Integration of multi-channel piezometry and electrical tomography to better define chemical heterogeneity in a landfill leachate plume within a sand aquifer

The Hanai-Bruggeman effective medium theory is used to relate bulk electrical conductivity, measured by surface and cross-borehole images, to fluid electrical conductivity, surface conductance, porosity and the geometry factor, in a medium- to fine-grained sand deposit. The change in bulk EC is caused by the presence of a landfill leachate plume. Repeated electrical images over a period of 16 months indicate that various segments of the plume are moving. The chemical constituents of the leachate plume have been determined by sampling from a bundled piezometer located in the electrical image field. Very close agreement is demonstrated between the fluid EC anomaly and the presence of elevated bulk EC indicating that the electrical images can be used to map the plume geometry and to monitor the movement of the plume segments.     

The impact of seasonal variations in DOC arising from a moorland peat catchment on coagulation with iron and aluminium salts

Natural organic matter (NOM) is one of the main sources of environmental pollution to drinking water supplies in much of the UK and the US. Whilst traditional treatment with trivalent coagulants has proven a successful strategy in the past, operational problems are now being reported during periods of elevated organic levels in the water. Characterisation of the pollutants in terms of polarity, molecular weight and charge, provides a method to understand the impact of the observed temporal and spatial variations in terms of a mechanistic parameter relevant to the treatment processes. Results from this study demonstrate that it is not simply the increased organic concentration, but also the change in NOM composition and character, which influences the impact on the treatment processes. Consequently, monitoring of these parameters provides an insight into how to manage the impact caused by environmental changes to the catchments.     

四川省境内核工业放射性废物污染的潜在危险及防治对策

本文通过对四川省境内核工业放射性废物污染的潜在危险分析，提出了污染的对策。     

亚热带地区潜流人工湿地木本植物筛选与净化潜力评价

为了解决亚热带地区人工湿地植物的冬季草本植物地上部分枯死的问题,本研究引入16种木本植物到潜流人工湿地中进行净化潜力筛选与评价,并对木本植物的适应形态特性、生理特性、氮磷积累量指标进行了聚类分析.结果表明,测试木本植物的成活率、株高增幅、根长增幅、根系活力、叶绿素含量、超氧化歧化酶、丙二醛、脯氨酸、过氧化物酶、生长量、氮磷平均浓度、氮磷的积累量都存在很大差异.采用建立的净化潜力评价体系将测试植物聚类分为3大类,较强的有夹竹桃、木槿,中等的有:棕榈、小叶迎春、栀子花、六月雪、龟甲冬青,较弱的有:大叶冬青、常春藤、金森女贞、金叶女贞、金边七里香、七里香、桂花、十大功劳、红叶石楠.     

鄱阳湖持久性有机污染物（POPs）长距离传输潜力模拟

利用TaPL3模型模拟研究了鄱阳湖5种典型持久性有机污染物(POPs)的长距离迁移潜力(LRTP)和总持久性(Pov),比较了不同污染物特征迁移距离(CTD)和Pov的大小,并以p,p’-DDT为例对关键参数进行了灵敏度分析.结果表明,p,p’-DDT、γ-HCH、HCB、PCP和2,3,7,8-TCDD排放到大气中,特征迁移距离(CTDAir)在432 km(2,3,7,8-TCDD)~86479 km(HCB)之间,总持久性(PovAir)在85.6 d(PCP)~2231 d(HCB)之间,土壤相是POPs的主要归宿,约占72.0%;排放到水体中,特征迁移距离(CTDWater)在4207 km(PCP)~1.19×105km(γ-HCH)之间,总持久性(PovWater)在103 d(PCP)~2890 d(HCB)之间,沉积物相是POPs的主要归宿,约占52.5%.环境介质中的半衰期和辛醇-水分配系数的对数是影响污染物CTD和Pov的主要理化性质参数.与同类研究相比,相关POPs在鄱阳湖的CTDAir处于中间水平,但CTDWater偏高,这与鄱阳湖的水体深度和水体流速这两个对CTDWater影响显著的参数较其它研究区域高有关.研究结果可为该地区POPs的环境过程及环境风险的研究提供科学依据.     

Reduction of DOM fractions and their trihalomethane formation potential in surface river water by in-line coagulation with ceramic membrane filtration

This research was aimed at investigating the reduction of DOM fractions and their trihalomethane formation potential （THMFP） by in-line coagulation with 0.1 μm ceramic membrane filtration. The combination of ceramic membrane filtration with a coagulation process is an alternative technology which can be applied to enhance conventional coagulation processes in the field of water treatment and drinking water production. The Ping River water （high turbidity water） was selected as the raw surface water because it is currently the main raw water source for water supply production in the urban and rural areas of Chiang Mai Province. From the investigation, the results showed that the highest percent reductions of DOC, UV-254, and THMFP （47.6%, 71.0%, and 67.4%, respectively） were achieved from in-line coagulation with ceramic membrane filtration at polyaluminum chloride dosage 40 mg/L. Resin adsorption techniques were employed to characterize the DOM in raw surface water and filtered water. The results showed that the use of a ceramic membrane with in-line coagulation was able to most efficiently reduce the hydrophobic fraction （HPOA） （68.5%）, which was then followed by the hydrophilic fraction （HPIA） （49.3%）. The greater mass DOC reduction of these two fractions provided the highest THMFP reductions （55.1% and 37.2%, respectively）. Furthermore, the in-line coagulation with ceramic membrane filtration was able to reduce the hydrophobic （HPOB） fraction which is characterized by high reactivity toward THM formation. The percent reduction of mass DOC and THMFP of HPOB by in-line coagulation with ceramic membrane filtration was 45.9% and 48.0%, respectively.     

Emission factors of polycyclic aromatic hydrocarbons from domestic coal combustion in China

Domestic coal stove is widely used in China, especially for countryside during heating period of winter, and polycyclic aromatic hydrocarbons （PAHs） are important in flue gas of the stove. By using dilution tunnel system, samples of both gaseous and particulate phases from domestic coal combustion were collected and 18 PAH species were analyzed by GC-MS. The average emission factors of total 18 PAH species was 171.73 mg/kg, ranging from 140.75 to 229.11 mg/kg for bituminous coals, while was 93.98 mg/kg, ranging from 58.48 to 129.47 mg/kg for anthracite coals. PAHs in gaseous phases occupied 95% of the total of PAHs emission of coal combustion. In particulate phase, 3-ring and 4- ring PAHs were the main components, accounting for 80% of the total particulate PAHs. The total toxicity potency evaluated by benzo[a]pyrene-equivalent carcinogenic power, sum of 7 carcinogenic PAH components and 2,3,7,8-tetrachlorodibenzodioxin had a similar tendency. And as a result, the toxic potential of bituminous coal was higher than that of anthracite coal. Efficient emission control should be conducted to reduce PAH emissions in order to protect ecosystem and human health.     

Effects of cathode potentials and nitrate concentrations on dissimilatory nitrate reductions by Pseudomonas alcaliphila in bioelectrochemical systems

The effects of cathode potentials and initial nitrate concentrations on nitrate reduction in bio- electrochemical systems （BESs） were reported. These factors could partition nitrate reduction between denitrification and dissimilatory nitrate reduction to ammonium （DNRA）. Pseudomonas alcaliphilastrain MBR utilized an electrode as the sole electron donor and nitrate as the sole electron acceptor. When the cathode potential was set from -0.3 to -I.1 V （vs. Ag/AgC1） at an initial nitrate concentration of 100 mg NO~-N/L, the DNRA electron recovery increased from （10.76 ± 1.6）% to （35.06 ± 0.99）%; the denitrification electron recovery decreased from （63.42 ± 1,32）% to （44.33 ± 1.92）%. When the initial nitrate concentration increased from （29.09 ± 0.24） to （490.97 ± 3.49） mg NO3-N/L at the same potential （-0.9 V）, denitrification electron recovery increased from （5.88 ± 1.08）% to （50.19 ±2.59）%; the DNRA electron recovery declined from （48.79 ±1.32）% to （16.02 ± 1.41）%. The prevalence of DNRA occurred at high ratios of electron donors to acceptors in the BESs and denitrification prevailed against DNRA under a lower ratio of electron donors to acceptors. These results had a potential application value of regulating the transformation of nitrate to N2 or ammonium in BESs for nitrate removal.     

中山市不同类型企业周边土壤重金属污染特性及潜在生态风险评价

以中山市不同类型涉重金属企业周边土壤(0~20cm)为调查对象,分析了土壤中重金属Cu、Zn、Pb、Cd、Cr、Hg和As的含量,采用地积累指数法和潜在生态危害指数法对土壤重金属污染进行了分析和评价。结果表明,除Pb外其它7种元素含量超过广东省背景值,不同类型土壤环境的污染程度地积累指数评价处于无-中度污染,潜在生态危害处于强度危害程度。统计分析表明,Cr、Ni、Cu、Zn具有显著相关性,不同类型企业周边土壤中重金属污染主要受Cr、Cu、Ni、Zn控制,其次是受As、Hg和Cd控制。     

安徽省垃圾填埋气CO_2减排潜力研究

采用IPCC与可生物降解两种预测模型对安徽省2020年城市生活垃圾填埋气甲烷产量进行预测,并分析比较模型预测结果;进而通过填埋气发电项目对安徽省垃圾填埋气二氧化碳减排潜力进行探讨。结果表明:预计到2020年,安徽总的生活垃圾清运量可达到758.9万吨,可产生的生活垃圾填埋气甲烷产量约45.5万吨,若这些甲烷气体不经处理直接排放到大气中,相当于排放约900万吨的CO2,因此,安徽省垃圾填埋气CO2减排潜力巨大,其基于清洁发展机制(CDM)的减排潜力可达1.46×109吨。该研究对促进安徽省CDM项目的开发,充分利用CDM资金促进安徽经济的可持续、健康发展具有一定的指导意义。