论文检索

总访问量：690597次

总访客量：28474人

所有论文

1. 题目: Effects of biochar/AQDS on As(Ⅲ)-adsorbed ferrihydrite reduction and arsenic (As) and iron (Fe) transformation: Abiotic and biological conditions
文章编号: N21120116
期刊: Chemosphere
作者: Wenhui An, Chuan Wu, Shengguo Xue, Ziyu Liu, Min Liu, Waichin Li
更新时间: 2021-12-01
摘要: Microbe induced iron (Fe) reduction play an important role in arsenic (As) transformation and the related secondary mineral formation. Meanwhile biochar could react as electron transfer shuttle for this process. Impact of biochar and model electron transfer shuttle anthraquinone-2,6-disulfonate (AQDS) on the chemical/biological iron reduction of As (Ⅲ)-adsorbed ferrihydrite and the solid-liquid redistribution of As in M1 buffer were studied. Fe reduction results in the release of As adsorbed on ferrihydrite into the solution. Under abiogenic conditions, both biochar and AQDS promoted ferrous production, the chemical oxidation of As(III) and As release. Inoculate with Shewanella oneidensis MR-1, AQDS has greater electronic shuttle function than biochar (with the maximum Fe (Ⅱ) contents: 154 mg/L > 76.6 mg/L respectively). However, only 12.8 mg/L As was released in the presence of AQDS, which was much lower than that in the presence of biochar (21.6 mg/L), and may be associated with the transformation of As speciation and the formation of secondary minerals. XRD and EDX-SEM confirmed that the As could be fixed by the generated secondary mineral vivianite. The relative contents of vivianite in biological control and AQDS addition were 2.7% and 18.4%, respectively. This study provides information on the transformation and migration of As and Fe with the addition of biochar under anaerobic conditions, which is potential to understand the mechanism of As(III)-contaminated soil remediation.

2. 题目: Both organic and integrated pest management of apple orchards maintain soil health as compared to a semi-natural reference system
文章编号: N21120115
期刊: Journal of Environmental Management
作者: Robin Daelemans, Eva Hulsmans, Olivier Honnay
更新时间: 2021-12-01
摘要: Growing concerns about the negative environmental impacts of agriculture have resulted in the increasing adoption of farming systems that try to reconcile crop production with environmental sustainability, such as organic farming. As organic farming refrains from using synthetic inputs, it heavenly relies on maintaining soil health. However, it is still poorly understood how organic management performs in terms of maintaining soil health in real commercial and heterogeneous farm settings as compared to conventional management, and especially as compared to a natural reference system. Here, we compared a set of soil health indicators among 24 commercial apple orchards that were either managed organically or conventionally using Integrated Pest Management (IPM) practices. In addition, we quantified the same indicators in 12 semi-natural grasslands as a benchmark to assess to what extent soil processes and functions have been degraded due to agricultural practices. As soil heath indicators, we quantified soil bulk density, organic matter content, organic carbon content, organic carbon stock, total nitrogen (N), potential heterotrophic respiration, potential net N mineralization, litter decomposition and litter stabilization, and we added the diversity of the herbaceous vegetation and the soil microbiome as covariates in our models. We found no differences between organic and IPM orchards, and neither of the farming systems showed evidence of impaired soil health compared to the semi-natural benchmark, with the exception of higher decomposition rates measured in both orchard types. We observed, however, high spatial variation in soil health between drive and crop rows within the orchards. Especially in the IPM orchards, crop rows showed impaired soil health compared to the adjacent drive rows, indicating that there is still opportunity to improve soil management in the IPM system. In addition, our results show that a considerable part of the variation in soil characteristics can be attributed to the study site, suggesting that both natural heterogeneity and personal management preferences by individual farmers are more important than the management system. Overall, and at least in terms of the soil variables measured in this study, our results suggest that perennial crop systems can be managed in a sustainable way, without jeopardizing soil health.

3. 题目: Decreased glomalin-related soil protein with nitrogen deposition in a 3-year-old Cunninghamia lanceolata plantation
文章编号: N21120114
期刊: Journal of Soils and Sediments
作者: Shuxian Jia, Xiaofei Liu, Weisheng Lin, Yong Zheng, Jianwei Li, Dafeng Hui, Jianfen Guo
更新时间: 2021-12-01
摘要: Purpose Glomalin-related soil protein (GRSP) is an essential component of soil organic C for maintaining soil quality and structure and plays a critical role in soil carbon (C) sequestration. However, how GRSP changes under nitrogen (N) deposition remains poorly understood. Materials and methods We assessed total GRSP (T-GRSP) and easily extractable GRSP (EE-GRSP) under a control (no N input), low N addition (LN, 40 kg N ha−1 year−1), and high N addition (HN, 80 kg N ha−1 year−1) treatments in 2015 and 2016 in a Chinese fir (Cunninghamia lanceolata) plantation in the subtropical China. We also analyzed soil properties contents and explored the stoichiometric ratios of soil organic C (SOC), total N (TN), and total phosphorus (TP) with GRSPs. Results Compared to the control, both T-GRSP and EE-GRSP were significantly reduced under the HN treatment, but had no significant difference under the LN treatment. The ratio of T-GRSP and EE-GRSP was reduced by the N addition. Soil organic C (SOC) and dissolved organic C (DOC) were significantly affected by N addition treatments. The ratios of GRSP-C to SOC and of EEGRSP-C to SOC ranged from 6.29 to 16.07% and 1.34 to 3.52%, respectively. T-GRSP and EE-GRSP were positively correlated with SOC/TN ratio, but negatively correlated with soil TN/TP and SOC/TP ratios. Conclusion Our results indicated that the GRSP reductions under N deposition in soil are mediated by soil C, N, and P stoichiometry, and particularly, the reduction of EE-GRSP by DOC. This study improved our mechanistic understanding of dynamics of GRSPs under increasing N enrichment in subtropical plantation ecosystems.

4. 题目: Nitrogen removal from poultry slaughterhouse wastewater in anaerobic-anoxic-aerobic combined reactor: Integrated effect of recirculation rate and hydraulic retention time
文章编号: N21120113
期刊: Journal of Environmental Management
作者: Carla Limberger Lopes, Tatiane Martins de Assis, Fernando Hermes Passig, Adriana Neres de Lima Model, Juliana Bortoli Rodrigues Mees, Francisco J. Cervantes, Jackeline T. Gotardo, Simone Damasceno Gomes
更新时间: 2021-12-01
摘要: The aim of this work was to assess the nitrogen removal from slaughterhouse wastewater in an anaerobic-anoxic-aerobic combined reactor, evaluating the integrated effect of recirculation rate and hydraulic retention time. The recirculation of the liquid phase from the aerobic zone to the anoxic zone was applied to promote the denitrification through the use of endogenous electron donors. Three recirculation rates (R: 0.5, 1 and 2) and three hydraulic retention times (14, 11 and 8 h) were applied. The operation of the reactor was divided into 3 steps (I, II, and III) according to the factors evaluated (recirculation rate and HRT), to achieve operational conditions that would allow satisfactory performance in the different compartments of the reactor. During the experiment the reactor was fed with average total nitrogen (TN) and chemical oxygen demand (COD) of 65 mg L−1 and 580 mg L−1, respectively. The denitrification efficiency (theoretical) and kinetics parameters for COD decay were calculated. The highest performance was verified in the Step III (R = 2) and HRT of 11 h with NH4+ and TN removals of 84% and 65%, respectively. The TN removal efficiency (65%) was considered satisfactory, since the theoretical denitrification efficiency expected for this condition (R = 2) is 67%, without addition of an external carbon source. The lowest nitrification efficiency values were obtained in HRT of 8 h in the Step I and II (R = 0.5 and 1, respectively), indicating that the nitrification time (3 h - aerobic phase) may be the limiting factor in this HRT. The COD removal efficiency was high in all assays (>95%). The values of the kinetic degradation constants of organic matter were close for all recirculation rates, and the highest values were recorded for the HRT of 8 h and R = 1 and R = 2 (−0.48 and −0.43, respectively).

5. 题目: Time-dependent climate impact of beef production – can carbon sequestration in soil offset enteric methane emissions?
文章编号: N21120112
期刊: Journal of Cleaner Production
作者: Torun Hammar, Per-Anders Hansson, Elin Röös
更新时间: 2021-12-01
摘要: The time-dependent climate impact of beef production, including changes in soil organic carbon, was examined in this study. A hypothetical suckler cow system located in south-east Sweden was analysed using a time-dependent life cycle assessment method in which yearly fluxes of greenhouse gases were considered and the climate impact in terms of temperature response over time was calculated. The climate impact expressed as carbon dioxide equivalents, i.e. global warming potential in a 100-year time perspective, was also calculated. The Introductory Carbon Balance Model was used for modelling yearly soil organic carbon changes from land use. The results showed an average carbon sequestration rate of 0.2 Mg C ha−1 and yr−1, so carbon sequestration could potentially counteract 15–22% of emissions arising from beef production (enteric fermentation, feed production and manure management), depending on system boundaries and production intensity. The temperature response, which showed a high initial increase due to methane emissions from enteric fermentation, started to level off after around 50 years due to the short atmospheric lifetime of methane. However, sustained production and associated methane emissions would maintain the temperature response and contribute to climate damage. A forage-grain beef system resulted in a lower climate impact than a forage-only beef system (due to higher slaughter age), even though more carbon was sequestered in the forage-only system.

6. 题目: FT-IR and synchronous fluorescence two-dimensional correlation spectroscopic analysis on the binding properties of mercury onto humic acids as influenced by pH modification and sulfide addition
文章编号: N21120111
期刊: Science of The Total Environment
作者: Hongwei Luo, Qianqian Cheng, Qingfeng Fan, Dongqin He, Xiaonan Wang, Jianqiang Sun, Jun Li, Xiangliang Pan
更新时间: 2021-12-01
摘要: Mercuric Hg2+ ion forms strong complexes with dissolved organic matter (DOM) in natural waters. The complexation of Hg2+ by sulfhydryl groups of DOM was regarded as the main mechanism for Hg2+-DOM interactions, particularly in anoxic sulfur and DOM-rich environments. In the present study, the influences of pH and sulfide addition on the molecular structure of Hg2+-DOM complexes and the characteristics of Hg2+ binding to DOM were investigated using FT-IR and synchronous fluorescence two-dimensional correlation spectroscopic analysis. Results showed that, during the Hg2+ binding process, the aromatic hydrogen CH in humic acids (HA) gave the fastest responses to pH perturbation and the S-reacted HA (S-HA) exhibited different reaction patterns from the unreacted HA. In S-HA, the esters/alcohols CO and carboxyl CO gave the fastest responses to Hg2+ binding. In the process of S-HA binding to Hg2+, the protein-like fractions including proteins, amino acids or monoaromatics played the leading role. Sulfide addition of HA enhanced the reactivity of small molecular weight compounds with low aromaticity and improved the binding ability of protein-like fractions to Hg2+. These findings provide a better understanding of the interaction mechanisms between Hg2+ and DOM at a molecular level and have important environmental implications in Hg2+ biogeochemical transformation, transport and cycling.

7. 题目: How does biochar aging affect NH3 volatilization and GHGs emissions from agricultural soils?
文章编号: N21120110
期刊: Environmental Pollution
作者: Yuanyuan Feng, Yanfang Feng, Qi Liu, Sen Chen, Pengfu Hou, Gerrard Poinern, Zhongtao Jiang, Derek Fawcett, Lihong Xue, Su Shiung Lam, Changlei Xia
更新时间: 2021-12-01
摘要: Biochar has been considered as a potential tool to mitigate soil ammonia (NH3) volatilization and greenhouse gases (GHGs) emissions in recent years. However, the aging effect of biochar on soils remains elusive, which introduces uncertainty on the effectiveness of biochar to mitigate global warming in a long term. Here, a meta-analysis of 22 published works of literature with 217 observations was conducted to systematically explore the aging effect of biochar on soil NH3 and GHGs emissions. The results show that, in comparison with the fresh biochar, the aging makes biochar more effective to decrease soil NH3 volatilization by 7% and less risk to contribute CH4 emissions by 11%. However, the mitigation effect of biochar on soil N2O emissions is decreased by 15% due to aging. Additionally, aging leads to a promotion effect on soil CO2 emissions by 25% than fresh biochar. Our findings suggest that along with aging, particularly the effect of artificial aging, biochar could further benefit the alleviation of soil NH3 volatilization, whereas its potential role to mitigate global warming may decrease. This study provides a systematic assessment of the aging effect of biochar to mitigate soil NH3 and GHGs, which can provide a scientific basis for the sustainable green development of biochar application.

8. 题目: Nutrient dynamics during composting of human excreta, cattle manure and organic waste affected by biochar
文章编号: N21120109
期刊: Journal of Environmental Quality
作者: Daniela Castro‐Herrera, Katharina Prost, Yonas Schäfer, Dong‐Gill Kim, Fantaw Yimer, Menfese Tadesse, Mersha Gebrehiwot, Nicolas Brüggemann
更新时间: 2021-12-01
摘要: Ecological sanitation via thermophilic composting could be a promising solution to the lack of sanitation and limited access to fertilizers, particularly in developing countries. Here, we conducted a 185-day thermophilic composting experiment with human excreta, and separately with cattle manure, mixed with kitchen scraps, teff straw, sawdust and biochar by using an appropriate-technology approach. We followed the dynamics of the most important macronutrients (N, P, K), temperature, moisture, pH, electrical conductivity, cation exchange capacity, as well as content of organic matter, organic C, Ca, Mg, and micronutrients throughout the process. Low N (<47%), P (<9%), K (<11%), Ca (<18%), and Mg (<21%) losses and the temperature profile indicated a well-functioning thermophilic composting process. Compost temperature reached values above 60°C for 7, 6, 5, and 8 consecutive days for treatments containing human excreta, human excreta amended with biochar, cattle manure, and cattle manure amended with biochar, respectively, suggesting a final compost product free of pathogens. The compost mixture with cattle manure and biochar reached a significantly higher temperature than the same variant without biochar, with a maximum value of 65.9°C on day 6. For all treatments, final germination index values >100% indicated compost maturity and absence of phytotoxic substances. Biochar addition reduced losses of organic matter (18−23%), C (33−42%), N (49−100%), and decreased the amount of extractable NO3– (32−36%) in the final compost. The tested ecological sanitation concept via thermophilic composting is thus a promising strategy to improve access to cheap fertilizer by safe and sustainable sanitation and waste management. Thermophilic temperature during composting suggests a safe treatment of human excreta. Phosphorus and K were preserved during composting, while Ca and Mg losses were low (<18%). Biochar reduced losses of organic matter (18−23%), C (33−42%) and N (49−100%) during composting. Biochar amendment reduced extractable nitrate content of the mature compost by 32−36%. Recycling nutrients from human excreta by thermophilic composting can improve food security.

9. 题目: A designed moderately thermophilic consortia with a better performance for leaching high grade fine lead-zinc sulfide ore
文章编号: N21120108
期刊: Journal of Environmental Management
作者: Siyu Zhou, Xiaojian Liao, Shoupeng Li, Xiaodi Fang, Zhijie Guan, Maoyou Ye, Shuiyu Sun
更新时间: 2021-12-01
摘要: Unwieldy fine sulfide ores are produced during mining; without being appropriately disposed of, they can cause environmental pollution and waste resources. This study investigated the leaching performance of a moderately thermophilic consortia (Leptospirillum ferriphilum + Acidithiobacillus caldus + Sulfobacillus benefaciens) for fine lead-zinc sulfide raw ore. The results showed this microbial community created a low pH, high ORP, and high cell concentration environment for mineral leaching, improving bioleaching efficiency. Under the action of this consortia, the zinc leaching rate reached 96.44 in 8 days, and reached 100% after 12 days. EPS analysis indicated that the consortia could mediate the secretion of more polysaccharides to ensure leaching efficiency. EPS levels and amino acids were the main factors affecting bioleaching. An analysis of mineral surface characteristics showed the consortia effectively leached pyrite and sphalerite from the fine sulfide ore, and prevented the mineral surface forming the jarosite that could hinder bioleaching. This study found that bioleaching reduced the potential environmental toxicity of the minerals, providing an important reference for guiding the bioleaching of unwieldy fine sulfide raw ore.

10. 题目: Effects of biochar on water quality and rice productivity under straw returning condition in a rice-wheat rotation region
文章编号: N21120107
期刊: Science of The Total Environment
作者: Yong Liu, Jiang Li, Xiyun Jiao, Huandi Li, Tiesong Hu, Hongzhe Jiang, Ali Mahmoud
更新时间: 2021-12-01
摘要: Straw returning is helpful to improve soil properties and realize the reutilization of agricultural waste. However, wheat straw returning may result in paddy water quality deterioration in rice-wheat rotation regions. This study conducted pot experiments of rice planting with different biochar application rates (0, 5, 20, and 40 t/hm2) under wheat straw returning conditions. The purposes are to investigate the applicability of biochar mixed with wheat straw returning to paddy fields and explore the effects of biochar on water quality, leaching losses of nitrogen (N) and phosphorus (P), and rice yield components. Results indicated that total straw returning reduced the water quality in paddy surface water and aggravated the leaching losses of N and P. Fortunately, the biochar application improved the negative effects caused by straw returning. 40 t/hm2 biochar mixed with straw returning significantly reduced the concentrations of COD and N in paddy surface water and N leaching loss were lower than straw returning treatment (ST), decreased by 48.33%, 41.01%, and 45.73%, respectively. Meanwhile, applying biochar at a rate of 20 t/hm2 with straw returning is suitable to control the diffusion of P. In addition, the ST treatment had no significant effect on rice yield, while the proper application rate of biochar under straw returning condition can improve rice yield and promote N utilization. 20 t/hm2 biochar treatment is more effective to improving rice yield (16.89%) and N use efficiency (NUE) (10.14%). These findings can provide a new method to solve the negative effects of total straw returning on the water environment and rice growth and guide the utilization of straw resources in the rice-wheat rotation regions.

11. 题目: Fabrication of lignin-based biochar containing multi-metal ferrite and efficient removal for oxytetracycline hydrochloride
文章编号: N21120106
期刊: Journal of Cleaner Production
作者: Huiting Lin, Shijie Qiu, Zhihao Wu, Xiaoxia Ye, Minghua Liu
更新时间: 2021-12-01
摘要: Efficient removal of oxytetracycline hydrochloride (OTC) from wastewater is of great significance but extremely challenging. Herein, a novel adsorbent lignin-based multi-metal ferrite biochar (FeNiZn-LBC) was synthesized through pyrolysis with controllable temperature and hydrothermal reaction using lignin of sinocalamus oldhami as raw material. The adsorption property of FeNiZn-LBC for OTC was systematically researched, and the results displayed that adsorption of FeNiZn-LBC to OTC accorded with the Langmuir model and the equilibrium adsorption capacity was 476 mg g−1. Notably, FeNiZn-LBC can be regenerated with 0.100 mol L−1 NaOH. Additionally, we raised rational explanations for the mechanisms of adsorption behavior based on the zeta potential and XPS spectra. The adsorption of FeNiZn-LBC for OTC was mainly controlled by the electrostatic interactions, hydrogen bonds and complexation involving FeNiZn-LBC and OTC, especially the metal-oxide bond (M-O) generated after loaded with multi-metal ferrite played a positive role in the removal of OTC from water. Our work highlighted the potential of FeNiZn-LBC for excellent adsorption of OTC in next generation.

12. 题目: Activation of persulfate for highly efficient degradation of metronidazole using Fe(II)-rich potassium doped magnetic biochar
文章编号: N21120105
期刊: Science of The Total Environment
作者: Jiayi Luo, Yunqiang Yi, Guangguo Ying, Zhanqiang Fang, Yifeng Zhang
更新时间: 2021-12-01
摘要: The content of active components in magnetic biochar, especially Fe(II), is closely related to its activation performance. Therefore, improving Fe(II) content in magnetic biochar is an ideal strategy to enhance the activation performance of magnetic biochar. In this study, the potassium-doped magnetic biochar was prepared and employed to activate persulfate for degradation of metronidazole. The degradation efficiency of metronidazole in potassium-doped magnetic biochar/persulfate system was 98.4%, which was 13.1 times higher than that in magnetic biochar/persulfate system. Free radicals quenching experiments and electron spin resonance analyses confirmed that surface-bound free radicals were responsible for metronidazole degradation followed the order of 1O2 > OH > SO4− > O2−. The doping of magnetic biochar with potassium increased its Fe(II) content, approximately 3.1 times higher than that of pristine magnetic biochar. The differences in Fe(II) content between potassium-doped magnetic biochar and magnetic biochar were the key reasons for the activation performance differences. Based on the ultra-high pressure liquid chromatography-quadrupole tandem time-of-flight mass spectrometer, the primary degradation intermediates of metronidazole were identified, and possible degrading pathways were proposed. Overall, this work provides an effective strategy to improve the activation performance of magnetic biochar.

13. 题目: Insights into the impacts of dissolved organic matter of different origins on bioaccumulation and translocation of per- and polyfluoroalkyl substances (PFASs) in wheat
文章编号: N21120104
期刊: Environmental Pollution
作者: Siqian Liu, Jian Zhou, Jia Guo, Zhuo Gao, Yibo Jia, Shunli Li, Tiecheng Wang, Lingyan Zhu
更新时间: 2021-12-01
摘要: Per- and polyfluoroalkyl substances (PFASs) have been found to be widely present in soil. Dissolved organic matter (DOM) in soil are supposed to greatly affect the bioavailability of PFASs in soil. Herein, hydroponic experiments were conducted to understand the impacts of two kinds of typical DOM, bovine serum albumin (BSA) and humic acid (HA), on the uptake and translocation of legacy PFASs and their emerging alternatives, perfluorooctane sulfonic acid (PFOS), perfluorooctane acid (PFOA), perfluorohexane sulfonic (PFHxS) and 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFESA) in wheat (Triticum aestivum L.). The results indicated that both HA and BSA significantly inhibited the bioaccumulation and translocation of PFASs in the roots and shoots of wheat, and the impacts of BSA were greater than HA. This difference was explained by the greater binding affinities of the four PFASs with BSA than with HA, as evidenced by the equilibrium dialysis and isothermal titration calorimetry (ITC) analyses. It was noting that inhibition impacts of the BSA-HA mixture (1:1) were lower than BSA alone. The results of Fourier transform infrared (FT-IR) spectroscopy and excitation-emission matrix (EEM) fluorescence spectroscopy suggested that HA could bind with the fluorescent tryptophan residues in BSA greatly, competing the binding sites with PFASs and forming a cover on the surface of BSA. As a result, the binding of PFASs with BSA-HA complex was much lower than that with BSA, but close to HA. The results of this study shed light on the impacts of DOM in soil on the bioaccumulation and translocation of PFASs in plants.

14. 题目: Capacity and Intensity Indicators to evaluate the effect of different crop sequences and cover crops on soil physical quality of two different textured soils from Pampas Region
文章编号: N21120103
期刊: Soil and Tillage Research
作者: M.P. Salazar, L.A. Lozano, R. Villarreal, A.B. Irizar, M. Barraco, N.G. Polich, C.G. Soracco
更新时间: 2021-12-01
摘要: Soil physical degradation is a current problem in Molisols of the Pampas Region under no-tillage (NT), that has been related to over-simplified agricultural systems with scarce or no rotations and long winter bare fallows. Soil physical quality (SPQ) is a key factor of soil health and productivity, as it controls root development and air and water fluxes and storage in the soil, which in turn affect nutrient uptake and plant growth. Cover crops have been proposed as a companion agricultural practice to improve NT performance and SPQ. The aim of this study was to evaluate the effect of the inclusion of winter cover crops in different cropping sequences on capacity and intensity indicators of SPQ in two soils of different texture under NT and to compare it with different traditional crop sequences, including non-agricultural plots. SPQ was evaluated at two different sites, one with a silty loam Argiudoll and the other with a sandy loam Hapludoll. Treatments included plots with and without cover crops, with different summer crop sequences (continuous soybean and corn – soybean rotations). Also, a corn – wheat/soybean rotation with and without pastures was evaluated. All treatments had more than 15 years under the same management. We measured soil organic carbon (SOC), and capacity SPQ indicators (bulk density, total porosity, pore size distribution, air capacity, plant available water, relative field capacity and S index). We also measured dynamic SPQ indicators derived from field infiltration tests (saturated and near saturation hydraulic conductivity, effective macro and mesoporosity, and porosity connectivity indexes for different pore families). On the silty loam Argiudoll, cover crops increased SOC but failed to improve SPQ. This was related to soil physical degradation and the low ability of these soils for structure regeneration. On the sandy loam Hapludoll, cover crops had mixed effects on SOC and pore size distribution, but increased near saturation hydraulic conductivity, in the case of the corn – soybean rotation with cover crops, reaching values similar to those of a natural grassland.

15. 题目: Adsorption of BDE-209 to Polyethylene Microplastics: Effect of Microplastics Property and Metal Ions
文章编号: N21120102
期刊: Water, Air, & Soil Pollution
作者: Yanfeng Zhu, Xiaoxiao Li, Liping Wang, Nan Hui, Jing Ma, Fu Chen
更新时间: 2021-12-01
摘要: In this work, the effect of polyethylene microplastics (MPs) on the adsorption of decabromodiphenyl ether (BDE-209) in a sandy loamy soil and aqueous solution was investigated by performing batch tests. Results show that the overall adsorption capacity of soil/MPs mixture decreased slightly after MPs spiking because of the dilution effect, namely MPs were weaker receptor for BDE-209 than the soil particles. The adsorption capacity increased with reducing the MPs size. The equilibrium adsorption amount of aged MPs (4.15 mg/kg) declined apparently compared with that of the original MPs (7.63 mg/kg). According to the fitting parameters of kinetic and isothermal adsorption study, the adsorption of BDE-209 by MPs was a heterogeneous and multi-layer uneven adsorption process. The existence of Cu2+ ions or humic acid exerted a negative impact on the adsorption of BDE-209. In summary, the findings of this work underline the potential significance of MPs as contaminant carriers in co-contaminated soils.

16. 题目: Digital mapping of GlobalSoilMap soil properties at a broad scale: A review
文章编号: N21120101
期刊: Geoderma
作者: Songchao Chen, Dominique Arrouays, Vera Leatitia Mulder, Laura Poggio, Budiman Minasny, Pierre Roudier, Zamir Libohova, Philippe Lagacherie, Zhou Shi, Jacqueline Hannam, Jeroen Meersmans, Anne C. Richer-de-Forges, Christian Walter
更新时间: 2021-12-01
摘要: Soils are essential for supporting food production and providing ecosystem services but are under pressure due to population growth, higher food demand, and land use competition. Because of the effort to ensure the sustainable use of soil resources, demand for current, updatable soil information capable of supporting decisions across scales is increasing. Digital soil mapping (DSM) addresses the drawbacks of conventional soil mapping and has been increasingly used for delivering soil information in a time- and cost-efficient manner with higher spatial resolution, better map accuracy, and quantified uncertainty estimates. We reviewed 244 articles published between January 2003 and July 2021 and then summarised the progress in broad-scale (spatial extent >10,000 km2) DSM, focusing on the 12 mandatory soil properties for GlobalSoilMap. We observed that DSM publications continued to increase exponentially; however, the majority (74.6%) focused on applications rather than methodology development. China, France, Australia, and the United States were the most active countries, and Africa and South America lacked country-based DSM products. Approximately 78% of articles focused on mapping soil organic matter/carbon content and soil organic carbon stocks because of their significant role in food security and climate regulation. Half the articles focused on soil information in topsoil only (<30 cm), and studies on deep soil (100–200 cm) were less represented (21.7%). Relief, organisms, and climate were the three most frequently used environmental covariates in DSM. Nonlinear models (i.e. machine learning) have been increasingly used in DSM for their capacity to manage complex interactions between soil information and environmental covariates. Soil pH was the best predicted soil property (average R2 of 0.60, 0.63, and 0.56 at 0–30, 30–100, and 100–200 cm). Other relatively well-predicted soil properties were clay, silt, sand, soil organic carbon (SOC), soil organic matter (SOM), SOC stocks, and bulk density, and coarse fragments and soil depth were poorly predicted (R2 < 0.28). In addition, decreasing model performance with deeper depth intervals was found for most soil properties. Further research should pursue rescuing legacy data, sampling new data guided by well-designed sampling schemas, collecting representative environmental covariates, improving the performance and interpretability of advanced spatial predictive models, relating performance indicators such as accuracy and precision to cost-benefit and risk assessment analysis for improving decision support; moving from static DSM to dynamic DSM; and providing high-quality, fine-resolution digital soil maps to address global challenges related to soil resources.

17. 题目: Synergistic effects of ball-milled biochar-supported exfoliated LDHs on phosphate adsorption: Insights into role of fine biochar support
文章编号: N21113008
期刊: Environmental Pollution
作者: Hangyu Li, Shihao Cui, Yi Tan, Yutao Peng, Xing Gao, Xiao Yang, Yan Ma, Xinyue He, Beibei Fan, Sen Yang, Qing Chen
更新时间: 2021-11-30
摘要: Although biochar supports were widely adopted to fabricate the biochar (BC) supported layered double hydroxides (LDHs) composites (LDH-BC) for efficient environmental remediation, few studies focus on the important role of biochar support in alleviating the stacking of LDHs and enhancing LDH-BC's performance. Through the analysis of the material structure-performance relationship, the “support effect” of fine biochar prepared by ball milling was carefully explored. Compared with the original LDHs on LDH-BC, the LDHs on ball milled biochar (LDH-BMBC) had smaller particle size (from 1123 nm to 586 nm), crystallite size (from 20.5 nm to 6.56 nm), more abundant O-containing functional groups, and larger surface area (370 m2 g−1) and porous structure. The Langmuir model revealed that the maximum theoretical phosphate adsorption capacity of LDH-BMBC (56.2 mg P g−1) was significantly higher than that of LDH-BC (27.6 mg P g−1). The leaching experiment proved that the addition of LDH-BMBC in calcareous soil could significantly reduce the release of soil total phosphate (46.1%) and molybdate reactive phosphate (40.4%), even though pristine BC and BMBC significantly enhanced the soil phosphate leaching. This work fabricated high-performance and eco-friendly LDH-BMBC for phosphate adsorption in solution and phosphate retention in soil and also provide valuable insights into fine biochar support effect on LDHs exfoliation, extending the practical use of the engineered ball milled biochars in environment remediation.

18. 题目: Biomass productivity, forest stability, carbon balance, and soil transformation of agricultural land afforestation: A case study of suitability of native tree species in the submontane zone in Czechia
文章编号: N21113007
期刊: CATENA
作者: Jan Cukor, Zdeněk Vacek, Stanislav Vacek, Rostislav Linda, Vilém Podrázský
更新时间: 2021-11-30
摘要: The increasing trend of afforestation is described in almost all European countries, however, the knowledge of the growth parameters of particular tree species on abandoned agricultural land is still incomplete. Therefore, the characteristics of young forest stands which are afforested with 5 native tree species (Norway spruce, European beech, English oak, sycamore maple, and small-leaved lime) were analyzed 14 years after afforestation. Afforestation had a positive influence on the soil physical characteristics with the highest porosity (58.2%) in spruce stands and water saturation (48.5%) in oak stands. Maple had the fastest initial growth and production with the highest mean annual increment (12.1 m3 ha−1 y-1) and total biomass production (200.8 t ha−1). Contrarily, the lowest production parameters were found in the beech stands with a low mean annual increment (1.4 m3 ha−1 y-1) and total biomass production (28.4 t ha−1). The most abundant carbon quantity in the soil and tree biomass together was sequestered in lime (125.1 t ha−1) followed by maple stands (124.5 t ha−1). On average, the total carbon balance was 67.4% stored in the tree biomass, and 32.6% in the soil for tree species evaluated together. The amount of carbon sequestered in the soil will increase in the following years in relation to overlying humus development, incorporation of soil organic carbon in the mineral soil horizons, as well as with tree biomass production. The study demonstrated a significant difference in growth potential, biomass production, soil transformation and carbon sequestration in native tree species stands established on former agricultural lands. Most importantly, the differences in carbon sequestration should be considered in future agricultural land afforestation to mitigate the negative impact of global climate change.

19. 题目: The stratification of soil organic carbon and total nitrogen affected by parent material and cropping system
文章编号: N21113006
期刊: CATENA
作者: Xin Zhang, Meng-Jia Li, Chao Yang, Lin-Qing Zhan, Wei Wu, Hong-Bin Liu
更新时间: 2021-11-30
摘要: The stratification ratio (SR) is a good indicator of the quantitative evaluation of the soil nutrient variation with depth, which is inter-related with nutrient cycles and agricultural productivity. However, the effects of the parent material and cropping system on the SR of soil organic carbon (SOC) and total nitrogen (TN) have received little attention. The current study collected 444, 437, and 363 soil samples at the depths of 0–20, 20–40, and 40–60 cm, respectively, in subtropical southwest China, where the predominant parent materials are alluvial deposits, purple shales, and limestone and the cropping systems are rice–upland crop rotation, upland crop rotation, and rice monoculture. A two-way analysis of variance (two-way ANOVA) and a redundancy analysis (RDA) were applied to investigate the effects of the parent material, cropping system, topography, and climate on SOC and TN contents, and the corresponding SR (SR1, 0–20 cm:20–40 cm; SR2, 0–20 cm:40–60 cm). Results indicated that the parent material and cropping system were the main factors linked to the SR of the SOC and TN, whereas topography and climate seemed to have weaker effects on the SR in the agricultural landscape. Generally, alluvial deposit- and purple shale-derived soils presented higher SR than limestone-derived soils. Rice–upland crop rotation systems increased the SR compared to rice monoculture and upland crop rotation systems. Exceptions were observed in rice–upland crop rotation and rice monoculture systems under limestone. The study highlighted the efficient SR indicator in examining the SOC and TN depth distribution corresponding to the parent material and cropping system and is expected to provide valuable information regarding the optimization of the cropping pattern in different lithological regions, thereby enhancing agricultural productivity.

20. 题目: Interactive effects of biochar amendment and lead toxicity on soil microbial community
文章编号: N21113005
期刊: Journal of Hazardous Materials
作者: Yongshan Wan, Richard Devereux, S. Elizabeth George, Jianjun Chen, , Matthew Noerpel, Kirk Scheckel
更新时间: 2021-11-30
摘要: This study determined the interactive effects of biochar and lead toxicity on the soil microbial community in a phytoextraction experiment. Arranged with a completely randomized design in a green house, banana liners were planted singly in a sandy soil spiked with Pb(NO3)2 at 0, 400 and 1200mgkg-1 and amended with bamboo biochar (pyrolyzing at 600oC) at 0, 1, 3%. Soil samples were taken from triplicated pots five months after planting and measured for (i) content of lead and organic carbon; (ii) lead speciation; and (iii) microbial community composition through 16S rRNA gene sequencing. DNA sequencing results showed that lead and biochar treatments had significant individual and interactive effects on soil microbial dissimilarities from taxonomic levels of phyla to genera. While some specific taxa were lead resistant, biochar addition apparently alleviated lead toxicity and increased their richness (e.g., Alkanibacter, Muciaginibacter, Burkholderiaceae, and Beggiatoaceae). Soil analysis data indicated that biochar not only helped retain more lead in the soil matrix but created a soil environment inducive for transformation of lead into highly insoluble pyromorphite. This study highlights the effectiveness of biochar for lead remediation and the sensitivity of soil microorganisms in sensing changes in soil environment and lead bioavailability.