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24681. 题目: Humic acid-assisted autohydrolysis of waste wheat straw to sustainably improve enzymatic hydrolysis
文章编号: N20031204
期刊: Bioresource Technology
作者: Wei Tang, Xinxing Wu, Chen Huang, Caoxing Huang, Chenhuan Lai, Qiang Yong
更新时间: 2020-03-12
摘要: Humic acid (HA), considered the main component of organic matter in the ash of waste wheat straw (WWS), has the potential to improve autohydrolysis through its function as a surfactant. In this work, a pre-washed WWS (PWWS) was subjected to autohydrolysis with addition of HA to explore whether its surfactant properties can provide benefit to biorefinery operations. Acquired results showed that HA acted as delignification agent likely due to its surfactant properties. Delignification was more than doubled at the maximum HA dosage (30 g/L) relative to the control, which allowed for enzymatic hydrolysis efficiency to also increase from 64.9% to 81.8%. The pretreated materials were further subjected to analysis structure characterization. The results showed that HA effectively reduced the surface lignin area of PWWS, lowering non-specific adsorption of lignin to enzymes. The autohydrolysis with HA was an effective technique to improve the subsequent cellulose enzymatic digestion by enhancing the delignification.

24682. 题目: Evaluation of biochar amendment on heavy metal resistant bacteria abundance in biosolids compost
文章编号: N20031203
期刊: Bioresource Technology
作者: Sanjeev Kumar Awasthi, Tao Liu, Mukesh Kumar Awasthi, Zengqiang Zhang
更新时间: 2020-03-12
摘要: The present investigation was design to evaluate the impact of different dosages of biochar on heavy metal resistant bacterial (HMRB) dynamic in biosolid (BS) compost. The bacterial abundance map was reveals that all the samples have 35 prominent genera and showed significant alteration of HMRB among the all biochar applied treatment. The main phyla identify in each treatments were Proteobacteria, Firmicutes and Chloroflexi, however, Pseudomonas, T78, Acinetobacter and Urebacillus were most abundant genera in all the treatment. The visualization of HMRB bio-diversity by bioinformatic tools and krona were clearly indicated a considerable difference in classification tree complexes and network analysis among the all biochar added treatments. Thus, in present study was found that HMRB like Paracoccus, Planomicrobium, Devosia and Agrobacterium viable hyper-thermo tolerant in BS compost. In addition, heat map analysis also confirmed that Proteobacteria, Firmicutes and Chloroflexi have significant correlation with physicochemical parameters.

24683. 题目: Hierarchical porous carbon derived from activated biochar as an eco-friendly electrode for the electrosorption of inorganic ions
文章编号: N20031202
期刊: Separation and Purification Technology
作者: Dinh Viet Cuong, Po-Chang Wu, Nei-Ling Liu, Chia-Hung Hou
更新时间: 2020-03-12
摘要: Hierarchical porous carbon (HPC) as an eco-friendly electrode material was fabricated from rice husk biochar using the hard template method for electrosorption of ions. The porous structure in HPC materials can be controlled by different activation times to optimize the material physicochemical and electrochemical properties. The HPC sample achieved a high specific surface area (1839 m2 g−1), large pore volume (1.21 cm3 g−1) and 58% mesopore to total pore volume ratio. The HPC electrode exhibited excellent electrochemical properties with a high specific capacitance of 120.5 F g−1 at 5 mV s−1 in a 1 M NaCl solution as well as good reversibility for capacitive charge storage. The large ion-accessible specific surface area, interconnected pore structure among micropores and mesopores, and large mesoporosity of the HPC electrode played crucial roles in the enhancement of the electrosorption performance. The HPC electrode exhibited a high electrosorption capacity of 8.11 mg g−1 and mean deionization rate of 0.92 mg g−1 min−1 for 20 mM NaCl in single-pass capacitive deionization. The associated charge efficiency and energy consumption were 48.1% and 0.064 kWh mol−1, respectively, indicating a low energy requirement of water desalination. Furthermore, the HPC electrode showed good regeneration ability in consecutive cycles for the removal of inorganic pollutants, i.e., NH4+, Mg2+ and Cu2+, with electrosorption capacities of 1.54, 1.53 and 0.52 mg g−1, respectively. Consequently, HPC from tailored activated rice husk biochar can provide a new opportunity to achieve high-performance electrosorption in various water and wastewater treatment processes.

24684. 题目: Denitrification rates in tidal marsh soils: The roles of soil texture, salinity, and nitrogen enrichment
文章编号: N20031201
期刊: European Journal of Soil Science
作者: M.J. HU, J. PEÑUELAS, J. SARDANS, J.F. HUANG, K. XU, C. TONG
更新时间: 2020-03-12
摘要: The denitrification rates of freshwater and oligohaline tidal marsh soils with different textures (loam and sandy soils) in a subtropical estuary, and their responses to nitrogen (N) loading, were investigated. In both marshes, the denitrification rates varied significantly with the season only in loam soil. The denitrification rates were highest in oligohaline marsh loam soil and lowest in freshwater marsh sandy soil. NH4NO3 addition significantly increased the denitrification rates of all the marsh soils. Our findings suggest that soil texture, soil organic matter (OM) content and low‐level increases in salinity all had large effects on denitrification, indicating that the dynamics of denitrification rates in estuarine marshes with low‐level salinity were controlled by the interaction of salinity and soil texture but mainly depended on OM content. We propose that denitrification in tidal marshes plays an important role in regulating current and future N loading into estuary and inshore coastal waters, especially for tidal freshwater marshes, which introduces great uncertainty to the N dynamics of estuaries under global changes. This article is protected by copyright. All rights reserved.

24685. 题目: Which slope aspect and gradient provides the best afforestation-driven soil carbon sequestration on the China's Loess Plateau?
文章编号: N20031119
期刊: Ecological Engineering
作者: Xiaofang Zhang, Jan F. Adamowski, Chunfang Liu, Junju Zhou, Guofeng Zhu, Xiaogang Dong, Jianjun Cao, Qi Feng
更新时间: 2020-03-11
摘要: On China's Loess Plateau, where the distribution of soil organic carbon (soil − Corg) is mainly influenced by topography, afforestation is an important strategy to sequester carbon and reduce soil erosion. To explore the effects of topography on soil − Corg, soil samples were obtained at six depths (0–0.1 m, 0.1–0.2 m, 0.2–0.4 m, 0.4–0.6 m, 0.6–0.8 m, and 0.8–1.0 m) from locations on the Loess Plateau which had supported apricot (Prunus armeniaca L.) growth for 16 years and differed in slope aspect (sunny or semi-sunny vs. shady or semi-shady) and gradient (14° ≤ S < 20°, 20° ≤ S < 25°, or 25° ≤ S ≤ 31°). Across a depth of 1.0 m, the mean soil − Corg and total soil carbon storage (soil − Ctot) under the shady slope were 7.23 g kg−1 and 77.41 Mg ha−1, respectively; while under the sunny slope, these were 6.81 g kg−1 and 74.22 Mg ha−1, respectively. Both the soil − Corg and soil − Ctot increased with slope gradient, with soil − Corg rising from 6.68 g kg−1 to 7.01 g kg−1, and to 7.34 g kg−1, and soil − Ctot changing from 72.60 Mg ha−1 to 75.35 Mg ha−1, and to 79.40 Mg ha−1, respectively. Slope aspect and gradient interacted in influencing soil − Corg, but not soil − Ctot. Across both slope aspect and gradient, roughly half of soil − Ctot was found within the first 0.4 m depth of soil. Overall a steep shady slope (vs. sunny gentle slope) was more favorable to the preservation of soil − Corg, and would, accordingly, be of greater importance with respect to soil − Corg protection and implementation of afforestation policy on the Loess Plateau and similar fragile environments worldwide.

24686. 题目: Hydrogen production from natural organic matter via cascading oxic-anoxic photocatalytic processes: An energy recovering water purification technology
文章编号: N20031118
期刊: Water Research
作者: Guocheng Huang, Zhengtao Xiao, Weiqian Zhen, Yaxin Fan, Cuiping Zeng, Chuanhao Li, Shengwei Liu, Po Keung Wong
更新时间: 2020-03-11
摘要: Photocatalysis provides a green strategy to produce the clean energy of H2. However, the realization of efficient H2 production is usually accomplished by the consumption of electron donors, which are costly energy carriers themselves. Here, we attempted to utilize the naturally abundant humic acid (HA), a representative natural organic matter (NOM), as the source of electron donor in a cascading oxic-anoxic photocatalytic system. Results showed that degradation of HA and remarkable H2 yield (1660.9 μmol g−1 h−1 at optimal condition) were obtained successively, whereas the anoxic photocatalytic treatment of pristine HA did not improve H2 yield but substantially eliminated the H2 production and HA degradation efficiency. These phenomena suggested the preoxidation process plays a vital role in counteracting the detrimental effect of HA on photocatalytic H2 production. Electrochemical measurement indicated that the preoxidized HA harbored more redox-active moieties than the untreated HA and thus leading to a higher photo-induced charge carrier separation efficiency. A variety of advanced spectroscopic analyses revealed that the photocatalytic oxic pre-treatment resulted in breakdown of chemically inert, electron mediating and chromophoric aromatic macrostructure of HA to form smaller sized oxygenated organic intermediates. These intermediates were more nucleophilic than the pristine HA and acted as sacrificial reagent in the subsequent anoxic process for boosting H2 production. This study showcases an energy recovering water remediation process and paves the way for the design of novel photocatalytic technologies for environmental application.

24687. 题目: Has compost with biochar added during the process added value over biochar or compost to increase disease suppression?
文章编号: N20031117
期刊: Applied Soil Ecology
作者: J. Debode, N. Ebrahimi, T. D'Hose, P. Cremelie, N. Viaene, B. Vandecasteele
更新时间: 2020-03-11
摘要: Adding biochar at the onset of composting has proven to be beneficial for this process, and when added to the soil, this biochar-blended (BB) compost has outperformed biochar on soil quality but had a similar effect as the compost. Because soil quality gets more and more attention as an important tool for soil health, pot trials were conducted to evaluate the effect of compost and biochar alone, and biochar-blended (BB) compost on disease suppression. In addition, it was investigated whether the disease suppression was associated with changes in soil quality (chemical, physical and biological soil properties). The two selected bio-assays were Rhizoctonia solani (basal rot) on lettuce and potato cyst nematodes (PCN) on potato. Both compost and BB compost released mineral N and thus increased lettuce and potato yield but biochar did not. None of the amendments affected the susceptibly of lettuce leaves to basal rot. Compost suppressed PCN while biochar had no effect on PCN reproduction. Moreover, BB compost reduced the suppressing effect of compost. We suggest that the inhibitory effect of biochar blended in compost might be attributed to the fungal biomass which was not increased in the BB compost-amended soil compared to compost-amended soil, and/or the absorbance of suppressive compounds by the high surface area of biochar. Interestingly, all three amendments reduced the water evaporation from the soil surface, which can have important implications for drought stress of plants.

24688. 题目: Impacts and interactions of biochar and biosolids on agricultural soil microbial communities during dry and wet-dry cycles
文章编号: N20031116
期刊: Applied Soil Ecology
作者: Daoyuan Wang, Mark L. Felice, Kate M. Scow
更新时间: 2020-03-11
摘要: Extreme hydrological processes, such as prolonged drought and frequent wet-dry cycles, are major consequences of climate change and can influence agroecosystems by altering soil microbial communities and associated processes. Two increasingly popular soil amendments, biosolids and biochar, may reduce the negative impacts of extreme hydrological processes as well as provide a low-cost carbon sequestration strategy, increase nutrient and soil water retention, and increase nutrient availability. We measured the response of microbial communities to amendments of biochar (walnut shell, 900 °C) and biosolids amendments, separate and mixed, under different water regimes. We used phospholipid fatty acid analysis (PLFA) to monitor microbial communities during a 12-week incubation experiment in which we applied different levels of biochar (0, 0.5 and 1% dry wt. added to dry soil) and biosolids (0 and 0.5% air-dry wt. added to dry soil) to agricultural soils under different soil moisture conditions (wet, drought, or wet-dry cycles). Biochar increased soil pH across the soil moisture and biosolids treatments at both 4-week and 12-week. Biosolids only significantly decreased soil pH in wet treatment and the change in soil pH was within 0.5 units. Biosolid increased soil mineral nitrogen. Biochar only increased microbial biomass at week 4 in the absence of biosolids, while biosolids increased microbial biomass regardless of biochar and water regime by 55% on average over 12 weeks. Drought and wet-dry cycles strongly influenced microbial communities in soil, reducing biomass and altering community composition. Biosolids amendment increased soil nutrient level, helped maintain soil microbial biomass and reduced impacts of soil moisture stress on soil microbial community. The effect of biochar on soil microbial community composition depended on its dose and soil nutrient conditions. The co-amendment of biosolids and biochar helped to reduce the changes in soil pH and mineral nitrogen. Amending soils with biosolids or biochar may provide an effective management tool to reduce the negative impact of drought and wet-dry cycles on microbial communities.

24689. 题目: Humification in extracellular polymeric substances (EPS) dominates methane release and EPS reconstruction during the sludge stabilization of high-solid anaerobic digestion
文章编号: N20031115
期刊: Water Research
作者: Yanfei Tang, Xiaohu Dai, Bin Dong, Yiqun Guo, Lingling Dai
更新时间: 2020-03-11
摘要: High-solid anaerobic digestion (HAD) can directly treat dewatered sewage sludge (total solid content ≥15%) with superior volume efficiency. Sludge stabilization during HAD is expected to achieve by throughout organic degradation and conversion towards methane-rich biogas release and humic formation. Sewage sludge is the combination of microbial zoogleas and theirs adsorption of organic and inorganic matter, in which the extracellular polymeric substances (EPS) account 60–80% of total sludge organic matter, inevitably participating most extracellular metabolic pathways. The interactions between EPS transformation and genetically annotated metabolic pathways were found in this research. In brief, noticing the highly cross-linked structures in EPS with major active components of humic substances (HS) and protein (PN), as PN hydrolysis and decomposition in EPS were enhanced in the high-solid anaerobic condition, the exposure of aromatic groups and sites in HS were considerable. HS release was the main factor shifting the electron exchange capacity and activity, which aided in energy metabolism of sludge microorganisms involved in redox reactions, especially the methanogenesis, thus in turn facilitating the PN degradation; Then, the screened humic groups and active protein derives might act as the beneficial precursors to regenerate neo-humic structures, whose significant bridging effect and signal role on stimulating amino acid biosynthesis, member transport and metallic complexation could further contribute to proteolytic condensation and EPS reconstruction. Hence, the in-depth sludge stabilization mechanism during HAD process was established for developing enlightening strategies.

24690. 题目: A new dynamic wetness index (DWI) predicts soil moisture persistence and correlates with key indicators of surface soil geochemistry
文章编号: N20031114
期刊: Geoderma
作者: Ming Li, Erika J. Foster, Phong V.V. Le, Qina Yan, Andrew Stumpf, Tingyu Hou, A.N. (Thanos) Papanicolaou, Kenneth M. Wacha, Christopher G. Wilson, Jingkuan Wang, Praveen Kumar, Timothy Filley
更新时间: 2020-03-11
摘要: Commonly, the topographic influence on soil hydrology is calculated as a Topographic Wetness Index (TWI), which often correlates with surface soil properties, such as carbon and nitrogen, across broad spatial scales. However, traditional TWI methods can be ineffective at capturing finer scale variations when depression filling approaches are used and they do not incorporate localized soil texture controls on infiltration. We developed a new Dynamic Wetness Index (DWI) that attempts to account for the persistence of soil moisture over time at the microtopographic scale (~1 m2) by including inputs of measured soil texture, and information from the Dhara modeling framework that incorporates canopy process and surface-subsurface hydrologic models. DWI and TWI values were correlated with measured soil geochemical properties across six study sites (four agricultural sites, one restored prairie, and one forest site) within the Upper Sangamon River Basin, in central Illinois, USA. Relative to TWI, DWI improved correlations with certain measured soil surface geochemistry (pH R = −0.53), δ13C R = 0.13, δ15N R = 0.44) and certain lignin phenols (vanillyl, cinnamyl/vanillyl, syringyl-vanillyl-cinnamyl/substituted fatty acids). DWI positively correlated with indicators of lignin oxidation, indicating that wetter soils have higher potential for lignin decomposition. In this small dataset, relative to TWI the data show DWI increased significance and decreased the range of correlations with soil moisture and certain surface soil geochemistry parameters driving plant chemistry decay and nitrogen cycling.

24691. 题目: Forest disturbances affect functional groups of macrofungi in young successional forests – harvests and fire lead to different fungal assemblages
文章编号: N20031113
期刊: Forest Ecology and Management
作者: Jari Kouki, Kauko Salo
更新时间: 2020-03-11
摘要: Fungal assemblages after a large-scale disturbance can be diverse and have functionally important roles in forests. However, fungi include several functional groups, and the responses of these groups to different forest disturbances is poorly understood. For example, ectomycorrhizal fungi may facilitate the establishment of a new tree cohort while saprotrophic fungi are able to decompose most of the dead organic material that result from the disturbance event. In this study, we examined how functionally different macrofungi respond to two major disturbances: fire (prescribed burning) and different intensities of timber harvest. We used large-scale field experiment where (1) fire and (2) harvest intensity were manipulated simultaneously in a factorial, replicated design. Three levels of harvests and an unharvested control were included, and sites were either burned or not. Fungi were surveyed before treatments in year 2000 and annually over three years (2001–2003) after the treatments. Fungi species were divided into ectomycorrhizal (ECM), saprophyte (SaM) and wood-associated fungi (WAM). The latter group mostly included Aphylloporoid wood-associated species (AWAM) and agarics. We observed also two biotrophic and one parasitic fungus but these were excluded from the assemblage-level analyses due to their rarity. Both number of sporocarps (fruiting bodies) and their biomass were measured. Fungal groups were affected by harvest and fire but the various fungal groups responded in different ways to the treatments. The ECM species were sensitive to timber harvests and disappeared from all the harvested sites. Fire in the unharvested sites did not negatively affect the ECM fungi. The SaM fungi responded quickly after disturbance, and their assemblage composition changed after fire and harvest. Species richness was reduced but fire promoted several pyrophilous SaM species, leading to major compositional changes in SaM species and the formation of distinct assemblages. The WAM species declined after harvests but fire tended to counteract the negative effects of timber harvesting. The results show that fungal groups respond in different ways to major disturbances in boreal forests. Early successional post-disturbance forests contribute to the maintenance of forest biodiversity, especially the specialist SaM species. However, the type of disturbance (fire or harvest) affect fungi in different ways. Understanding the assemblage dynamics of decomposer and other fungi is crucial when estimating how changes in forest disturbance regimes may affect nutrient and carbon cycling, as well as the maintenance of forest biodiversity.

24692. 题目: Estimation of total nitrogen and organic carbon contents in mine soils with NIR reflectance spectroscopy and various chemometric methods
文章编号: N20031112
期刊: Geoderma
作者: Anna Pudełko, Marcin Chodak
更新时间: 2020-03-11
摘要: Rapid analytical methods are needed to measure organic carbon (OC) and total nitrogen (Nt) contents in reclaimed mine soils. Near infrared spectroscopy (NIRS) with appropriate chemometric techniques could be used for OC and Nt monitoring in the mine soils. The aim of this study was to compare efficiency of NIR-based models developed using various chemometric approaches to predict OC and Nt contents in afforested mine soils. The studied approaches were: partial least square regression (PLSR), principal component regression (PCR) and artificial neural networks based on the entire spectral data (ANN), the principal components (PCA-ANN) and the latent variables (PLS-ANN) calculated from the spectral data. The samples (n = 90) of uppermost mine soil horizons (0–20 cm) were taken from the reclaimed dump of Bełchatów lignite mine (Poland) and measured for the OC content by dry combustion and for the Nt content by Kjehldahl method. The samples were air-dried, finely ground and their NIR spectra (1000 nm–2500 nm) were recorded. The models were developed using 60 samples while the remaining 30 samples were used for independent validation. All the tested chemometric approaches (except the ANN model for OC) yielded excellent models useful for quantitative estimations. The PLSR models were promising at the calibration stage (values of ratio of inter-quartile distance to standard error of prediction (RPIQC) were 7.00 and 4.22 for Nt and OC, respectively) however in the validation they performed less successfully (RPIQV = 3.08 for Nt and RPIQV = 2.75). The accuracy of ANN models based on the entire spectra was similar to PLSR or PCR models. However, the ANN based on reduced spectral data (PCA-ANN and PLS-ANN) performed distinctly better. The most accurate predictive models for the OC and Nt contents were obtained using PCA-ANN approach (RPIQV = 3.64 and 2.90, for Nt and OC, respectively). The results indicate that NIRS coupled with ANN based on the reduced spectral data can be successfully applied to measure the OC and Nt contents in mine soils.

24693. 题目: The comparison of dissolved organic matter in hydrochars and biochars from pig manure
文章编号: N20031111
期刊: Science of The Total Environment
作者: Chengfang Song, Shengdao Shan, Chao Yang, Cheng Zhang, Xiaoqing Zhou, Qi Ma, Kim Yrjälä, Huabao Zheng, Yucheng Cao
更新时间: 2020-03-11
摘要: Dissolved organic matter (DOM) has an important effect on soil fertility, activity of microorganisms and transport of contaminants. In this study, DOM released by the hydrochar and biochar prepared under various conditions from pig manure, was assessed using a combination of UV–Visible spectroscopy, fluorescence excitation-emission (EEM) spectrophotometry and 1H-nuclear magnetic resonance (1H NMR). The dissolved organic carbon (DOC) extracted from the hydrochar and biochar ranged from 3.34–11.96% and 0.38–0.48%, respectively, and the highest DOM was released by HCK0.5 (180 °C and 0.5% KOH). The aliphatic compounds were most common in DOM which mainly included three humic acid-like and one protein-like substance. The hydrochar-DOM had a larger molecular weight and lower aromaticity than biochar-DOM, but the effect of temperature on the DOM characteristics of hydrochar and biochar was opposite. The acidic treatment increased the content of functional groups containing oxygen and nitrogen in hydrochar-DOM, and alkaline treatment increased the content of aliphatic compounds. The results obtained are beneficial to select carbonation process and guide the rational application of hydrochar and biochar from pig manure in soil remediation field.

24694. 题目: Decreasing underwater ultraviolet radiation exposure strongly driven by increasing ultraviolet attenuation in lakes in eastern and southwest China
文章编号: N20031110
期刊: Science of The Total Environment
作者: Yunlin Zhang, Kun Shi, Qichao Zhou, Yongqiang Zhou, Yibo Zhang, Boqiang Qin, Jianming Deng
更新时间: 2020-03-11
摘要: Underwater light attenuation plays an important role in modulating aquatic ecosystems and is considered a sentinel of climate change and human activity. However, knowledge of the long-term exposure of underwater ultraviolet radiation (UVR) in aquatic ecosystem is still very limited. We carried out extensive UVR measurements in different seasons in five lakes at different altitudes, collected long-term Secchi disk depth (SDD) data, developed the models between UVR diffuse attenuation coefficient (Kd) and SDD, and further assessed the long-term underwater UVR exposure. Observation results from five lakes including 259 samples showed large spatial variabilities of Kd(313) (UVB) from 0.83 to 5.91 m−1 and Kd(340) (UVA) from 0.51 to 4.67 m−1. Chromophoric dissolved organic matter (CDOM) absorption coefficients were significantly correlated with Kd(313) and Kd(340). Thus, the effects of climate change and human activity on CDOM abundance, source and composition may significantly alter UVR attenuation in aquatic environments. The long-term underwater UVR exposure, which was estimated from significant positive correlations between 1/SDD and Kd(313) and Kd(340), and incident UVR, significantly decreased in Lake Fuxianhu, Lake Erhai, and Lake Qiandaohu. The regime shift from clear water state to turbid state in Lake Erhai around 2001–2003 dramatically decreased underwater UVR exposure. In conclusion, increasing UVR attenuation played a more important role in determining underwater UVR exposure than decreasing incident UVR with the relative contributions of 89.9% and 87.7% in Lake Fuxianhu, 98.0% and 97.7% in Lake Erhai, 94.4% and 92.5% in Lake Qiandaohu for UVB and UVA exposure, respectively. This is the first study to elucidate the long-term trend of underwater UVR exposure considering both increasing UVR attenuation and decreasing incident UVR.

24695. 题目: Intensive land uses modify assembly process and potential metabolic function of edaphic bacterial communities in the Yellow River Delta, China
文章编号: N20031109
期刊: Science of The Total Environment
作者: Yuxan Zou, Jiaguo Yan, Shengwei Hou, Yujun Yi, Baoshan Cui
更新时间: 2020-03-11
摘要: Coastal reclamation is a global threat to natural ecosystems, disturbing biological community structure, diversity and ecological function through habitat conversion. We have limited insights into the changes brought about by coastal reclamation for different land-use types. We used the Yellow River Delta (YRD) as a model because it is a region with intensive land reclamation, and we investigated the structural and functional variations of bacterial communities and their relations to edaphic properties under different land-use types. Our results showed that the high soil organic carbon (SOC), nitrate concentrations and salinity were found in oil field, aquaculture pond and salt pan, respectively, and low values in natural wetland. Land use was found to have significant influence on bacterial community diversity. To investigate the phylogenetic conservation of specific traits, we analyzed the relationship between soil bacterial assembly processes and edaphic properties. Bacterial traits phylogenetically conserved, and differs in depth. Our findings suggest that SOC served as a deep trait due to it negative correlation with deeper branches of phylogenetic clustering, while nitrate functioned as a shallow trait due to its positive correlation with phylogenetic clustering at finer branches. Soil salinity acted as a complex trait effected on both finer and deeper branches. Further potential functional gene co-occurrence network analysis revealed that land reclamation induced shifts of metabolic function by altering the functional gene connectivity. We found that the photosynthesis pathway was enriched in hub modules related to oil field (OF), while methane metabolism was enriched in hub modules linked to sea cucumber pond (CP1). In addition, two-component systems (TCS) were enriched with nitrate, ammonia, SOC and salinity-related modules. Therefore, our study highlights the importance of integrating multi-function and multi-process identification and prediction of coastal diverse reclamation impacts on coastal ecosystems.

24696. 题目: Does terracing enhance soil organic carbon sequestration? A national-scale data analysis in China
文章编号: N20031108
期刊: Science of The Total Environment
作者: Die Chen, Wei Wei, Stefani Daryanto, Paolo Tarolli
更新时间: 2020-03-11
摘要: Terracing practice is expected to reserve soil organic carbon (SOC) pools, which are the key components for maintaining soil fertility and land productivity. In China such practice is widespread from center to south since ancient time. In this work, to reveal the spatial-temporal variation characteristics of SOC under different terraced sites in China, we conducted a meta-analysis on 78 studies regarding terracing effects on SOC sequestration. The between-group heterogeneity analysis indicated that terracing land use, age, climatic background, and slope gradient were critical factors for SOC sequestration, while terracing structure and soil depth were not. Overall, for China's landscapes, terracing increased SOC sequestration by 32.4% on average. Relative to other terracing structures, level ditches and half-moon terraces receive more rainwater and fertile topsoil from upper slopes due to their specific concave structures. Terracing in those areas with lower temperatures and less precipitation showed higher SOC sequestration. The extent of SOC sequestration due to terracing was primarily determined by land use type. Reforestation terraces could increase SOC sequestration markedly by eliminating water erosion and related soil carbon loss. The terracing aged 1–2 years leads to a decrease of 6.4% averagely on SOC sequestration, likely because the breakdown of soil aggregates through soil excavation and redistribution improves the decomposition of SOC. Furthermore, terracing aged over five years was more effective on SOC sequestration. Since this study offered a useful synthesis on multiple terracing factors affecting soil carbon in China, it can help to provide a wiser utilization and management of terracing to maximize SOC sequestration, and to make better terracing practices in the context of global change.

24697. 题目: Removal of organic and inorganic matters from secondary effluent using resin adsorption and reuse of desorption eluate using ozone oxidation
文章编号: N20031107
期刊: Chemosphere
作者: Qimeng Li, Xiang Li, Jing Sun, Haiou Song, Ji Wu, Guoxiang Wang, Aimin Li
更新时间: 2020-03-11
摘要: This study aimed to compare the effectiveness of MAER and L20 resin for the adsorption treatment of secondary effluent, and evaluate the applicability of ozone oxidation for the reuse of desorption eluate. Bench-scale adsorption experiments showed that the MAER resin exhibited higher efficiency than L20 resin in removal of COD within 600 treated bed volumes (BV), which declined from 32.5% to 14.1% in the first and sixth treatment loading of 100 BV. On the other hand, the L20 resin displayed obviously higher removal efficiency of total nitrogen (TN) than MAER resin within 600 BV, which dropped from 74.6% to 9.8% at the same condition. The ozone oxidation treatment could achieve desirable reuse of desorption eluate, although its chemical oxygen demand (COD) concentration increased gradually in line with the reuse numbers. The uptake of COD, TN and total phosphorus declined steadily by using ozone treated eluate as the regenerant in successive adsorption-desorption cycles, but increased obviously with a new batch of regenerant. Overall, the resin adsorption could efficiently remove organic and inorganic matters from secondary effluent, while the treatment loop including desorption eluate oxidation and eluate reuse could markedly enhance the concentration ratio of treated effluent.

24698. 题目: Impact of Soil Biochar Incorporation on the Uptake of Heavy Metals Present in Wastewater by Spinach Plants
文章编号: N20031106
期刊: Water, Air, & Soil Pollution
作者: Christopher Nzediegwu, Shiv Prasher, Eman Elsayed, Jaskaran Dhiman, Ali Mawof, Ramanbhai Patel
更新时间: 2020-03-11
摘要: The effect of plantain peel biochar on the uptake of six heavy metals (Cd, Cr, Cu, Fe, Pb and Zn) in spinach (Spinacia oleracea L.) irrigated with untreated wastewater was investigated in nine outdoor lysimeters (0.45 m diameter × 1.0 m height) arranged in a completely randomised design with three replicates. The lysimeters were packed with sandy soil (bulk density 1.35 Mg m−3) and brought to field capacity 1 day before starting the experiment. Biochar (1% w/w) was mixed in the top 0.10 m of soil under biochar amendment. Spinach were planted in each lysimeter, irrigated (every 10 days for 4 times in total), harvested (harvest 1 and harvest 2) and analysed for the heavy metals. Spinach leaves accumulated more heavy metals than the roots and stems. Biochar amendment did not affect the translocation of heavy metals (Cd, Cu, Cr, Fe and Pb) to spinach leaves, possibly due to competition with other compounds in the soil solution. However, the biochar amendment improved CEC and increased the pH of soils which resulted in a 42% reduction of translocation of Zn in spinach leaves. Assuming daily spinach consumption of 200 g per person, Zn in spinach grown in soil amended with biochar would be below the provisional maximum tolerable daily intake limit for adults (20 mg) as prescribed by WHO/FAO/IAEA. Consumption of spinach grown with wastewater in soil without biochar amendment may not be safe because of Zn toxicity. Likewise, the concentration of Cd, above CODEX permissible levels in the spinach leaves and eleven times higher in wastewater than freshwater irrigation, raises a concern for consumers in developing countries where untreated wastewater is often used for irrigation.

24699. 题目: Effect of aluminum modification of rice straw–based biochar on arsenate adsorption
文章编号: N20031105
期刊: Journal of Soils and Sediments
作者: Xian He, Jun Jiang, Zhineng Hong, Xiaoying Pan, Ying Dong, Renkou Xu
更新时间: 2020-03-11
摘要: Purpose To evaluate the adsorption capacity of aluminum-modified biochars for arsenate (As(V)) and the effect of the biochars on As(V) adsorption by acidic Ultisols.Materials and methods Rice straw was collected from Yingtan, Jiangxi Province. Rice straw and the biochar derived from rice straw were both treated with aluminum (Al) to prepare two kinds of Al-modified biochars. An Ultisol was collected from Jinxian, Jiangxi Province, and an indoor incubation was used to prepare biochar-ameliorated soil. Zeta potential and Fourier transform infrared spectroscopy (FTIR) were used to characterize the effects of Al modification on surface charge and functional groups of the biochars. The batch method was used to investigate the adsorption and desorption of As(V) by the biochars and the soil. Arsenic in equilibrium solution was determined using hydride generation–atomic fluorescence spectrometry. Results and discussion The yield of biochar derived from Al-treated rice straw was significantly greater than that of the biochar from untreated rice straw. The Al content of Al-treated biochar from rice straw was higher than that of biochar derived from Al-treated rice straw. Modification did not change the morphology of Al oxide on biochar. Zeta potential of the two modified biochars changed to a positive value compared with that of unmodified biochar, and more change in zeta potential was observed for the Al-treated biochar from rice straw than that of biochar derived from Al-treated rice straw. After As(V) was adsorbed by the two modified biochars, new absorption peaks were found in the FTIR spectra from the biochars at 892 cm−1 (biochar from Al-treated rice straw) and 884 cm−1 (Al-treated biochar from rice straw). The peaks suggested that a chemical bond was formed between As(V) and Al on biochars during As(V) adsorption. The two Al-modified biochars adsorbed much more As(V) than the unmodified biochar. The desorption of adsorbed As(V) in the modified biochars was very low, which indicated that specific adsorption was the dominant mechanism for As(V) adsorption. The addition of modified biochar promoted the adsorption of As(V) by the Ultisol. Moreover, Al-treated biochar from rice straw enhanced As(V) adsorption by the soil more than the biochar derived from Al-treated rice straw. Conclusions Compared with the effect of adding unmodified biochar, adding either of the two Al-modified biochars significantly enhanced the adsorption of As(V) by the Ultisol. Therefore, Al-modified biochar can be used to immobilize As(V) in arsenic-contaminated soils, especially in acidic soils.

24700. 题目: Effect of ageing process on bisphenol A sorption and retention in agricultural soils amended with biochar
文章编号: N20031104
期刊: Environmental Science and Pollution Research
作者: Junguang Liu, Lingling Liu, Yuehong Shu, Shaojun Jiang, Renlong Huang, Zhenzhen Jia, Dongyang Wei
更新时间: 2020-03-11
摘要: The ageing of biochar and organic pollutant itself in soils can both influence the retention of organic pollutant in field soils. In this study, column experiments were adopted to determine the effect of ageing process on bisphenol A (BPA) sorption and retention in two typical Chinese agricultural soils with lychee branch biochar added. The effect of biochar ageing on soil organic matter (SOM) was specially investigated. Experimental results showed that the addition of biochar significantly increased the condensation and rigid of SOM, which could further increase with biochar ageing in soils. As a result, the addition of biochar significantly increased BPA sorption capacity (5.86 times and 3.30 times) and retention rate (13.60 times and 4.47 times) in fluvo-aquic soil and phaeozem respectively, while BPA sorption capacity and retention rate decreased obviously after biochar ageing in the two soils for 2 months as compared with the freshly incorporated biochar treatments, which may be attributed to the surface coverage and/or pore blockage of some sorption sites owning to DOC. With biochar incorporated, 2 months of BPA ageing increased BPA retention rate by about 4.50 times in both soils as compared with BPA newly spiked treatments. The results of this study could provide important parameters for prediction and control of organic pollutants such as BPA in soils.