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24181. 题目: Assessing the role of native herbaceous legumes in the nitrogen cycle of regularly burned loblolly pine forests
文章编号: N19021708
期刊: Forest Ecology and Management
作者: Joseph J. Hendricks, J. Blake Holland, John S. Hubbartt
更新时间: 2019-02-17
摘要: Prescribed burning is one of the most commonly used management practices in pine (Pinus spp.) forests of the southeastern United States. There is concern, however, that burning may lead to excessive losses of nitrogen (N), thereby decreasing forest productivity. The N losses due to burning may be potentially countered via symbiotic N₂-fixation by native and naturalized herbaceous legumes that may thrive in burned forests. However, the rates and controls of N input via legume N₂-fixation in these ecosystems are poorly understood. The objectives of this study were to measure legume abundance, biomass, N₂-fixation, substrate quality, and associated environmental controls in regularly burned loblolly pine (P. taeda) forests. The study sites were located in four management blocks at the Piedmont National Wildlife Refuge. This assessment revealed a total of 23 legume species in 9 genera. Legume abundance averaged 12.95 ± 2.30 individuals m⁻², and collectively Centrosema virginianum, Chamaecrista nictitans, Desmodium marilandicum, Galactia volubilis, and Lespedeza procumbens constituted 70.8% of the total legume abundance. Legumes comprised 17.1% of the understory aboveground biomass, and legume foliage, stem, and total (foliage + stem) biomass estimates averaged 15.38 ± 3.18, 20.88 ± 4.01, 36.26 ± 6.95 g m⁻², respectively. Legume foliar N concentration averaged 2.22 ± 0.06% (ranging from 1.42−2.83%), and all legume foliar N concentrations were significantly higher than the average foliar values for blackberry (Rubus spp., 1.10 ± 0.05%) and the aggregate of non-leguminous forbs (1.03 ± 0.08%) that grew concurrently with the legumes in the study sites. N₂-fixation assessments, based on the differential between legume and non-N₂-fixing reference plant foliar N concentrations, indicated that approximately 50% of legume N was derived from the atmosphere. Legume foliage tissues exhibited relatively high substrate quality indices such as high N concentrations, low lignin concentrations (average of 14.3 ± 1.9%), and correspondingly low lignin:N ratios (average of 6.7 ± 0.9) indicative of tissues that exhibit rapid mass loss and N mineralization rates during decomposition. Canopy openness was the environmental variable that was most strongly correlated with foliar N and areal biomass among the dominant legume species. The estimated N input of 0.14 g m⁻² yr⁻¹ via N₂-fixation may compensate for N losses due to relatively low intensity and infrequent understory burns during a stand rotation. Additional studies are needed to more comprehensively assess legume N₂-fixation inputs, associated environmental constraints, and practical field applications which may increase N input via symbiotic N₂-fixation in regularly burned pine forest ecosystems.
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24182. 题目: Comparison of organic compounds in char and soot from the combustion of biomass in boilers of various emission classes
文章编号: N19021707
期刊: Journal of Environmental Management
作者: Jana Růžičková, Marek Kucbel, Helena Raclavská, Barbora Švédová, Konstantin Raclavský, Dagmar Juchelková
更新时间: 2019-02-17
摘要: The combustion of biomass in boilers of emission classes 2 and 3 produces deposits in the form of char and soot inside the combustion chamber. Char and soot differ in content of elemental carbon (EC) and organic carbon (OC) as well as in the content of organic compounds. Deposits from boilers of emission class 2 contain higher amounts of OC and EC than those from boilers of emission class 3. The only exception is deposits formed by the combustion of briquettes from hardwood in boilers of emission class 3 that contained approximately by up to 60 percent higher amount of OC and by approx. 100% more EC than deposits from combustion in boilers of emission class 2. Deposits identified as char are characterized by dominant organic compounds derived from thermic degradation of cellulose, lignin, phytosterols, terpenes, their alteration products, and aromatic hydrocarbons. Deposits identified as soot have dominant PAHs, compounds containing oxygen (furans, benzofurans, phenols) and compounds containing aliphatic nitrogen (benzonitrile). Char from boilers of emission class 2 contains approx. by 80% more alkanes and cycloalkanes, by 80% more nitriles, by 50% more carboxyl acids, by 230% more anhydrosaccharides, phytosterols and by 180% more PAHs. These differences can be utilized for identification of burned fuel.

24183. 题目: Influence of edaphic conditions and nitrogen fertilizers on cadmium and zinc phytoextraction efficiency of Noccaea caerulescens
文章编号: N19021706
期刊: Science of The Total Environment
作者: Arnaud Jacobs, Nausicaa Noret, Alexandre Van Baekel, Amandine Liénard, Gilles Colinet, Thomas Drouet
更新时间: 2019-02-17
摘要: The success of cadmium phytoextraction operations with Noccaea caerulescens varies by a factor of 70 between sites of trials. However, soil factors driving the efficiency of cadmium (Cd) and zinc (Zn) phytoextraction are still poorly understood, as are the effects of nitrogen fertilizers. We studied biomass production and Cd and Zn uptake by two contrasting populations of N. caerulescens, Ganges (metallicolous) and Wilwerwiltz (non-metallicolous) grown in pots on a range of 24 field contaminated soils for 20 weeks. The addition of KNO₃ and NH₄NO₃ fertilizers was also tested. Using model averaging of multiple regression models, we show that the major drivers of N. caerulescens growth are physical soil factors such as organic matter and soil bulk density while trace metal accumulation mainly relies on soil Cd and Zn exchangeable concentrations. We confirm the negative effect of soil copper (Cu) on growth, even at exchangeable concentrations below 30 mg kg⁻¹, and therefore on uptake efficiency, while increasing soil lead (Pb) content was related to increased biomass probably due to a protective effect against soil pathogens. Finally, there is a small positive effect of nitrogen fertilization on biomass production only in soils with low initial nitrogen content (under 25 μg g⁻¹ NO₃⁻), while above this value, the positive impact of initial nitrogen content is offset by lower shoot Cd and Zn concentrations. Our data bring substantial information regarding the physico-chemical properties to ensure N. caerulescens growth: a soil bulk density under 1.05 kg/dm³, organic matter above 7% and pH under 7.5. We show that phytoextraction efficiency is maximal for moderate soil contamination in Cd (2–10 mg kg⁻¹) and Zn (300–1000 mg kg⁻¹).
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24184. 题目: Steaming combined with biochar application eliminates negative plant-soil feedback for sanqi cultivation
文章编号: N19021705
期刊: Soil and Tillage Research
作者: Min Yang, Ye Yuan, Huichuan Huang, Chen Ye, Cunwu Guo, Yanguo Xu, Wenpeng Wang, Xiahong He, Yixiang Liu, Shusheng Zhu
更新时间: 2019-02-17
摘要: Eliminating negative plant-soil feedback (NPSF) in agricultural production systems is the key step in maintaining soil health and sustainable crop production. Sanqi (Panax notoginseng) has been severely hampered by NPSF due to the build-up of soilborne pathogens and the accumulation of autotoxic ginsenosides. Steaming on soil followed by adding biochar was investigated. Greenhouse experiments demonstrated that consecutively cultivated soil treated with steaming (90 °C for 15 min) significantly increased seed germination rates and seedling survival rates of sanqi, but biochar amendment had no effects. The combination of steaming with biochar amendments (8 g L⁻¹) was more effective on seed germination and seedling survival rates as well as increasing the biomass of sanqi than applying steaming alone. Steaming slightly degraded the content of autotoxic ginsenosides in the soil and completely eliminated the population of soilborne pathogens, including Ilyonectria spp. and Fusarium spp., in consecutively cultivated soil, and enhanced the release of nutritive substances into soil. Biochar showed a high adsorption capacity for autotoxic ginsenosides, and increased nutrient supplementation. Steaming plus biochar could effectively eliminate the negative effects of soilborne pathogens and autotoxicants to P. notoginseng. Four years of field studies further confirmed that consecutively cultivated soil could be successfully replanted after steaming plus biochar application. Thus, steaming plus biochar amendment was a promising practice for enhancing soil quality and health.
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24185. 题目: Slurry acidification and anaerobic digestion affects the speciation and vertical movement of particulate and nanoparticulate phosphorus in soil after cattle slurry application
文章编号: N19021704
期刊: Soil and Tillage Research
作者: Yuhong Li, David L. Jones, Qing Chen, David R. Chadwick
更新时间: 2019-02-17
摘要: Livestock slurry contains a large amount of particulate organic matter. When applied to soil these particles can act as carriers transporting phosphorus (P) through and over soils to watercourses. Little is known, however, about how slurry treatment (e.g. acidification and anaerobic digestion) may affect slurry particle size distribution and P forms within the particulate fraction. To characterize the small slurry particles, we separated untreated, acidified and anaerobically digested cattle slurry into 0.45–63 μm, <0.45 μm, <100 kDa and <3 kDa fractions and determined their P speciation. To understand the role of slurry particles on P leaching/translocation in soil, we applied the <63 μm, <0.45 μm and <100 kDa fractions of untreated and processed slurries to the surface of an unplanted agricultural, sand-textured soil in laboratory microcosms and studied P movement under a simulated rainfall regime. Results showed that the 0.45–63 μm particulate fraction accounted for >60% of total P content of the untreated and anaerobically digested cattle slurries. Acidification reduced the total P quantity of the 0.45–63 μm fraction by 26% through dissolution and desorption, resulting in a greater P in the <0.45 μm fraction. Anaerobic digestion increased the total P content of the 0.45–63 μm fraction, as the decomposition and breakdown of coarser particles transferred more P to this fraction. After application to soil, 3.3% of the added inorganic P and 1.7% of the added organic P was found in the leachate in the untreated <63 μm treatment. The 0.45–63 μm particulate fraction largely contributed to this P leaching, while the nanoparticulate fraction (3 kDa-0.45 μm) contained little P and had no appreciable effect on P leaching. Overall, acidification had no impact on P leaching. In contrast, anaerobic digestion increased inorganic P leaching by 67% and organic P leaching by 127%. In conclusion, our findings highlight the importance of the 0.45–63 μm fraction in P transport through soil, and the enhanced bioavailability and mobility of P following anaerobic digestion. These need greater consideration in future studies promoting the sustainable use of livestock waste and P recovery technologies.

24186. 题目: Rehabilitation of a highly saline-sodic soil using a rubble barrier and organic amendments
文章编号: N19021703
期刊: Soil and Tillage Research
作者: Elizabeth Chávez-García, Christina Siebe
更新时间: 2019-02-17
摘要: The application of biochar and compost is a promising alternative to recover salt-degraded soils. However, in areas where the main source of salinity comes from the groundwater, it is also necessary to restrict the capillary rise of salts by means of a barrier. In this study, we show results of a field experiment, in which we tested the effect of a rubble barrier and the addition of biochar and compost on the establishment of a salt-tolerant grass (Distichlis spicata) in a highly saline-sodic soil. Our results showed that the capillary barrier: i) diminished the electrical conductivity and the CO₂ fluxes by about one third to one half the values without barrier for both variables, ii) decreased the topsoil moisture (without barrier ca. 25–35%; barrier-zone ca. 15–25%), and iii) promoted the plant growth. Organic amendments did not show any effect. However, high-dose treatments had lower moisture content than the unamended ones (ca. 3–6% less water). Arrival of new plant species occurred preferably in the barrier-zone. We conclude that the barrier is an effective tool to decrease the soil salinity, but irrigation is needed to overcome smaller soil moisture during the dry season. Pyrochar was the most recommendable amendment to be used. However, biochar and compost doses were insufficient for the rehabilitation of this highly saline-sodic soil. The natural emergence of plant species (Suaeda torreyana, Kochia scoparia and Sonchus oleraceus) can improve the rehabilitation activities in an effective and inexpensive way. Urban residues can effectively be used to establish a plant cover in saline-sodic soils.
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24187. 题目: Stimulation of anaerobic biofilm development in the presence of low concentrations of toxic aromatic pollutants
文章编号: N19021702
期刊: Bioresource Technology
作者: Qian Hu, Na Zhou, Eldon R. Rene, Dexiu Wu, Dezhi Sun, Bin Qiu
更新时间: 2019-02-17
摘要: The main aim of this work was to stimulate biofilm formation in the presence of wastewater containing aromatic compounds with different toxicities (EC₅₀). The results indicated that wastewater with an EC₅₀ value > 85% accelerates the attachment of bacteria onto the bio-carriers because the toxic wastewater stimulates the production of extracellular polymeric substances (EPS) from the seed sludge. In order to understand the role of EPS on biofilm development, experiments were conducted using the seed sludge, from which the soluble, loosely bound, and tightly bound EPS were removed. The soluble EPS fraction was determined to be crucial for biofilm development. Firmicutes bacterium and Clostridium chromoreductans survived and were enriched in the formed biofilms in our study, which can resist toxic aromatics.
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24188. 题目: Degradation of 4-nonylphenol in marine sediments by persulfate over magnetically modified biochars
文章编号: N19021701
期刊: Bioresource Technology
作者: Cheng-Di Dong, Chiu-Wen Chen, Mei-Ling Tsai, Jih-Hsing Chang, Syue-Yu Lyu, Chang-Mao Hung
更新时间: 2019-02-17
摘要: In this study, an environmentally friendly and economically viable bamboo biochar (BB) was modified by Fe₃O₄ and was applied for the treatment of real river sediments containing the endocrine disruptor chemical (EDC) 4-nonylphenol (4-NP). The microporosity of Fe₃O₄−BB was clearly observed from the N₂ adsorption isotherms. The catalytic performance of Fe₃O₄−BB is highly dependent on pH and the catalyst dosage. The degradation efficiency of 4-NP (85%) was achieved at pH 3.0 using an initial dosage of 3.33 g L^-1 Fe₃O₄−BB and 2.3×10^-5 M persulfate (PS) in a biochar−sediment system. The kinetic behavior of 4-NP degradation with catalysis can be accounted by using the Langmuir-Hinshelwood type kinetic model. The MTT assay results indicated that Fe₃O₄−BB has a low potent cytotoxic effect and is therefore suitable for application in remediation of contaminated sediment.
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24189. 题目: Streambed Organic Matter Controls on Carbon Dioxide and Methane Emissions from Streams
文章编号: N19021617
期刊: Environmental Science & Technology
作者: Paul Romeijn, Sophie A Comer-Warner, Sami Ullah, David M. Hannah, Stefan Krause
更新时间: 2019-02-16
摘要: Greenhouse gas (GHG) emissions of carbon dioxide (CO₂) and methane (CH₄) from streambeds are currently understudied. There is a paucity of research exploring organic matter (OM) controls on GHG production by microbial metabolic activity in streambeds, which is a major knowledge gap given the increased inputs of allochthonous carbon to streams, especially in agricultural catchments. This study aims to contribute to closing this knowledge gap by quantifying how contrasting OM contents in different sediments affect streambed GHG production and associated microbial metabolic activity. We demonstrate, by means of an incubation experiment, that streambed sediments have the potential to produce substantial amounts of GHG, controlled by sediment OM quantity and quality. We observed streambed CO₂ production rates that can account for 35% of total stream evasion estimated in previous studies, ranging between 1.4 and 86% under optimal conditions. Methane production varied stronger than CO₂ between different geologic backgrounds, suggesting OM quality controls between streambed sediments. Moreover, our results indicate that streambed sediments may produce much more CO₂ than quantified to date, depending on the quantity and quality of the organic matter, which has direct implications for global estimates of C fluxes in stream ecosystems.

24190. 题目: The effect of understory on cation binding reactions and aluminium behaviour in acidic soils under spruce forest stands (Southern Poland)
文章编号: N19021616
期刊: Biogeochemistry
作者: Krystyna Ciarkowska, Anna Miechówka
更新时间: 2019-02-16
摘要: Acidic forest soils with two dominant understories, bilberry (Vaccinium myrtillus L.) or alpine lady fern (Athyrium distentifolium Tausch ex Opiz), have been investigated to evaluate the influence of the understory on sorption properties and aluminium behaviour. We investigated acidity, cation exchange properties, organic matter content (SOM) and quality as well as Al bonding to organic matter in humus horizons of soils taken from two different locations. SOM was the major contributor to total cation exchange capacity (CEC_t) and effective cation exchange capacity (CEC_e), and a strong relationship was found between SOM and both CEC_t and CEC_e, independently of the understory and location. SOM differed in quality, having more fulvic acids in soils under bilberry than in soils under alpine lady fern. For that reason, SOM in soils under bilberry complexed more Al in the exchangeable form in the soluble fulvic acid fraction such that they could be easily washed out, while in soils under alpine lady fern aluminium was mainly bound more stably. We also found that the chemical character of Al depended on the understory type. In soils under bilberry the relation between base saturation and pH could be successfully modelled by a modified Henderson–Hasselbalch equation when Al was considered as a base cation, which is typical for forest podzols. However, in soils under alpine lady fern, this model was efficient only when Al was treated as an acid cation. We concluded that alpine lady fern as the main understory species reduces solubility and potential toxicity of aluminium, thus significantly affecting soil biogeochemistry.

24191. 题目: Anthropogenic nitrogen deposition increases soil carbon by enhancing new carbon of the soil aggregate formation
文章编号: N19021615
期刊: Journal of Geophysical Research: Biogeosciences
作者: Ruiying Chang, Wenjun Zhou, Yunting Fang, Haijian Bing, Xiangyang Sun, Genxu Wang
更新时间: 2019-02-16
摘要: Anthropogenic nitrogen (N) deposition can most likely increase temperate forest soil organic carbon (SOC) storage. Increased SOC is usually suggested to be associated with the suppression of SOC decomposition, which has been hypothesized to be due to the decrease in the activity of lignin‐degrading extracellular enzymes and/or the decrease in soil acidity under N‐addition. However, the potential mechanism of SOC protection derived from N‐addition is less understood. Here, in a low‐deposition temperate montane forest, short‐term N‐addition could increase SOC storage in the aggregate fraction but not in the bulk soil. N‐induced SOC accumulation was partly associated with the suppressed SOC decomposition (indicated by lower soil respiration) that resulted from the reduced microbial biomass rather than from decreased lignin‐degrading enzyme activity or from reduced soil acidity. In addition, N‐addition promoted soil aggregate formation, which could partly suppress SOC decomposition by protecting new carbon that originated from plant litter residue to a greater degree, while dissolved organic carbon retention in the mineral soils played a limited role in the SOC sequestration derived from N‐addition, at least in the short term. A conceptual model was proposed and highlighted a new underlying mechanism of new carbon protection by enhanced aggregate formation, other than the role of microbial suppression, to explain the positive effect of anthropogenic N deposition on forest SOC.

24192. 题目: Biochar mediates activation of aged nanoscale ZVI by Shewanella putrefaciens CN32 to enhance the degradation of Pentachlorophenol
文章编号: N19021614
期刊: Chemical Engineering Journal
作者: Hui Li, Shuai Chen, Lu Yao Ren, Li Yang Zhou, Xue Jun Tan, Yu Zhu, Carolina Belver, Jorge Bedia, Jie Yang
更新时间: 2019-02-16
摘要: The bioreduction of aged nanoscale zero valent iron (NZVI) by Shewanella putrefaciens CN32 (CN32) in the presence of different biochar materials was conducted to understand how biochars mediated the activation of aged NZVI to enhance the removal efficiency of contaminants. The results indicated that the prepared biochars contained different oxygen-containing functional groups (such as -O-C=O, -COOH, C=O, C-O, C-C, C-H and C=C). The biochars significantly enhance electron transfer from CN32 to aged NZVI, thus accelerating reductive dechlorination of Pentachlorophenol (PCP). The maximum PCP degradation rate (k_max) was 2.45 mg·L⁻¹·d⁻¹, which was 2.6 times greater than that of the biochar-free control (0.94 mg·L⁻¹·d⁻¹). The intermediates of phenol were detected after 30 days, likely indicating that reductive dechlorination was the dechlorination pathway of PCP. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis showed that vivianite, as a secondary mineral, was formed during the bioreduction aged NZVI-BC600 (Biochar prepared at 600°C with NZVI activation) by CN32. Vivianite was formed mainly through the reaction of Fe(II) and PO₄^3-. The combined electrochemical and electron paramagnetic resonance analysis might suggest that biochar associated semiquinone radical (C=O) were likely involved in the bioreduction of aged NZVI. This study provided some theoretical support for further research on biochar mediated bioreduction activation of aged NZVI to enhance the degradation of contaminants.
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24193. 题目: Adsorptive and reductive removal of U(VI) by Dictyophora indusiate-derived biochar supported sulfide NZVI from wastewater
文章编号: N19021613
期刊: Chemical Engineering Journal
作者: Hongwei Pang, Zhuofan Diao, Xiangxue Wang, Yan Ma, Shujun Yu, Hongtao Zhu, Zhongshan Chen, Baowei Hu, Jianrong Chen, Xiangke Wang
更新时间: 2019-02-16
摘要: Nanoscale zero-valent iron (NZVI) has been considered as a potential scavenger for U(VI) elimination from aqueous environment. To decrease the aggregation and to improve antioxidation, sulfidation technology and biochar were applied to modify NZVI. In this work, Dictyophora indusiate-derived biochar supported sulfide NZVI (DI-SNZVI) was synthesized and applied for U(VI) elimination. The excellent behaviors of kinetics (3 h for equilibrium), thermodynamic research and maximum removal amounts (427.9 mg·g^-1 at pH = 5.0 and 298 K) revealed the outstanding performances of DI-SNZVI in U(VI) removal. The cycle experiments and different water system investigations further illustrated its potential ability for real applications. Moreover, the abundant functional groups and FeS_x shell of DI-SNZVI were proved to be responsible for the enhanced removal of U(VI). In the end, the macroscopic and XPS study revealed that U(VI) elimination mechanisms were synergistic attributed to the adsorptive and reductive processes. This paper highlighted the biochar-based sulfide NZVI for efficient U(VI) elimination in environmental pollution management.
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24194. 题目: Effects of biochar and zeolite soil amendments with foliar proline spray on nickel immobilization, nutritional quality and nickel concentrations in wheat
文章编号: N19021612
期刊: Ecotoxicology and Environmental Safety
作者: Ali Khan Shahbaz, Pia Muhammad Adnan Ramzani, Rashid Saeed, Veysel Turan, Muhammad Iqbal, Karolina Lewińska, Farhat Abbas, Muhammad Saqib, Hafiz Muhammad Tauqeer, Mutahar Iqbal, Maryam Fatima, Mahmood-ur Rahman
更新时间: 2019-02-16
摘要: Since Ni-rich soils are a threat to the environment, growing edible crops on Ni-rich soils can pose a serious risk to human, animal, plant and ecosystem health and, hence, is considered as a challenging task for the researchers. Contrarily, limiting the bioavailability of Ni in such soils upon the addition of suitable amendments cum foliar spray of proteinogenic amino acids having an objective to alleviate stress to crop plants can considerably reduce the environmental risk. In this pot trail, we substantiate the effects of biochar (BR) and zeolite (ZL) addition in the soil along with proline (PN) spray on the resistance, and stress responses of wheat against Ni as well as on Ni translocation and accumulation in wheat plants grown on a Ni-rich soil contaminated by electroplating effluent. The treatments, applied with and without PN spray, involved: no amendment; BR; ZL; and a concoction of both amendments (BR50%+ZL50%). We found that BR50%+ZL50% treatment significantly immobilized Ni in the soil, reduced its accumulation in the shoot, root, and grain, blocked membrane lipid peroxidation and showed an improvement in photosynthetic parameters, the status of antioxidant activities, grain biochemistry and grain yield, compared to the control. Interestingly, exogenous PN spray caused a significant additive effect on the aforementioned parameters in the wheat plants grown on BR50%+ZL50% treated soil. Our results involved a reduced Ni bioavailability in wheat rhizosphere due to BR50%+ZL50% in soil and, furthermore, the additive effect of PN spray to scavenging ROS, obstructing peroxidation of lipid membrane and, thus providing resilience to wheat plant against Ni stress. The suggested technique can make Ni-rich soils suitable for cultivation and production of high-quality food by minimizing Ni bioavailability and toxicity to plants.

24195. 题目: Mapping soil organic matter contents at field level with Cubist, Random Forest and kriging
文章编号: N19021611
期刊: Geoderma
作者: Nastaran Pouladi, Anders Bjørn Møller, Salman Tabatabai, Mogens H. Greve
更新时间: 2019-02-16
摘要: The soil organic matter (SOM) content is strongly related to soil fertility and greenhouse gas emissions. Knowledge of the soil SOM content is therefore necessary for efficient and sustainable management practices. In this study, we compare the performance of five machine learning techniques for the prediction of SOM contents using remote sensing, proximal soil sensors and topographic data as environmental predictor. The methods used were kriging, Cubist, Random Forest and regression-kriging (Cubist- kriging and Random Forest kriging). 285 soil samples were collected from a 10 ha field in Denmark. 75% of the data were used for training and 25% for validation. NDVI (Normalized Difference Vegetation Index), RVI (Ratio Vegetation Index), DVI (Difference Vegetation Index) and SAVI (Soil-Adjusted Vegetation Index) were derived from Sentinel 2 images with 10 m resolution as auxiliary variables. Topographic variables were derived from a digital elevation model (DEM) with 1.6 m resolution. The performance of the methods was compared based on the coefficient of determination (R²) and root mean square error (RMSE). The results showed that kriging achieved the best performance, followed by regression-kriging. The models using only Cubist and Random forest had the poorest performance. The results, therefore, demonstrate that kriging can predict SOM contents without the need of auxiliary variables for fields with high sampling densities.

24196. 题目: How relationships between soil organic matter parameters and soil structure characteristics are affected by the long-term fertilization of a sandy soil
文章编号: N19021610
期刊: Geoderma
作者: Vladimír Šimanský, Martin Juriga, Jerzy Jonczak, Łukasz Uzarowicz, Wojciech Stępień
更新时间: 2019-02-16
摘要: Refining our understanding of how soil structure develops is important because soil structure has a major influence on plant growth. Recent studies show positive correlations between soil organic matter and soil structure. However, the question remains: how are the relationships between soil organic matter (SOM) parameters and soil structure characteristics affected by the long-term fertilization of a sandy soil In contrast to most other studies on SOM vs. soil structure, the present study is composed of long-term field experiments (a total of 3 experiments) with durations of 25, 41 and 94 years. In this paper, the impact of the long-term application of mineral fertilizers and manure on the SOM and soil structure of a sandy soil is quantified, and the relationships between the SOM and soil structure of a sandy soil with a dependence on the length of fertilizer application are determined. Soil samples were collected from all three long-term field experiments in central Poland, which were located at Skierniewice experimental station including a 94-year-old experiment with mineral fertilization, a 41-year-old experiment with mineral fertilization and a 25-year-old experiment with mineral fertilization + farmyard manure (FYM) in a 4-year cycle. In the spring of 2017, soil samples were collected (Co – no fertilizers, NPK – NPK fertilizers, CaNPK – CaNPK fertilizers). In the 94-year-old experiment, the content of soil organic carbon (SOC) in Co, NPK and CaNPK was 4.07, 5.89 and 5.99 g kg⁻¹, respectively. An increase in the SOC content under fertilization was also found in the other two experiments. In the 25-year-old experiment, the SOC contents in FYM, FYM + NPK and FYM + CaNPK were 6.07, 8.36 and 7.63 g kg⁻¹, respectively, and in the 41-year-old experiment, the SOC contents in Co, NPK and CaNPK were 6.38, 10.1 and 7.80 g kg⁻¹, respectively. The content of labile carbon (C_L) increased significantly in the fertilized treatments only in the 94-year-old experiment. The contents of humic substances significantly increased in the soil of fertilized treatments in the 25- and 41-year-old experiments. In all fertilized treatments, the humus quality significantly decreased. After 94 years of mineral fertilization, the content of water-stable macroaggregates (WSA_ma) in size fractions > 5 and 5–2 mm was significantly higher in the NPK than in the Co and CaNPK treatments. After 94 years of mineral fertilization, the mean weight diameter of aggregates for dry sieving (MWD_d) differed between Co (0.41) and both treatments of mineral fertilization (NPK: 0.88; CaNPK: 1.70). The application of FYM with CaNPK resulted in a statistically significant decrease in aggregate stability (Sw) in the 25-year-old experiment. For Co and NPK treatments in the 41-year-old experiment, the contents of WSA_ma > 5 mm were 41% and 51% lower, respectively, whereas the content of WSA_ma 5–3 mm was lower by 40% and 50%, respectively, which was higher than that for the CaNPK treatment. The aggregate stability significantly decreased due to NPK application in the soil of the 41-year-old experiment. The number of correlations between SOM parameters and the soil structure decreased in the following order: 94-year-old experiment with mineral fertilization > 41-year-old experiment with mineral fertilization > 25-year-old experiment with mineral fertilization + FYM.

24197. 题目: Extraction, recovery and characterization of structural extracellular polymeric substances from anammox granular sludge
文章编号: N19021609
期刊: Journal of Environmental Management
作者: Tommaso Lotti, Emiliano Carretti, Debora Berti, Maria Raffaella Martina, Claudio Lubello, Francesca Malpei
更新时间: 2019-02-16
摘要: The composition and colloidal properties of extracellular polymeric substances (EPS) from anammox granular sludge were investigated through a complete set of spectroscopic and scattering techniques. To fully characterize EPS, we developed a robust and reproducible extraction/recovery protocol specific for anammox biofilms, based on the change of water affinity under alternated alkaline and acidic conditions, each monitored with Z-potential and dynamic light scattering analysis. This method enabled both extraction as a colloidal suspension and recovery as a solid of large amounts of EPS (0.38 ± 0.04 and 0.21 ± 0.02 g/g, respectively), including for the first time its structural components. The dominance of the proteinaceous fraction was revealed by all methods tested, resulting in the highest protein/carbohydrates ratio reported for biofilms applied in the wastewater sector. The abundance of proteinaceous ordered structures and in particular of cross-β motifs was detected, indicating for the first time the presence of amyloid-like aggregates in anammox EPS, and suggesting the key role of the protein fraction in determining the mechanical properties of the parent biofilm. The robustness and reproducibility of the proposed method fill the current gap towards a reliable full-scale recovery as well as towards an accurate and meaningful investigation of anammox EPS and pave the way for further exploration of their applicative potential thus stimulating the desirable shift from the current wastewater treatment perspective towards biorefinery in a circular economy context.
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24198. 题目: Effects of biochar on bacterial communities in a newly established landfill cover topsoil
文章编号: N19021608
期刊: Journal of Environmental Management
作者: James Tsz Fung Wong, Xunwen Chen, Wenjing Deng, Yemao Chai, Charles Wang Wai Ng, Ming Hung Wong
更新时间: 2019-02-16
摘要: Recent studies revealed the benefits of applying biochar in landfill final cover soil, such as adsorbing odorous compounds and promoting microbial methane oxidation. Most of these processes are related to the soil bacterial communities. However, the effects of biochar application on the overall bacterial community in newly established landfill cover soil are not yet understood, especially in field condition. The objective of the present field study is to investigate the effects of biochar on the diversity of soil bacterial community 3 months after incubation (short–term). Landfill final cover topsoil (0.6 m) was amended with 0 (control), 5, and 10% (w/w) of biochar derived from peanut–shell and wheat straw. Soil bacterial communities were analysed using the 16S rRNA–based T–RFLP approach. Biochar application significantly (p < 0.05) increased the diversity of soil bacterial communities. The Shannon diversity index of bacterial communities in soil amended with 5 and 10% of biochar was increased from 3.34 to 3.85 and 3.92, respectively. There were four bacterial phyla recorded found at both control and amended soils, namely Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. In addition, Gemmatimonadetes was found only in soil amended with 10% biochar. The interactions between soil bacterial communities and measured soil parameters including moisture content, electrical conductivity, total organic matter, total nitrogen and total phosphorus were found to be statistically non-significant (p > 0.05), according to the canonical correspondence analysis (CCA). This may be due to the highly heterogeneous nature of landfill soil. Results from this study revealed that short-term biochar application already altered the soil physicochemical properties and increased the diversity of soil bacterial communities.

24199. 题目: Efficacy of vermitechnology integration with Upflow Anaerobic Sludge Blanket (UASB) and activated sludge for metal stabilization: A compliance study on fractionation and biosorption
文章编号: N19021607
期刊: Journal of Environmental Management
作者: Kaling Taki, Anindita Gogoi, Payal Mazumder, Satya Sunder Bhattacharya, Manish Kumar
更新时间: 2019-02-16
摘要: Efficacy of vermi-transformation for metal partitioning and transformation from Upflow Anaerobic Sludge Blanket (UASB) and Activated Sludge (AS) was investigated. Sludge samples were mixed with cow dung (CD) in two combinations (1:1 (UASB/AS:CD)) & (2:1(UASB/AS: CD)). Fractionation study revealed that Zn, Cd & Pb were associated with reducible fractions, and Cr, Cu with oxidizable fractions. Higher removal efficiency for 1:1 (UASB/AS: CD) combination over 2:1 (UASB/AS: CD) implies the non-significant contribution of cow dung during the metal stabilization process. After vermi-remediation, maximum metal removal was achieved at 1:1 ratio than 2:1 in AS. In UASB, 1:1 ratio worked better for Cr, Zn & Cd, whereas for Cu & Zn 2:1 ratio resulted in efficient removal. Overall for both AS and UASB, efficiency was found to be higher in 1:1 treatment ratio. The value of K_d (Bio sorption) was highest in Cu followed by Cr, which indicates the closer association with the metal bound organic matter (R² ≥ 0.99). Based on the compliance study between two estimated sorption coefficients K_d (Biosorption & Fractions), vermi-remediation was found to be effective for AS than UASB. Therefore, the obtained results clearly validate the feasibility of integration of vermi-remediation as a potential promising ecological techniques for removing metal contaminant from the wastewater. Further research is required to study the decontamination of emerging contaminants with such integrated technology, which have physico-chemical properties different than metal ions.
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24200. 题目: Construction of magnetic lignin-based adsorbent and its adsorption properties for dyes
文章编号: N19021606
期刊: Journal of Hazardous Materials
作者: Chenglong Jiang, Xiaohong Wang, Demeng Qin, Wenxin Da, Bingxia Hou, Chen Hao, Jingbo Wu
更新时间: 2019-02-16
摘要: The magnetic lignin-based adsorbent (Fe₃O₄/C-ACLS) has been successfully prepared and applied to adsorbing azo dyes Congo red, Titan yellow and Eriochrome blue black R. The samples were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray powder diffraction (XRD), vibration sample magnetometer (VSM), Raman spectroscopy and elemental analysis. In the process of adsorption, five kinds of influencing factors and recycling regeneration were discussed, and the adsorption mechanisms such as kinetics, isotherm, thermodynamics were explored. The results show that Fe₃O₄/C-ACLS can remove 98%, 92% and 99% of Congo red, Titan yellow and Eriochrome blue black R, respectively. Under the same conditions, the removal rate was 87%, 84% and 88% after 5 times adsorption cycle, respectively. Pseudo-first-order, pseudo-second-order kinetics, Elovich model and intraparticle diffusion model were studied, and the results show that the adsorption process conforms to pseudo-second-order kinetics model, and the diffusion rate is controlled by many steps. The results of isotherm model and thermodynamics show that the adsorption process is consistent with Langmuir model and is mainly a spontaneous chemical endothermic process of monolayer.
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