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24721. 题目: Improved chlorine and chromium ion removal from leather processing wastewater by biocharcoal-based capacitive deionization
文章编号: N19090402
期刊: Separation and Purification Technology
作者: Zhaoyang Du, Weijun Tian, Kaili Qiao, Jing Zhao, Liang Wang, Wenlong Xie, Meile Chu, Tiantian Song
更新时间: 2019-09-04
摘要: Red oak biocharcoal, a novel electrode material that is inexpensive and highly conductive, was used for capacitive deionization (CDI) to simultaneously remove Cl- and Cr3+ from leather processing wastewater. The results showed that both the carbonization temperature and time played important roles in reducing the resistivity (ρ) of biocharcoal. Additionally, at 1000 °C and 3 h, the ρ value was reduced from 4.68 to 1.19 Ω·cm after the addition of Fe2O3. KOH impregnation enhanced the desalination capacity of the biocharcoal electrodes by increasing the specific surface area and hydrophilicity. Under the optimal operating parameters (voltage of 1.8 V, flow rate of 10 ml/min and electrode spacing of 2 mm), the KOBC15 electrode exhibited a maximum adsorption capacity of 13.79 mg/g. After 10 cycles of CDI system operation, the removal rates of Cl- and Cr3+ reached 86.7% and 100%, respectively, in simulated leather processing wastewater. This work provides new ideas and methods for the treatment of high-salinity wastewater.
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24722. 题目: Fungal laccase-mediated humification of estrogens in aquatic ecosystems
文章编号: N19090401
期刊: Water Research
作者: Mingyu Chen, Michael Gatheru Waigi, Shunyao Li, Kai Sun, Youbin Si
更新时间: 2019-09-04
摘要: Estrogens are a category of non-degradable organic pollutants prevalent in aquatic environments with reported health risks in human and wildlife reproduction. A biotechnological approach is proposed for utilizing fungal laccase-mediated humification reactions (L-MHRs) to remove estrogens from water. Through a reactive radical-mediated C–C, C–O–C, or C–N–C covalent coupling mechanism, multifarious complex polymeric structures are generated having limited solubilities, which significantly reduces their estrogenic activity and ecotoxicity. This review highlights the available literature associated with the self/cross-coupling mechanism of fungal L-MHRs in catalyzing the single-electron oxidation of estrogens and humic acid (HA). Advances in identifying unknown estrogen-HA cross-coupling products using high-resolution mass spectrometry combined with 13C-isotope labeling and 13C NMR may provide key research directions beneficial to aquatic ecological restoration measures.
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24723. 题目: Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial
文章编号: N19090310
期刊: Nature Geoscience
作者: Graham A. Shields, Benjamin J. W. Mills, Maoyan Zhu, Timothy D. Raub, Stuart J. Daines, Timothy M. Lenton
更新时间: 2019-09-03
摘要: The Neoproterozoic era witnessed a succession of biological innovations that culminated in diverse animal body plans and behaviours during the Ediacaran–Cambrian radiations. Intriguingly, this interval is also marked by perturbations to the global carbon cycle, as evidenced by extreme fluctuations in climate and carbon isotopes. The Neoproterozoic isotope record has defied parsimonious explanation because sustained 12C-enrichment (low δ13C) in seawater seems to imply that substantially more oxygen was consumed by organic carbon oxidation than could possibly have been available. We propose a solution to this problem, in which carbon and oxygen cycles can maintain dynamic equilibrium during negative δ13C excursions when surplus oxidant is generated through bacterial reduction of sulfate that originates from evaporite weathering. Coupling of evaporite dissolution with pyrite burial drives a positive feedback loop whereby net oxidation of marine organic carbon can sustain greenhouse forcing of chemical weathering, nutrient input and ocean margin euxinia. Our proposed framework is particularly applicable to the late Ediacaran 'Shuram' isotope excursion that directly preceded the emergence of energetic metazoan metabolisms during the Ediacaran–Cambrian transition. Here we show that non-steady-state sulfate dynamics contributed to climate change, episodic ocean oxygenation and opportunistic radiations of aerobic life during the Neoproterozoic era.
24724. 题目: The impact of biochar on soil carbon sequestration: Meta-analytical approach to evaluating environmental and economic advantages
文章编号: N19090309
期刊: Journal of Environmental Management
作者: Supriya Majumder, Surama Neogi, Tanushree Dutta, Michael A. Powel, Pabitra Banik
更新时间: 2019-09-03
摘要: Soil carbon (SC) is important for food security, ecosystem functioning, and environmental health, especially in light of global climate change. The physico-chemical character of biochar (pyrolyzed crop residue) has been shown to augment SC levels. This review systematically compares the environmental and economic benefits of applying crop residue versus biochar produced from crop residues to soils and the potential implications for SC sequestration. Crop residues enhance the mineralization rate of SC, while biochar can increase or decrease SC depending on the types of biochar/soil and duration. Therefore, converting crop residues to biochar may be more efficient for sequestering SC, but may/may not be more cost-effective. In this review, special emphasis is given to understanding the underlying mechanisms and biogeochemical processes of biochar production, in particular: surface (crystallinity), redox, and ability to control electron transfer reactions. By using meta-analytics, we determined the role of biochar compared to crop residue to enhance the status of organic SC.
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24725. 题目: Biochar slows gross nitrification and gasses N emission via lower autotrophic nitrification in paddy soils
文章编号: N19090308
期刊: Journal of Soils and Sediments
作者: Fayong Li, Xinqiang Liang, Shuang He, Meiru Li, Yucheng Cao, Jin Zhang, Guangming Tian
更新时间: 2019-09-03
摘要: Purpose: Laboratory incubation experiments using 15N stable isotope labeling and acetylene suppression techniques were conducted to compare the autotrophic nitrification and heterotrophic nitrification rates with the addition of swine manure (SW) and swine-manure-derived biochar (SWB) in two paddy soils. Materials and methods: SW and SWB were applied at four N-based amendment levels, namely control (0 mg N kg−1), low (1.1 mg N kg−1), medium (2.2 mg N kg−1), and high (4.4 mg N kg−1). Twenty-five milliliters of C2H2 gas were injected into each storage bottle to inhibit autotrophic nitrification in soil. At the end of the preincubation period, 160 mg kg−1 15N-glycine were added to each storage bottle to stimulate heterotrophic nitrification in soil. Results and discussion: Results showed that SW increased the NH4+-N content by 3.5 to 17.5 mg kg−1 in both soils, while SWB decreased it by 0.1 to 4.7 mg kg−1 compared to control group, regardless of whether autotrophic nitrification was inhibited. Both SW and SWB enhanced NO3−-N accumulation in the two soils compared to control group when autotrophic nitrification was not inhibited; however, NO3−-N concentration in the soil with SWB was up to 24% lower than that with the same level of SW addition. NH3 volatilization rates were elevated at all the SW and SWB amendment levels, although only SW led to higher N2O emission rates. Compared with SW, high level of SWB significantly decreased N2O emissions by 78 to 84% in the loam and clay loam soils. The increase in NH3 volatilization, soil NO3−-N accumulation, and autotrophic nitrification rate were greater with SW than with SWB. Higher rates of soil heterotrophic nitrification were observed in SWB-amended soils than in SW-amended soils with a high (4.4 mg N kg−1) amendment level. Conclusions: Our results suggest that SWB is less likely to increase NO3−-N accumulation in soil and contributes more to the lower soil autotrophic nitrification rate compared with SW. Although SWB can promote heterotrophic nitrification, it generally inhibits the autotrophic nitrification process and slows the increment pace of the gross nitrification in paddy soils.
24726. 题目: Phosphogypsum as a novel modifier for distillers grains biochar removal of phosphate from water
文章编号: N19090307
期刊: Chemosphere
作者: Bing Wang, Guoqi Lian, Xinqing Lee, Bin Gao, Ling Li, Taoze Liu, Xueyang Zhang, Yulin Zheng
更新时间: 2019-09-03
摘要: A novel biochar composite was fabricated via the pyrolysis of distillers grains treated phosphogypsum for phosphate removal from water. Batch adsorption experiments were performed on the adsorption characteristics of phosphate. Effects of pyrolysis temperature, solution pH, the dosage of adsorbent, ambient temperature on phosphate adsorption were also investigated. The results demonstrated that the optimum initial solution pH for phosphate adsorption was 6.0, and high pyrolysis temperature was favorable for phosphate adsorption. The optimal dosage of biochar was 1.25 g L−1. A pseudo-second-order kinetic model can well explain the adsorption kinetics, indicative of the energetically heterogeneous solid surface of the composite. The maximum phosphate adsorption capacity of the phosphogypsum modified biochar obtained from Langmuir isotherm reached 102.4 mg g−1 which was almost five times that of distillers grains biochar alone (21.5 mg g−1). The mechanism is mainly attributed to electrostatic adsorption, surface precipitation and ligand exchange. The ideal adsorption performance indicated that biochar supported phosphogypsum can be used as high-quality adsorbent for phosphate removal in wastewater treatment.
24727. 题目: Infiltration behavior of heavy metals in runoff through soil amended with biochar as bulking agent
文章编号: N19090306
期刊: Environmental Pollution
作者: Ling Zhao, Hongyan Nan, Yue Kan, Xiaoyun Xu, Hao Qiu, Xinde Cao
更新时间: 2019-09-03
摘要: Biochar as a porous carbon material could be used for improving soil physical and chemical properties, while insufficient attention has been paid to potential risks induced by infiltration of heavy metals in the runoff water flowing through biochar-amended soil. Four different soil-biochar matrices with same volumes were constructed including soil alone (M1), biochar alone (M2), soil-biochar layering (M3) and soil-biochar mixing (M4). Leaching experiments were conducted with Pb, Cu, and Zn contaminated runoff water. Results showed that biochar amendment greatly improved the water permeation, and the infiltration rates in M2, M3, and M4 were 2.85–23.0 mm min−1, being much higher than those in M1 (1.33–4.05 mm min−1), though the rates decreased as the leaching volumes increased. However, biochar induced more Pb, Cu, and Zn infiltrated through soil-biochar matrix. After 350-L leaching, M1 retained about 95% Pb, 90% Cu, and 36% Zn, while M2 only retained 4.80% Pb, 17.4% Cu, and 4.01% Zn; about 30% Pb, 80% Cu, and 15% Zn were retained in M3 and M4. Notably, Zn was trapped first and then re-leached into the filtrate, which resulted in a much higher effluent Zn than the influent Zn at the later stage. However, the unit weight of biochar showed a higher capacity for retaining heavy metals compared to per unit of soil. Under the dynamic water flow, all benefits and disadvantages induced by biochar were weakened with its physical disintegration. Biochar as soil amendment can enhance plant growth via ameliorating soil structure, while it would pose risks to environment because of large penetration of heavy metals. If biochar was compacted to form a denser physical structure, perhaps more heavy metals could be retained.
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24728. 题目: A comparative study on biochar properties and Cd adsorption behavior under effects of ageing processes of leaching, acidification and oxidation
文章编号: N19090305
期刊: Environmental Pollution
作者: Ruihai Chang, Saran P. Sohi, Fanqi Jing, Yuyan Liu, Jiawei Chen
更新时间: 2019-09-03
摘要: Biochar has potential to control the bioavailability and migration of potentially toxic heavy metals in soil by adsorption. Natural ageing in the environment may change the physicochemical properties and adsorption function of biochar over the long-term. The present study compared the effects of different simulated ageing treatments on Cd adsorption of high and low temperature biochar from straw of corn (Zea mays). Fresh and aged biochars were systematically characterized by elemental analysis, FTIR, XPS, Zeta, SEM-EDS, XRD and the composition of their mineral ash. The adsorption of Cd to fresh and aged biochars was then assessed under the influence of pH. Drawing the results together the effects of ageing on the extent and mode of Cd adsorption could be elucidated. The results showed that the adsorption capacity of fresh biochar produced at 650 °C was higher than of biochar made at 350 °C, and that mineral co-precipitation plays a dominant role in Cd sorption. Leaching removed organic and inorganic ash components from biochars, markedly diminishing the capacity of the high temperature biochar to adsorb Cd. The adsorption performance of the low temperature biochar was dependent on surface complexation. The adsorption capacity of low-temperature biochar was markedly enhanced by oxygen-containing functional groups formed through acidification and oxidation. The long-term benefits of biochar in the management of polluted soil require a rethink, considering the contrasting ageing behavior of different temperature biochar and their response to different ageing environments.
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24729. 题目: Stabilization of per- and polyfluoroalkyl substances (PFASs) with colloidal activated carbon (PlumeStop®) as a function of soil clay and organic matter content
文章编号: N19090304
期刊: Journal of Environmental Management
作者: M. Sorengard, Dan Berggren Kleja, Lutz Ahrens
更新时间: 2019-09-03
摘要: The global problem of contamination of drinking water sources and the aquatic environment with per- and polyfluoroalkyl substances (PFASs) originating from highly contaminated soils is addressed in this study. For the first time, a colloidal activated carbon (AC) product (PlumeStop®) was systematically assessed for PFASs stabilization in soil. Colloidal (particle size 0.1–1.1 μm) AC has the advantage that field application is non-intrusive, comprising injection under high pressure in situ at PFAS-contaminated soil hotspots. In the assessment, 10 different soil mixtures with gradually increasing organic carbon and clay fractions were spiked with 18 different PFASs of varying perfluorocarbon chain length and four different functional groups and aged for one year. Equilibrium leaching tests showed that the ability of colloidal AC to increase sorption of PFASs to soil was highly dependent on PFAS perfluorocarbon chain length. The best treatment efficiency was observed for perfluorocarbon chain lengths 6–7 at which colloidal AC resulted in sorption of 81%, 85%, and 86% for perfluorooctanoate (PFOA), 6:2 fluorotelomer sulfonate (6:2 FTSA) and perfluorohexane sulfonate, (PFHxS), respectively. Sorption of individual PFASs decreased significantly (p < 0.05) with increasing organic carbon content in soil treated with colloidal AC indicating stearic hindrance of the ACs pore structure. On the other hand, the sorption of the majority of PFASs increased significantly (p < 0.05) with increasing clay content in colloidal AC-treated soil, which can be explained by increase in surface area that colloidal AC can sorb to. Overall, the results indicate that the colloidal AC product tested can be useful in remediation approaches for certain PFASs under specific field conditions and PFAS contamination.
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24730. 题目: The discrepant mobility of antibiotic resistant genes: Evidence from their spatial distribution in sewage sludge flocs
文章编号: N19090303
期刊: Science of The Total Environment
作者: Pinjing He, Yizhou Zhou, Liming Shao, Jinghua Huang, Zhan Yang, Fan Lü
更新时间: 2019-09-03
摘要: The present study stratified excess activated sludge from six municipal wastewater treatment plants into four extracellular fractions including supernatant, slime, slightly-bond extracellular polymeric substances (LB-EPS) and tightly-bond EPS (TB-EPS) and one intracellular fraction (pellet) according to their different degrees of tight binding to sludge microbial aggregates and determined the abundance of seven antibiotic resistance genes (ARGs) (sul-I, sul-II, tet-C, tet-X, blaTEM, mefA and cat) and one mobile genetic elements (MGEs) (IntI-1) in each fraction. Extracellular ARGs were found to make up 0.1% - 74.2% of total ARGs, while the ratio of extracellular DNA to total DNA was only 1.2% - 4.2%, implying that EPS was a major ARG reservoir in sewage sludge. The genes of sul-I, tet-C and mefA have the highest mobility owing to a large proportion ranging from 0.5% to 32.7% in the fractions of LB-EPS, slime and supernatant, which indicates an increased risk of mediating the transfer of ARGs to environment. Comparatively, the proportion of blaTEM in the TB-EPS of sludge accounted for 0.3%–34.9% and caused limited-mobility. Sul-II, tet-X and cat and IntI-1, made up approximately 82.6% - 99.6% proportion in the cells, and were thus less mobile. This study proposes that ARGs and MGEs can have different mobilities. Those located in the outermost layers of sludge have a higher mobility potential of propagation into the natural environment during wastewater treatment and sludge utilization, leading to an increased risk of transferability.
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24731. 题目: Plant diversity and soil stoichiometry regulates the changes in multifunctionality during pine temperate forest secondary succession
文章编号: N19090302
期刊: Science of The Total Environment
作者: Manuel Esteban Lucas-Borja, Manuel Delgado-Baquerizo
更新时间: 2019-09-03
摘要: The shift in ecosystem multifunctionality during ecosystem succession (years to decades) remains largely unexplored. In this study, we used a 120-year-old pine temperate forest chronosequence (1: 1–19 years, stage 2: 20–39 years, stage 3: 40–59 years, stage 4: 60–79 years, stage 5: 80–99 years, stage 6: 100–120 years) to evaluate the role that time plays in shaping ecosystem multifunctionality (nutrient cycling, carbon stocks, water regulation, decomposition and wood production), and found that, over the first century, ecosystem functioning gradually increased every ~50 years. Such a result was maintained for individual groups of ecosystem functions and services including nutrient cycling, carbon stocks, decomposition and wood production. Plant diversity and soil stoichiometry (C:N ratio) were the major environmental predictors for the changes in ecosystem multifunctionality during forest secondary succession. Plant diversity increased during ecosystem succession and was positively related to ecosystem multifunctionality. The soil C:N ratio decreased during ecosystem succession and was negatively related to multifunctionality. Our results suggest that increases in aboveground resource heterogeneity (higher plant diversity) and organic matter quality (lower soil C:N ratios) could help explain the increases in multifunctionality over a century of forest development. Our work illustrates the importance of time in shaping multifunctionality during the first century of ecosystem succession, and further provide important insights for the management of temperate forest ecosystems.
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24732. 题目: Catalytic ozonation of emerging pollutant and reduction of toxic by-products in secondary effluent matrix and effluent organic matter reaction activity
文章编号: N19090301
期刊: Water Research
作者: Yuting Zhang, Yechen An, Chao Liu, Yiping Wang, Zilong Song, Yanning Li, Weidong Meng, Fei Qi, Bingbing Xu, Jean-Philippe Croue, Donghai Yuan, Amir Ikhlaq
更新时间: 2019-09-03
摘要: In this study, the performance of LaCoO3 (LCO) catalytic ozonation was evaluated comprehensively, including the degradation efficiency of benzotriazole (BZA) as a typical emerging pollutant, toxic bromate reduction and the disinfection by-products (DBPs) precursors removal ability in effluent organic matter (EfOM), as well as EfOM reactive activity in catalytic ozonation. Additionally, the reduction of toxic halogenated by-products in (catalytic) ozonation was reported, which was not focused on previous researches before. Results showed that LCO catalytic ozonation improved the removal efficiency of BZA, UV254 and SUVA via enhanced HO· formation. Interestingly, LCO catalytic ozonation showed the ability on the reduction of aldehydes and toxic halogenated organic by-products. Moreover, the formed [trichloromethane (TCM)], [bromochloroacetonitrile (BCAN)] and [dichloroacetamide (DCAcAm)] decreased significantly in catalytic ozonation. Catalytic ozonation was also able to remove DBPs precursors to decline the formation of DBPs, such as TCM, bromodichloromethane (BDCM), trichloroacetonitrile (TCAN) and trichloronitromethane (TCNM). This process was involved in the transformation of EfOM in catalytic ozonation, which was confirmed by multi-spectrum methods, two-dimensional correlation spectroscopy (2D-COS) and hetero-spectral 2D-COS. In summary, LCO was shown to be an effective catalyst to improve the performance of the sole ozonation on the removal of emerging contaminants and DBPs precursors, as well as toxic by-products reduction. Additionally, the strategy of toxic by-products reduction in catalytic ozonation was proposed. Results indicated this technology was an important contribution on removal of refractory organics and formation of toxic by-products in water supply and wastewater treatment industry.
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24733. 题目: Assessing the carbon assimilation and production of benthic archaeal lipid biomarkers using lipid-RIP
文章编号: N19090209
期刊: Geochimica et Cosmochimica Acta
作者: Thomas W. Evans, Sarah Coffinet, Martin Könneke, Julius S. Lipp, Kevin W. Becker, Marcus Elvert, Verena Heuer, Kai-Uwe Hinrichs
更新时间: 2019-09-02
摘要: Distributional patterns of intact polar lipids (IPLs) suggest that archaea are abundant in marine subsurface sediments. However, the production of archaeal lipids remains largely unresolved. We performed a lipid radioisotope probing (lipid-RIP) experiment using 14C-bicarbonate and 2-14C-acetate with surface and methanogenic marine sediments from the Rhone delta (Mediterranean Sea) to investigate mechanisms of carbon assimilation and to assess biomass production of benthic archaea. The direct determination of carbon assimilation rates into diagnostic IPLs in the experiments with 14C-bicarbonate were up to 9 times higher than in the incubations with 2-14C-acetate, implying that autotrophy is an important carbon pathway for the benthic archaea in the Rhone delta sediments. Production rates of polyglycosidic archaeols (AR) were one to two orders of magnitude higher than those of mono- and polyglycosidic glycerol dialkyl glycerol tetraethers (GDGTs), suggesting that the former IPLs are good biomarkers for active benthic archaea in marine sediments. In contrast, the low production rates of the monoglycosidic AR and GDGTs, indicates that a large fraction of these IPLs may represent fossil sedimentary remains from the water column. Unexpectedly, the lipid production rates of AR and GDGT core lipids (CLs) were similar to those of polyglycosidic IPLs. Considering the relatively short period of incubation (21 days), this suggests that CLs may be actively synthesized by benthic archaea in marine sediments and are not exclusively formed from the degradation of IPL precursors.
24734. 题目: Group I alkenones and Isochrysidales in the world’s largest maar lakes and their potential paleoclimate applications
文章编号: N19090208
期刊: Organic Geochemistry
作者: Karen J. Wang, Jonathan A. O'Donnell, William M. Longo, Linda Amaral-Zettler, Gaoyuan Li, Yuan Yao, Yongsong Huang
更新时间: 2019-09-02
摘要: The Espenberg maar lakes on the Seward Peninsula, Alaska, are the largest volcanic crater lakes in the world and contain the longest known lacustrine sedimentary archives in Alaska. The lack of glacial-aged marine sedimentary archives around the Bering Land Bridge due to exposure of the shelf during sea level low-stands makes these lakes highly valuable for understanding the region’s past climate and environmental changes. Located en route to humanity’s last colonized American continents, the Seward Peninsula’s climate and environments during the last glacial period bear major anthropological significance. However, a lack of quantitative proxies has so far hampered exploration of these lakes for paleoclimate reconstructions. Here we report, for the first time, the discovery of abundant Group I alkenones and Isochrysidales in surface sediments from three maar lakes: White Fish, North Killeak and Devil Mountain, using a combination of lipid biomarker and 18S rRNA gene sequencing analyses. Our discovery adds to the expanding list of oligotrophic freshwater lakes where Group I alkenones are found, and water chemistry data contribute to the understanding of the environmental controls on Group I Isochrysidales. Our results further confirm the use of the U37K index of Group I alkenones as a proxy for the mean temperature of the spring isotherm (MTSI) and RIK37 as a quantitative measurement for Isochrysidales group mixing. We also demonstrate the analytical challenges for analyzing alkenones in freshwater lakes and the effectiveness of eliminating coelution using silver thiolate chromatographic material (AgTCM).
24735. 题目: Occurrence of organic compounds in groundwater of Saudi Arabia
文章编号: N19090207
期刊: Environmental Monitoring and Assessment
作者: Abdulaziz S. Alquwaizany, Sulaiman M. Alfadul, Mujahid A. Khan, Abdulrahman I. Alabdulaaly
更新时间: 2019-09-02
摘要: The presence of organic compounds in drinking water is well recognized in many developing countries; however, the occurrence of organic contaminants in the groundwater of Saudi Arabia, which is the main source of drinking water in the country, is not well documented. A national comprehensive study was carried out to assess the occurrence of organic compounds in groundwater wells used for drinking water purpose, in different regions of Saudi Arabia. A total of 993 well water samples were collected from all 13 administrative regions of the kingdom. Samples were analyzed for a total of 131 organic compounds using the standard methods. The results indicated that total organic carbon values were in the range of 0.01 to 84.13 mg/L with an average weighted value of 12.61 mg/L. Organic compounds were detected in only 9 regions, with 19.84% of the samples containing organic compounds. Only 96 wells (9.67%) showed contents of organic compounds above the safe limits. Pesticides were not detected in any of the well water samples. Overall, organic compounds were found in only 197 out of 993 wells (19.84%) in the whole country. Most of the wells containing organic compounds were located in residential, industrial, and agriculture areas. Riyadh region and Eastern Province were found to have the most affected wells as compared to other regions. Several regions did not show any organic compounds in the well waters. It can be said that the problem of groundwater contamination with organic compounds in Saudi Arabia is not acute and is manageable at present. It is, however, recommended that a regular monitoring of drinking water wells of all regions should be carried out by the competent authorities for organic compounds to know any contamination if and when it happens. Preventing such contaminants from reaching drinking water sources and protecting drinking water well heads from such contaminants remains a priority.
24736. 题目: New insight into the impact of biochar during vermi-stabilization of divergent biowastes: Literature synthesis and research pursuits
文章编号: N19090206
期刊: Chemosphere
作者: Muhammad Bilal Khan, Xiaoqiang Cui, Ghulam Jilani, Lin Tang, Min Lu, Xuerui Cao, Zulfiqar Ali Sahito, Yasir Hamid, Bilal Hussain, Xiaoe Yang, Zhenli He
更新时间: 2019-09-02
摘要: Biochar amendment for compost stabilization of divergent biowastes is gaining considerable attention due to environmental, agronomic and economic benefits. Research to date exhibits its favorable physico-chemical characteristics, viz. greater porosity, surface area, amount of functional groups, and cation exchange capacity (CEC), which allow interface with main nutrient cycles, favor microbial activities during composting, and improve the reproduction of earthworms during vermicomposting. Biochar amendment during composting and vermicomposting of biowastes boosts physico-chemical properties of compost mixture, microbial activities and organic matter degradation; and reduces nitrogen loss and emission of greenhouse gases (GHGs). It also improves the quality of final compost by increasing concentration of plant available nutrients, enhancing maturity, decreasing composting duration and reducing the toxicity of compost. Due to these characteristics, biochar could be considered a beneficial additive for the stabilization of different biowastes during composting and vermicomposting processes. Hence, good quality vermicompost, efficient recycling and management of biowastes could be achieved by addition of biochar through composting and vermicomposting.
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24737. 题目: PFOA and PFOS removal by ion exchange for water reuse and drinking applications: Role of organic matter characteristics
文章编号: N19090205
期刊: Environmental Science: Water Research & Technology
作者: Fuhar Dixit, Madjid Mohseni, Benoit Barbeau, Shadan Ghavam Mostafavi
更新时间: 2019-09-02
摘要: Perfluoroalkyl substances (PFAS) are drinking water contaminants of emerging concern due to their persistence in the environment and tendency to bio-accumulate. Although anionic ion exchange (IX) resins offer a cost-effective alternative for removing PFAS from natural waters, the studies on PFAS removal by IX under the influence of variable characteristics of the organic compounds present in the natural water sources, have been overlooked. This is critically important given that the organic matter (OM) characteristics are spatially variable and can change seasonally. In the present study, a strongly basic anion exchange resin was used to remove two of the most persistent PFAS, namely Per-fluorooctanoic acid (PFOA) and Per-fluorooctanesulfonic acid (PFOS). Factors influencing the uptake behavior included the PFOA and PFOS concentrations, resin dosage, and background OM characteristics, more specifically the charge density and molecular weight distribution of source water OM. The equivalent background concentration (EBC) was employed to evaluate the competitive uptake between OM and PFAS. Experimental data were fitted to different mathematical and physical models to evaluate the competitive interactions. Further, IX was able to achieve complete PFAS removal with simultaneous >60% Dissolved Organic Carbon (DOC) removal. Evidences of size exclusion and pore blockage were also observed in the presence of humics and larger molecular weight organic fractions. Results of this study indicate that IX exhibits great potential for simultaneous OM and PFAS removal for drinking and potable water reuse applications.
24738. 题目: Hydrothermal synthesizing sludge-based magnetite catalyst from ferric sludge and biosolids: Formation mechanism and catalytic performance
文章编号: N19090204
期刊: Science of The Total Environment
作者: He Zhang, Gang Xue, Hong Chen, Xiang Li
更新时间: 2019-09-02
摘要: Sludge-based magnetite catalyst (SBMC) containing Fe3O4 was synthesized by hydrothermal (HT) of biosolids and ferric sludge, which is a promising wasted sludge recycling way. The protein and carbohydrate, main representative compounds in biosolids, were used to explore the SBMC formation mechanism. A part of carbohydrate and the produced Maillard reaction products (MRPs) derived from two substrates via Maillard reaction (MR) were confirmed to participate in Fe3+ reduction. The MR accompanied by substrates humification, making MRPs own strong chelation activity. The MRPs (50–100 kDa) reflected the strongest relative reducing and chelation activity, mainly involving in Fe3O4 synthesis. Furthermore, the SBMC was verified as an efficient Fenton-like catalyst for aniline with 77.9% removal efficiency. The OH and O2– both contributed to the degradation, differing from only OH playing function in traditional Fenton-like system, implying biochar in SBMC could mediate the reactive oxygen species generating by Fe3O4, and benefit its catalytic performance.
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24739. 题目: Application of Simplicillium chinense for Cd and Pb biosorption and enhancing heavy metal phytoremediation of soils
文章编号: N19090203
期刊: Science of The Total Environment
作者: Zhongmin Jin, Songqiang Deng, Yuchen Wen, Yifeng Jin, Lin Pan, Yanfu Zhang, Tom Black, Kevin C. Jones, Hao Zhang, Dayi Zhang
更新时间: 2019-09-02
摘要: Phytoremediation is an effective approach to control soil heavy metal pollution. This study isolated a fungus strain from soils contaminated by cadmium (Cd) and lead (Pb) in Zhalong Wetland (China), which was identified as Simplicillium chinense QD10 via both genotypic and phenotypic analysis. The performance and mechanism of S. chinense QD10 in Cd and Pb adsorption was unraveled by morphological analysis and biosorption test, and its roles in ameliorating phytoremediation by Phragmites communis were tested in pot-experiments. Cd biosorption was attributed to the formation of Cd-chelate, whereas Pb was predominantly adsorbed by extracellular polymeric substances. Metal biosorption followed Langmuir isotherm, and the maximum biosorption capacity was 88.5 and 57.8 g/kg for Cd and Pb, respectively. Colonized in soils, such biosorption behavior of S. chinense QD10 can generate gradients of available Cr or Pb and drive their enrichment. Accordingly, S. chinense QD10 amendment significantly enhanced the phytoextraction of Cd and Pb by P. communis, possibly attributing to rhizospheric enrichment of Cd or Pb and defending effects on plants, explained by the significant removal of acid-extractable and reducible metals in soils and the increase of Cd and Pb content in P. communis tissues. The present study explored the mechanisms of S. chinense QD10 in Cd and Pb biosorption and proved its potential in ameliorating the phytoremediation performance at metal contaminated sites.
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24740. 题目: Biochar with near-neutral pH reduces ammonia volatilization and improves plant growth in a soil-plant system: A closed chamber experiment
文章编号: N19090202
期刊: Science of The Total Environment
作者: Sanchita Mandal, Erica Donner, Euan Smith, Binoy Sarkar, Enzo Lombi
更新时间: 2019-09-02
摘要: Ammonia (NH3) volatilization is considered as one of the major mechanisms responsible for the loss of nitrogen (N) from soil-plant systems worldwide. This study investigated the effect of biochar amendment to a calcareous soil (pH 7.8) on NH3 volatilization and plant N uptake. In particular, the effect of biochar's feedstock and application rate on both NH3 volatilization and plant growth were quantified using a specially designed closed chamber system. Two well-characterized biochars prepared from poultry manure (PM-BC) and green waste compost (GW-BC) were applied to the soil (0, 0.5, 1, 1.5 and 2% w/w equivalent to 0, 7.5, 15, 22 and 30 t ha−1) and wheat (Triticum aestivum, variety: Calingiri) was grown for 30 days. Both PM-BC and GW-BC decreased NH3 volatilization to a similar degree (by 47 and 38%, respectively), in the soil-plant system compared to the unamended control. Higher plant biomass production of up to 70% was obtained in the closed chamber systems with the addition of biochar. The increase in plant biomass was due to the reduction in N loss as NH3 gas, thereby increasing the N supply to the plants. Plant N uptake was improved by as much as 58% with biochar addition when additional NPK nutrients were supplied to the soil. This study demonstrates that the application of biochars can mitigate NH3 emission from calcareous agricultural cropping soil and that the retained N is plant-available and can improve wheat biomass yield.
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