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Efect of operating parameters on sulfide biotransformation to sulfur

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Journal of environmental Sciences 2013年第12期25卷 2417-2421页

作者： Weiguo Liu Cunzhen Liang Jiaqing Chen Ling Zhu College of Resources and environmental engineering Wuhan University of Technology Department of environmental engineering Beijing Institute of Petrochemical Technology

A laboratory-scale bioreactor with polyethylene semi-soft packing was constructed and utilized to determine the efficlency of sulfide biotransformation to sulfur under various operating parameters. Sodium sulfide dissolved in tap water was pumped into the bioreactor as sulfide for biological desulfurization. The sulfide, sulfur and sulfate-S in the effluent and the sulfide purged as gas-phase HzS were determined to investigate the effects of operating parameters, such as pH, DO, hydraulic retention time （HRT）, temperature and salinity, on the sulfide oxidation products. The activity of bacteria was highest at pH 7.8-8.2. The maximal sulfide removal load was 7.25 kg/（m^3·day）, with a 322.07 mg/L influent sulfide concentration and 4.80 mg/L DO. The increase of DO value corresponds to a decrease in the sulfur yield. The reactor had the highest sulfide removal load and sulfur yield at 2.55 mg/L DO. HRT had little effect on desulfurization efficiency when the sulfide removal load was kept constant. The most effective desulfurization temperature was 33℃. The sulfide removal load decreased from 2.85 to 0.51 kg/（m^***） with increasing salinity from 0.5% to 2.5% （m/m）.

关键词： sulfide sulfur biotransformation operating parameters

Distribution and mode of occurrence of uranium in bottom ash derived from high-germanium coals

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Journal of environmental Sciences 2016年第5期28卷 91-98页

作者： Yinglong Sun Guangxia Qi Xuefei Lei Hui Xu Lei Li Chao Yuan Yi Wang Department of environmental engineering School of Environment Tsinghua University Department of environmental Science and engineering School of Food and Chemical EngineeringBeijing Technology and Business University

The radioactivity of uranium in radioactive coal bottom ash（CBA） may be a potential danger to the ambient environment and human health. Concerning the limited research on the distribution and mode of occurrence of uranium in CBA, we herein report our investigations into this topic using a number of techniques including a five-step Tessier sequential extraction, hydrogen fluoride（HF） leaching, Siroquant（Rietveld） quantification, magnetic separation, and electron probe microanalysis（EPMA）. The Tessier sequential extraction showed that the uranium in the residual and Fe–Mn oxide fractions was dominant（59.1%and 34.9%, respectively）. The former was mainly incorporated into aluminosilicates,retained with glass and cristobalite, whereas the latter was especially enriched in the magnetic fraction, of which about 50% was present with magnetite（Fe_3O_4） and the rest in other iron oxides. In addition, the uranium in the magnetic fraction was 2.6 times that in the non-magnetic fraction. The experimental findings in this work may be important for establishing an effective strategy to reduce radioactivity from CBA for the protection of our local environment.

关键词： Coal bottom ash Uranium Radioactivity Tessier sequential extraction Magnetic separation

Nanofiltration for drinking water treatment: a review

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Frontiers of Chemical Science and engineering 2022年第5期16卷 681-698页

作者： Hao Guo Xianhui Li Wulin Yang Zhikan Yao Ying Mei Lu Elfa Peng Zhe Yang Senlin Shao Chuyang Y.Tang Membrane-based environmental&sustainable Technology(MembEST)Group Department of Civil EngineeringThe University of Hong KongHong KongChina Key Laboratory for City Cluster environmental Safety and Green Development of the Ministry of Education Institute of Environmental and Ecological EngineeringGuangdong University of TechnologyGuangzhou 510006China College of environmental Science and engineering Peking UniversityBeijing 100871China College of Chemical and Biological engineering Zhejiang UniversityHangzhou 310027China Research and Development Center for Watershed environmental Eco-engineering Advanced Institute of Natural SciencesBeijing Normal UniversityZhuhai 519087China School of Civil engineering Wuhan UniversityWuhan 430072China

In recent decades,nanofiltration(NF)is considered as a promising separation technique to produce drinking water from different types of water *** this paper,we comprehensively reviewed the progress of NFbased drinking water treatment,through summarizing the development of materials/fabrication and applications of NF membranes in various scenarios including surface water treatment,groundwater treatment,water reuse,brackish water treatment,and point of use *** not only summarized the removal of target major pollutants(e.g.,hardness,pathogen,and natural organic matter),but also paid attention to the removal of micropollutants of major concern(e.g.,disinfection byproducts,per-and polyfluoroalkyl substances,and arsenic).We highlighted that,for different applications,fit-for-purpose design is needed to improve the separation capability for target compounds of NF membranes in addition to their removal of *** and perspectives on membrane fouling control,chlorine resistance,integrity,and selectivity are also discussed to provide potential insights for future development of high-efficiency NF membranes for stable and reliable drinking water treatment.

关键词： nanofiltration drinking water disinfection byproducts micropollutants selectivity

Capture and electro-splitting of CO_2 in molten salts

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Journal of Energy Chemistry 2019年第1期28卷 128-143页

作者： Wei Weng Lizi Tang Wei Xiao School of Resource and environmental Sciences Hubei International Scientific and Technological Cooperation Base of Sustainable Resource and EnergyWuhan University

Due to the serious greenhouse gas effects caused by the increasing concentration of atmospheric CO_2,carbon capture and storage(CCS) has been an important area of research and many technologies are developed within this field. Molten salt CO_2 capture and electrochemical transformation(MSCC-ET) process is a desirable method due to a high CO_2 solubility, a wide potential window of molten salts and easily-controlled electrode reactions. Generally, electro-splitting CO_2 in molten salts begins with CO_2 absorption reactions to form CO_3^(2-), which is then followed by the carbon deposition at the cathode and O_2 evolution at the anode. As a result, CO_2 is electro-converted to O_2 and carbon with different morphologies, compositions, microstructures and functional properties. This report introduces the MSCC-ET process, summarizes the reactions occurring in the molten salts and at the electrode surfaces, as well as the morphological variations of the cathodic products. The inert anode materials, cost estimation and scale-up evaluation of the process are then discussed. It is presumed that with a comprehensive understanding of the electrode reactions during electrolysis and the functional properties of carbon materials obtained during CO_2 electro-splitting can provide a foundation for further developing this environmentally friendly process.

关键词： CO2 electro-splitting Molten salt electrolysis Inert anodes Cost evaluation

Urban stormwater disinfection, quality variability during storage and influence on the freshwater algae: Implications for reuse safety

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Journal of environmental Sciences 2023年第2期124卷 655-666页

作者： Shanshan Fan Gang Wen An Liu College of Chemistry and environmental engineering Shenzhen UniversityShenzhen 518060China Shaanxi Key Laboratory of environmental engineering Xi’an University of Architecture and TechnologyXi’an 710055China Water Science and environmental engineering Research Center College of Chemistry and Environmental EngineeringShenzhen UniversityShenzhen 518060China

Stormwater reuse is one of the most important ways to mitigate water resource ***,urban stormwater contains many bacteria species,which threaten the reuse ***,stormwater disinfection is highly *** disinfection has been widely conducted in the drinking water and reclaimed water,it is rarely carried out for *** study collected the roof stormwater and undertook chlorination *** typical bacteria,Escherichia coli(***)and Staphylococcus aureus(***)were selected in this study to investigate the disinfection *** is found that bacteria species present in the stormwater had an important influence on disinfection efficiency while the original stormwater quality did not show an obvious ***,when the disinfected stormwater was stored,the stormwater quality was highly variable during its storage process and the variability was affected by bacteria *** *** containing stormwater showed a high variability of quality and *** significantly ***,the *** containing stormwater quality had a relatively low variability and *** did not significantly ***,it is noted that after storage,the dissolved form of stormwater was more positive to the freshwater algae’s growth while the particulate form(including bacteria and other particulate matters)was *** implies that a further treatment such as filtration is needed before the stored stormwater is recharged into receiving waters in order to remove particulate *** research outcomes can provide useful insight to effective stormwater disinfection and ensure reuse safety.

关键词： Stormwater quality Stormwater disinfection Stormwater storage Stormwater reuse Escherichia coli Staphylococcus aureus

Fabrication of mono-dispersed cerium oxide nanopowders via mixed solvothermal route

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Journal of Rare Earths 2010年第S1期28卷 139-143页

作者：王富星王志峰吴茂燕郭迅达王春宏张明 College of Chemistry and Chemical engineering Yangzhou University Jiangsu Province Key Laboratory of environmental Material and environmental engineering

Monodisperse and single-phase cerium oxide nanopowders were synthesized by mixed solvothermal route,Ce(NO3) 3·6H2O as raw materials,poly(vinylpyrrolidone) (PVP) as stable agent. The cerium oxide nanopowders could be controlled from 50 to 60 nm by adjusting the ratio between ethanol absolute and water at 160 °C. With methanol instead of ethanol absolute,the reaction temperature could be lowered to 130 °C.

关键词： cerium dioxide mixed solvothermal particle size distribution rare earths

Effects of yttrium under lead stress on growth and physiological characteristics of Microcystis aeruginosa

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Journal of Rare Earths 2016年第7期34卷 747-756页

作者：武阳王应军杜金戈王章鸿吴清莲 Department of environmental engineering College of Environment Sichuan Agricultural University Department of environmental engineering School of Energy and Environment Southeast University

Yttrium is a main kind of rare earth elements （REEs） with wide applications in modem industry and farming. Lead has been considered to be one of the most important heavy metal pollutants due to its environmental persistence and tendency. In order to clarify the effects of REEs on cyanobacteria in case of suffering heavy metal pollutants, we investigated the effect of different concentrations of yttrium ion （y3＋） on the common blue-green microalgae Microcystis aeruginosa, grown under conditions of lead ion （Pb2＋） stress. Growth and physiological status were tested involving several important enzyme of antioxidant defense system （superoxide dismutase （SOD）, peroxidase （POD）, catalase （CAT）, malondiadehyde （MDA）, chlorophyll a （Chl-a）, soluble sugar and Microcystin-LR （MC-LR） in cultured experiments. Results indicated that growth ofM. aeruginosa was stimulated when treated less than 0.50 mg/L y3-and 0.20 mg/L is the optimum concentration. With the increasing content of Chl-a and activity of SOD, POD, CAT at the 12th day at relatively low concentration of y3＋ treatment （〈0.20 mg/L）, enhancement of photosynthesis and the improvement of eliminating active oxygen on M. aeruginosa were observed. On the contrast, soluble sugar content on algae reduced as the treatment of initial y3＋ concentration was in the range of 0.00-0.50 mg/L. Besides, there was a significant accumulation in both contents of MDA and MC-LR exposed from 1.00 to 5.00 mg/L y3＋, indicating that the ruin of antioxidant defense system and further aggravation to the existence of algal cell may be due to MC-LR releasing. M. aeruginosa might suffer a more positive physiological impact for exposure of relatively low y3＋ concentration against Pb2＋ stress harm, which provided a far-reaching significance on blue-green algae research.

关键词： yttrium lead MC-LR rare earth elements Microcystis aeruginosa

Effect of ultraviolet mutagenesis on heterotrophic strain mutation and bioleaching of low grade copper ore

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Journal of Central South University 2017年第10期24卷 2245-2252页

作者： WU Ai-xiang HU Kai-jian WANG Hong-jiang ZHANG Ai-qing YANG Ying School of Civil and environmental engineering University of Science and Technology Beijing School of Resources and environmental engineering Jiangxi University of Science and Technology

The effect of ultraviolet mutagenesis on a heterotrophic strain(Providencia JAT-1) mutation was studied and bioleaching of low grade copper ore with mutant bacteria was investigated. The results show that the activity of bacteria was improved after ultraviolet mutagenesis; the best irradiation time was 120 s. Compared to the original bacteria, the cells density of mutant bacteria at stationary phase increased by 26% and ammonia produced by mutant bacteria increased by 12%. Higher activity of bacteria leads to a higher copper extraction rate. The bioleaching performance of Providencia JAT-1 was improved after UV mutagenesis. The copper extraction rate with mutant bacteria increased by 10.6% compared to the original bacteria. The ore surface was corroded and the fine particles were absent after bioleaching. Free copper oxide and copper silicates could be leached out easily by using JAT-1; a small part of the copper sulfide can also be leached out. Bioleaching using JAT-1 is more effective than ammonia leaching and copper extraction rate with mutant bacteria was 21.1% higher than that by ammonia leaching under the same condition.

关键词： ultraviolet mutagenesis bioleaching heterotrophic strain ammonia low grade copper ore

Heavy Metal Adsorption Properties of Marine Algae Durvilliea Potatorum,Ecklonia Radiata and Laminaria Japonica

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Chinese Journal of Chemical engineering 1998年第1期6卷 72-76页

作者：虞启明 Jose T.Matheickal Jozef Latten School of environmental engineering Griffith University

1 INTRODUCTIONBiosorption of heavy metals using biosorbents derived from suitable biomass is a new tech-nology for the removal and recovery of heavy metals from industrial waste *** ad-vantages of the biosorption technology include rapid reduction of dissolved heavy metal ionsconcentration to 10-6and 10-9levels,use of inexpensive and non-hazardous biosorbents,useof existing adsorption process equipment and therefore low operating costs,high uptake ca-pacity and specificity for selective heavy metal removals,and low interference from

关键词： biosorption heavy metal removal marine algae