摘要：
The heterogeneous Fenton-like systems induced by Fe-containing minerals have been largely applied for the degradation of organic pollutants. However, few studies have been conducted on biochar (BC) as an additive to Fenton-like systems mediated by iron-containing minerals. In this study, the addition of BC prepared at different temperatures was found to significantly enhance the degradation of contaminants in the tourmaline-mediated Fenton-like system (TM/H(2)O(2)) using Rhodamine B (RhB) as the target contaminant. Furthermore, the hydrochloric acid-modified BC prepared at 700°C (BC700(HCl)) could achieve complete degradation of high concentrations of RhB in the BC700(HCl)/TM/H(2)O(2) system. Free radical quenching experiments showed that TM/H(2)O(2) system removed contaminants mainly mediated by the free radical pathway. After adding BC, the removal of contaminants is mainly mediated by the non-free radical pathway in BC700(HCl)/TM/H(2)O(2) system which was confirmed by the Electron paramagnetic resonance (EPR) experiments and electrochemical impedance spectroscopy (EIS). In addition, BC700(HCl) had broad feasibility in the degradation of other organic pollutants (Methylene Blue (MB) 100%, Methyl Orange (MO) 100%, and tetracycline (TC) 91.47%) in the tourmaline-mediated Fenton-like system. Possible pathways for the degradation of RhB by the BC700(HCl)/TM/H(2)O(2) system were also proposed.
摘要：
Sediment is the internal and external source of water environment pollution, so sediment remediation is the premise of water body purification. Sediment microbial fuel cell (SMFC) can remove the organic pollutants in sediment by electroactive microorganisms, compete with methanogens for electrons, and realize resource recycling, methane emission inhibiting and energy recovering. Due to these characteristics, SMFC have attracted wide attention for sediment remediation. In this paper, we comprehensively summarized the recent advances of SMFC in the following areas: (1) The advantages and disadvantages of current applied sediment remediation technologies; (2) The basic principles and influencing factors of SMFC; (3) The application of SMFC for pollutant removal, phosphorus transformation and remote monitoring and power supply; (4) Enhancement strategies for SMFC in sediments remediation such as SMFC coupled with constructed wetland, aquatic plant and iron-based reaction. Finally, we have summarized the drawback of SMFC and discuss the future development directions of applying SMFC for sediment bioremediation.
作者机构：
[Chi, Nianping; Yang, Zhenwen] Hunan City Univ, Hunan Prov Engn &Technol Res Ctr Rural Water Qual, Sch Municipal & Geomatics Engn, Yiyang 413000, Hunan, Peoples R China.;[Li, Xuhao; Feng, Li] Guangdong Univ Technol, Sch Civil & Transportat Engn, Guangzhou 510006, Peoples R China.;[Zhu, Junren] Chongqing City Management Coll, Chongqing 401331, Peoples R China.;[Jiang, Zhenzhen] Chongqing Vocat Inst Engn, Chongqing 402260, Peoples R China.;[Zheng, Huaili] Chongqing Univ, Key Lab Three Gorges Reservoir Reg Ecoenvironm, Minist Educ, Chongqing 400045, Peoples R China.
通讯机构：
[Li Feng] S;School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, 510006, China
关键词：
Biodegradability;Dyeing wastewater;Electro- Ce(III) process;Energy consumption;Medium oxidation;Reactive red 2
摘要：
Reactive red 2 (RR2) azo dye wastewater poses a serious hazard to the water environment health, so using a novel and efficient Electro- Ce(III) (E- Ce(III)) process takes on a critical significance in treating RR2 dye wastewater. In this study, the effects of a variety of single-factor conditions on RR2 removal efficiency were evaluated in depth. The results indicated that the optimal experimental conditions are as reaction temperature of 25°C, Na(2)SO(4) concentration of 25mM, Ce(III) concentration of 0.3mM, pH of 4.0, and current density of 40.0mA/cm(2). When the RR2 dye wastewater was treated for 40min under the optimal experimental conditions, a high removal rate of 99.8% for RR2 was obtained. It is suggested that the background ion PO(4)(3-) in the dye wastewater inhibits the E-Ce (III) process, whereas Cl- facilitates this process. Moreover, the yield of Ce(IV) increases with the increase of the current density. At the current density of 40.0mA/cm(2), a reasonable energy consumption of 3.85kW h/gTOC for the process was obtained after the 3-h treatment. The effects of different degradation processes (including Direct Electrooxidation (DEO), single Ce(III), and E-Ce (III)) on RR2 removal efficiency and TOC change were compared. The types of oxidizing substances in the E-Ce (III) process were detected, and the mechanism of RR2 oxidative degradation in the E-Ce (III) process was summarized. The result suggests that the E-Ce (III) process has low power consumption. Meanwhile, in the E-Ce (III) process, free reactive Ce(IV) with strong oxidation is continuously generated, RR2 can be efficiently degraded. And the continuous cycle transformation between Ce(III) and Ce(IV) maintains the strong oxidation of the process. The contribution of free reactive Ce(IV) and DEO to RR2 degradation was obtained as 58.8% and 39.8%, respectively. The combined effect of Ce(IV) and DEO played a major role in the E-Ce (III) process, while ·OH exhibited a relatively weak effect (nearly 1.4%). RR2 was comprised of 13 major intermediates, and the biodegradability of wastewater was improved significantly after treatment, thus facilitating the further mineralization and biodegradation of the products. The E- Ce(III) process is novel, efficient, and environment-friendly, and has a large market application space, suggesting that it can be applied as an efficient, economic, and sustainable water treatment process.
摘要：
This paper examined the impacts of different pretreatments on the characteristics of biochar and its adsorption behavior for Pb(2+). Biochar with combined pretreatment of water-washing and freeze-drying (W-FD-PB) performed a maximum adsorption capacity for Pb(2+) of 406.99mg/g, higher than that of 266.02mg/g on water-washing pretreated biochar (W-PB) and 188.21mg/g on directly pyrolyzed biochar (PB). This is because the water-washing process partially removed the K and Na, resulting in the relatively enriched Ca and Mg on W-FD-PB. And the freeze-drying pretreatment broke the fiber structure of pomelo peel, favoring the development of a fluffy surface and large specific surface area during pyrolysis. Quantitative mechanism analysis implied that cation ion exchange and precipitation were the driving forces in Pb(2+) adsorption on biochar, and both mechanisms were enhanced during Pb(2+) adsorption on W-FD-PB. Furthermore, adding W-FD-PB to Pb-contaminated soil increased the soil pH and significantly reduced the availability of Pb.
作者机构：
[Chen, Yaoning; Tang, Ping; Chen, Li; Jiang, Hongjuan; Liu, Yihuan; Luo, Xinli] College of Environmental Science and Engineering, Hunan University, Changsha;410082, China;Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha;[Li, Yuanping] College of Municipal and Mapping Engineering, Hunan City University, Hunan, Yiyang;413000, China
通讯机构：
[Yaoning Chen; Yuanping Li] C;College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China<&wdkj&>Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China<&wdkj&>College of Municipal and Mapping Engineering, Hunan City University, Yiyang, Hunan, 413000, China
摘要：
The potential risk of various contaminants in water has recently attracted public attention. Biochars and modified biochars have been widely developed for environmental remediation. Metal and heteroatom co-doped biochar composites (MHBCs) quickly caught the interest of researchers with more active sites and higher affinity for contaminants compared to single-doped biochar by metal or heteroatoms. This study provides a comprehensive review of MHBCs in wastewater decontamination. Firstly, the main fabrication methods of MHBCs were external doping and internal doping, with external doping being the most common. Secondly, the applications of MHBCs as adsorbents and catalysts in water treatment were introduced emphatically, which mainly included the removal of metals, antibiotics, dyes, pesticides, phenols, and other organic contaminants. Thirdly, the removal mechanisms of contaminants by MHBCs were deeply discussed in adsorption, oxidation and reduction, and degradation. Furthermore, the influencing factors for the removal of contaminants by MHBCs were also summarized, including the physicochemical properties of MHBCs, and environmental variables of pH and co-existing substance. Finally, futural challenges of MHBCs are proposed in the leaching toxicity of metal from MHBCs, the choice of heteroatoms on the fabrication for MHBCs, and the application in the composite system and soil remediation.
摘要：
Diclofenac (DCF), as a typical representative of PPCPs, has potential ecotoxicity to the water environment. In this study, ultrasound (US) enhanced ferrous sulfide (FeS)-activated persulfate (PDS) technology (US/FeS/PDS) was used to degrade DCF. By comparing the degradation effects of US, US/PDS, FeS/PDS and US/FeS/PDS systems on DCF, this study confirmed the synergy and strengthening effects of US. The influences of single-factor experimental conditions on the US/FeS/PDS system were investigated and optimized. The FeS catalysts before and after the reaction were characterized and analyzed by X-ray diffractometer (XRD) and X-ray photoelectron spectroscopy (XPS). The heterogeneous reaction proceeded on the surface of FeS, and a small part of FeS(2) was formed on FeS surface. During the reaction, the proportion of S(2-) on the catalyst surface decreased from 51% to 44%. Correspondingly, the proportion of S(x)(2-) increased from 21% to 26%. It indicated that S(2-) was oxidized into S(x)(2-) in the reaction, and the loss electrons of S(2-) caused the reduction of Fe(3+) to Fe(2+)on the FeS surface, which promoted the cycle between Fe(2+) and Fe(3+) in turn. Furthermore, SO(4)(-) and ‧OH were the main active free radicals, of which the contribution rate of ‧OH was about 34.4%, while that of SO(4)(-) was approximately 52.2%. In US/FeS/PDS, the introduction of US could promote the dissolution of iron on the FeS surface. US contributed to the formation of a redox power motor between S(2-)S(x)(2-) and Fe(2+)-Fe(3+), which continuously decomposed PDS to generate sufficient active SO(4)(-) and ‧OH radicals, thereby efficiently and continuously degrading DCF. Finally, the related mechanism of DCF degradation by US/FeS/PDS was summarized. Overall, US/FeS/PDS can not only efficiently degrade and remove DCF, but also has potential application value in organic pollution removal and wastewater purification.
通讯机构：
[Yaoning Chen; Yuanping Li] C;College of Environmental Science and Engineering, Hunan University, Changsha, 410082, China<&wdkj&>Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, China<&wdkj&>College of Municipal and Mapping Engineering, Hunan City University, Yiyang, Hunan, 413000, China
期刊：
International Journal of Environmental Research and Public Health,2018年15(5):1032- ISSN：1661-7827
通讯作者：
Zhang, Qiuwen;Zhang, Gui
作者机构：
[Zhang, Xike; Zhang, Qiuwen] Huazhong Univ Sci & Technol, Sch Hydropower & Informat Engn, Wuhan 430074, Hubei, Peoples R China.;[Zhang, Xike; Nie, Zhiping] Hunan City Univ, Sch Municipal & Mapping Engn, Yiyang 413000, Peoples R China.;[Zhang, Gui; Que, Huafei] Cent South Univ Forestry & Technol, Key Lab Digital Dongting Lake Basin Hunan Prov, Changsha 410004, Hunan, Peoples R China.;[Gui, Zifan] Shenzhen Garden Management Ctr, Shenzhen 518000, Peoples R China.
通讯机构：
[Zhang, Qiuwen] H;[Zhang, Gui] C;Huazhong Univ Sci & Technol, Sch Hydropower & Informat Engn, Wuhan 430074, Hubei, Peoples R China.;Cent South Univ Forestry & Technol, Key Lab Digital Dongting Lake Basin Hunan Prov, Changsha 410004, Hunan, Peoples R China.
关键词：
daily land surface temperature;forecasting;data-driven;hybrid model;Ensemble Empirical Mode Decomposition (EEMD);Long Short-Term Memory (LSTM);Neural Network (NN);Dongting Lake basin
摘要：
Daily land surface temperature (LST) forecasting is of great significance for application in climate-related, agricultural, eco-environmental, or industrial studies. Hybrid data-driven prediction models using Ensemble Empirical Mode Composition (EEMD) coupled with Machine Learning (ML) algorithms are useful for achieving these purposes because they can reduce the difficulty of modeling, require less history data, are easy to develop, and are less complex than physical models. In this article, a computationally simple, less data-intensive, fast and efficient novel hybrid data-driven model called the EEMD Long Short-Term Memory (LSTM) neural network, namely EEMD-LSTM, is proposed to reduce the difficulty of modeling and to improve prediction accuracy. The daily LST data series from the Mapoling and Zhijaing stations in the Dongting Lake basin, central south China, from 1 January 2014 to 31 December 2016 is used as a case study. The EEMD is firstly employed to decompose the original daily LST data series into many Intrinsic Mode Functions (IMFs) and a single residue item. Then, the Partial Autocorrelation Function (PACF) is used to obtain the number of input data sample points for LSTM models. Next, the LSTM models are constructed to predict the decompositions. All the predicted results of the decompositions are aggregated as the final daily LST. Finally, the prediction performance of the hybrid EEMD-LSTM model is assessed in terms of the Mean Square Error (MSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), Root Mean Square Error (RMSE), Pearson Correlation Coefficient (CC) and Nash-Sutcliffe Coefficient of Efficiency (NSCE). To validate the hybrid data-driven model, the hybrid EEMD-LSTM model is compared with the Recurrent Neural Network (RNN), LSTM and Empirical Mode Decomposition (EMD) coupled with RNN, EMD-LSTM and EEMD-RNN models, and their comparison results demonstrate that the hybrid EEMD-LSTM model performs better than the other five models. The scatterplots of the predicted results of the six models versus the original daily LST data series show that the hybrid EEMD-LSTM model is superior to the other five models. It is concluded that the proposed hybrid EEMD-LSTM model in this study is a suitable tool for temperature forecasting.
摘要：
Studies were performed to evaluate influence of biochar addition on physico-chemical process, heavy metals transformation and bacterial community diversity during composting of sediment with agricultural wastes. Simultaneously, the relationships between those parameters including heavy metals and bacterial community compositions were evaluated by redundancy analysis (RDA). The results show that the extraction efficiency of DTPA extractable heavy metals decreased in both piles, and reduced more in pile with biochar addition about 0.1-2.96%. Biochar addition dramatically influenced the bacterial community structure during the composting process. Moreover, the bacterial community composition was significantly correlated with C/N ratio, water soluble carbon (WSC), and organic matter (OM) (P < 0.05) in pile with biochar addition; while significantly correlated with temperature, WSC, and C/N ratio in pile which was free of biochar. This study would provide some valuable information for improving the composting for disposal of river sediment with heavy metals contamination. (C) 2017 Elsevier Ltd. All rights reserved.
作者机构：
[陈耀宁; 苟宇; 伍艳馨; 陈艳容; 刘耀; 汪元南; 张道利; 朱福造; Zeng, Guang-Ming] College of Environment Science and Engineering, Hunan University, Changsha;410082, China;Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Changsha;[黎媛萍] College of Municipal and Mapping Engineering, Hunan City University, Yiyang;413000, China
作者机构：
[陈耀宁; 汪元南; 陈艳容; 伍艳馨; 苟宇; 朱福造; 张道利; 刘耀; Zeng, Guang-Ming] College of Environment Science and Engineering, Hunan University, Changsha;410082, China;Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Changsha;[黎媛萍] College of Municipal and Mapping Engineering, Hunan City University, Yiyang;413000, China
摘要：
This paper studied the degradation of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) in contaminated soil under composting and natural conditions, respectively. BDE-47 residue in agricultural waste-composting pile was determined during 45-day composting. The microbial communities were determined by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and the relationships between the DGGE results and physico-chemical parameters were evaluated by redundancy analysis (RDA) and heatmap-clustering analysis. The results showed that the degradation rate of BDE-47 was significantly higher in agricultural waste-composting pile compared with control group, which was enhanced up to almost 15 % at the end of composting. There were different environmental factors which affected the distribution of composting bacterial and fungal communities. The bacterial community composition was more significantly affected by the addition of BDE-47 compared with other physico-chemical parameters, and BDE-47 had stronger influences on bacterial community than fungal community during the composting. Meanwhile, the most variation in distribution of fungal community was explained by pile temperature.
