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12721. 题目: Spectroscopic study on transformations of dissolved organic matter in coal-to-liquids wastewater under integrated chemical oxidation and biological treatment process
文章编号: N18072120
期刊: Journal of Environmental Sciences
作者: Siwei Peng, Xuwen He, Hongwei Pan
更新时间: 2018-07-21
摘要: A large amount of wastewater containing various toxic organic contaminants is produced during coal-to-liquids process. In this study, several spectroscopic methods were used to monitor the transformation of organic pollutants during an integrated chemical oxidation and biological process. The results showed that the hydrophobic acid fraction increased after Fenton oxidation, which was likely due to the production of small-molecule organic acids. Soluble microbial products were generated during biological treatment processes, which were degraded after ozonation; meanwhile, the hydrophilic base and acid components increased. Ultraviolet-visible spectroscopic analysis indicated that peaks at the absorption wavelengths of 280 and 254 nm, which are associated with aromatic substances, were detected in the raw water. The aromatic substances were gradually removed, becoming undetectable after biological aeration filter (BAF) treatment. Fourier transform infrared spectroscopy analysis revealed that the functional groups of phenols; benzene, toluene, ethylbenzene, and xylene (BTEX); aromatic hydrocarbons; aliphatic acids; aldehydes; and esters were present in raw wastewater. The organic substances were oxidized into small molecules after Fenton treatment. Aromatic hydrocarbons were effectively removed through bioadsorption and biodegradation after BAF process. Biodegradable organic matter was reduced and finally became undetectable after anoxic–oxic treatment in combination with a membrane bioreactor. Four fluorescent components were fractionated and obtained via excitation–emission matrix parallel factor analysis (EEM-PARAFAC). Dissolved organic matter fractionation in conjunction with EEM-PARAFAC was able to monitor more precisely the evolution of characteristic organic contaminants.
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12722. 题目: Influence of sodium dodecyl sulfate coating on adsorption of methylene blue by biochar from aqueous solution
文章编号: N18072119
期刊: Journal of Environmental Sciences
作者: Wei Que, Luhua Jiang, Chen Wang, Yunguo Liu, Zhiwei Zeng, Xiaohua Wang, Qimeng Ning, Shaoheng Liu, Peng Zhang, Shaobo Liu
更新时间: 2018-07-21
摘要: Biochar is regarded as a promising new class of materials due to its multifunctional character and the possibility of effectively coupling different properties. With increasing introduction into the environment, environmental chemicals such as surfactants will load onto the released biochar and change its physicochemical characteristics and adsorption behavior toward pollutants. In this study, sodium dodecyl sulfate (SDS), as one type of anionic surfactant, was coated onto biochar with different loading amounts. The influence of SDS loading onto biochar's physicochemical properties were investigated by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, zeta potential and Brunauer–Emmett–Teller (BET) surface area and pore size distribution analysis. Results showed that the pore size of the biochar decreased gradually with the increase of SDS loading because of the surface-adsorption and pore-blocking processes; the pH of the point of zero charge (pHPZC) decreased with increasing SDS loading. Although surface-coating with SDS decreased the pore size of the biochar, its adsorption capacity toward Methylene Blue (MB) significantly increased. The biochar-bound SDS introduced functional groups and negative charges to the biochar surface, which could thus enhance the adsorption of MB via hydrogen bonding and electrostatic interaction. The results can shed light on the underlying mechanism of the influence of anionic surfactants on the adsorption of MB by biochar.
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12723. 题目: Sediment granulometry and salinity drive spatial and seasonal variability of an estuarine demersal fish assemblage dominated by juvenile fish
文章编号: N18072118
期刊: Estuarine, Coastal and Shelf Science
作者: Yureidy Cabrera Páez, Consuelo María Aguilar-Betancourt, Gaspar González-Sansón, Fátima Negrete Rodríguez, Michelle Gray
更新时间: 2018-07-21
摘要: Abiotic factors are known to structure estuarine fish communities; however, their effects on the ichthyofauna are not yet clear. The objective of this study was to evaluate abundance and composition, by species and size, of the demersal ichthyofauna in a Mexican Central Pacific lagoon, and correlate its spatial and seasonal variations with selected abiotic factors. Eight sampling campaigns were conducted in representative months of the dry and rainy seasons between April 2015 and February 2017. Salinity, temperature and sediment granulometry were recorded. A total of 10 093 individuals of 64 species were collected and measured for total length. Of the 22 most abundant species, 19 were mainly juveniles (>50%). Diapterus brevirostris, Achirus mazatlanus, Centropomus robalito and Lutjanus argentiventris comprised more than 80% of the total collection. PERMANOVA yielded significant differences in fish community composition between sites and months, and post hoc tests resulted in four homogenous, significantly different groups of sites based on fish assemblage composition. These groups of sites lie well ordered along a west-east axis inside the lagoon. Two well separated seasonal groups of months were defined, namely dry season (February, April) and rainy season (July, October). The spatial changes in abundance and composition of the fish fauna were primarily explained by the Site factor in a spatial scale, while the Month factor influenced to a lesser degree the community structure on a seasonal scale. Redundancy analysis showed the type of sediment, the bottom salinity and the organic matter content were highly correlated with the composition and abundance of ichthyofauna in the lagoon. One species group (dominated by D. brevirostris, C. robalito and A. mazatlanus) was found to be highly positively correlated with percentage of mud and organic matter but negatively correlated with bottom salinity. Another species group (dominated by Diodon holocanthus, Eucinostomus dowii, Sphoeroides annulatus and Chaetodon humeralis) was highly correlated with percentage of sand and bottom salinity. A high number of juveniles in the catches also validates the Barra de Navidad lagoon as a probable nursery area.

12724. 题目: Optical properties of straw-derived dissolved organic matter and growth inhibition of Microcystis aeruginosa by straw-derived dissolved organic matter via photo-generated hydrogen peroxide
文章编号: N18072117
期刊: Environmental Pollution
作者: Hua Ma, Liping Huang, Jie Zhang, Dezhi Shi, Jixiang Yang
更新时间: 2018-07-21
摘要: Recent advances in research on algae inhibition by using low-cost straw proposed a possible mechanism that reactive oxygen species (ROS) generated by the solar irradiation of straw-derived dissolved organic matter (DOM) might contribute to cyanobacteria inhibition. However, this process is not clearly understood. Here, DOM from three types of straw (barley, rice, and wheat) and natural organic matter (NOM) isolates were investigated in terms of their photochemical properties and ROS generating abilities. Results demonstrated that the DOM derived from the aeration decomposition of barley straw (A-DOMbs) yielded the best formation efficiencies of hydrogen peroxide (H2O2) and hydroxyl radicals ( OH) under solar-simulated irradiation in all organic matter samples. Correlation analysis implies that optical parameters and phenolic hydroxyl group contents can signify ROS generating abilities of different DOM solutions. Bioassay results show that A-DOMbs possesses the highest inhibition performance for M. aeruginosa in all DOM samples, much higher than those of NOM isolates. The addition of catalase greatly relieves the inhibition performance, making the loss of chlorophyll a content decreased from 37.14% to 7.83% in 2 h for A-DOMbs, which implies that for cyanobacteria growth inhibition, photochemically-produced H2O2 from SOM is far more important than singlet oxygen (1O2),· OH, and even SOM itself. Our results show that H2O2 photochemically generated from straw-derived DOM is able to result in rapid inhibition of M. aeruginosa in a relatively short period, furthering the understanding of complicated mechanisms of cyanobacteria inhibition by using low-cost straw in eutrophic waters.
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12725. 题目: Unraveling microbial turnover and non-extractable residues of bromoxynil in soil microcosms with 13C-isotope probing
文章编号: N18072116
期刊: Environmental Pollution
作者: Karolina M. Nowak, Markus Telscher, Erika Seidel, Anja Miltner
更新时间: 2018-07-21
摘要: Bromoxynil is a widely used nitrile herbicide applied to maize and other cereals in many countries. To date, still little is known about bromoxynil turnover and the structural identity of bromoxynil non-extractable residues (NER) which are reported to occur in high amounts. Therefore, we investigated the microbial turnover of 13C-labeled bromoxynil for 32 days. A focus was laid on the estimation of biogenic NER based on the turnover of 13C into amino acids (AA). At the end, 25% of 13C6-bromoxynil equivalents were mineralized, 2% assigned to extractable residues and 72.5% to NER. Based on 12% in the 13C-total AA and an assumed share of AA of 50% in microbial biomass we arrived at 24% of total 13C-biogenic NER. About 33% of the total 13C-NER could thus be explained by 13C-biogenic NER; 67% was unknown and by definition xenobiotic NER with potential for toxicity. The 13C label from 13C6-bromoxynil was mainly detected in the humic acids (28.5%), but significant amounts were also found in non-humics (17.6%), fulvic acids (13.2%) and humins (12.7%). The 13C-total amino acids hydrolyzed from humic acids, humins and fulvic acids amounted to 5.2%, 6.1% and 1.2% of 13C6-bromoxynil equivalents, respectively, corresponding to total 13C-biogenic NER amounts of 10.4%, 12.2% and 2.4%. The humins contained mostly 13C-biogenic NER, whereas the humic and fulvic acids may be dominated by the xenobiotic NER. Due to the high proportion of unknown 13C-NER and particularly in the humic and fulvic acids, future studies should focus on the detailed characterization of these fractions.
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12726. 题目: Comparison of organic matter removals in single-component and bi-component systems using enhanced coagulation and magnetic ion exchange (MIEX) adsorption
文章编号: N18072115
期刊: Chemosphere
作者: Yingying Chen, Weiying Xu, Hongjian Zhu, Dong Wei, Ning Wang, Mengting Li
更新时间: 2018-07-21
摘要: Natural organic matter (NOM) in aquatic environments have a significant impact on NOM-organic compound interactions, which could strongly affect the distribution and transformation of organic compounds during water treatment. This study focused on the removals of NOM (humic acid, HA) and synthetic organic matter (ibuprofen, IBP) through enhanced coagulation and magnetic ion exchange (MIEX) resin adsorption in single and bi-component systems. Two coagulants, traditional aluminum sulfate (AS) and lab-prepared polyaluminum chloride (PACl), were employed. The charge properties, particle size distribution, and fractal dimension (Df) during organic matter removal were studied in both the single and bi-component systems to explore the purification behaviors and mechanistic effects of interactions between coagulants, MIEX, and organic matters. The experimental results indicated that the Al-based coagulants could remove over 80% of HA in both the single and IBP-HA combined systems, while the presence of HA could considerably improve the IBP removal rate. The aggregates formed during single-component coagulation were larger, but weaker and more loosely structured than those formed in the bi-component system under the same coagulation conditions. In the single-component system, the maximum removal efficiencies of IBP and HA by MIEX adsorption were 65% and 72%, respectively, at a resin dosage of 20.0 mL/L and mixing time of 60 min. Under the same conditions, the removals of these components in the bi-component system were improved to 68% and 98%, respectively. The reaction rate between IBP and MIEX resin was found faster than that between HA and MIEX resin.
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12727. 题目: The role of the anode material and water matrix in the electrochemical oxidation of norfloxacin
文章编号: N18072114
期刊: Chemosphere
作者: Salatiel W. da Silva, Emma M.O. Navarro, Marco A.S. Rodrigues, Andréa M. Bernardes, Valentín Pérez-Herranz
更新时间: 2018-07-21
摘要: The roles of the anode material, boron-doped diamond (BDD), with different boron (B) and substrate Silicon (Si) or Niobium (Nb) content, and one dimensionally stable anode (DSA ), were evaluated in the oxidation of norfloxacin (NOR) by electrochemical advanced oxidation process (EAOP). The effect of other components in real wastewater on the performance of EAOP was also studied. The anode materials were characterized by cyclic voltammetry, regarding diamond quality, electro-generation of oxidants and NOR oxidation mechanism (direct and/or indirect). The results showed that the anode material influences on the NOR oxidation pathway, due to distinct characteristics of the substrate and the coating. Apparently, low difference in diamond-sp /sp2-carbon ratio (Si/BDD100 × Si/BDD2500) does not leads to significant differences in the EAOP. On the other hand, the variation in the sp /sp2 ratio seems to be higher when Si/BDD2500 and Nb/BDD2500 are compared, which would explain the best current efficiency result for Si substrate. However, the Nb substrate presented a similar current efficiency and a 60% lower energy consumption. Dissolved organic matter (DOM) present in the real wastewater affect the EAOP-Nb/BDD due to HO and persulfate ions scavenged. However, when supporting electrolyte was added to a real wastewater spiked with NOR, the NOR decay reaches similar values found to the synthetic one. Due to the energy saving and mechanical properties, Nb substrate presents some technological advantages in relation to Si, which can facilitate the application to industrial levels.

12728. 题目: Chromium uptake by lettuce as affected by the application of organic matter and Cr(VI)-irrigation water: Implications to the land use and water management
文章编号: N18072113
期刊: Chemosphere
作者: Stavros Raptis, Dionisios Gasparatos, Maria Economou-Eliopoulos, Anastasios Petridis
更新时间: 2018-07-21
摘要: Toxic chromium [(Cr(VI)] in food chain has created an alarming situation for human life and ecosystems. The present study through a greenhouse pot experiment aims to (a) investigate the ability of organic matter in reducing Cr uptake by lettuce (Lactuca sativa L.) from a sandy loam soil irrigating with Cr(VI)-water, (b) to provide a way for the restriction of Cr transfer from contaminated soils and irrigation water to plants/crops and (c) to contribute to the better management of soil (land) and water use, without reduction of the agricultural production. Since soil and groundwater contamination by Cr is a potential risk in a worldwide scale, due to industrial activities and/or natural processes, organic carbon may play a key role in the mobility of added Cr(VI) to soil via irrigation water, in a significant way. The cultivation of lettuce, using organic matter in the form of leonardite (10 and 30 wt%) and Cr(VI)-irrigation water (100, 200 and 300 mgL 1), showed that the uptake of Cr in both shoots and roots increased with increasing concentration of Cr in the irrigation water. The highest Cr values in shoots (average = 10 mg/kg) and in roots (average = 28 mg/kg) were recorded in those plants cultivated in soil after the addition of Cr(VI)- water without organic matter, whereas the lowest Cr values in shoots (average = 0.44 mg/kg) and in roots (average = 0.7 mg/kg) were recorded in those plants cultivated in soil with addition of 30 wt% organic matter. The used leonardite as organic matter that is an oxidized form of lignite, due to its high content of humic acid is considered to be a useful organic fertilizer that provides possibilities for combining food production with soil protection. Therefore, the application of the natural organic material leonardite, as a land management technique, seems to be a cost-effective method consistent to related protocols for the protection of the soil quality.
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12729. 题目: Screening of biological sulfate reduction conditions for sulfidogenesis promotion using a methanogenic granular sludge
文章编号: N18072112
期刊: Chemosphere
作者: M. Mora, J. Lafuente, D. Gabriel
更新时间: 2018-07-21
摘要: Effluents containing great amounts of oxidized sulfur compounds, such as sulfate or sulfite, can be valorized as elemental sulfur from a sequential reduction-oxidation biological process. However, the most important, challenging step to be optimized is the reduction of sulfate. The present study aimed at seeking out the optimal conditions to promote sulfidogenesis instead of methanogenesis using waste carbon sources and a methanogenic granular sludge. Crude glycerol showed better results in terms of the consumed COD/S-Sulfate ratio compared with acetate, cheese whey, pig slurry, and vinasse. Then, the screening of several conditions (T, pH, and COD/S-Sulfate ratio) and the effects of air presence and dissolved sulfide inhibition on sulfate reduction was carried out. Sulfidogenesis was promoted at 35 °C, pH = 8.5, COD/S-Sulfate ratio above 7.0 g O2 g-1 S, microaerophilic conditions, and dissolved sulfide concentrations below 250 mg S2 L-1. These conditions were tested for nearly 3 months in the startup and operation of a 2 L UASB reactor. An inlet sulfate concentration of 220 mg S L-1 and an HRT of 2 h were set. Removal efficiencies of approximately 90% were obtained with less than 20% of organic matter destined for biogas production.

12730. 题目: What is driving the NF-κB response in environmental water extracts?
文章编号: N18072111
期刊: Chemosphere
作者: Peta A. Neale, Frederic D.L. Leusch, Beate I. Escher
更新时间: 2018-07-21
摘要: In vitro bioassays are increasingly applied for water quality monitoring, with assays indicative of adaptive stress responses commonly included in test batteries. The NF-κB assay is responsive to surface water and wastewater extracts, but the causative compounds are unknown and micropollutants typically found in water do not activate the NF-κB assay. The current study aimed to investigate if co-extracted organic matter and/or endotoxins could cause the NF-κB response in surface water extracts. The effect of model bacterial lipopolysaccharides (LPS) and dissolved organic carbon (DOC) was evaluated in the NF-κB assay both before and after solid-phase extraction (SPE), with 7% effect recovery for LPS and between 7 and 52% effect recovery for DOC observed. The NF-κB response, endotoxin activity, micropollutant concentration and total organic carbon concentration was measured in four surface water extracts. All water extracts showed a response in the NF-κB assay, but the detected micropollutants could not explain the effect. Comparison of predicted bioanalytical equivalent concentrations based on micropollutant, DOC and endotoxin concentrations in surface water with experimental bioanalytical equivalent concentrations suggest that co-extracted endotoxins are the most important drivers of the observed effect, with DOC only having a minor contribution. While in vitro bioassays typically detect mixtures of organic micropollutants, the current study shows that the NF-κB assay can integrate the effects of co-extracted endotoxins. Given that endotoxins can pose a risk for human health, the NF-κB assay is a valuable inclusion in bioanalytical test batteries used for water quality monitoring.
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12731. 题目: Influence of electrode placement for mobilising and removing metals during electrodialytic remediation of metals from shooting range soil
文章编号: N18072110
期刊: Chemosphere
作者: Kristine B. Pedersen, Pernille E. Jensen, Lisbeth M. Ottosen, John Barlindhaug
更新时间: 2018-07-21
摘要: Electrodialytic remediation was applied to a shooting range soil to investigate the influence of electrode placement on the removal and binding of metals during the treatment. The set-up was based on a 2-compartment cell, in which the cathode was separated from the soil by a cation exchange membrane and the anode was placed directly in the soil, thereby introducing protons and oxygen directly in the soil. Mobilisation of metals from less available fractions (oxidisable and residual) in the soil occurred, due to oxidation/dissolution of insoluble/soluble organic matter and possibly metal oxides in the residual fraction. The transport via electromigration out of the soil and/or re-precipitation in other fractions of the soil (oxidisable, reducible, exchangeable) depended on the metal. More than 30% of the initial content of Mn, Cd, Cu, Pb and Zn and less than 20% of the initial content of Al, Fe, K, Mg, As, Cr and Ni was transported out of the soil. By decreasing the distance between the electrodes from 3.0 to 1.5 cm, the removal of the targeted metal for remediation, Pb, was improved by more than 200%, from 14 to 31%. A similar removal could be achieved in experiments with long distance between electrodes (3.0 cm) by increasing the current intensity from 4 to 10 mA and/or the remediation time from 7 to 35 d. The experiments showed that the design and optimisation of electrodialytic remediation depends on the targeted metal and metal partitioning.

12732. 题目: Amendment of soil by biochars and activated carbons to reduce chlordecone bioavailability in piglets
文章编号: N18072109
期刊: Chemosphere
作者: M. Delannoy, S. Yehya, D. Techer, A. Razafitianamaharavo, A. Richard, G. Caria, M. Baroudi, E. Montargès-Pelletier, G. Rychen, C. Feidt
更新时间: 2018-07-21
摘要: Chlordecone (Kepone or CLD) is a highly persistent pesticide formerly used in French West Indies. Nowadays high levels of this pesticide are still found in soils which represent a subsequent source of contamination for outdoor-reared animals. In that context, sequestering matrices like biochars or activated carbons (ACs) are believed to efficiently decrease the bioavailability of such compounds when added to contaminated soils. The present study intends to test the respective efficiency of soil amendment strategies using commercial ACs or biochars (obtained by a 500 °C or 700 °C pyrolysis of 4 distinct type of wood). This study involved three experimental steps. The first one characterized specific surface areas of biochars and ACs. The second one assessed CLD-availability of contaminated artificial soils (50 μg g-1 of Dry Matter) amended with 5% of biochar or AC (mass basis). The third one assessed CLD bioavailability of those artificial soils through an in vivo assay. To limit ethically the number of animals, selections of the most promising media were performed between each experimental steps. Forty four castrated male 40-day-old piglets were exposed during 10 day by amended artificial soils according to their group (n = 4). Only treatment groups exposed through amended soil with AC presented a significant decrease of concentrations of CLD in liver and adipose tissue in comparison with the control group (p < 0.001). A non-significant decrease was obtained by amending artificial soil with biochars. This decrease was particularly high for a coconut shell activated carbon were relative bioavailability was found lower than 3.2% for both tissues. This study leads to conclude that AC introduced in CLD contaminated soil should strongly reduce CLD bioavailability.

12733. 题目: Effects of tea plantation age on soil aggregate-associated C- and N-cycling enzyme activities in the hilly areas of Western Sichuan, China
文章编号: N18072108
期刊: CATENA
作者: Shengqiang Wang, Tingxuan Li, Zicheng Zheng
更新时间: 2018-07-21
摘要: Research on the changes of soil carbon (C)- and nitrogen (N)-cycling enzyme activities within aggregate fractions is essential for improving our understanding of soil organic matter (SOM) dynamics in agricultural ecosystems. However, the short- and long-term implications of the conversion of abandoned croplands to tea (Camellia sinensis L.) plantations on enzyme activities associated with aggregate fractions remains poorly understood. In the present study, we hypothesized that (i) the concentrations of soil organic C and total N would increase as the tea plantations continued to age, and (ii) the potential of SOM decomposition would differ with the stage of tea cultivation, as there would be significant changes in the activities of soil C- and N-cycling enzymes over time. The activities of β-glucosidase, invertase, urease, and protease were analyzed in different size fractions of soil aggregates that were collected from 0 to 20 cm depth in four tea plantations with the same cultivar (Sichuan tea) of various ages (16-, 23-, 31-, and 53-years) in the hilly areas of Western Sichuan, China. The aggregates were separated using a dry-sieving procedure into four fractions, namely, large (>2 mm), medium (2–1 mm), small (1–0.25 mm) macro-aggregates, and micro-aggregates (<0.25 mm). In the early stage (in the first 23-years), tea cultivation contributed to a significant increase in organic C and total N stocks in the whole-soil, and these changes were primarily reflected in the increases of such elements stocks in the large macro-aggregates. For example, the increase in organic C stock associated with large macro-aggregates in the early stage accounted for 99.64% of the increase in organic C stock in the whole-soil. In the later stage (after 23-years), however, the increases in organic C and total N stocks in the whole-soil were primarily reflected in the increases of such elements stocks in the small macro-aggregates. Meanwhile, soil C- and N-cycling enzyme activities associated with the large macro-aggregates were significantly increased in the first 23-years of tea cultivation. These results indicated that young tea plantations in the early stage had limitations with respect to the potential for SOM sequestration; however, as the tea plantations matured under the present system of management, the SOM sequestration has improved.

12734. 题目: Ameliorating some quality properties of an erosion-prone soil using biochar produced from dairy wastewater sludge
文章编号: N18072107
期刊: CATENA
作者: Seyed Hamidreza Sadeghi, Mohammad Hossein Ghavimi Panah, Habibollah Younesi, Hossein Kheirfam
更新时间: 2018-07-21
摘要: Land degradation due to decline in soil quality and wastewater pollution is a major challenge for ecosystems sustainability, worldwide. Hence, utilizing adaptable and multi-objective strategies is essential to address environmental challenges. To this end, we produced a biochar from air-dried dairy wastewater sludge (i.e., Kalleh Dairy Company, Iran) through pyrolysis process at 300–350 °C which led to reduction in initial heavy metals contents. The produced biochar was then used to improve the soil quality of a highly degradable soil. Some important nutrients and heavy metals of dairy wastewater and produced biochar were measured by acid digestion/ICP-MS. We then spread two rates of the biochar (400 and 800 g m-2) over the surface of the small-scale boxes (0.5 × 0.5 × 0.5-m) filled by an erosion-prone soil collected from the Chalus Watershed, Northern Iran, and left for 30 days. The carbon (C), nitrogen (N) and organic matter (OM) content, and also carbon/nitrogen (C/N) ratio of treated soil were measured to assess effect of the produced biochar on soil quality improvement. The results showed that some contents of the measured heavy metals (i.e., Pb, Ni, Al, Cr, Mn, Fe and Zn) in the produced biochar significantly (p < 0.01) reduced compared to those of the raw dairy wastewater. Additionally, application of two dosages of 400 and 800 g m-2 of biochar to the study soil increased C, N, OM and C/N of the soil at tunes of 2.67–5.5; 2–3 and 2.67–5.5 times, and 22–61%, respectively, in comparison with untreated soils (control). By and large, converting the wastewater as an environmental pollution source to biochar and using it as an eco-friendly soil amendment is a multi-objective and adaptive approach for the ecosystem management.
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12735. 题目: Effect of vegetation type and season on microbial biomass carbon in Central Himalayan forest soils, India
文章编号: N18072106
期刊: CATENA
作者: Kiran Bargali, Vijyeta Manral, Kirtika Padalia, S.S. Bargali, V.P. Upadhyay
更新时间: 2018-07-21
摘要: Soil microbial biomass is an important component of soil organic matter constituting from 2 to 5% of the soil organic carbon and play a significant role in the cycling of nutrients and overall organic matter dynamics. The present study assessed the effects of three forest types (Banj-oak forest, Chir-pine forest and Mixed oak-pine forest) on the soil physico-chemical properties and microbial biomass Carbon in Central Himalaya, India. The soil microbial biomass carbon was determined by chloroform fumigation extraction method. In the 2 year of study period, the soil microbial biomass carbon (Cmic) was significantly higher in Mixed oak-pine forest (681 ± 1.81–763 ± 1.82 μg g-1) than in the Banj-oak (518 ± 1.50–576 ± 1.73 μg g-1) and Chir-pine forest (418 ± 1.42–507 ± 2.05 μg g-1). Though insignificant, all the forest types showed distinct seasonal variations in microbial biomass carbon with a minimum value in winter season and maximum value in rainy season. The soil microbial quotients (Cmic to Corg) were higher in Chir-pine (2.52–4.18) and Banj-oak forest (2.26–4.02) than those reported in Mixed oak-pine forest (1.44–2.24). These results indicate that Mixed oak-pine forest is better in sustaining the soil microbial biomass and soil nutrients than Banj-oak and Chir-pine forest. It recommends that nutrients rich Mixed oak-pine forest should be preferred as a forest management practice to promote microbial diversity, their activities and soil quality enhancement in Central Himalayan forests.

12736. 题目: Factors that influence soil total phosphorus sources on dam fields that are part of ecological construction programs on the Loess Plateau, China
文章编号: N18072105
期刊: CATENA
作者: Yuting Cheng, Peng Li, Guoce Xu, Zhanbin Li, Kunxia Yu, Shengdong Cheng, Binhua Zhao, Feichao Wang
更新时间: 2018-07-21
摘要: Terraces and check-dam construction are widely used to control soil and water on the Loess Plateau, China. However, it is not known whether dam fields behave as soil phosphorus sources or sinks. This study quantitatively assessed the effects of check-dam and terrace construction on soil total phosphorus (STP). It also investigated the factors that influenced STP. A total of 1010 soil samples (five land uses and five soil depths) were collected in a small watershed on the Loess Plateau. The probability density function of the Weibull distribution was used to analyze the STP sources on the dam field land. The results showed that the highest STP concentration was recorded in the dam field land. Furthermore, the STP concentration mean values for the five land-use types decreased in the following order: dam field > terraced land > grassland > forestland > sloping cropland. The highest clay content value was also recorded in the dam field land. Soil total phosphorus was significantly and positively correlated to soil organic carbon (SOC), but negatively correlated to sand content (P < 0.01) in all areas. Across the entire soil profile down to 60 cm depth, the STP levels for the five land-uses were dam field, 2.78 kg/m2; terrace, 2.86 kg/m2; grassland, 2.98 kg/m2; forestland, 2.84 kg/m2; and sloping cropland, 2.83 kg/m2. The percentage contributions made by the four land use types to the soil total phosphorus deposited in the dam field were 50% (sloping cropland), 33% (grassland) and 17% (forestland). Therefore, check dam constructions behave as a sink for soil phosphorus on the Loess Plateau, China.

12737. 题目: Soil carbon sequestration potential as affected by soil physical and climatic factors under different land uses in a semiarid region
文章编号: N18072104
期刊: CATENA
作者: Elham Alidoust, Majid Afyuni, Mohammad Ali Hajabbasi, Mohammad Reza Mosaddeghi
更新时间: 2018-07-21
摘要: Carbon (C) sequestration in soil is recognized as a possible solution for climate change mitigation. Different land uses may alter carbon sequestration in soil. In the semiarid regions of central Iran, during the last decades, land use changes from native cover to farmlands have altered the C sink role of soil to a source of CO2 emission to the atmosphere. This study was conducted to evaluate and compare changes and the potential of soil organic carbon (SOC) sequestration from 1988 to 2014, under different land uses, in western central Iran (Lordegan). The land uses included pasture, forest, rain-fed, and irrigated farmlands. Soil (450 samples) from 50 points across the study basin (390 km2) was collected in three depth increments (0–5, 5–15 and 15–30 cm) during three sampling times (June and November 2014, and June 2015). Mean SOC concentrations in the pasture, forest, rain-fed and irrigated farmlands were 10.3, 20.2, 9.2 and 10.1 g kg-1, respectively. The SOC concentration in the forest soil was significantly greater than the other land uses, and any reduction in forestland area would lead to the SOC stock decline. About 1390 Gg organic carbon was found to be stored in the top 0–30 cm depth of the study area. Comparing land use maps between 1988 and 2014 indicated an alteration in the relative contribution of each land use across the study area leading to SOC stock reduction by 100 Gg carbon during this period. The results showed that all studied soils comprised non-complexed clay, suggesting a considerable potential capacity for sequestering carbon. The results also indicated that the SOC controlling factors varied considerably among different land uses and soil depths. Mean weight diameter of aggregates (MWD), bulk density, clay and sand content, and altitude were identified as the important controlling variables by the stepwise multiple linear regression analysis.

12738. 题目: Soil surface quality assessment in rangeland ecosystems with different protection levels, central Iran
文章编号: N18072103
期刊: CATENA
作者: Azita Molaeinasab, Hossein Bashari, Mostafa Tarkesh Esfahani, Mohammad Reza Mosaddeghi
更新时间: 2018-07-21
摘要: This study aimed to evaluate the application of landscape function analysis (LFA) and some soil quality indicators for the assessment of the structure and function of Steppe rangelands in arid regions of Ghamishloo National Park, Isfahan, central Iran. Three zones with different protection levels/grazing intensities, including a national park with wild herbivores, a peripheral protected area where both livestock and wild herbivores were present, and an adjacent grazing-free area where wild herbivores were absent, were selected. Eleven soil surface indicators were assessed to measure soil stability, infiltration, and nutrient cycling indices in various zones. Eighty-seven soil samples were collected in the study area and their characteristics, including pH, electrical conductivity (EC), total nitrogen, phosphate, soil organic carbon (SOC), particulate organic matter (POM), microbial respiration, and mean weight diameter (MWD), were measured. The results showed that although structural attributes (patch area index and landscape organization index) and LFA functional attributes varied significantly between the sites with various management histories (P < 0.05), these attributes along with total patch area and number of patches per 10 m did not have significant differences between the protected and grazing-free area. Most soil quality indicators were also significantly different between the national park and grazing-free area, but MWD, SOC, and POM were not significantly different between the protected and grazing-free areas (P < 0.05). High protection level (i.e. lower grazing impact) led to more soil stability and higher proportion of macro-aggregates in the national park area compared to other areas. The methods used in this study are applicable for exploring the role of national parks in maintaining the structure and function of ecosystems in similar ecoregions.

12739. 题目: Three years of management with cover crops protecting sloping olive groves soils, carbon and water effects on gypsiferous soil
文章编号: N18072102
期刊: CATENA
作者: Blanca Sastre, Maria Jose Marques, Andrés García-Díaz, Ramón Bienes
更新时间: 2018-07-21
摘要: Soils of olive grove are usually managed by tillage, leading to organic matter depletion and soil structure degradation. Cover crops to protect soils have been revealed as a sustainable land management practice for erosion control and remediation of degraded soils, but in some cases, water competition can be a problem, all these effects (particularly soil water) are site and climate specific. A trial in a rainfed olive grove in gypsiferous soils under semiarid Mediterranean climatic conditions has been set up in Central Spain. Several parameters (plant cover, root density, organic carbon, organic nitrogen, aggregate stability, porosity, infiltration, water storage and soil penetration resistance) have been studied under different management practices: three types of cover crops, two annuals (legume and barley) and one permanent (Brachypodium distachyon); and minimum tillage. After three years of treatments, slight improvements in particulate organic carbon, aggregate stability, microporosity at 0–5 cm depth and soil water storage at 30 cm were found in cover crops; B. distachyon also increased organic carbon, and improved C/N ratio and available water. >3 years of a sustainable land management are needed to recover olive groves soil quality in gypsiferous soils under semiarid climate. In this study, cover crops facilitated carbon stratification, higher SOC content in deeper layers are important in the context of carbon sequestration.
图文摘要:

12740. 题目: Sorption of tetracycline on H3PO4 modified biochar derived from rice straw and swine manure
文章编号: N18072101
期刊: Bioresource Technology
作者: Tingwei Chen, Ling Luo, Shihuai Deng, Guozhong Shi, Shirong Zhang, Yanzong Zhang, Ouping Deng, Lilin Wang, Jing Zhang, Luoyu Wei
更新时间: 2018-07-21
摘要: Currently, the information about the sorption of tetracycline (TC) on animal manure derived biochar was rare although plant residue derived biochar showed high sorption of TC). Therefore, this study explored the sorption of TC on swine manure derived biochar, and compared with rice straw derived biochar simultaneously. Also, H3PO4 was adopted to modify both types of biochar. The sorption kinetic and isotherm data showed H3PO4 modification enhanced the sorption of TC on both types of biochar (especially swine-manure-biochar), and indicated the chemisorptions including H-bonding and π-π electron donor acceptor interaction might be the primary mechanism. Moreover, the strengthened electrostatic attraction between TC and biochars might largely explain the enhanced sorption capacity of TC along with pH increasing from 5.0 to 9.0. At the same conditions, swine manure derived biochar demonstrated lower sorption capacity of TC than rice straw biochar, but still could be good material for the sorption of TC.

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