KDF滤料去除自来水中铅、铬和镉的试验研究

选用合金滤料(KDF55)对自来水进行深度处理,以研究对水中铅、铬和镉的去除效果。试验结果表明,KDF55对水中重金属离子有较好的去除效果,在保证一定接触时间的条件下,对自来水中铅、铬和镉的去除率分别为77.9%、86.5%和70.1%。研究表明:KDF55对自来水中铅、铬和镉有稳定的去除效果。     

长江口新成陆区域土壤重金属分布及风险评价——以上海市横沙东滩为例

为了解长江口新成陆区域土壤中重金属污染特征及其生态风险,对上海市横沙东滩71个采样点土壤中8种重金属(铜、铬、镍、锌、铅、镉、砷、汞)的含量进行检测和统计分析,并结合蒙特卡洛模拟对其生态风险进行评价。结果表明：(1)表层土壤中重金属的含量由高到低依次为锌、铬、镍、铅、铜、砷、镉、汞,其平均值均低于上海市土壤背景值。铬、镍、锌、铅、汞服从对数正态分布,铜、镉、砷既不服从正态分布也非对数正态分布。(2) Hakanson潜在生态风险指数法评价结果表明,各重金属潜在生态风险因子高低顺序为汞>镉>砷>镍>铅>铜>铬>锌,8种重金属的潜在生态风险指数(RI)为36.80～150.96,处于轻微至中等生态风险水平,且以轻微生态风险水平为主(概率为93.34%)。ERL/ERM法评价结果表明,8种重金属时常发生生态风险的概率极小(<0.72%),镉、铅、锌、铜、汞、铬、砷很少或者无负面生态风险,而镍则偶尔发生生态风险(概率为95.04%)。8种重金属总体发生生态风险的等级和频率均较低,但部分重金属(如汞、镍)须予以一定关注。     

臭氧预氧化强化混凝处理微污染水源水中试效能研究

为了使某水库微污染水源水达到生活饮用水卫生标准,在低温低浊和常温两种情况下,采用臭氧预氧化强化混凝工艺对微污染水源水中的有机物、浊度和色度等污染物进行中试去除研究。结果表明,臭氧预氧化与强化混凝联用工艺对有机污染物、浊度和色度都有良好的去除效果,并且具有很强的抗冲击负荷能力。在低温低浊和常温两种情况下,工艺出水高锰酸盐指数(CODMn)、浊度和色度分别为2.33~2.99mg/L、≤0.74NTU、≤6.89度,均满足《生活饮用水卫生标准》(GB5749—2006)的要求。     

我国饮用水源的重金属污染及治理技术深化问题

本文在调研我国各主要饮用水水体重金属污染现状及其污染特点的基础上，提出汞、镉、铬、铅为主要的重金属污染物，通过分析现阶段国内外净化水质技术，认为尚不能去除高背景载体下的微量重金属污染，进而提出有待深入开展研究的建议。     

不同pH值条件下重金属捕集剂有效性的研究

采用高分子有机捕集剂与废水中的多种重金属离子发生螯合反应,生成稳定且不溶于水的金属螯合物来去除废水中的重金属离子。对4种捕集剂在不同pH值的条件下对含有汞、铜、镉、铅等重金属污水的去除效果进行了试验研究。结果表明,利用重金属捕集剂方法处理重金属废水的效率较高,有很好的应用前景。     

伊通河长春段地表水中铅、铬、镉形态变化规律

对2003~2006年伊通河长春段6个地表水监测断面中重金属铅、铬、镉形态变化规律进行了研究。结果表明:地表水中铅和铬的年平均浓度呈递增态势;镉的浓度随流程的增加而增加,年平均浓度也呈递增趋势。此外,研究区域内铅主要以PbCO3、Pb3(PO4)2和Pb2+等3种形态存在,铬以CrO42-的形态存在,镉的存在形态以Cd2+为主,其中2006年铬超标约1.4倍,对水体的危害最大,镉有接近超标呈逐年升高的趋势。     

珠江长州断面底泥重金属污染潜在生态危害评价

测定了珠江广州河段长州断面底泥中重金属镉、铬、铜、铅的质量比,采用Tessier形态分类法对它们在底泥中的存在形态进行了提取和测定。监测分析表明,该断面底泥中镉、铬、铜、铅质量浓度均高于全国湖泊底泥中的平均值。该断面底泥中镉、铬、铜、铅质量比分别为广东土壤背景值的49.50倍、3.62倍、14.24倍、5.51倍,底泥成为这些重金属的富集地。镉以可交换态为主,占总量的比例为47.47%;铬和铅以残渣态为主,占总量的比例分别为42.35%和47.28%;铜主要以有机态及硫化物结合态为主,占49.06%;残渣态较低,占18.26%。采用潜在生态危害指数法对该断面底泥中的镉、铬、铜、铅进行了潜在生态危害评价,结果表明:镉潜在生态危害强,铬、铜、铅的潜在生态危害轻微。     

饮用水水源中重金属污染防控技术与对策

1 水源水体重金属污染现状 关于重金属目前尚无严格定义,通常将密度大于5 g/cm3的金属称为重金属,约40余种.从环保角度而言,重金属污染是指由重金属或其化合物引起的环境污染,如汞(Hg)、铬(Cr)、镉(Cd)和铅(Pb)等,习惯上将砷(As)污染也归于重金属污染一类.对水源水体产生污染的重金属主要有砷(As)、汞(Hg)、铬(Cr)、镉(Cd)和铅(Pb)等,其主要来源于电镀、冶金、采矿、化工等行业.由于重金属污染物在水体中具有高稳定性和难降解特性,极易对水生生态系统产生危害,并可通过食物链富积直接或间接地影响人类健康.20世纪发生在日本的著名环境公害事件——骨痛病事件和水俣病事件就是分别由镉和汞的水体污染引起的.重金属污染已成为当今世界上最严重的环境问题之一.     

重金属对黄土pH值的影响

文中研究了重金属铅、锅对黄土区pH值的影响，通过试验分析得出：随着重金属离子浓度的增大黄土区的pH值会减小，但浓度增大到一定程度后，将使黄土的pH值变化趋于某一稳定的值。重金属铅对黄土区的pH影响要大于镉。     

黄河泥沙与重金属污染物相互作用研究现状

20世纪80年代以来,国内外学者对重金属在泥沙颗粒上的吸附、解吸研究都很活跃,且取得了不少成果,研究内容包括吸附动力学方程、泥沙和水环境特征(泥沙粒度、矿物成分、pH值、温度等)对吸附的影响、水体中重金属的化学稳定性等。粗细不同的泥沙对重金属污染物的吸附能力差异很大,泥沙颗粒越细,比表面积越大,吸附能力越强;在同一重金属初始浓度下,重金属从溶液中的去除量随pH值的升高而增加;水体中含沙量增加时,单位泥沙对重金属的吸附量先增加后降低。     

湖北鄂州城市湖泊底泥重金属空间分布特征与污染评价

以湖北省鄂州市某湖泊底泥重金属为研究对象,在调查和分析的基础上,采用地质累积指数和潜在生态危害指数对底泥中的重金属分布以及污染状况进行评价。结果表明:从柱状底泥纵向分布来看,该湖底泥重金属含量整体上呈现从上到下递减的变化趋势,上层底泥重金属含量最高;从空间分布上看,3个湖区重金属污染程度排序是西湖区域＞东湖区域＞中湖区域。地质累积指数评价结果显示该湖底泥重金属主要以无污染—中度污染为主,底泥中重金属污染程度的大小排序为Cd＞Zn＞Cu＞Pb＞Ni＞Cr＞Hg＞As;潜在生态危害指数法的评价结果显示底泥中As、Ni、Cu、Pb、Cr和Zn生态风险水平较低,Cd和Hg存在着不同程度的潜在生态风险,Cd的潜在生态风险最高。研究成果为该湖泊的污染调查和评价分析提供参考,并为湖泊后续的保护和水环境系统的可持续发展提供科学依据。     

The impact of a sewage treatment plant's effluent on sediment quality in a small bay in Lake Geneva (Switzerland–France). Part 2: Temporal evolution of heavy metals

The Bay of Vidy is the most contaminated area of Lake Geneva, Switzerland, as a result of the release of treated and untreated waste water from the municipal sewage treatment plant of the city of Lausanne and its surroundings. The reconstruction of the historical deposition of heavy metals in the sediment of the bay has been performed by the analysis of several dated (radiocaesium) sediment cores. The presence of sewage‐derived contaminants in the Bay of Vidy since the beginning of the sewage treatment plant's operations in 1964 is clearly observed, when a sharp increase in heavy metal contents is recorded, with maximum concentrations of cadmium, copper, zinc and lead occurring between the late 1960s and early 1970s. Despite considerable improvement in recent times, the present concentrations of the investigated heavy metals in sediments of the Bay of Vidy are still higher than concentrations measured at the centre of the lake, the latter close to Lake Geneva's natural background values. It is concluded that the quantity of heavy metals deposited in the bay is considerable and, because of sediment instability, will constitute a potential hazard for biota.     

镉污染底泥电动修复影响因素研究

以镉(Cd)含量为2mg/kg污染底泥为研究对象,使用电动修复技术对污染底泥中的Cd进行脱除。研究了不同电极板间电压、化学增强剂种类以及电极材料对体系电流、温度、电导率、底泥含水率以及重金属含量的变化,试验结果表明:使用阳离子聚丙烯酰胺(CPAM)作为化学增强剂,使用多孔碳作为电极,极板间电压30V,同时在0.05MPa的压力下进行抽滤,底泥含水率在5h内由75%下降到34.17%,重金属镉含量由2mg/kg下降到0.178mg/kg,脱除率达到91.12%,修复后的底泥中镉的含量满足《土壤环境质量标准》(GB 15618-1995)中对镉含量的一级标准要求,达到了对污染底泥脱水过程中脱除重金属的目的。     

高浊度河口颗粒态重金属对泥沙运动的指示作用

作者根据1994年6月长江口、杭州湾的水质调查资料，分析了这类高浊度河口颗粒态重金属的分布规律。研究表明，在长江口和杭州湾内，悬沙和表层沉积物中Cu、Pb、Cd分布特征相似，尤其在杭州湾中部水域，二者重金属含量呈趋同的态势。细颗粒泥沙是颗粒态重金属的主要载体。在高浊度河口，动力沉积过程为控制颗粒态重金属分布和输移的主要因子，颗粒态重金属的分布对泥沙运动具有指示作用，悬沙和表层沉积物中重金属元素的分布反映了长江口泥沙向杭州湾输移的事实。     

Heavy metal concentrations in fish of Lake Balaton

The concentration of heavy metals (cadmium, copper, lead, mercury and zinc) found in muscle, gills and liver of eel, bream and pike‐perch living in Lake Balaton (Hungary) varied significantly between fish species and organs. The toxic metals in the muscle of fish, except for cadmium in bream, were below the maximum permissible level for human consumption. Cadmium concentrations above the maximum permissible level occurred in autumn in a few small individuals of bream, which, because they have poor culinary value and are seldom consumed, does not represent a risk for humans. Cadmium, copper, lead and zinc levels proved to be higher in eel and bream compared to pike‐perch, while high mercury concentrations were found in the predator fish, pike‐perch. Mercury accumulated most in the muscle in each species, while other metals were found in higher levels in the gills and liver. Seasonal differences were found for cadmium in each species and for lead in eel; the concentrations being elevated in autumn compared to spring. The fish species studied as bio‐monitors demonstrated that the overall heavy metal pollution of Lake Balaton is not significant, although, during summer an increase of cadmium and lead loading could occur at the catchment area and in the lake. Studies on the size (age) dependency of heavy metal concentrations showed that, in most cases, none or a negative relationship exists for each organ and metal in all species studied, and a positive regression coefficient was characteristic only on some occasions for mercury, cadmium and lead.     

生物表面活性剂对河道底泥重金属的淋洗效果比较

为了比较生物表面活性剂性质、活性剂浓度和淋洗时间等对河道底泥中重金属淋洗效果的影响。研究中选取了3种不同的生物活性剂即茶皂素、皂角苷和槐糖脂。研究结果表明:活性剂不同,淋洗效果不同;生物活性剂的胶束形成性质会影响淋洗效果;在3种活性剂中,临界胶束浓度低的槐糖脂淋洗效果最好;此外,活性剂浓度为8%时,淋洗效果已达到最佳。淋洗时间对淋洗效果的研究则证明:茶皂素、皂角苷和槐糖脂对重金属淋洗动力学过程可以用Elovich方程进行描述,淋洗过程为非均相扩散过程。研究中还对淋洗前后重金属形态进行了分析,淋洗可以有效去除底泥中弱结合态(离子交换态和碳酸盐结合态)重金属,使得强结合态的重金属所占比例增加,从而降低重金属的生物有效性。     

Assessment of sediment quality of a tropical lake using sediment quality standards

Sediments are often reservoirs of contaminants in aquatic waterbodies, and their quality can be an indicator of the health of their ecosystems. Heavy metal pollution in sediments is highly significant because of their persistent and bioaccumulative nature. In this regard, sediment quality guidelines (SQG) are useful for categorizing sediment quality with respect to the contaminant level in them. An attempt was made in this study to assess the sediment quality of the Akkulam‐Veli (AV) Lake system on the basis of guidelines that incorporate assessment scales that differ in their approaches. Some link threshold levels of heavy metal concentrations on the basis of their likelihood to cause adverse effects, while others classify the sediment concentration ranges that correspond to the degrees of toxicity caused by them. The sediment quality of the study area was assessed by combining the available guidelines to formulate two new approaches in this study. Based on this approach, AV Lake is highly polluted with respect to chromium (Cr), nickel (Ni) and lead (Pb), while arsenic (As) and cadmium (Cd) are non‐polluting with a negligible potential for adverse effects.     

南通市河流底泥重金属污染及潜在生态风险评价

通过对南通市区5条主要河道柱状底泥样品重金属元素质量比的实验分析,探讨河道重金属污染的分布特征,并进行潜在生态风险评价。结果表明:①各重金属元素质量比均超过土壤背景值,污染较重,其中Hg污染最为严重;②重金属污染在垂直分布上分为未受干扰、正常沉积的"表层高、底层低"和受清淤治理措施影响的非正常沉积的"表层低、底层高"两种分布格局,在水平分布上具有"城市中间河流高、外围河流低"和"中上游河段高、下游河段低"的分布特征;③从重金属污染的潜在生态风险看,濠河和法伦寺河潜在生态风险强,姚港河生态风险中等,任港河和南川河生态风险轻微。各重金属元素对生态风险的影响程度大小依次为:HgCuZnCrPb。