陕西潼关金矿区太峪河底泥重金属元素的含量及污染评价

通过对潼关金矿区太峪河和太峪水库底泥中重金属元素总量的调查,探讨了金矿开发活动中重金属元素对河流底泥的污染程度。研究结果表明,除As外,河流底泥中重金属元素的含量与尾矿渣中重金属元素的含量变化一致,表明其主要来源于尾矿渣,但又明显高于尾矿渣。在同一地点河流底泥中重金属元素的含量平均高出河水中的1048.61～666030.08倍,呈显著富集。以邻近地区不受工矿活动影响的河流底泥重金属元素的含量均值作为评价参比值,太峪河底泥受到了Hg、Pb、Cd、Cu、Zn元素的极度污染,单项污染超标倍数及综合污染指数法评价结果表明,Hg、Pb、Cd平均污染超标倍数达366.90、217.42和149.97,是底泥中最主要的污染元素。河流底泥重金属元素的综合污染指数高达278.97,表明河流的复合污染亦呈极度状态。太峪河底泥受重金属元素极度污染的现实提示,矿区的环境防治工作已刻不容缓。     

我国环境保护进展及政策

近年来,在党中央、国务院的正确领导下,各地、各部门深入贯彻落实科学发展观,把污染减排作为调整经济结构、转变发展方式的重要抓手和突破口,放在更加突出的位置,采取综合措施,加快污染治理,推动力度进一步加大,政策措施进一步落实,减排工作取得突破性进展,二氧化硫和COD排放量实现双下降,环保工作取得积极进展。     

地下连续墙治理地下水污染

介绍一种治理已被严重污染的地下水的方法。即修建一道底部深入到不透水岩层的地下墙,把污染物封闭在由底部不透水岩层和周围地下防渗墙组成的“地下盆”中,降低周围地下水中有害物质的浓度,然后再治理封闭圈内的污染物,以达到彻底根治地下水污染的目的。     

Permeable Reactive Barrier for the treatment of contaminated surface water in Katedan industrial development area, Hyderabad, India

Permeable Reactive Barrier （PRB） is an emplacement of inert material （s） in the subsurface, designed to intercept a contaminated plume, provides a preferential flow path through the reactive media, and transforms the contaminant into environmentally acceptable forms to attain concentration remediation goals at the discharge of the barrier. The phenomena, which help in remediation within PRB, are adsorption/sorption, precipitation, oxidation/reduction and biodegradation. Various materials like zero-valent iron, zero-valent bi-metals, natural zeolites, organic carbon, fly ash, zeolites, limestone, activated alumina, apatites, etc. have been tried by many researchers to remove organic and inorganic contaminants. In USA, Canada, and many European countries commercial full-scale and pilot scale PRBs are successfully working. The design and installation of full scale PRBs needs laboratory treatability and dynamic flow column experiments？ The concept of PRB is being applied to treat contaminated surface water in the Katedan industrial area, Hyderabad, India. National Geophysical Research Institute （NGRI）, Hyderabad, India, conducted systematic studies in collaboration with Norwegian Geotechnical Institute （NGI）, Norway, to develop PRB technique to decontaminate the surface water pollution due to industrial effluent. A site assessment study in the Katedan Industrial Area, were carried out and water, soil and sediment from the lakes of the area were found to be polluted with high concentrations of heavy metals like As, Pb, Cr, Cd, Ni, etc. Adsorption studies at NGRI with synthetic samples and in-situ industrial effluent using different reactive media for removing contaminants like arsenic, chromium, cadmium, copper, nickel, lead and zinc have been carried out and yielded satisfactory results. The performance of zero-valent iron and limestone is encouraging in removing As,     

Microwave-assisted extraction of organochlorine pesticides from sediments and determination by gas chromatograph with electron capture detection

A simple and rapid procedure to extract organochlorine pesticides （OCPs） from sediments by means of microwave energy is proposed. Sediment samples were irradiated with microwaves in a closed vessel system while immersed in hexane-acetone （1 ： 1, v/v）. The sample extracts were cleaned up using solid phase extraction with Florisil as adsorbent. Pesticides were eluted with hexane-ethyl acetate （80 ： 20, v/v） and determined by gas chromatographic separation with electron capture detection. Three oven programs were assayed with two different solvent mixtures in order to achieve adequate experimental conditions for the complete extraction of organochlorine pesticides from the matrix. Different variables such as the composition of extraction solvent,     

Attenuation of aqueous metal transport at two natural acid rock drainage occurrences in the Yukon Territory, Canada

Naturally acidic drainage associated with pyritic black shale has been observed in many locations in the Yukon Territory. While not necessarily linked to known mineral deposits, most of these natural acid rock drainage occurrences show elevated dissolved concentrations of trace elements, especially zinc, nickel, copper, cadmium and arsenic. Based on field observations, microbial investigation, chemical analyses and geochemical modeling, the fate and transport of potentially deleterious elements at two natural acid drainage occurrences with slightly different settings are examined. The Macintosh Creek is a small, acidic stream （pH 2.98-3.40）, 2 km long, located in the Macmillan Pass area of east-central Yukon amidst known sedimentary exhalative massive sulfide mineralization but remains undisturbed by exploration activities. Its trace metal content is apparently derived from groundwater discharges, which gave as much as 5.0, 2.5, 0.7, 0.13 and 0.03 mg/L ofZn, Ni, Cu and As, respectively. Interaction and sorption reactions with algal mats, biofilms and iron oxyhydroxides appear to be the dominant mechanisms attenuating aqueous contaminant transport along the stream. Cryogenic precipitation further consolidates the ferricrete formation and reduces the mobility of the sorbed metals. The tributaries of the Engineering Creek along the Dempster Highway in northern Yukon drain through a series of dolomite, phyllite, argillite, limestone, black shale, sandstone and conglomerate with no known concentration of mineralization. In this area, the water chemistry fully reflects the local geology with acidic streams invariably associated with black shale occurrences. Groundwater seeps in the headwaters area of the km-180 Creek completely enclosed in black shale gave pH 3.0 and as much as 148, 39, 2.9 and 9.1 mg/L of Zn, Ni, Cu and As, respectively. Sorption with iron oxyhydroxide and organic matter appear to dominate the attenuation of contaminant transport along the stream. However, once entered into carbonate-dominated terrains, secondary carbonate minerals exercise additional geochemical control on the local water chemistry as a result of neutralization.     

辽河干流铁岭段近五年水质污染趋势分析

依据辽河干流铁岭段4个水质监测断面近5年的监测数据,对主要超标项目的变化趋势进行分析,并对开发、保护和利用水资源以及加强水资源的管理,提出了合理化建议.