市政污泥中重金属处置技术研究进展

论述了市政污泥中重金属的污染来源、污染现状及危害,着重阐述了市政污泥中重金属的处置技术及其优缺点,并对重金属处置的研究进行展望,为市政污泥中重金属污染治理的相关工作提供技术支持。     

水质对附子中重金属元素的影响

为了探究附子产地水质重金属对附子重金属的影响。采集并测定江安河及涪江江油段河水中Cd、As、Cr、Sb、Pb、Hg、Zn、Tl、Cu、Ba、Mn、Fe 12种重金属元素,与近年来附子重金属元素进行Spearman相关性分析。结果表明,江油产生附子中重金属元素平均质量浓度均未超过国家规定限量,江油产生附子与涪江江油段河水中重金属元素质量浓度显著相关(P<0.05),涪江水质是影响附子重金属元素质量浓度的重要因素之一。附子中Cr、Mn、Fe等3个元素质量浓度与河水中的差异较大,部分样品中Cd超标,可能由于水质以外的污染途径以及附子自身对特定重金属元素的富集能力影响。     

与核电站为邻

正2011年3月11日日本福岛核电站发生事故后,人们对高风险技术,尤其是核电技术有了深深的怀疑。尽管德国表示今后要逐步废止核电技术,但世界各国对核电的研发和使用仍方兴未艾。2月7日,一份《关于请求停止江西彭泽核电厂项目建设的报告》的文件在微博上引发热     

Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops

Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely： inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil （total or bioavailable concentration） that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include： soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity.     

Removal of copper ions from electroplating rinse water using electrodeionization

An improved configuration of the membrane stack was adopted in the electrodeionization （EDI） cell to prevent precipitation of bivalent metal hydroxide during the running. The operational parameters that influenced the removal of copper ions from the dilute solution were optimized. The result showed that a moderate decrease in the inlet pH value and a moderate increase in the applied voltage could achieve a better removal effect. The steady process of electroplating wastewater treatment could be achieved with a removal efficiency of more than 99.5% and an enrichment factor of 5-14. The concentration of copper in purified water was less than 0.23 mg/L. This demonstrated the applicability of recovering heavy metal ions and purified water from electroplating effluent for industrial reuse.     

新乡市郊区农田土壤耕层重金属铅的抽样分析

通过对新乡市郊区4个乡镇的45个村庄农田土壤耕层重金属铅(Pb)抽样分析结果表明:不同乡镇农田土壤耕层中重金属铅含量不同,同一乡镇同一村庄的不同地块重金属铅含量也不相同.4个乡镇的土壤耕层铅含量的平均值大小顺序为:牧野乡＞和平路办事处(乡)＞小店乡＞电源产业园乡,铅含量平均值分别为17.92mg/kg,16.61 mg/kg,14.31 mg/kg,13.58 mg/kg,在45个村庄中铅含量最高的是牧野乡朱庄村的一块耕地,含量为28.22 mg/kg,而铅含量最低的是电源产业园乡前河头村的一块耕地,含量仅为7.09 mgkg-1,均未超过国家<土壤环境质量标准>(GB-15618-1995)中规定的铅含量≤350 mg/kg,所测土壤均未受到铅污染.     

重金属元素对青菜的污染

针对重金属元素对青菜的污染情况进行了论述。     

水体中重金属离子的电化学检测

重金属是引起水体污染的重要因素,将对环境及社会生活带来灾难性后果.综述目前水体中重金属检测所使用的一些技术手段.着重介绍电化学方法在检测水体中重金属离子的原理、方法和该法的优势特点.