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17381. 题目: Different forms of nitrogen deposition show variable effects on soil organic nitrogen turnover in a temperate forest
文章编号: N21090103
期刊: Applied Soil Ecology
作者: Jihui Tian, Kai Wei, Tao Sun, Nan Jiang, Zhenhua Chen, Jiao Feng, Kunzheng Cai, Lijun Chen
更新时间: 2021-09-01
摘要: The mineralization of soil organic nitrogen (N) catalyzed by N-hydrolyzing enzymes plays a major role in ecosystems N cycling. However, the responses of this biochemical process to N deposition, particularly different N types, remain unclear. Here, a field experiment was conducted in a temperate forest to investigate how different types of N deposition influences the interaction between soil organic N fractions and N-hydrolyzing enzymes, i.e., protease, N-acetyl-β-glucosaminidase, urease and amidase in the 0–10 cm and 10–20 cm layers. Four treatments including nil N (CK), inorganic N (NH4NO3, IN), organic N (urea and glycine 1:1, ON) and mixed N (inorganic and organic N 7:3, Mix-N) deposition were included. We found no effects of IN deposition on N-hydrolyzing enzymes activities and soil organic N fractions. In contrast, ON and Mix-N deposition significantly increased urease activity in surface soil and protease, urease, and amidase activities in subsoil. Mix-N deposition resulted in the greatest increase in hydrolysable ammonia-N (85%), labile organic N (76%) and stable organic N (101%), followed by ON deposition. Moreover, structural equation modeling revealed that amidohydrolases (urease and amidase) was actively involved in the conversion of labile organic N to ammonia-N, which was promoted by ON and Mix-N deposition but showed no response to IN deposition. In summary, mixed inorganic and organic N deposition favors the accumulation and subsequent enzymatic turnover of organic N in forest soils. Our findings suggest that different components in N deposition should be considered when examining N deposition effects on ecosystem N cycling.

17382. 题目: Biochar as an Additive to Modify Biopitch Binder for Carbon Anodes
文章编号: N21090102
期刊: ACS Sustainable Chemistry & Engineering
作者: Ying Lu, Asem Hussein, Julien Lauzon-Gauthier, Thierry Ollevier, Houshang Alamdari
更新时间: 2021-09-01
摘要: Looking for alternative materials to coal-tar pitch (CTP), as a binder in anode manufacturing, in aluminum production is of great interest. Such a material should be able to mitigate the cost and health issues without decreasing the carbon anode quality. Biopitch (BP) could be considered as a potential candidate. Previous studies show that biomass-based pitch has generally a low coking value compared to that of CTP, which might negatively affect its properties as a binder in carbon anodes. To increase its coking value, biopitch was modified by using additives. A solid bio-based material, namely, biochar, was considered as an additive. The prepared biopitch samples, containing different quantities of biochars, were analyzed for their softening point (SP), QI content, coking value (CV), molecular weight distribution, viscosity, surface tension, chemical groups, and surface composition, as well as their wettability with coke particles. The differences in texture and topography of different pitches, as well as the interface between pitch and aggregate particles in sessile drop after wettability test, were studied. The results revealed that increasing the quantities of biochars in biopitch increases their coking value, QI content, density, viscosity, and softening point. Furthermore, biochar addition only shows a minor influence on surface tension and molecular weight distribution of biopitch. An optimum amount (9.0 wt %) of biochar addition in biopitch could therefore be beneficial in anode formulation while using biopitch as a binder, compared to those of the reference anodes. The properties of the laboratory anodes (green/baked density, air/CO2 reactivity, compressive strength and electrical resistivity, carbon structure of the carbonized pitch) were investigated. Addition of biochar into biopitch could reduce the overall consumption of biopitch in the carbon anode formulation.

17383. 题目: Improved Pb(II) removal in aqueous solution by sulfide@biochar and polysaccharose-FeS@ biochar composites: Efficiencies and mechanisms
文章编号: N21090101
期刊: Chemosphere
作者: Renrong Liu, Yaohong Zhang, Baowei Hu, Hai Wang
更新时间: 2021-09-01
摘要: Novel biochars, namely nano iron sulfide@ walnut shell biochar (FeS@WNS), Starch-FeS@WNS and Chitosan-FeS@WNS, were prepared by WNS loaded with nano FeS and starch (or chitosan). Nano FeS can be effectively improved lead ions (Pb(II)) removal and starch (or chitosan) improved the stability of FeS and the defect of easy agglomeration. The materials were characterized by SEM, EDS, FTIR and XRD, and the preparation was successful. The adsorption capacity of Pb(II) reached 63.5, 80.0, 84.7 mg g−1 under 0.5 g L−1 of FeS@WNS, Starch-FeS@WNS and Chitosan-FeS@WNS. The adsorption of Pb(II) on the materials was more consistent with the pseudo-second-order kinetic model (K2 = 0.001–0.005 g (mg·min)−1, R2 = 0.980–0.999) and Langmuir model (R2 = 0.974–1.00), indicating that the adsorption of Pb(II) was mainly monolayer adsorption dominated by chemical adsorption. △G < 0 (-3.7∼-6.97) and △H > 0 (1.56–20.49) indicated that the reaction was a spontaneous endothermic process. The mechanisms of Pb(II) removal from aqueous solutions involved electrostatic attraction, hydrogen bonding, physical adsorption, ion exchange, and oxidoreduction. Additionally, stability and reusability of FeS@WNS, Starch-FeS@WNS and Chitosan-FeS@WNS was good. The novel sorbents of Starch-FeS@WNS and Chitosan-FeS@WNS can be used in Pb(II) wastewater treatment.

17384. 题目: Carbon source type can affect tetracycline removal by Pseudomonas sp. TC952 through regulation of extracellular polymeric substances composition and production
文章编号: N21083130
期刊: Science of The Total Environment
作者: Zewen Tan, Maman Hassan Abdoulahi, Xiuyue Yang, Yanmei Zhu, Beini Gong, Yongtao Li
更新时间: 2021-08-31
摘要: The objective of this work is to elucidate the mechanism of tetracycline (TC) removal by Pseudomonas sp. TC952. The TC removal characteristics of strain TC952 under various environmental conditions were studied. Results showed that the bio-removal efficiency was significantly affected by initial TC and peptone concentration, pH values, divalent metal ion (Zn2+) and carbon source, and the strain TC952 efficiently removed approximately 72.8% of TC within 6 days with 10 g/L peptone. The best conditions for strain TC952 to remove TC are as follows: initial TC concentration is 50 mg/L, solution initial pH is 7, Zn2+ concentration is 0.1 μg/L, carbon source is peptone. And through intra- and extracellular fractions assay and extracellular polymeric substances (EPS) component analysis, TC removal by strain TC952 was mainly attributed to the adsorption by bacterial EPS and bacterial cell. Furthermore, different carbon source affected the EPS production content and component of strain TC952, so EPS produced under peptone and serine conditions could bio-adsorb TC and formed a buffer area outside the cells, thus reducing or preventing TC from entering the bacteria cells. All the results obtained showed that secretion of EPS and adsorption of TC by EPS and bacterial cell wall may be a common way for bacteria to reduce TC in the environment, which brought novel insights for better management of TC contamination by functional bacteria and for understanding the natural removal process of antibiotics by microorganisms in the environment.

17385. 题目: Magnetized manganese-doped watermelon rind biochar as a novel low-cost catalyst for improving oxygen reduction reaction in microbial fuel cells
文章编号: N21083129
期刊: Science of The Total Environment
作者: Jiwei Jiang, Shixuan Zhang, Shengnan Li, Wenlu Zeng, Fengxiang Li, Wei Wang
更新时间: 2021-08-31
摘要: Microbial fuel cells (MFCs) are promising equipment for water treatment and power generation. The catalyst used in the oxygen reduction reaction (ORR) at the cathode is a critical factor for efficacy of MFCs. Therefore, it is important to develop cost-effective cathode catalysts to enhance application of MFCs. In the current study, a novel cathode catalyst was developed, which was annealed with watermelon rind as raw material and transition metals including iron, and manganese were introduced. The 700Mn/Fe@WRC catalyst, which was annealed at 700 °C, exhibited excellent electrochemical performance. The high relative content of pyridine nitrogen caused by the inherent nitrogen element of the watermelon rind and the high content of iron and manganese elements introduced resulted in increase in electrochemical surface area to 657.6 m2/g. The number of electrons transferred ORR was 3.96, indicating that ORR occurs through a four-electron pathway. The maximum power density of MFCs was 399.3 ± 7.4 mW/m2 with a fitting total internal resistance of 15.242 Ω, and the removal efficiency of COD was 97.1 ± 1.2%. The cost of the 700Mn/Fe@WRC catalyst was approximately 0.15 $/g, which is significantly lower compared with Pt/C (33.0 $/g). Experimental verification showed that the 700Mn/Fe@WRC prepared using the economical watermelon rind biochar (WRC) is an excellent substitute for non-precious metal catalysts used in MFCs.

17386. 题目: Mechanism of removal and degradation characteristics of dicamba by biochar prepared from Fe-modified sludge
文章编号: N21083128
期刊: Journal of Environmental Management
作者: Chunli Wan, Huiqi Li, Lianfa Zhao, Zhengwen Li, Chen Zhang, Xuejun Tan, Xiang Liu
更新时间: 2021-08-31
摘要: The pyrolysis of excess sludge derived from wastewater treatment plants to prepare biochar can achieve the mass-reduction and harmlessness of solid waste, but it is also necessary to further explore the application prospect of these biochars as a resource for wastewater treatment. In this study, Fe-modified biochar (BC–Fe) was prepared by pyrolysis of excess sludge modified by FeCl3 solution. The molecular structure, elemental valence state, and composition of biochars were comprehensively investigated. The results showed that, compared with the biochar prepared from sludge without modification (BC-blank), the O/C ratio of BC-Fe increased from 0.07 to 0.12, and the (N + O)/C ratio increased from 0.21 to 0.27, indicating increased polarity and weakened aromaticity. The ratio of integrated intensity of the D band and G band in the Raman spectrum increased from 1.34 to 2.40, showing the increased defect structure of the biochar obtained by Fe modification. In the reaction between BC-Fe and dicamba, the removal rate of dicamba reached 92.1% within 180 min, which was far higher than the 17.8% of BC-blank. It was confirmed the adsorption removal dominated and accounted for 70.6% of the dicamba removal by BC-Fe, and the adsorption capacity of biochar could be significantly enhanced by Fe-modification by 5.3 times. Moreover, the persistent free radicals (PFRs) on the surface of biochar was detected by an electron paramagnetic resonance analyzer, and the decline of PFRs signals after the reaction revealed that PFRs participated in the degradation process of dicamba. Through Q-TOF analysis, it could be concluded that dicamba was first converted to 3,6-dichlorosalicylic acid (DCSA) by PFRs reduction and then further transformed to 3,6-dichlorogentisic acid (DCGA). This study provided a reference for the understanding of the removal mechanism of dicamba by Fe-modified biochar and offered an application potential of biochar derived from Fe-containing sludge for the pollution control of dicamba pesticide pollutants.

17387. 题目: Enhancing the decomposition of extracellular polymeric substances and the recovery of short-chain fatty acids from waste activated sludge: analysis of the performance and mechanism of co-treatment by free nitrous acid and calcium peroxide
文章编号: N21083127
期刊: Journal of Hazardous Materials
作者: Jing Wang, Yu Lou, Kun Feng, Huihui Zhou, Bingfeng Liu, Guojun Xie, Defeng Xing
更新时间: 2021-08-31
摘要: At present, the bioproduction of short-chain fatty acids (SCFAs) from waste activated sludge (WAS) has attracted worldwide attention due to the demand of carbon neutrality during waste treatment. Calcium peroxide (CaO2) has been reported to be an effective method for the solubilization of WAS and the accumulation of SCFAs, but the high reagent cost limits its industrial application. Therefore, free nitrous acid (FNA) was introduced into the WAS pretreatment system to assist with CaO2 for enhancing the disruption of extracellular polymeric substances (EPS) and the subsequent acidogenesis process. The results showed that FNA and CaO2 synergistically enhanced EPS decomposition and the release of biodegradable organic compounds during pretreatment. The highest soluble chemical oxygen demand (3.1- and 2.6-fold higher compared to individual pretreatments at the same concentrations) after pretreatment and the highest SCFAs accumulation (2.0- and 6.4-fold compared to individual pretreatments at the same concentrations) after a 2-day fermentation period was observed in the FNA + CaO2 (0.15g/g VSS) co-treated group. Therefore, the FNA + CaO2 (0.15g/g VSS) co-treatment was determined to be the optimal strategy for ensuring the disintegration of the EPS matrix and enhancing the accumulation of SCFAs in pretreated sludge during anaerobic digestion.

17388. 题目: Utilization of the UAE date palm leaf biochar in carbon dioxide capture and sequestration processes
文章编号: N21083126
期刊: Journal of Environmental Management
作者: Imen Ben Salem, Maisa El Gamal, Manish Sharma, Suhaib Hameedi, Fares M. Howari
更新时间: 2021-08-31
摘要: This paper evaluates the potential use of date palm leaf biochar as a climate change solution through CO2 capture and sequestration. The pyrolysis of date palm leaf was performed at different temperatures 300°, 400°, 500°, and 600 °C. The physicochemical characteristics of the synthesized biochar were examined using Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX), Fourier transforms infrared spectroscopy (FTIR), Thermogravimetric analysis (TGA), and X-ray diffraction analysis (XRD). Direct gas-solid interaction was carried out in an integrated Fluidized Bed Reactor (FBR), connected with a gas analyzer for maximum and effective mixing between the biochar and CO2. LabView program was used as data acquisition for an instantaneous calculation of CO2 adsorption. This study showed that the date palm biochar as porous carbon-based materials has high CO2 adsorption capacity through physisorption and chemisorption progressions. The adsorption results showed a maximum CO2 capture percentage of 0.09 kg CO2/kg, 0.15 kg CO2/kg, 0.20 kg CO2/kg, and 0.25 kg CO2/kg palm biochar synthesized at 300 °C, 400 °C, 500 °C, and 600 °C, respectively. This paper paid attention to the inexpensive technology applied in CO2 sequestration, where fluidization provides well mixing of biochar particles with low operation cost.

17389. 题目: Deep removal of organic matter in glyphosate contained industrial waste salt by dielectric barrier discharge plasma
文章编号: N21083125
期刊: Journal of Environmental Chemical Engineering
作者: Xiaoping Wang, Yunjiang Gong, Jiayuan Qin, Jun Cheng, Cheng Gong, Debin Jiang
更新时间: 2021-08-31
摘要: The cyclic utilization of industrial waste salt can not only solve its environmental pollution problem but also reclaim the available resources. The deep removal of organic pollutants is one of the main challenges for the reuse of waste salt. In this study, dielectric barrier discharge (DBD) plasma is used to remove organic pollutants from simulated industrial waste salt containing glyphosate. Experimental results indicate that DBD plasma can reduce deeply the content of organic matters in waste salt. The decrease of total organic carbon (TOC) is affected by discharge voltage, gas flow rate, initial TOC and water content. For the simulated waste salt with an initial TOC content of 48.1mg/kg, the finial TOC content decreased to 9.5mg/kg after a 25minute DBD plasma treatment at the discharge voltage of 14.0kV, the water content of 10%, and the air flow rate of 0.5L/min. The maximum energy efficiency of TOC removal is 116.5mg/(kW.h). A reaction mechanism of refining of the waste salt was proposed based on the detection and analysis of the degradation intermediates and mineralized products. The results of this study show that non-thermal plasma can be used to refine the organic matter contained waste salt with no production of waste water, which has a good prospect of research and application.

17390. 题目: Evaluating river driftwood as a feedstock for biochar production
文章编号: N21083124
期刊: Waste Management
作者: Abdullah F. Qatarneh, Capucine Dupont, Virginia Ruiz-Villanueva, Denilson da Silva Perez, Radwa M. Ashour, Hervé Piégay, Mário J. Franca
更新时间: 2021-08-31
摘要: Driftwood in river catchments might pose a hazard for the safety of infrastructures, such as dams and river dwellers, and thus is often removed. Génissiat dam in France presents a case study where annually approximately 1300 tons of driftwood are removed to prevent driftwood sinking and to protect the dam infrastructure. Collected river driftwood is rarely studied for utilization purposes and is commonly combusted or landfilled. However, driftwood can be valorized for biochar production through pyrolysis or hydrothermal carbonization (HTC). This study follows a novel approach in characterizing river driftwood by identifying the different common genera present at Génissiat dam on the upper Rhône, France. Moreover, the research provides for the first time a comprehensive analysis of river driftwood different physico-chemical properties, such as moisture content, major elemental composition (CHNSO), HHV, and macromolecular composition (cellulose, hemicellulose, lignin, and extractives). The study shows that the transportation of driftwood through rivers can enhance its properties by reducing the bark content resulting in lower ash content. Results indicate that driftwood can be mixed and further processed as a feedstock regardless of their genera and type for biochar production by pyrolysis or hydrothermal carbonization.

17391. 题目: Removal of tetracycline from wastewater using magnetic biochar: A comparative study of performance based on the preparation method
文章编号: N21083123
期刊: Environmental Technology & Innovation
作者: Feng Gao, Zhenxuan Xu, Yingjie Dai
更新时间: 2021-08-31
摘要: This study aimed to compare the removal effect of tetracycline (TC) by magnetic biochar, (BC) prepared via two magnetization methods: coprecipitation (MBC-1) and pyrolysis impregnation (MBC-2) The TC removal effects of MBC-1 and MBC-2 were compared. The samples were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller analysis (BET), and Zeta potential. Effects of contact time, initial TC concentration, pH, adsorption kinetics, and isotherms were studied. The results showed that the adsorption processes of TC with MBC-1 and MBC-2 were fitted with a pseudo-second-order kinetics model and that the Langmuir isotherm model was most suitable for the adsorption data of MBC-1 and MBC-2. The maximum adsorption capacities of MBC-1 (42.31 mg/g) and MBC-2 (24.31 mg/g) were greater than that of the primitive BC (PBC, 12.10 mg/g), indicating that magnetization effectively promotes the adsorption of TC. MBC-1 contains 2.3 times as much iron as MBC-2, and iron oxides provide –OH groups that act as donors and acceptors of hydrogen bonds, thus enhancing the hydrogen-bonding interactions between MBC-1 or MBC-2 and TC. Compared with MBC-2, MBC-1,could provide oxygen-containing functional groups as reactive sites. The prepared magnetic BCs using coprecipitation form an optimized method for removing TC from water to promote clean production. It also provides a new method of comprehensive utilization of waste mushroom matrix for the sustainable development of the edible mushroom industry.

17392. 题目: Biochars’ adsorption performance towards moxifloxacin and ofloxacin in aqueous solution: Role of pyrolysis temperature and biomass type
文章编号: N21083122
期刊: Environmental Technology & Innovation
作者: Lubna Akhtar, Mahtab Ahmad, Sajid Iqbal, Ahmed A. Abdelhafez, Muhammad Taqi Mehran
更新时间: 2021-08-31
摘要: Three different biomass wastes (rice husk, sawdust, and municipal organic waste) were thermally converted to value-added biochars at two pyrolytic temperatures of 300 °C and 700 °C. Resulted biochars were evaluated for their adsorption potential for the two most widely used fluoroquinolone antibiotics, i.e. moxifloxacin and ofloxacin, through sorption experiments. The results showed that biochars pyrolyzed at 300 °C removed a higher percentage of tested antibiotics (up to 96.18 %) than those produced at 700 °C (up to 38.74 %). The Langmuir and Freundlich isotherm models fitted well to the sorption data of the antibiotics indicating monolayer to multilayer adsorption onto the biochars. The adsorption kinetics data of both moxifloxacin and ofloxacin was well fitted to the pseudo-second-order model, suggesting that chemisorption could be the dominant mechanism of adsorption of antibiotics onto different biochars. Among all the biochars, the organic waste-derived biochar (synthesized at 300 °C) was the best adsorbent, with an adsorption potential of 39.10 and 57.10 mg g−1 for moxifloxacin and ofloxacin, respectively. Relatively greater adsorption of moxifloxacin than ofloxacin was due to its high polar surface area. The possible cause of chemisorption of antibiotics onto low-temperature (300 °C) biochars was hydrogen bonding and polar interactions. On the whole, the results indicated that biochar produced from organic waste has significant adsorption potential to remove moxifloxacin and ofloxacin from an aqueous solution.

17393. 题目: Machine learning exploration of the direct and indirect roles of Fe impregnation on Cr(VI) removal by engineered biochar
文章编号: N21083121
期刊: Chemical Engineering Journal
作者: Xinzhe Zhu, Zibo Xu, Siming You, Michael Komárek, Daniel S. Alessi, Xiangzhou Yuan, Kumuduni Niroshika Palansooriya, Yong Sik Ok, Daniel C.W. Tsang
更新时间: 2021-08-31
摘要: Data mining and knowledge discovery by machine learning (ML) have recently come into application in environmental remediation, especially the exploration for the multifactorial process such as hexavalent chromium [Cr(VI)] removal by iron-biochar composite (Fe-BC). The Cr(VI) removal capacity of Fe-BC was concurrently controlled by impregnated iron species (Fe0/Fe2+/Fe3+), carbon properties, and iron-carbon interactions, while the current lab-scale research could hardly untangle the overall relationships with the Cr(VI) removal experiments of one or several Fe-BCs under different research frameworks. Herein, we investigated the impacts of various microscopic material properties of Fe-BC on aqueous Cr(VI) removal by ML approach and highlighted the variations of biochar properties after iron impregnation. Our results suggested that the direct impacts of impregnated-iron contents on the Cr(VI) removal were limited, possibly related to undistinguished Fe species in the ML models, in which the roles of different iron species on Cr(VI) removal might be counteracted. Instead, the impacts of impregnated iron on the Cr(VI) removal were embodied indirectly by altering the biochar properties. Surface oxygen-containing functional groups (SOFGs) contents on biochar played a pivotal role in Cr(VI) removal according to the ML models. The condensed polyaromatic carbon matrices of BC and Fe-BC with a high content of non-polar carbon were also proved to be conducive to Cr(VI) removal. The ML models developed in this study consider surface functionalities information of BC and Fe-BC and offer a more accurate prediction for Cr(VI) removal, and the information mining behind models can act as a vital reference for the rational design of engineered biochar to remove aqueous Cr(VI).

17394. 题目: The effectiveness of digital soil mapping with temporal variables in modeling soil organic carbon changes
文章编号: N21083120
期刊: Geoderma
作者: Ren-Min Yang, Li-An Liu, Xin Zhang, Ri-Xing He, Chang-Ming Zhu, Zhong-Qi Zhang, Jian-Guo Li
更新时间: 2021-08-31
摘要: The effectiveness of using changes in environmental conditions to explain the spatiotemporal variability in soil organic carbon (SOC) with digital soil mapping (DSM) requires investigation. In this study, temporal variables representing temporal patterns of climate, vegetation, and land cover factors were explored. Models to predict SOC stocks were developed using a random forest algorithm and data from China during two periods (the 1980s and 2010s). We forecasted and hindcasted the developed models and assessed their temporal projections against temporally independent data. Models were developed for both periods using different sets of variables (with/without temporal variables), and their temporal projections were compared. The important temporal variables were identified by applying the recursive feature elimination algorithm. The results showed that the performances of temporal projections for the 1980s and 2010s were improved by approximately 17% and 47%, respectively, when temporal variables were included in the models. Spatially, the maps of changes in SOC stocks derived from the models that included temporal variables presented stronger associations with temporal changes in climate, vegetation, and land cover than those derived from the models that did not include temporal variables. This work highlights that variation in SOC stocks can be linked to temporal patterns of environmental factors. The findings also provide evidence that the application of temporal patterns of environmental factors to DSM models can be useful for the large-scale prediction of changes in SOC.

17395. 题目: A review on persulfates activation by functional biochar for organic contaminants removal: synthesis, characterizations, radical determination, and mechanism
文章编号: N21083119
期刊: Journal of Environmental Chemical Engineering
作者: Chongqing Wang, Rong Huang, Ruirui Sun, Jiapeng Yang, Mika Sillanpää
更新时间: 2021-08-31
摘要: In recent years, refractory organic pollutants (ROPs) have been progressively detected in wastewater. Persulfates (peroxymonosulfate and peroxydisulfate)-based advanced oxidation processes (PS-AOPs) are efficient for ROPs degradation. Biochar and its composites, which have the dual advantages of adsorption and catalysis, have been widely used in PS-AOPs. Research advances on PS activation by biochar-based materials are systematically summarized, including biochar modifications, characterizations, radical determinations, and catalytic mechanism. Biochar modifications applied to PS-AOPs are introduced involving morphology regulation, heteroatomic doping, and metals loading. Characterization techniques are described to reveal the physicochemical properties of biochar-based catalysts. Various methods for radical determinations are discussed. The catalytic mechanism in the PS-AOPs is depicted from the point of radical pathway and non-radical pathway. Based on current knowledge, the perspectives and challenges that may be encountered in basic research and practical applications are put forward. This review offers novel insights into catalyst design and better understanding of PS-AOPs.

17396. 题目: Effect of site hydrological conditions and soil aggregate sizes on the stabilization of heavy metals (Cu, Ni, Pb, Zn) by biochar
文章编号: N21083118
期刊: Science of The Total Environment
作者: Jiali Shentu, Xiaoxiao Li, Ruifang Han, Qianqian Chen, Dongsheng Shen, Shengqi Qi
更新时间: 2021-08-31
摘要: Biochar is a popular material that would effectively immobilize heavy metals in soil, which can greatly decrease the health risk of heavy metals. Although many previous studies have studied the immobilization of heavy metals by biochar, the influence of hydrological conditions on the immobilization effect is still not clear. This paper carried out column experiments to study the effect of fluctuating groundwater table on Cu, Ni, Pb, Zn distribution and speciation with the addition of biochar from pyrolysis of swine manure. Experimental results showed that biochar could significantly decrease the leaching toxicity of Cu and Ni by 24.4% and 44.7% respectively, while the immobilization effect of Pb and Zn was relatively insignificant. The average reduction percentage of bioavailable Cu was 14.5%, 39.5% and 33.3% in the unsaturated zone, fluctuating zone and saturated zone respectively, showing the better immobilization effect in the fluctuating zone and saturated zone. The residual fraction of heavy metals increased significantly after the addition of biochar, and the increase of residual fraction was larger in small soil aggregates. This study helped illustrate the influence of hydrological conditions and soil aggregate sizes on the stabilization effect of heavy metals by biochar, which could be used to guide the remediation process of sites contaminated by heavy metals.

17397. 题目: Underlying mechanisms for the impacts of molecular structures and water chemistry on the enrichment of poly/perfluoroalkyl substances in aqueous aerosol
文章编号: N21083117
期刊: Science of The Total Environment
作者: Yao Li, Xiaoyong Yu, Xin Chen, Jun Yin, Wenjue Zhong, Lingyan Zhu
更新时间: 2021-08-31
摘要: Enrichment of ionic poly/perfluoroalkyl substances (PFASs) in aqueous aerosol (AA) is an important pathway for them to enter atmosphere. In this study, the enrichment behaviors of 12 legacy and emerging PFASs in AA in both single solute and mixed solutions were investigated. The enrichment factors (EF) displayed a general increasing trend with the fluorinated carbon chain length. For the first time, a robust Quantitative Structure-Property Relationship (QSPR) model coupled with partial least-square method was established with fifteen quantum chemical descriptors. Four molecular descriptors, including dipole moment (μ), molecular weight (MW), the maximal value of the molecular surface potential (Vs, max) and molecular volume (V) were identified as the key structural variables affecting the PFASs enrichment. Inorganic salts and humic acid (HA) which are common in seawater, facilitated the PFASs enrichment as a result of enhanced hydrophobicity and the bridging effect caused by divalent cations. The typical cationic and anionic surfactants, cetyltrimethylammonium bromide and sodium dodecyl sulfate, both inhibited the enrichment due to the competition between PFASs and surfactants. It is interesting that 6:2 chlorinated polyfluorinated ether sulfonate (F53B) had the highest EF among the 12 PFASs, implying its strong potential of atmosphere transport.

17398. 题目: Preparation of sugarcane bagasse biochar/nano-iron oxide composite and mechanism of its Cr (VI) adsorption in water
文章编号: N21083116
期刊: Journal of Cleaner Production
作者: Liji Bai, Xiujuan Su, Jinpeng Feng, Shaojian Ma
更新时间: 2021-08-31
摘要: In this study, a sugarcane bagasse biochar/nano-iron oxide composite was prepared via a one-pot pyrolysis method by using the sugarcane bagasse-based solid waste and microwave as the raw material and energy source, respectively. The developed composite was characterized by BET, XRD, FT-IR and TEM and was applied for the removal of Cr (VI) from water. The composite was observed to be mainly composed of amorphous carbon, Fe3O4 and Fe2O3. The iron oxides were uniformly embedded on the surface of the carbon layer by van der Waals force. The sugarcane bagasse-based biochar/nano-iron oxide composite material exhibited an optimal Cr (VI) adsorption capacity of 55 mg/g under the experimental conditions specified in this study. The Cr (VI) adsorption mechanism of the Fe2O3/Fe3O4/WBC composite was explained through FTIR, XPS, charge transfer analyses, and density functional theory calculations (DFT). The deposition of Cr (VI) on the surface of the composite was attributed to electrostatic interaction, redox reactions and complexation between the Fe2O3/Fe3O4/WBC composite and Cr (VI) contained in the solution.

17399. 题目: Isoscape models of the Southern Ocean: predicting spatial and temporal variability in carbon and nitrogen isotope compositions of particulate organic matter
文章编号: N21083115
期刊: Global Biogeochemical Cycles
作者: Katie St John Glew, Boris Espinasse, Brian P.V. Hunt, Evgeny A. Pakhomov, Sarah J. Bury, Matt Pinkerton, Scott D. Nodder, Andres Gutiérrez Rodríguez, Karl Safi, Julie C.S. Brown, Laura Graham, Robert B. Dunbar, David A. Mucciarone, Sarah Magozzi, Chris Somes, Clive N. Trueman
更新时间: 2021-08-31
摘要: Polar marine ecosystems are particularly vulnerable to the effects of climate change. Warming temperatures, freshening seawater and disruption to sea ice formation potentially all have cascading effects on food webs. New approaches are needed to better understand spatio-temporal interactions among biogeochemical processes at the base of Southern Ocean food webs. In marine systems, isoscapes (models of the spatial variation in the stable isotopic composition) of carbon and nitrogen have proven useful in identifying spatial variation in a range of biogeochemical processes, such as nutrient utilization by phytoplankton. Isoscapes provide a baseline for interpreting stable isotope compositions of higher trophic level animals in movement, migration and diet research. Here, we produce carbon and nitrogen isoscapes across the entire Southern Ocean (>40°S) using surface particulate organic matter isotope data, collected over the past 50 years. We use Integrated Nested Laplace Approximation -based approaches to predict mean annual isoscapes and four seasonal isoscapes using a suite of environmental data as predictor variables. Clear spatial gradients in δ13C and δ15N values were predicted across the Southern Ocean, consistent with previous statistical and mechanistic views of isotopic variability in this region. We identify strong seasonal variability in both carbon and nitrogen isoscapes, with key implications for the use of static or annual average isoscape baselines in animal studies attempting to document seasonal migratory or foraging behaviours.

17400. 题目: An assessment of integrated amendments of biochar and soil replacement on the phytotoxicity of metal(loid)s in rotated radish-soya bean-amaranth in a mining acidy soil
文章编号: N21083114
期刊: Chemosphere
作者: Shaojun Jiang, Guangling Dai, Jie Zhou, Jie Zhong, Junguang Liu, Yuehong Shu
更新时间: 2021-08-31
摘要: Knowledge is insufficient on feasible remediation techniques to agricultural soils contaminated by multiple heavy metal(loid)s with elevated concentrations and extreme acidy from acid mine drainages (AMD). We aimed to elucidate the effect of integrated biochar (BC) and soil replacement on improving the mining soil properties and then alleviating the phytotoxicity of As, Pb, Cd, Cu, and Zn on radish (Raphanus sativus L.)-soya bean (Glycine max Merr.) -amaranth (Amaranthus tricolor L.) rotation and the potential risk of crops to human health. Biochar and soil replacement showed outstanding effects on improving soil properties by increasing soil pH values, reducing available metal(loid)s, and enhancing the activity of catalase, urease and acid phosphatase. Also, the integrated technique regulated the physiological disorders of crops caused by metal(loid)s, specifically increasing chlorophyll content and reducing malondialdehyde (MDA) in the three crops, and reducing the content of metal(loid)s in edible parts of plants. The combination of biochar and soil replacement exhibited better remediation effect than the single application of biochar or soil replacement, which played different roles in remediating mining farmland. Biochar exhibited efficacy in soil pH amelioration, metal stabilization and soil enzyme activity enhancement, while soil replacement alleviated metal(loid)s stress through the dilution effect. Among the 8 treatments, only biochar combined with 35% (S35BC) and 50% (S50BC) of replaced soil could achieve the safe production of the three crops under the three-season crop rotation.