentrations of PM₁₀ and PM_2.5 decreased year by year from 2016 to 2020. The annual concentrations of PM_2.5 decreased by 20.3 μg/m³, and the annual concentrations of PM₁₀ decreased by 47.3 μg/m³. The days with concentrations of PM₁₀ exceeding the standards decreased by 82 days, with a decrease of 66.7%. The days with concentrations of PM_2.5 exceeding the standards decreased by 40 days, with a decrease of 35.4%. The concentration values of PM₁₀ and PM_2.5 were roughly consistent with the monthly and daily trends. The change in monthly concentrations was U-shaped, and the change in daily concentrations showed a double-peak behavior. The highest concentrations of particulate matter appeared at about 8:00~9:00 am and 11:00 pm, and they were greatly affected by human activity. The proportion of particles of 0~1.0 μm decreased by 1.94%, and the proportion of particles of 0~2.5 μm decreased by 2.00% from 2016 to 2020. A multivariate linear regression model to calculate the concentrations of the pollutants was established. This study provides a reference for the comprehensive analysis and control of air pollutants in Xi’an and even worldwide. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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14 pages, 1409 KiB

Open AccessArticle

Comparison of the Application of Three Methods for the Determination of Outdoor PM_2.5 Design Concentrations for Fresh Air Filtration Systems in China

by Xin Zhang, Hao Sun, Kaipeng Li, Xingxin Nie, Yuesheng Fan, Huan Wang and Jingyao Ma

Int. J. Environ. Res. Public Health 2022, 19(24), 16537; https://doi.org/10.3390/ijerph192416537 - 9 Dec 2022

Cited by 10 | Viewed by 1711

Abstract

With the increasing popularity of fresh-air filtration systems, the methods of determining the outdoor PM_2.5 design concentration have become more important. However, the monitoring of atmospheric fine particles in China started relatively late, and there are relatively few cities with complete data, [...] Read more.

With the increasing popularity of fresh-air filtration systems, the methods of determining the outdoor PM_2.5 design concentration have become more important. However, the monitoring of atmospheric fine particles in China started relatively late, and there are relatively few cities with complete data, with obvious regional differences, which led to many problems in the selection of air filters for fresh-air filtration systems. In this paper, three methods of determining outdoor PM_2.5 design concentration were analyzed using the daily average concentration of PM_2.5 in 31 provincial capital cities from 2016 to 2020. Six typical cities in different regions were also taken as examples. The advantages and disadvantages of the three existing statistical methods were compared and analyzed, as well as the corresponding differences in the selection of outdoor PM_2.5 concentration value on the filter systems. The results showed that the method of mathematical induction was more accurate and reasonable for the calculation of outdoor PM_2.5 design concentrations. The local outdoor PM_2.5 design concentration could be quickly calculated using the recommended coefficient K and annual average PM_2.5 concentration of the region, especially for small and medium-sized cities without monitoring data. However, the recommended coefficient K should be provided based on the specific region, and should be divided into values for strict conditions and normal conditions during use. This would provide a simple and effective way to select the correct air filters for practical engineering. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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15 pages, 4295 KiB

Open AccessArticle

Large Semi-Membrane Covered Composting System Improves the Spatial Homogeneity and Efficiency of Fermentation

by Xiaoxi Sun, Guangqun Huang, Yuanping Huang, Chen Fang, Xueqin He and Yongjun Zheng

Int. J. Environ. Res. Public Health 2022, 19(23), 15503; https://doi.org/10.3390/ijerph192315503 - 23 Nov 2022

Cited by 2 | Viewed by 2354

Abstract

Homogenous spatial distribution of fermentation characteristics, local anaerobic conditions, and large amounts of greenhouse gas (GHGs) emissions are common problems in large-scale aerobic composting systems. The aim of this study was to examine the effects of a semi-membrane covering on the spatial homogeneity [...] Read more.

Homogenous spatial distribution of fermentation characteristics, local anaerobic conditions, and large amounts of greenhouse gas (GHGs) emissions are common problems in large-scale aerobic composting systems. The aim of this study was to examine the effects of a semi-membrane covering on the spatial homogeneity and efficiency of fermentation in aerobic composting systems. In the covered group, the pile was covered with a semi-membrane, while in the non-covered group (control group), the pile was uncovered. The covered group entered the high-temperature period earlier and the spatial gradient difference in the group was smaller compared with the non-covered group. The moisture content loss ratio (5.91%) in the covered group was slower than that in the non-covered group (10.78%), and the covered group had a more homogeneous spatial distribution of water. The degradation rate of organic matter in the non-covered group (11.39%) was faster than that in the covered group (10.21%). The final germination index in the covered group (85.82%) was higher than that of the non-covered group (82.79%) and the spatial gradient difference in the covered group was smaller. Compared with the non-covered group, the oxygen consumption rate in the covered group was higher. The GHG emissions (by 30.36%) and power consumption in the covered group were reduced more significantly. The spatial microbial diversity of the non-covered group was greater compared with the covered group. This work shows that aerobic compost covered with a semi-membrane can improve the space homogeneity and efficiency of fermentation. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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16 pages, 2106 KiB

Open AccessArticle

How Biochar Derived from Pond Cypress (Taxodium Ascendens) Evolved with Pyrolysis Temperature and Time and Their End Efficacy Evaluation

by Shuai Zhang, Haibo Hu, Xiangdong Jia, Xia Wang, Jianyu Chen, Can Cheng, Xichuan Jia, Zhaoming Wu and Li Zhu

Int. J. Environ. Res. Public Health 2022, 19(18), 11205; https://doi.org/10.3390/ijerph191811205 - 6 Sep 2022

Cited by 3 | Viewed by 2044

Abstract

Biomass type, pyrolysis temperature, and duration can affect biochar properties simultaneously. To further clarify the mechanism of this interaction, the branch and leaf parts of Pond cypress (Taxodium ascendens) were separately pyrolyzed at four peak temperatures (350 °C, 450 °C, 650 [...] Read more.

Biomass type, pyrolysis temperature, and duration can affect biochar properties simultaneously. To further clarify the mechanism of this interaction, the branch and leaf parts of Pond cypress (Taxodium ascendens) were separately pyrolyzed at four peak temperatures (350 °C, 450 °C, 650 °C, and 750 °C) for three different durations (0.5 h, 1 h, and 2 h) in this study. The resulting biochar properties were measured, which included the yield, specific surface area (SSA), pH, EC (electricity conductivity), the bulk and surface elemental composition, and the contents of moisture, ash, fixed carbon, and volatile matter. The results showed that the pyrolysis temperature was more determinant for the modification of all biochar, but the residence time had a significant effect on the yield, pH, and SSA of branch-based biochar (B-biochar) at specific temperatures. However, such a phenomenon only happened on the pH of leaf-based biochar (L-biochar). Results: (1) With the temperature at 350 and 650 °C, the residence time had a significant effect on the yield of B-biochar. (2) The pH of B-biochar and L-biochar varied considerably between durations when the heating temperature hit 650 and 750 °C. (3) The SSA of B-biochar possessed an obvious fluctuation with the time during the pyrolysis from 650 to 750 °C. According to the properties measured above, the principal component and the cluster analysis classified the 24 types of biochar made in this experiment into four groups and revealed that an obvious disparity existed between B-biochar and L-biochar that were pyrolyzed at temperatures ranging from 450 to 750 °C, which suggested that biomass type was the primary factor for biochar-making. All this information can provide valuable references for the optimization of biochar-making in the real world. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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17 pages, 3155 KiB

Open AccessArticle

A Comprehensive Hydrothermal Co-Liquefaction of Diverse Biowastes for Energy-Dense Biocrude Production: Synergistic and Antagonistic Effects

by Guanyu Zhang, Kejie Wang, Quan Liu, Lujia Han and Xuesong Zhang

Int. J. Environ. Res. Public Health 2022, 19(17), 10499; https://doi.org/10.3390/ijerph191710499 - 23 Aug 2022

Cited by 10 | Viewed by 2496

Abstract

Hydrothermal co-liquefaction (co-HTL) is a promising technology to valorize binary or even ternary biowastes into bioenergy. However, the complex biochemical compositions and unclear synergistic effect prevent the development of this technology. Thus, this study explored a comprehensive co-HTL of representative biowastes to investigate [...] Read more.

Hydrothermal co-liquefaction (co-HTL) is a promising technology to valorize binary or even ternary biowastes into bioenergy. However, the complex biochemical compositions and unclear synergistic effect prevent the development of this technology. Thus, this study explored a comprehensive co-HTL of representative biowastes to investigate the synergistic and antagonistic effects. An apparent synergistic effect on biocrude yield was observed when sewage sludge was co-liquefied with cow manure or wheat straw. Further, the co-HTL of sewage sludge-cow manure was investigated in a detailed manner. The highest yield (21.84 wt%) of biocrude, with a positive synergistic effect (11.37%), the highest energy recovery (47.48%), and a moderate biocrude HHV (34.31 MJ/kg) were achieved from co-HTL at 350 °C for 30 min. Hydrochar and gas products were also characterized to unravel the reaction pathways. Accordingly, this work indicates that sewage sludge co-liquefied with other biowastes can serve as a multi-purpose solution for biowaste treatment and bioenergy production. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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15 pages, 2630 KiB

Open AccessArticle

Steam Gasification of Torrefied/Carbonized Wheat Straw for H₂-Enriched Syngas Production and Tar Reduction

by Kejie Wang, Ge Kong, Guanyu Zhang, Xin Zhang, Lujia Han and Xuesong Zhang

Int. J. Environ. Res. Public Health 2022, 19(17), 10475; https://doi.org/10.3390/ijerph191710475 - 23 Aug 2022

Cited by 21 | Viewed by 2706

Abstract

Torrefaction/carbonization integrated with steam gasification of agricultural biomass for gas production and tar reduction was not investigated. The aim of this study was to evaluate the influence of the torrefaction/carbonization severity on H₂-enriched syngas production and tar reduction during steam gasification [...] Read more.

Torrefaction/carbonization integrated with steam gasification of agricultural biomass for gas production and tar reduction was not investigated. The aim of this study was to evaluate the influence of the torrefaction/carbonization severity on H₂-enriched syngas production and tar reduction during steam gasification of wheat straw (WS). The torrefaction/carbonization experiments were initially performed at 220–500 °C to examine the effect of pretreated temperature on the fuel properties of torrefied/carbonized WS. Then, the gasification temperature (700–900 °C) was optimized at 900 °C in terms of gas formation behaviors. Afterward, steam gasification of raw and torrefied/carbonized WS feedstocks was conducted. WS carbonized at 500 °C (WS-500) possessed the highest H₂ concentration (54.21 vol%) and syngas purity (85.59%), while the maximum H₂/CO molar ratio (1.83), high carbon conversion efficiency (90.33 C%) and cold gas efficiency (109.24%) were observed for WS torrefied at 280 °C. Notably, the cumulative gas yield, H₂ yield, and syngas yield respectively reached 102.68 mmol/g, 55.66 mmol/g, and 87.89 mmol/g from steam gasification of WS-500. In addition, the carbonized WS feedstocks, especially WS-500, revealed a lower tar content. Simply put, integrating torrefaction/carbonization with steam gasification provided a novel and effective route to manufacture H₂-enriched syngas with extremely low tar content from agricultural biomass. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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31 pages, 3501 KiB

Open AccessArticle

Integrated AHP-TOPSIS under a Fuzzy Environment for the Selection of Waste-To-Energy Technologies in Ghana: A Performance Analysis and Socio-Enviro-Economic Feasibility Study

by Sandylove Afrane, Jeffrey Dankwa Ampah, Ephraim Bonah Agyekum, Prince Oppong Amoh, Abdulfatah Abdu Yusuf, Islam Md Rizwanul Fattah, Ebenezer Agbozo, Elmazeg Elgamli, Mokhtar Shouran, Guozhu Mao and Salah Kamel

Int. J. Environ. Res. Public Health 2022, 19(14), 8428; https://doi.org/10.3390/ijerph19148428 - 10 Jul 2022

Cited by 22 | Viewed by 5043

Abstract

Energy recovery from waste presents a promising alternative for several countries, including Ghana, which has struggled with unsustainable waste treatment methods and an inadequate power supply for several decades. The current study adopts a comprehensive multi-criteria decision-making approach for the selection of an [...] Read more.

Energy recovery from waste presents a promising alternative for several countries, including Ghana, which has struggled with unsustainable waste treatment methods and an inadequate power supply for several decades. The current study adopts a comprehensive multi-criteria decision-making approach for the selection of an optimal waste-to-energy (WtE) technology for implementation in Ghana. Four WtE technologies are evaluated against twelve selection criteria. An integrated AHP-fuzzy TOPSIS method is applied to estimate the criteria’s weights and rank the WtE alternatives. From the AHP results, technical criteria obtained the highest priority weight, while social criteria emerged as the least important in the selection process. The overall ranking order of WtE technologies obtained by fuzzy TOPSIS is as follows: anaerobic digestion > gasification > pyrolysis > plasma gasification. The sensitivity analysis indicates highly consistent and sturdy results regarding the optimal selection. This study recommends adopting a hybrid system of anaerobic digestion and gasification technologies, as this offers a well-balanced system under all of the evaluation criteria compared to the standalone systems. The results of the current study may help the government of Ghana and other prospective investors select a suitable WtE technology, and could serve as an index system for future WtE research in Ghana. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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16 pages, 4050 KiB

Open AccessArticle

Investigation of Synergistic Effects and Kinetics on Co-Pyrolysis of Alternanthera philoxeroides and Waste Tires

by Awsan Shujaa Aldeen, Jiapeng Wang, Bo Zhang, Shuying Tian, Zhixiang Xu and Huiyan Zhang

Int. J. Environ. Res. Public Health 2022, 19(12), 7101; https://doi.org/10.3390/ijerph19127101 - 9 Jun 2022

Cited by 1 | Viewed by 2185

Abstract

A thermogravimetric analysis is used to analyze the thermal kinetics and investigate the synergistic effects between Alternanthera philoxeroides (AP) and waste tires (WTS) in a temperature range of 50–900 °C under three heating rates (15, 25, and 35 °C/min). Two model-free methods (FWO [...] Read more.

A thermogravimetric analysis is used to analyze the thermal kinetics and investigate the synergistic effects between Alternanthera philoxeroides (AP) and waste tires (WTS) in a temperature range of 50–900 °C under three heating rates (15, 25, and 35 °C/min). Two model-free methods (FWO and KAS) and a model-fitting method (CR) were applied to calculate the activation energy. Results revealed that heating rates had no significant effect on the pyrolysis operation. The addition of WTS improved the thermal degradation of the samples as the samples had more than one stage during the main reaction period. A promoting synergistic effect was found in the blend 75A25WT and obtained the lowest activation energy among all the blends without a catalyst, while the blend 50A50WT exhibited an inhibiting effect. On the other hand, the addition of HZSM-5 accelerated the reaction time and obtained the lowest activation energy among all the blends without a catalyst. Furthermore, ΔW of 75A25WT+C was the lowest, indicating that the blend with a catalyst exhibited the strongest synergistic effect. This research confirmed that the addition of WTS improved the thermal parameters of the samples and clarified the capacity of HZSM-5 to reduce the activation energy. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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17 pages, 4442 KiB

Open AccessArticle

Untargeted Metabolomics Profiling of Bioactive Compounds under Varying Digestate Storage Conditions: Assessment of Antioxidant and Antifungal Activity

by Jiaxin Lu, Atif Muhmood, Panagiotis Tsapekos, Xian Cui, Yuwen Guo, Yi Zheng, Yizhan Qiu, Pan Wang and Lianhai Ren

Int. J. Environ. Res. Public Health 2022, 19(8), 4923; https://doi.org/10.3390/ijerph19084923 - 18 Apr 2022

Cited by 3 | Viewed by 2555

Abstract

The rapid development of biogas plants in China has generated large quantities of digestate. The disparity between the continuity of biogas plant operation and the seasonality of digestate utilization has led to the need to store digestate. Therefore, untargeted profiling of bioactive compounds [...] Read more.

The rapid development of biogas plants in China has generated large quantities of digestate. The disparity between the continuity of biogas plant operation and the seasonality of digestate utilization has led to the need to store digestate. Therefore, untargeted profiling of bioactive compounds in the digestate stored under aerobic and anaerobic conditions was performed. The antioxidant and antifungal activity of digestate stored under varying conditions was likewise assessed. The results delineated that digestate storage under varying conditions brought about the degradation of organic acids, alkenes, aldehydes, alcohols, ketones, ethers, amino acids and their derivatives, and esters, leading to the stabilization of digestate components. Together, these new data revealed that digestate storage for up to 20 days under aerobic conditions promotes glycine, serine, and threonine degradation pathways and enhances biotin and vitamins production. In contrast, anaerobic storage enhances the taurine and hypotaurine metabolic pathways and increases the derivation of antimicrobial substances, such as indole alkaloids. Moreover, digestate storage under anaerobic conditions promotes antioxidant and antifungal activity more than storage under aerobic conditions. These findings can contribute to the future development of high-value agricultural products from digestate and the sustainability of biogas plants. Further studies are required for the untargeted metabolomic of digestate under storage to explore the underlying mechanisms of promoting disease resistance by the digestate upon land application. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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Review

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14 pages, 5319 KiB

Open AccessReview

Metal–Organic Framework (MOF) Derivatives as Promising Chemiresistive Gas Sensing Materials: A Review

by Huijie Wei, Huiyan Zhang, Bing Song, Kaiping Yuan, Hongbin Xiao, Yunyi Cao and Qi Cao

Int. J. Environ. Res. Public Health 2023, 20(5), 4388; https://doi.org/10.3390/ijerph20054388 - 1 Mar 2023

Cited by 30 | Viewed by 4781

Abstract

The emission of harmful gases has seriously exceeded relative standards with the rapid development of modern industry, which has shown various negative impacts on human health and the natural environment. Recently, metal–organic frameworks (MOFs)-based materials have been widely used as chemiresistive gas sensing [...] Read more.

The emission of harmful gases has seriously exceeded relative standards with the rapid development of modern industry, which has shown various negative impacts on human health and the natural environment. Recently, metal–organic frameworks (MOFs)-based materials have been widely used as chemiresistive gas sensing materials for the sensitive detection and monitoring of harmful gases such as NO_x, H₂S, and many volatile organic compounds (VOCs). In particular, the derivatives of MOFs, which are usually semiconducting metal oxides and oxide–carbon composites, hold great potential to prompt the surface reactions with analytes and thus output amplified resistance changing signals of the chemiresistors, due to their high specific surface areas, versatile structural tunability, diversified surface architectures, as well as their superior selectivity. In this review, we introduce the recent progress in applying sophisticated MOFs-derived materials for chemiresistive gas sensors, with specific emphasis placed on the synthesis and structural regulation of the MOF derivatives, and the promoted surface reaction mechanisms between MOF derivatives and gas analytes. Furthermore, the practical application of MOF derivatives for chemiresistive sensing of NO₂, H₂S, and typical VOCs (e.g., acetone and ethanol) has been discussed in detail. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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21 pages, 5187 KiB

Open AccessReview

Biodegradable Electrospun Nanofiber Membranes as Promising Candidates for the Development of Face Masks

by Rujun Shen, Yunlong Guo, Shuaijie Wang, Ayikezi Tuerxun, Jiaqi He and Ye Bian

Int. J. Environ. Res. Public Health 2023, 20(2), 1306; https://doi.org/10.3390/ijerph20021306 - 11 Jan 2023

Cited by 15 | Viewed by 3953

Abstract

Aerosol particles, such as the widespread COVID-19 recently, have posed a great threat to humans. Combat experience has proven that masks can protect against viruses; however, the epidemic in recent years has caused serious environmental pollution from plastic medical supplies, especially masks. Degradable [...] Read more.

Aerosol particles, such as the widespread COVID-19 recently, have posed a great threat to humans. Combat experience has proven that masks can protect against viruses; however, the epidemic in recent years has caused serious environmental pollution from plastic medical supplies, especially masks. Degradable filters are promising candidates to alleviate this problem. Degradable nanofiber filters, which are developed by the electrospinning technique, can achieve superior filtration performance. This review focuses on the basic introduction to air filtration, the general aspects of face masks, and nanofibers. Furthermore, the progress of the state of art degradable electrospun nanofiber filters have been summarized, such as silk fibroin (SF), polylactic acid (PLA), chitosan, cellulose, and zein. Finally, the challenges and future development are highlighted. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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27 pages, 2351 KiB

Open AccessReview

Challenges and Priorities of Municipal Solid Waste Management in Cambodia

by Dek Vimean Pheakdey, Nguyen Van Quan, Tran Dang Khanh and Tran Dang Xuan

Int. J. Environ. Res. Public Health 2022, 19(14), 8458; https://doi.org/10.3390/ijerph19148458 - 11 Jul 2022

Cited by 29 | Viewed by 16597

Abstract

Municipal solid waste (MSW) management is one of the utmost challenges for Cambodia’s city and district centers. The unsound management of MSW has detrimentally affected the environment and human health. In the present study, an attempt has been made to provide a comprehensive [...] Read more.

Municipal solid waste (MSW) management is one of the utmost challenges for Cambodia’s city and district centers. The unsound management of MSW has detrimentally affected the environment and human health. In the present study, an attempt has been made to provide a comprehensive insight into the generation and characteristics, policies and legislation frameworks, management arrangement, collection, treatment, and disposal of MSW. The experience of developed and developing countries and the challenges and priorities of MSW management in Cambodia are also highlighted. In Cambodia, about 4.78 million tons of MSW were generated in 2020, with a 0.78 kg/capita/day generation rate. Only 86% of cities and districts have access to MSW collection services. The current practice of MSW management is reliance on landfill (44%). There are 164 landfills operating countrywide, receiving about 5749 tons of MSW per day. Recycling, incineration, and composting share 4%, 4%, and 2% of MSW generation, respectively. In 2021, the total revenue that was recovered from recyclables was USD 56M. The study concludes several major challenges and proposes valuable suggestions, which may be beneficial for the improvement of the current system to support the sustainable management of MSW in Cambodia. Full article

(This article belongs to the Special Issue Biomass Energy Utilization, Waste Management and Air Pollution Control)

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