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22621. 题目: Permafrost thawing puts the frozen carbon at risk over the Tibetan Plateau | |||||
22622. 题目: A critical review on arsenic removal from water using biochar-based sorbents: The significance of modification and redox reactions Biochar is considered to be the cost-effective, environmentally-friendly and sustainable sorbent that has an extraordinary potential to efficiently remove toxic elements, including arsenic (As) from water. Until now, no review has focused to understand various important and intriguing aspects on biochar use as a sorbent for As removal from water, either pristine or modified. This review discusses various factors governing As removal potential of biochars (e.g., pH, biochar dose and physico-chemical properties of biochar), sequestration mechanisms, fate of sorbed As on biochar and the redox-mediated interactions between biochar and As. The significance of biochar-derived materials for the treatment of As-contaminated drinking water/wastewater and their potential regeneration ability is also critically discussed, which has not been previously elaborated. This comprehensive review article could be greatly valuable for scientists, policymakers, water treatment industries, environmentalists and graduate students, who are involved in biochar-As research. The review covers some new overarching and key scientific opportunities for the remediation of As-contaminated water using biochar-based materials, which is a potential health risk to millions of people worldwide. | |||||
22623. 题目: Integrated process for membrane fouling mitigation and organic pollutants removal using copper oxide modified ceramic hollow fiber membrane with in-situ peroxymonosulfate activation A novel CuO modified ceramic hollow fiber membrane for in-situ peroxymonosulfate (PMS) activation was developed and employed in surface water treatment. The performance of membrane fouling control and organic pollutants removal was systematically investigated. The results indicated that compared with pristine membrane, CuO modified ceramic hollow fiber membrane significantly improved the removal of dissolved organic carbon (DOC) and UV absorbance at 254 nm (UV254) in surface water. The removal rate increased with the increase of CuO loading content because of the reduction of the membrane surface pore size, but declined with the increase of PMS dosage due to the degradation products of incomplete mineralization passing through the membrane. The fluorescent compounds in surface water were efficiently removed by the CuO modified ceramic hollow fiber membrane and enhanced with the increase of PMS dosage and CuO loading content. The CuO modified ceramic hollow fiber membrane with in-situ PMS activation exhibits excellent antifouling property to natural organic matter (NOM) in surface water. Both the reversible and irreversible fouling decreased with the increase of PMS dosage while the membrane fouling would be slightly intensified with increased loading of CuO on the membrane, suggesting the trade-off relation between PMS dosage and CuO loading content. In addition, the degradation efficiency of organic pollutants in surface water was dramatically enhanced by the CuO modified ceramic hollow fiber membrane via incorporation of in-situ PMS oxidation process. High removal performance after five cycles of experiments showed the superior stability and reusability of the CuO modified ceramic hollow fiber membrane. | |||||
22624. 题目: Organic amendment increases soil respiration in a greenhouse vegetable production system through decreasing soil organic carbon recalcitrance and increasing carbon-degrading microbial activity | |||||
22625. 题目: Evaluation of carbon mineralization and structural alterations of organic carbon in high-moor peat soils during incubation | |||||
22626. 题目: Tracking changes in soil organic carbon across the heterogeneous agricultural landscape of the Lower Fraser Valley of British Columbia Increasing soil organic carbon (SOC) can improve the capacity of agricultural systems to both adapt to and mitigate climate change. Despite its importance, the current understanding of the magnitude or even the direction of SOC change in agricultural landscapes is limited. While changes in land use/land cover (LULC) and climate are among the main drivers of changes in SOC, their relative importance for the spatiotemporal assessment of SOC is unclear. This study evaluated LULC and SOC dynamics using archived and recent soil samples, remote sensing, and digital soil mapping in the Lower Fraser Valley of British Columbia, Canada. We combined both pixel- and object-based analysis of Landsat satellite imagery to assess LULC changes from 1984 to 2018. We achieved an overall accuracy of 81% and kappa coefficient of 0.77 for LULC classification using a random forest model. For predicting SOC for the same time period, we applied soil and vegetation indices derived from Landsat images, topographic indices, historic soil survey variables, and climate data in a random forest model. The SOC prediction of 2018 resulted in a coefficient of determination (R2) of 0.67, concordance correlation coefficient (CCC) of 0.76, and normalized root mean square error (nRMSE) of 0.12. For 1984, the SOC prediction accuracies were 0.46, 0.58, and 0.18 for R2, CCC, and nRMSE, respectively. We detected SOC loss in 61%, gain in 12%, while 27% remained unchanged across the study area. Although we detected large losses of SOC due to LULC change, the majority of the SOC losses across the landscape were attributed to areas that were remained in the same type of agricultural production since 1984. Climate variability did not, however, have a strong effect on SOC changes. These results can inform decision making in the study area to support sustainable LULC management for enhancing SOC sequestration. | |||||
22627. 题目: The aggregation and sedimentation of two different sized copper oxide nanoparticles in soil solutions: Dependence on pH and dissolved organic matter Copper oxide nanoparticles (CuO NPs) in soil have received considerable attention because of their potential impact on the environment. In the present study, the stability of CuO NPs (50 nm and 80 nm) in eight soil solutions as well as the major influencing factors was investigated. The results showed that hetero-aggregation between natural colloids and NPs dominated the first stage of aggregation, afterwards the two different sized CuO NPs exhibited different aggregation behaviors. The aggregation of 80 nm CuO was inconspicuous except for notable aggregation observed in JX soil solution where the zeta potential of CuO NPs is close to zero. While for 50 nm CuO NPs, the aggregate size sharply decreased and the aggregates gradually reached a stable state. Further, the sedimentation rate and residual concentration of 50 nm CuO were found to be greater than those of 80 nm CuO. The residual amount of 80 nm CuO in the JX soil solution was lower than those in other soil solutions owing to the lowest zeta potential of the NPs. The pH of the soil solution has a significant effect on the stability of CuO NPs because of the shifting of the zeta potential of the NPs. In addition, dissolved organic carbon showed a statistically significant positive correlation with the residual concentration of CuO NPs. These findings imply the properties of CuO NPs as well as environmental factors including pH and DOC play key role in determining the fate, transport, and bioavailability of CuO NPs in soils. | |||||
22628. 题目: Effects of pyrolysis temperature on soil-plant-microbe responses to Solidago canadensis L.-derived biochar in coastal saline-alkali soil Because salinity of coastal soils is drastically increasing, the application of biochars to saline-alkali soil amendments has attracted considerable attention. Various Solidago-canadensis-L.-derived biochars prepared through pyrolysis from 400 to 600 °C were applied to coastal saline-alkali soil samples to optimise the biochar pyrolysis temperature and investigate its actual ecological responses. All biochars reduced the soil bulk density and exchangeable sodium stress and increased soil water-holding capacity, cation exchange capacity, and organic matter content. Principal-component-analysis results showed that pyrolysis temperature played an important role in the potential application of biochars to improve the coastal saline-alkali soil, mainly contributed to ameliorating exchangeable sodium stress and decreasing biochar-soluble toxic compounds. Furthermore, soil bulk density and organic matter, as well as carboxylic acids, phenolic acids and amines of biochar were major driving factors for bacterial community composition. Compared to low-temperature biochar (pyrolyzed below 550 °C), which showed higher toxicity for Brassica chinensis L. growth due to the higher content of carboxylic acids, phenols and amines, high-temperature biochar (pyrolyzed at or above 550 °C) possessed less amounts of these toxic functional groups, more beneficial soil bacteria and healthier for plant growth. Therefore, high-temperature biochar could be applied as an effective soil amendment to ameliorate the coastal saline-alkali soil with acceptable environmental risk. | |||||
22629. 题目: The remediation of PAH contaminated sediment with mangrove plant and its derived biochars | |||||
22630. 题目: Application of rapeseed residue increases soil organic matter, microbial biomass, and enzyme activity and mitigates cadmium pollution risk in paddy fields Rapeseed (Brassica napus L.) is a winter oil crop and biodiesel resource that has been widely cultivated in the southern part of China. Applying rapeseed residue (RSD) to summer rice fields is a common agricultural practice under rice−rapeseed double cropping systems. However, in Cd−contaminated paddy fields, the influence mechanisms of this agricultural practice on the migration and distribution of Cd fractions in soil are not clear. Therefore, a field experiment was carried out to analyse the changes in soil pH, organic matter (OM), microbial biomass carbon (MBC) and nitrogen (MBN), enzyme activity (urease (UA), acid phosphatase (ACP), and dehydrogenase (DH)), Cd distribution fractions, and Cd concentration in rice tissues after RSD application. The results showed that RSD treatment significantly increased the soil OM and MBC concentrations and UA, ACP, and DH activities, decreased the soil acetic acid−extractable fraction of Cd (ACI–Cd), and increased the reducible fraction of Cd (Red–Cd). The formation of stable organic complexes and chelates upon application of RSD is a result of the high affinity of Cd for soil OM. The activities of soil ACP, DH and MBC can well reflect Cd ecotoxicity in soil, particularly the DH activity. In addition, RSD application was helpful in inducing iron plaque formation. The barrier effect of iron plaque resulted in reduced Cd accumulation in different tissues of rice. The health risk of rice consumption also decreased as a result of RSD application; it decreased by 0.89–30.0% and 24.1–51.7% in the two tested fields. Overall, the application of RSD was increased soil OM, microbial biomass, and enzyme activity, and these changes was instrumental in reduce the risk of cadmium pollution in rice fields. | |||||
22631. 题目: Survival, growth and element translocation by 4 plant species growing on acidogenic gold mine tailings in Québec Mining activities create nutrient-poor sites that can be impacted by heavy metal solubilization. The introduction of plants into these environments can lead to organic matter deposition that can bind metals and limit their migration in the environment. This study aimed to determine which of four pioneer plant species (Alnus alnobetula ssp. crispa, Alnus incana ssp. rugosa, Larix laricina and Picea glauca) could survive and grow on undisturbed acidogenic gold mine tailings in Northwestern Québec. After three growing seasons, all four outplanted species successfully established on the tailings without the use of organic amendments. Spruce and larch showed lower growth than the two species of alders, which had high survival rates and aerial biomass production per plot. None of the studied species had high metal translocation rates into leaf tissue despite high metal concentrations in the tailings. This study demonstrates the importance of preliminary field trials to optimize plant biomass and biodiversity on reclamation sites and to mitigate the risk of heavy metal translocation into plant tissues. Our results suggest that the reclamation of acidogenic tailings, without the use of capping materials, warrants further study. | |||||
22632. 题目: Can soil properties and land use explain glomalin-related soil protein (GRSP) accumulation? A nationwide survey in France Organic matter plays essential roles in soil, including physical stabilization, nutrient storage and carbon sequestration. An operationally defined fraction of soil organic matter known as glomalin or glomalin-related soil protein, GRSP, is obtained by autoclaving soil in citrate solution. It is reputed to be of fungal origin, very stable and responsible for enhanced soil physical stability. This is the first nationwide survey of GRSP content in soil and was conducted to test the hypotheses on the origin and identity of GRSP. Nearly 200 archived soils were selected on the basis of organic matter content from the French National Soil Inventory, representing mostly cropland, grassland and woodland land uses. Two fractions of GRSP were measured, easily extractable (GRSPEE) and total (GRSPT), extraction. The median values of GRSPEE and GRSPT were 0.7 and 2 g kg−1 respectively, with a strong correlation between the two fractions. Scatter plots and cubist modelling were used to explore the relationships between the contents of the two GRSP fractions and both soil properties and land use. Land use effects were almost entirely attributable to soil characteristics. No evidence was found to support the hypotheses that GRSP is solely of fungal origin, nor that easily extracted GRSP is more recent that the total fraction, although this does not disprove either hypothesis. Soil organic matter was enriched in GRSP C-depleted cropland soils and lower in C-rich woodland, this may result from inherent stability or differences in plant-related composition of carbon input. | |||||
22633. 题目: Role of Extracellular Polymeric Substances in Microbial Reduction of Arsenate to Arsenite by Escherichia coli and Bacillus subtilis | |||||
22634. 题目: Organic management improves soil phosphorus availability and microbial properties in a tea plantation after land conversion from longan (Dimocarpus longan) Studies on the transformation of P fractions under different land uses and management practices remain scarce, especially in tropical regions. Hence, we investigated the P fraction, microbial communities and soil chemical properties after the conversion of a longan orchard (LO) into an organic tea plantation (OTP) and a conventional tea plantation (CTP) in Hainan, China. At 0–10 cm and 10–20 cm soil depths, the conversion of the LO into the OTP increased the contents of labile P (Resin-P, NaHCO3-Pi and NaHCO3-Po), moderately labile P (NaOH-Pi and NaOH-Po) and occluded P (Sonicate-Pi and Sonicate-Po) but decreased the contents of Ca-P (HCl-Pi) and residual P (stable P), whereas converting the LO into the CTP increased the Ca-P and residual P but decreased the labile P, moderately labile P and occluded P. In addition, at the 0–10 cm soil depth, the bacteria, fungi, actinomycetes, arbuscular mycorrhizal fungal (AMF) and total phospholipid fatty acid (PLFA) biomass were decreased in the CTP, but only the total PLFA was increased in the OTP. However, at the 10–20 cm soil depth, the total PLFA, fungi, and AMF were increased in the OTP, whereas all the PLFA biomarkers remained unchanged in the CTP compared to those in the LO. Furthermore, the labile P, moderately labile P, occluded P and Ca-P in the 0–10 cm layer were related to the soil chemical properties and microbially related groups such as the TK, NO3−, NH4+, acid phosphatase activity (APA), fungi, AMF and bacteria. However, at the 10–20 cm soil depth, these fractions were only associated with soil chemical properties such as the TK, NO3−, NH4+ and APA. Our results revealed that the land use altered the soil P fractions as well as the microbial biomass and activity related to soil P cycling, and organic management practices enhanced the soil P availability more than conventional management practices. | |||||
22635. 题目: Land‐use conversion changes deep soil organic carbon stock in Chinese Loess Plateau Land‐use change is a key factor driving changes in soil organic carbon (SOC) sequestration worldwide. However, the changes in deep (> 100 cm) SOC stock following land‐use conversion have not been fully elucidated. In this study, to determine the changes in deep SOC stock (to a depth of 400 cm) resulting from conversion of cropland to woodland, shrubland and grassland on the Chinese Loess Plateau, 469 observations from peer‐reviewed publications and original measured data were synthesized. The results were as follows. (a) SOC stock increased significantly at 0–100 and 100–200 cm layers regardless land‐use conversion types. (b) Carbon loss occurred in the 200–400 cm layers due to land‐use conversion. (c) Changes in SOC stock varied with restoration age, except for conversion of cropland to grassland. Specifically, SOC stock increased with restoration age in the upper 200 cm layers, whereas that in the 200–400 cm layers first increased and then decreased in the middle to later stages under conversion to woodland and shrubland. (d) Initial SOC stock and rainfall zones had significant effects on the changes of deep SOC stock. (e) Furthermore, an accumulation of 1 Mg ha−1 in the upper 100 cm was associated with an approximately 0.45 Mg ha−1 increase in the 100–400 cm soil layers. These results indicate that land‐use conversion, particularly conversion of cropland to woodland, changes deep (>100 cm) SOC stock, and restoration age should be taken into consideration when assessing deep carbon sequestration. This article is protected by copyright. All rights reserved. | |||||
22636. 题目: Macroalgal metabolism and lateral carbon flows can create significant carbon sinks | |||||
22637. 题目: Chemical characterization in hydraulic fracturing flowback and produced water (HF-FPW) of shale gas in Sichuan of China | |||||
22638. 题目: Effects of heavy metals released from sediment accelerated by artificial sweeteners and humic acid on a green algae Scenedesmus obliquus Artificial sweeteners (ASs) are emerging polar organic contaminants, which can chelate with heavy metals in the environment. Recently, the ASs have been widely detected in the aquatic environment. However, little is known about the influence of ASs on the mobility and toxicity of heavy metals associated in sediment. In the present study, the release of heavy metals from a lake sediment and the toxicity to a green algae Scenedesmus obliquus were examined in the presence of two most frequently detected ASs, acesulfame and sucralose, and humic acid (HA), respectively. The existence of 1.00–100 mg/L of acesulfame, sucralose, and HA enhanced the release rates (Rrelease) of Cd, Cu, and Pb from the virgin lake sediment significantly by up to 46.7%, 86.0%, and 79.9%, respectively. Further, the results from microcosm experiments revealed that the existence of 1.00–10.0 mg/L of acesulfame, sucralose, and HA in the water phase prompted the release and toxicity of heavy metals associated with Cd- and Cu-spiked sediment, and the promotion capacity followed the order of HA > acesulfame > sucralose. The inhibitions on cell-specific growth rate (μ) of the algae were found increasing significantly with the elevated levels of acesulfame and HA (p < 0.05). Additionally, photosynthesis of the algae was affected by the co-existence of ASs or HA and heavy metals released from sediments, as indicated by the changes in fluorescence parameters. The present study provides valuable insight into the likelihood of the combined effect of ASs and heavy metals on aquatic organisms. | |||||
22639. 题目: Biochar derived from red algae for efficient remediation of 4-nonylphenol from marine sediments 4-Nonylphenol (4-NP), a phenolic endocrine disruptor chemical (EDC), is known to have high toxicity to aquatic organisms and humans. The remediation of 4-NP-contaminated marine sediments was studied using red algae-based biochar (RAB) thermochemically synthesized from Agardhiella subulata with simple pyrolysis process under different temperatures of 300–900 °C in CO2 atmosphere. The RAB was characterized by XRD, Raman, FTIR spectroscopy, and zeta potential measurements. The calcium in RAB efficiently activated sodium percarbonate (SPC) to generate reactive radicals for the catalytic degradation of 4-NP at pH 9.0. The oxygen-containing functional groups reacted with H2O2, which increased the generation of reactive radicals under alkaline pH condition. Ca2+ ion was the active species responsible for 4-NP degradation. CaO/CaCO3 on RAB surface enhanced direct electron transfer, increased HO production, and 4-NP degradation in marine sediments. Langmuir‒Hinshelwood type kinetics well described the 4-NP degradation process. Remediation of contaminated sediments using RAB could be a sustainable approach toward closed-loop biomass cycling in the degradation of 4-NP contaminants. | |||||
22640. 题目: The influence of nutrient management on soil organic carbon storage, crop production, and yield stability varies under different climates Our understanding on how soil organic carbon (SOC) storage, crop yield, and yield stability are influenced by climate is limited. To critically examine this, the impact of long-term (≥10 years) application of nutrient management practices on SOC storage, crop productivity, and yield stability were evaluated under different climatic conditions in China using a meta-analysis approach. The cropping area of China was divided into four distinct groups based on local climatic conditions (warm dry, DW; warm moist, WM; cool dry, CD; cool moist, CM). Results indicated that the impact of nutrient management practices on SOC storage, crop yield, and yield stability varies under different climatic zone in China. The use of unbalanced mineral fertilizer (UMF), and balanced mineral fertilizer (BMF) led to a loss in SOC storage by 6%, and 11% under CM climatic zone and gains in DW, WM, and CD climates. Organic fertilizers (OF), combined unbalanced mineral and organic fertilizers (UMOF), and combined balanced mineral and organic fertilizers (BMOF) were able to sustain and enhance SOC storage under all climatic conditions. However, the largest increase in SOC storage across all climates was seen for BMOF. Further, corresponding values of crop productivity and yield stability were also highest for BMOF among all the nutrient management treatments. A linear-plateau model indicated that maximal yield responsive SOC stock (Copt) levels ranged from 33.43 to 45.51 Mg C ha−1 for rice (Oryza sativa), maize (Zea mays), and wheat (Triticum aestivum) production. To enhance and sustain SOC storage, and crop productivity of croplands under different climates, BMOF appears to be the most appropriate nutrient management strategy. Our findings demonstrate that it is essential to optimize nutrient management strategies according to the local climate to protect soil from SOC losses, and for achieving sustainable crop production. | |||||
