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17581. 题目: Pretreatment for alleviation of RO membrane fouling in dyeing wastewater reclamation
文章编号: N22010118
期刊: Chemosphere
作者: Gen-Qiang Chen, Yin-Hu Wu, Yu-Jun Tan, Zhuo Chen, Xing Tong, Yuan Bai, Li-Wei Luo, Hao-Bin Wang, Yu-Qing Xu, Zi-Wei Zhang, Nozomu Ikuno, Hong-Ying Hu
更新时间: 2022-01-01
摘要: Adsorption and coagulation were commonly used to alleviate reverse osmosis (RO) membrane fouling caused by dissolved organic matters (DOM), but the effects of changed composition and structure of DOM in dyeing wastewater after adsorption and coagulation on RO membrane fouling have seldom been studied. This study aimed at resolving the mechanism how the RO membrane fouling during dyeing wastewater treatment was alleviated by using adsorption and coagulation. The dyeing wastewater caused serious RO membrane fouling. Pretreatment with granular activated carbon (GAC), polyferric sulfate (PFS) and polyaluminum chloride (PACl) were conducted. It was shown that GAC could remove most of the DOM (95%) and preferred to adsorb protein, hydrophobic neutrals and fluorescent compounds. Both coagulants of PFS and PACl preferred to remove polysaccharides (the removal rate was 9–19% higher than that of DOM), high-MW compounds and these compounds with high fouling potential. Afterwards, the RO membrane fouling potential of the dyeing wastewater was tested. The GAC and PFS performed well to alleviate fouling. After GAC treatment, the decline rate of RO flux was similar to that of raw wastewater after 6-fold dilution. With pretreatment by PFS or PACl, the fouling potential of dyeing wastewater was much lower than that of raw wastewater after diluted to the same DOM content. Changes in polysaccharides content in the DOM had more effects on RO membrane fouling than that of proteins after these pretreatment. Although the DOM changed significantly after pretreatment, the fouling type was still intermediate blocking.

17582. 题目: Estimates of protein in coastal marsh soils: A case study of the utility of the Bradford assay for quantifying soil protein
文章编号: N22010117
期刊: Geoderma
作者: S. Alex McClellan, Edward A. Laws, Tracy Elsey-Quirk
更新时间: 2022-01-01
摘要: The fraction of soil protein extracted by autoclaving soil (AESP) has emerged as a potential indicator of available organic nitrogen (N), aggregate stability, and soil carbon (C) storage potential. Estimates of AESP are often based on colorimetric assays—primarily the Bradford assay—yet the results of these assays can be confounded by interference from polyphenolic contaminants of soil protein extracts. The extent to which polyphenolic interference in the Bradford assay may contribute to over- or underestimation of AESP content and whether a correction can be made for the interference has remained unclear. Here, we present a case study of how Bradford-based estimates of AESP compared to maximum and minimum estimates of AESP across two chronosequences of marsh soils that ranged widely in soil organic matter concentration (20–580 mg·g−1). Our maximum estimates were based on the amount of N in the dialyzed extracts; our minimum estimates were based on the proportion of the extracted N that was accounted for by hydrolysable amino acids. We observed that the Bradford-based estimates usually followed trends that were qualitatively similar to those of the maximum and minimum estimates across different marshes. However, the Bradford-based estimates were almost always greater than the maxima (by up to 450%) and never below the minima. This extent of overestimation was positively correlated with the C:N ratio of the extracts, but the relationships between the overestimates and C:N ratios differed between the two chronosequences. Contrary to what has been previously suggested, the dilution of extracts only exacerbated the extent of overestimation in the Bradford assay. Instead of a continued reliance on the Bradford assay for AESP measurements, we propose that the N content of semi-purified soil extracts serve as a surrogate metric for AESP, primarily because it may be more amenable to inter-study comparisons while still being feasible for most soil laboratories.

17583. 题目: Glendonite concretion formation due to dead organism decomposition
文章编号: N22010116
期刊: Sedimentary Geology
作者: Yusuke Muramiya, Hidekazu Yoshida, Masayo Minami, Tomoyuki Mikami, Toshinori Kobayashi, Kousuke Sekiuchi, Nagayoshi Katsuta
更新时间: 2022-01-01
摘要: Glendonite is generally accepted as a calcite pseudomorph after ikaite (CaCO3·6H2O) and is commonly preserved in spherical carbonate concretions known as glendonite concretions in marine sedimentary rocks. Although they have widely attracted attention as environmental indicators, the detailed geochemical process underlying glendonites formation is not fully understood. Here to show the glendonite concretion formation process, we conducted detailed macro- and microscopic observations, carbon and oxygen isotopic analyses (δ13C and δ18O), chemical composition analyses, and elemental mapping of glendonite concretions from four Cenozoic marine sedimentary strata in Japan. The occurrence of glendonite and concretions around dead organisms such as bivalves, ghost shrimp, or soft-bodied organisms forming ichnofossils, and the negative δ13C values of glendonite concretions around −20‰ to −10‰ showed that organic matter in dead organisms served as a carbon source for both ikaite crystals and the surrounding concretions. Highly concentrated phosphorus and its distribution patterns in glendonite concretions showed that changes of phosphate concentration in porewater play a crucial role in the sequential formation process from ikaite crystallization to syngenetically surrounding calcite concretion growth. The sequential processes of glendonite concretion formation progressed rapidly owing to the supply of bicarbonate during the decomposition of organisms in marine sediments. Our work provides a phosphate concentration-controlled growth model of glendonite concretion involving organic decomposition that can be used to evaluate paleoporewater chemical conditions during early diagenesis.

17584. 题目: Water reclamation and microbial community investigation: treatment of tetramethylammonium hydroxide wastewater through an anaerobic osmotic membrane bioreactor hybrid system
文章编号: N22010115
期刊: Journal of Hazardous Materials
作者: Hau-Ming Chang, Shiao-Shing Chen, Shiang-Sheng Hsiao, Wen-Shing Chang, I-Chieh Chien, Chinh Cong Duong, Thi Xuan Quynh Nguyen
更新时间: 2022-01-01
摘要: Tetramethylammonium hydroxide (TMAH) is a toxic photoresist developer used in the photolithography process in thin-film transistor liquid crystal display (TFT-LCD) production, and it can be removed through anaerobic treatment. TMAH cannot be released into the environment because of its higher toxicity. A tight membrane, such as a forward osmosis (FO) membrane, together with an anaerobic biological process can ensure that no TMAH is released into the environment. Thus, for the first time, an anaerobic osmotic membrane bioreactor (AnOMBR) hybrid system was developed in this study to treat a low-strength TMAH wastewater and to simultaneously investigate its microbial community. Microfiltration extraction was used to mitigate the salinity accumulation, and a periodically physical water cleaning was utilized to mitigate the FO membrane fouling. The diluted draw solute (MgSO4) was reconcentrated and reused by a membrane distillation (MD) process in the AnOMBR to achieve 99.99% TMAH removal in this AnOMBR-MD hybrid system, thereby ensuring that no TMAH is released into the natural environment. Moreover, the membrane fouling in the feed and draw sides were analyzed through the fluorescence excitation-emission matrix (FEEM) spectrophotometry to confirm that the humic acid-like materials were the primary membrane fouling components in this AnOMBR. Additionally, 16S rRNA metagenomics analysis indicated that Methanosaeta was the predominant contributor to methanogenesis and proliferated during the long-term operation. The methane yield was increased from 0.2 to 0.26L CH4/g COD when the methanogen species acclimatized to the saline system.

17585. 题目: Afforestation influences soil organic carbon and its fractions associated with aggregates in a karst region of Southwest China
文章编号: N22010114
期刊: Science of The Total Environment
作者: Pujia Yu, Yixuan Li, Shiwei Liu, Jinlian Liu, Zhi Ding, Mingguo Ma, Xuguang Tang
更新时间: 2022-01-01
摘要: Variations in soil organic carbon (SOC) and its fractions within soil aggregates in response to land-use change are important to understand the carbon cycles in terrestrial ecosystem. However, responses of total SOC, SOC fractions, and SOC stability in different soil aggregates to land-use change are less addressed, especially in karst regions with serious land degradation. Therefore, bulk soil samples were collected under four land uses with similar geographical characteristics and previous framing practices including farmland (FL), Bamboo forest (BA), landscape tree planting (LAT), and orange orchards (ORO) in a karst region of Southwest China. Contents of total SOC and three carbon fractions based on their degree of oxidizability (F1, very labile; F2, inert; F3, oxidizable resistant) in bulk soil and different soil aggregates (macro-aggregate, micro-aggregate, and silt+clay fraction) were measured. Afforestation significantly increased contents of total SOC and three carbon fractions in bulk soil and soil aggregates, and the influence was more obvious in macro-aggregate than the other aggregates. Contents of total SOC, F1, F2, and F3 under afforestation land increased by 41.73%, 58.19%, 33.91%, and 40.55%, respectively, in bulk soil, by 55.60%, 79.24%, 121.77%, and 43.30%, respectively, in macro-aggregate, by 52.80%, 33.57%, 20.14%, and 75.02%, respectively, in micro-aggregate, and by 26.21%, 35.60%, 29.26%, and 23.75%, respectively, in silt+clay fraction than those under FL. In bulk soil and soil aggregates, proportions of F1, F2, and F3 in total SOC ranged from 0.11 to 0.18, from 0.13 to 0.22, and from 0.60 to 0.73, respectively, suggesting that the stable carbon was the predominant carbon fraction in the study area. Afforestation decreased the values of stability of SOC in macro-aggregate and silt+clay fraction, while it increased the value in micro-aggregate. Although both BA and ORO had higher SOC content in bulk soil than the LAT, but the SOC stability in bulk soil under BA was significantly lower than that under ORO. In conclude, afforestation form FL improved SOC content and altered SOC stability in bulk soil and soil aggregates, and conversion of FL to ORO might be the best choice to increase SOC sequestration in the four land-use types compared in karst regions of Southwest China.

17586. 题目: An integrated investigation on anaerobic membrane-based thickening of fecal sludge and the role of extracellular polymeric substances (EPS) in solid-liquid separation
文章编号: N22010113
期刊: Journal of Environmental Management
作者: Muhammad Arslan Shahid, Nida Maqbool, Sher Jamal Khan
更新时间: 2022-01-01
摘要: Pre-thickening or primary treatment of fecal sludge (FS) is a major bottleneck in designing fecal sludge treatment plants. This research demonstrates a practical analysis to improve the thickening efficiency of FS using woven fiber microfiltration membrane. A laboratory-scale anaerobic membrane-based thickening tank (MBTT) was investigated. Firstly, the system was operated with unconditioned FS at a flux range of 1–3 L/m2h. Secondly, the system was operated at an optimized flux of 2 L/m2h with conditioners, chitosan, and charcoal dust, at their optimized dosages reported in previous studies. It was observed that the solids accumulation in MBTT was linear and was specific to net solids accumulation. Feed FS was thickened to around 15% of total solids (TS) in 9–14 days. The overall solids accumulation rate was higher with conditioned FS. The less EPS accumulation and higher dewaterability in conditioned FS reduced the brushing frequency of the membrane and consequently, the average filtration duration per cycle was increased. Strong correlations of dewatering time with floc size, EPS, and electrical conductivity, indicated that higher EPS in FS tends to form flocs which can increase the dewatering rate in unstabilized FS. In permeate, the average TS and CODt removal observed were 72–78% and 87–91%, respectively.

17587. 题目: Granule size informs the characteristics and performance of microalgal-bacterial granular sludge for wastewater treatment
文章编号: N22010112
期刊: Bioresource Technology
作者: Meng Zhang, Bin Ji, Shulian Wang, Jun Gu, Yu Liu
更新时间: 2022-01-01
摘要: In this study, four groups of microalgal-bacterial granules with averaged diameters of about 356, 760, 951 and 1,444 µm were used to investigate their characteristics and performance in treating wastewater. A strong correlation between extracellular polymeric substances of microalgal-bacterial granules and the granule size was observed. Moreover, granule size showed a positive effect on the specific organics removal rate, but being negative for ammonium and phosphorus removal. It appeared that granule size could be used as a useful index to reflect the synergistic interactions between microalgae and bacteria in terms of the abundances, distributions and functional species of microalgae and bacteria in the microalgal-bacterial granules. This study is expected to offer new insights into the size-dependent performances of microalgal-bacterial granules for wastewater treatment.

17588. 题目: Coagulants put phosphate-accumulating organisms at a competitive disadvantage with glycogen-accumulating organisms in biological phosphorus removal system
文章编号: N22010111
期刊: Bioresource Technology
作者: Wen-Jing Xia, Hao Wang, Lin-Qian Yu, Gui-Feng Li, Jin-Rui Xiong, Xiao-Yan Zhu, Xue-Chao Wang, Jia-Rui Zhang, Bao-Cheng Huang, Ren-Cun Jin
更新时间: 2022-01-01
摘要: Enhanced biological phosphorus removal (EBPR) process is susceptible to the changed operation condition, which results in an unstable treatment performance. In this work, long-term effect of coagulants addition, aluminum salt for the reactor R1 and iron salt for the reactor R2, on EBPR systems was comprehensively evaluated. Results showed that during the initial 30 days’ coagulant addition, effluent chemical oxygen demand and phosphorus can be reduced below 25 and 0.5 mg·L-1, respectively. Further supply of metal salts would stimulate microbial extracellular polymeric substance excretion and induce reactive oxygen species accumulation, which destroyed the cell membrane integrity and deteriorated the phosphorus removal performance. Moreover, coagulants would decrease the relative abundance of Candidatus Accumulibacter while increase the relative abundance of Candidatus Competibacter, leading phosphors accumulating organisms in a disadvantage position. The results of this work might be valuable for the operation of chemical assisted biological phosphorus removal bioreactor.

17589. 题目: The quantity and stability of soil organic carbon following vegetation degradation in a salt-affected region of Northeastern China
文章编号: N22010110
期刊: CATENA
作者: Pujia Yu, Yixuan Li, Shiwei Liu, Zhi Ding, Aichun Zhang, Xuguang Tang
更新时间: 2022-01-01
摘要: Understanding the influence of vegetation conversion induced by land degradation on soil organic carbon (SOC) dynamics provides a basis for the sustainable use of grasslands. While labile carbon fractions often vary with the type of vegetation, little is known about whether and how vegetation degradation affects the recalcitrant carbon fraction that is highly resistant to oxidation. Here, we studied the influence of vegetation degradation on changes in SOC and four oxidizable fractions with different stabilities in Northeastern China. The soil was collected from a vegetation degradation sequence, including Leymus chinensis (LEY, native grassland), Puccinellia tenuiflora (PUC, light degradation), Chloris virgata (CHL, moderate degradation), and Suaeda heteroptera (SUA, severe degradation). Contents of total SOC and four oxidizable SOC fractions extracted under a gradient of oxidation (F1, very labile; F2, labile; F3, less labile; F4, oxidizable resistant) were measured using a modified Walkley-Black method. Results showed that the contents of total SOC and oxidizable SOC fractions were significantly different under different vegetation types and soil depths. Under PUC, CHL, and SUA, contents of total SOC (29.0%, 34.3%, and 55.4%, respectively), F1 (22.5%, 20.8%, and 40.8%, respectively), F2 (28.2%, 53.8%, and 72.1%, respectively), F3 (52.0%, 40.6%, and 66.2%, respectively), and F4 (15.0%, 21.9%, and 42.8%, respectively) were lower than those under LEY. Vegetation degradation had a significant effect on the F4 fraction as well as the F1, F2, and F3 fractions. Regression coefficients of the relationship between oxidizable SOC fractions as a function of total SOC showed that these fractions, as a proportion of total SOC, were 22% for F1 and F2, 26% for F3, and 31% for F4. There were no significant differences in the percentages of active carbon fractions (F1 + F2) in total SOC and the lability of total SOC among the four vegetation types. These findings suggest that the recalcitrant carbon fraction can be affected by land degradation as well as the labile carbon fraction, and that shifts in land use affect the contents of total SOC and its fractions, but have no effect on the stability of SOC in semi-arid areas.

17590. 题目: Enhancing robustness of halophilic aerobic granule sludge by granular activated carbon at decreasing temperature
文章编号: N22010109
期刊: Chemosphere
作者: Fei Han, Mengru Zhang, Zhe Liu, Yufei Han, Qian Li, Weizhi Zhou
更新时间: 2022-01-01
摘要: High salinity seriously inhibits the growth and metabolism of microorganisms, resulting in poor settleability, excessive biomass loss and low treatment efficiency of biological wastewater treatment systems. The development of halophilic aerobic granular sludge (HAGS) is a feasible strategy for addressing this challenge. However, there are problems with the granulation of HAGS and the stability of granules at decreasing temperatures. In this study, granular activated carbon (GAC) with a large specific surface area and good biocompatibility was used to enhance the robustness of HAGS. The results showed that the addition of GAC shortened the granulation time from 60 d (control system) to 35 d (GAC-addition system). The proteins contents of extracellular polymeric substances (EPS) in the GAC-addition system was significantly higher (p < 0.05) than that in the control system during granulation. Satisfactory NH4+-N and chemical oxygen demand (COD) removal efficiencies reached more than 96% in both systems at 18–26 °C. When the operating temperature was lower than 15 °C, the GAC-addition system exhibited better NH4+-N removal performance (>80%) than the control system (<60%). Moreover, the abundance of almost all nitrogen metabolism-related genes in the GAC-addition system was higher than that in the control system. During the granulation process, the enrichment of functional microorganisms, including family Flavobacteriaceae, Rhodobacteraceae, and Cryomorphaceae, may promote the production of EPS by significantly upregulating (p < 0.05) the metabolic pathway “Signaling Molecules and Interaction” in the GAC-addition system. The overexpression of the nitrogen assimilation gene glnA in heterotrophic bacteria (Halomonas and Marinobacterium) may promote the conversion of inorganic nitrogen to extracellular proteins to adapt to the decreased operational temperature. Our findings confirm that GAC addition is a simple but effective strategy to accelerate granulation and enhance the robustness of HAGS in saline wastewater treatment.

17591. 题目: Phosphorous partitioning in sediments by particle size distribution in shallow lakes: From its mechanisms and patterns to its ecological implications
文章编号: N22010108
期刊: Science of The Total Environment
作者: Peiyao Deng, Qitao Yi, Jin Zhang, Conghui Wang, Yihan Chen, Tao Zhang, Wenqing Shi
更新时间: 2022-01-01
摘要: This study revealed a general pattern of P partitioning onto sediment particles that has ecological implications for shallow lakes. Six individual sediment samples from two large shallow lakes in eastern China were sieved into five sediment particle size classes ranging from 0.5 μm to 50 μm. These particle size groupings were subjected to P fractionation and P adsorption isotherm analyses as well as bioavailable P bioassays. A P-adding experiment was used to validate the initial P partitioning onto the sediment particles. Multiple lines of evidence revealed that P partitioning onto the particles was dependent on the amounts of P adsorbents or P-containing compounds in the sediments, such as iron and aluminum oxides, organic matter, and calcium compounds. An exponential equation, c(x) = cmaxexp(−kdx), was proposed to describe the relationship between the partitioning of bioavailable P and particle size. In the equation, cmax represents the maximum P concentration adsorbed by the finest particles, and kd is a constant reflecting the decrease in the P concentration with particle size (x).

17592. 题目: Modelling soil organic carbon using vegetation indices across large catchments in eastern Australia
文章编号: N22010107
期刊: Science of The Total Environment
作者: V.R. Kunkel, Tony Wells, G. Hancock
更新时间: 2022-01-01
摘要: Soil organic carbon (SOC) is an important soil component. However, examining SOC at the large catchment scale is difficult due to the intensive labour requirements. This study examines SOC distribution at large (>500 km2) catchment scales using field-sampled SOC data and remote sensed vegetation indices located in eastern Australia (Krui River catchment - 562 km2; Merriwa River catchment – 808 km2) on grazing land-use basalt soil. The SOC data obtained was compared to digital elevation model (DEM) derived elevation and insolation data, as well as Normalised Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) values corresponding to each sample site. These indices were obtained from the MODIS sensor (Terra/Aqua) and Landsat series satellites. Vegetation Indices (VI) captured immediately prior to sampling demonstrated a poor correlation with SOC. The use of multiple, aggregated, prior VI data sets provided a good match with SOC. The strongest match occurred for Landsat 8 EVI, indicating that VIs with higher spatial and spectral resolution, which can account for atmospheric interference, have the potential to produce more accurate SOC mapping (Krui samples in 2006, R2 = 0.31, P < 0.01; Krui sampled in 2014, R2 = 0.41, P < 0.01; Merriwa samples in 2015, R2 = 0.37, P < 0.01). A sensitivity test for both remote sensing platforms demonstrated that the findings were robust. The results demonstrate that VIs are a reliable surrogate for historical vegetation growth in pasture dominated landscapes and therefore soil carbon inputs allowing for mapping of SOC across large catchment scales. Both Landsat and MODIS produced similar results and demonstrate that SOC can be reliably predicted at the large catchment scale and for different catchments in this environment with RMSE range of 0.79 to 1.06. The method and data can be applied globally and provides a new method for environmental assessment.

17593. 题目: Farmland abandonment decreases soil bioavailable phosphorus but increases organic phosphorus in the mid-hills of Nepal
文章编号: N22010106
期刊: CATENA
作者: Xin Tian, Haijian Bing, Yanhong Wu, He Zhu, Wei Zhao, Qingqing He, Donghong Xiong
更新时间: 2022-01-01
摘要: Global land use changes (LUCs) have been comprehensively modulated by human activities, yet the direction and magnitude of the LUCs’ effects on soil phosphorus (P) cycling in mountain regions remain unclear. Here, the variations in the concentrations and stocks of soil bioavailable phosphorus (Bio-P) and its supply pathways were explored in four land uses (farmland, abandoned land, shrub and forest) from the mid-hills of Nepal. After farmland abandonment, the concentrations of soil Bio-P decreased significantly especially in the forest, while organic P presented an opposite case. Compared with the farmland, the stocks of soil Bio-P in the abandoned land, shrub and forest decreased 30.3%, 42.2% and 73.1%, respectively, and those of organic P in the abandoned land and forest increased 19.2% and 52.2%, respectively. This was mainly attributed to the increased aboveground biomass, while soil microorganisms had a limited role in organic matter decomposition because of the low soil moisture. Relative to the farmland affected by fertilization, more complex factors (e.g., pH, MBP, SOC and clay) regulated soil P fractions in other lands where Bio-P was mainly supplied by secondary mineral P, followed by primary mineral P and occluded P. Soil erosion caused an evident P loss in farmland, while forest had a great potential to conserve soil P. This study provides new insights into the cycling of soil P under the LUCs in mountain regions, which will serve as a foundation for the sustainable use of soil P resources for livelihood and land management.

17594. 题目: Divergences of soil carbon turnover and regulation in alpine steppes and meadows on the Tibetan Plateau
文章编号: N22010105
期刊: Science of The Total Environment
作者: Yanzhang Huang, Zhongbao Xin, Jinhao Liu, Qianjin Liu
更新时间: 2022-01-01
摘要: The grasslands of the Tibetan Plateau store approximately 2.5% of global soil organic carbon (SOC) and considerable soil inorganic carbon (SIC) and have the potential to become a vast carbon source or sink as climate change progresses. However, the soil carbon (C) sequestration mechanisms that occur across large-scale natural gradients remain unclear. Here, humic substances (HS) were utilized to trace soil C turnover at 0–20 cm, and we compared divergences among three main grassland types (alpine meadow, alpine steppe, and artificial plantation) using structural equation modeling (SEM). The results showed that the alpine meadows sequestered the most soil C (63.99 ± 4.41 g kg−1 SOC and 4.11 ± 0.63 g kg−1 SIC), sequestering 2–3 times more than the alpine steppe ecosystems (19.78 ± 1.98 g kg−1 SOC and 9.21 ± 0.66 g kg−1 SIC). The alpine steppe and artificial plantation regions have strong C sink potential due to their low C/N ratios (P < 0.05). Importantly, SIC played an important role in the alpine steppes, accounting for nearly 26–37% of soil C. The ratios of recalcitrant HS to SOC were estimated as 46.50%, 65.09%, and 78.17% in the alpine meadow, alpine steppe, and artificial plantation ecosystems, respectively, indicating that SOC in the alpine meadow was the most sensitive to climate change. Fulvic acid (FA) accounted for 50.86% of SOC in the 0–20-cm interval, contributing most to the formation of SOC in all vegetation types. In addition, in contrast to climatic controls on soil C turnover in the alpine meadow, climate conditions rarely controlled C turnover in the alpine steppe. Moreover, sand and silt were the main soil minerals involved in C turnover in alpine meadow and alpine steppe ecosystems, respectively. Our study improves understanding of the mechanism by which soil C sinks form on the Tibetan Plateau under warming and wetting conditions.

17595. 题目: Production of artificial humic acid from biomass residues by a non-catalytic hydrothermal process
文章编号: N22010104
期刊: Journal of Cleaner Production
作者: Yuchao Shao, Menggang Bao, Weizhong Huo, Rong Ye, Yanqing Liu, Wenjing Lu
更新时间: 2022-01-01
摘要: Humic substance is vital for soil fertility and has wide applications such as soil remediation agents, organic fertilizer and adsorbents. The results of pH effect on artificial humic acids (AHAs) production demonstrated that acid hydrothermal conditions are favorable for biomass waste dissolution and formation of AHA precursors such as saccharides, furans, organic acids and phenols; whereas alkaline hydrothermal conditions are suitable for AHAs production from these precursors. Enhanced humification from biomass waste with a combined acid - alkaline hydrothermal process was proposed. The solid product known as hydrochar was reduced to only 5 wt% after this process indicating the significant improvement of dissolution and transformation. The AHAs concentration of 28.28 ± 0.98 wt% obtained from corn stalk was the highest yield so far, 10 times higher than ever reported. The carbon flow analysis indicated that the selectivity of AHA-C was 43.2% of the initial carbon in corn stalk. Our study provides a new way of mass production of AHAs in short period, which has great potential for industry application.

17596. 题目: Influences of humic acid on the release of polybrominated diphenyl ethers from plastic waste in landfills under different environmental conditions
文章编号: N22010103
期刊: Ecotoxicology and Environmental Safety
作者: Yifan Zhang, Ying Yuan, Wenbing Tan
更新时间: 2022-01-01
摘要: Landfill-formed humic acid are an important substance in landfill leachate. The effect of landfill-formed humic acid in different environments (temperature and surfactant concentrations) on the release of chemicals from plastic waste remains unknown. In order to explore the pollution release rates of polybrominated diphenyl ethers (PBDEs) in different plastic waste, humic acid were used as the extractant to conduct leaching simulation tests to study the effects of time, temperature, and surfactant (sodium dodecyl benzene sulfonate (SDBS)) concentrations on the release of PBDEs in waste. This waste includes polypropylene random pipes (PPRP), polyethylene of raised temperature resistance pipes (PERTP), polyvinyl chloride pipes (PVCP), polypropylene plastic benches (PPB), polypropylene washing machines (PPWM), polystyrene television (PSTV), and flame-retardant acrylonitrile butadiene styrene (FRABS). The leaching amounts of PBDEs had significant linear growth over time. Among them, the leaching amount of PBDEs in daily plastics is lower than dismantling plastics. The rate of leaching of BDE-209 was greater than the other congeners, with a leaching amount of up to 93.10%. Different types of waste exhibited different changes with temperature and surfactants concentrations. Among all the waste types, the leaching amounts of PBDEs in PPRP and PERTP gradually increased with increasing temperature. Surfactants within a certain concentration range can promote the release of PBDEs. The purpose of the research is to explore the dissolution law of PBDEs of different plastic products and the same product in different environment, provides a theoretical basis for the management and risk control of landfills.

17597. 题目: Biochar regulates bacterial-fungal diversity and associated enzymatic activity during sheep manure composting
文章编号: N22010102
期刊: Bioresource Technology
作者: Yumin Duan, Mukesh Kumar Awasthi, Huanhuan Wu, Jianfeng Yang, Zelin Li, Xinhua Ni, Jiatao Zhang, Zengqiang Zhang, Huike Li
更新时间: 2022-01-01
摘要: Aimed to evaluate the coexistence of bacterial and fungal diversity and their correlation with enzymatic activity in response to biochar. This study performed aerobic composting based on typical agricultural wastes of sheep manure with additive apple tree branch biochar at distinct concentration (0, 2.5, 5, 7.5, 10 and 12.5% corresponding from T1 to T6). The result demonstrated that appropriate amendment of biochar enriched bacterial diversity (1646–1686 OTUs) but interestingly decreased fungal diversity (542–630 OTUs) compared to control (1444 and 682 OTUs). Biochar addition enhanced all enzymatic activities and its correlation with bacterial was more complex than fungal community (786 and 359 connect edges). The dominant microbes comprised of Firmicutes (45.2–35.2%), Proteobacteria (14.0–17.5%), Basidiomycota (32.4–49.5%) and Ascomycota (11.3–37.5%) among all the treatments. Overall, biochar regulates the composting microenvironment by influencing the microbial diversity and associated enzymatic activities.

17598. 题目: N-acyl-homoserine lactones in extracellular polymeric substances from sludge for enhanced chloramphenicol-degrading anode biofilm formation in microbial fuel cells
文章编号: N22010101
期刊: Environmental Research
作者: Xiayuan Wu, Lina Zhang, Zuopeng Lv, Fengxue Xin, Weiliang Dong, Guannan Liu, Yan Li, Honghua Jia
更新时间: 2022-01-01
摘要: Exploring an efficient acclimation strategy to obtain robust bioanodes is of practical significance for antibiotic wastewater treatment by bioelectrochemical systems (BESs). This study investigated the effects of two acclimation conditions on chloramphenicol (CAP)-degrading anode biofilm formation in microbial fuel cells (MFCs). The one was continuously added the extracellular polymeric substances (EPS) extracted from anaerobic sludge and increasing concentrations of CAP after the first start-up phase, while the other was added the EPS-1 (N-acyl-homoserine lactones, namely AHLs were extracted from the EPS) at the same conditions. The results demonstrated that AHLs in the sludge EPS played a crucial role for enhanced CAP-degrading anode biofilm formation in MFCs. The AHL-regulation could not only maintain stable voltage outputs but also significantly accelerate CAP removal in the EPS MFC. The maximum voltage of 653.83 mV and CAP removal rate of 1.21 ± 0.05 mg/L·h were attained from the EPS MFC at 30 mg/L of CAP, which were 0.84 and 1.57 times higher than those from the EPS-1 MFC, respectively. These improvements were largely caused by the thick and 3D structured biofilm, strong and homogeneous cell viability throughout the biofilm, and high protein/polysaccharide ratio along with more conductive contents in the biofilm EPS. Additionally, AHLs facilitated the formation of a biofilm with rich biodiversity and balanced bacterial proportions, leading to more beneficial mutualism among different functional bacteria. More bi-functional bacteria (for electricity generation and antibiotic resistance/degradation) were specifically enriched by AHLs as well. These findings provide quorum sensing theoretical knowledge and practical instruction for rapid antibiotic-degrading electrode biofilm acclimation in BESs.

17599. 题目: Simultaneous productions of biodiesel and biochar from krill
文章编号: N21123117
期刊: Journal of Cleaner Production
作者: Minyoung Kim, Hye-Bin Kim, Sungyup Jung, Jong-Min Jung, Kun-Yi Andrew Lin, Jörg Rinklebe, Kitae Baek, Eilhann E. Kwion
更新时间: 2021-12-31
摘要: The Antarctic krill, referring to Euphausia superba, feeds phytoplankton, grown up with photosynthesis for CO2 fixation. Therefore, the use of krill as a raw feedstock for energy production is a highly carbon negative approach, not disturbing the food supply chain of human. Although the krill has high lipid content (up to 40 wt.%, dry basis), its use as a raw feedstock for biodiesel production has not been considered. In this study, the feasibility of Euphausia superba to be used as a biodiesel feedstock was scrutinized. Prior to biodiesel production, an annual biodiesel production potential from the krill without disruption of ecosystems was estimated (129% larger than current biodiesel production in Korea). Because krill oil contains high fraction impurities, (trans)esterification with acid catalyst resulted in low yield of biodiesel (6.5 wt.%), while non-catalytic transesterification achieved 94.7 wt.% of biodiesel yield. To maximize the utilization of krill, solid residue obtained after biodiesel production was synthesized to krill biochars, and they were used as sorptive materials for adsorption of toxic chemicals. Among different model pollutants (Cd(II), Cr(VI), and methylene blue), krill biochar had the best adsorption capacity for Cd(II) (13.7 mg g−1), which is comparable value with other studies.

17600. 题目: Interaction of heavy metals and biocide/herbicide from stormwater runoff of buildings with dissolved organic matter
文章编号: N21123116
期刊: Science of The Total Environment
作者: Panfeng Zhu, Oliver Knoop, Brigitte Helmreich
更新时间: 2021-12-31
摘要: Stormwater runoff from roofs and façades can be contaminated by heavy metals and biocide/herbicide. High efficiency on-site treatment methods are now urgently needed to safeguard the ecosystem. The basis for developing such treatment facilities is an in-depth understanding of their interactions with dissolved organic matter (DOM), as this affects their migration in the environment. Hence, the interaction between copper (Cu), zinc (Zn), benzyl-dimethyl-tetradecylammonium chloride dihydrate (BAC), mecoprop-P (MCPP) and DOM at pH 5 to 9 were investigated separately in this study. The evaluation of the interaction processes were achieved by applying excitation emission matrix and parallel factor analysis (EEM-PARAFAC) to titration samples; obtained data were fitted by two different models. Mechanisms involved in BAC/MCPP-DOM were revealed by Fourier-transform infrared spectroscopy (FTIR) and two-dimensional correlation spectrum (2D-COS) analysis. Results showed that the applied DOM was composed of the two different fluorescent components C1 and C2. More interaction with C1 than with C2 was observed for both Cu/Zn and BAC/MCPP. Increasing the pH enhanced the interaction between Cu/Zn and DOM. At pH 5 with a maximum quencher addition, the remaining fluorescence of CuC1 and ZnC1 were 15.7% and 87.1%, respectively. Corresponding data at pH 9 decreased to 3% and 69.5%. Contrarily, interaction between BAC/MCPP and DOM was impaired by high pH conditions. The increase of pH from 5 to 9 with maximum BAC and MCPP added raised the remaining fluorescence of BAC-C1 and MCPP-C1 by 15.9% and 21.3% separately. The fitting outcomes from the Ryan-Weber equation (Cu/Zn titration) and the Stern-Volmer equation (BAC/MCPP titration) corresponded well with the titration studies. FTIR coupled with 2D-COS analysis revealed that mechanisms involved in BAC/MCPP titration include hydrogen bonding, π-π interaction, and electrostatic effect. The order of mechanisms taking effect during interaction with DOM is affected by the molecular structure of BAC/MCPP.