Impact of organic manure on the phytoremediation potential of Vetiveria zizanioides in chromium-contaminated soil

Chromium is a pollutant present in electroplating waste water and its removal is necessary for the protection of the environment. Vetiveria zizanioides (VZ) was grown in chromium effluent concentrations of 50, 100 and 200 mg kg ^?1 soil amended with organic manure and the potential for phytoremediation was determined. The amounts of Cr in plant tissues (root and shoot), soil and percentage electrolyte leakage of VZ roots were analysed. From the results, VZ amended with organic manure showed the greatest potential for Cr removal because of its faster growth and larger biomass achieved over the whole length of the experiment. In this study, 92.25% Cr removal efficiency was obtained with a Cr concentration of 50 mg kg ^?1 soil and removal efficiencies of 90.5% and 85% were obtained with 100 and 200 mg kg^?1, respectively after a period of two months of VZ growth.     

Biochemical constituents and bioaccumulation as biomarkers in the green mussel Perna viridis with reference to silver and chromium toxicity

The sublethal effect of silver and chromium on some biochemical constituents was studied in the green mussel Perna viridis. The results revealed an overall reduction in total protein, total DNA, total RNA, glycogen, protein bound sugars and total lipid in the gill, hepatopancreas, and ovary of the mussels exposed to metals individually and in combination when compared with control. It was apparent that mussels exposed to mixtures of metals exhibited highly significant (P?P?P?相似文献   

Assessment of cadmium,chromium, and copper levels in market fruit samples in Meerut,North India

The levels of cadmium (Cd), chromium (Cr), and copper (Cu) were assessed in 24 fruit species in Meerut, North India using atomic absorption spectrometry. Data showed that Cd concentrations in fruits except banana, pomegranate, papaya, orange, and cherry were above the recommended maximum allowable limit of Food and Agriculture Organization (FAO)/World Health Organization (WHO) (0.2 µg/g). Average Cr concentrations in all analyzed fruit samples were also found higher than the safe limit of FAO/WHO (2.3 µg/g). In contrast, fruits viz. banana, lychees, papaya, Indian apple, Asian apple, and tiger nut showed concentration of Cu below the recommended safe limit (40 µg/g). Our study demonstrated that concentration of studied heavy metals in all tested samples varied according to fruit species and respective contaminants. Data suggest that more strict rules/standards need to be applied by National/International regulatory agencies in order to make these important fruit items free from heavy metals contamination and protect the consumer.     

Cadmium and chromium in human lung tissue in relation to smoking and lung cancer

The pulmonary Cd and Cr content was determined from 53 lung cancer patients operated for cancer and from 39 patients who died of non‐malignant diseases. The results were correlated with smoking habits, pulmonary emphysema and occupational history. Both the pulmonary Cd and Cr increased with the amount of smoking. In ex‐smokers the Cr content in lung tissue did not diminish with the time since stopping smoking, but the Cd did follow the half‐life of about 9 years. The pulmonary Cd, compared with smoking habits, behaved similarly in both the lung cancer and control patients, whereas Cr in the lung cancer patients could not be explained solely by smoking, but some of the cancer patients may have been occupationally exposed to Cr. Speciation was not studied.     

Absorption and retention of polydimethylsiloxanes (silicones) in fish: Preliminary experiments†

Hydrophobicity and bioaccumulation potential of linear and cyclic polydimethylsiloxane (PDMS) oligomers were estimated by reversed‐phase liquid chromatography and feeding experiments with guppies (Poecilia reticulata). PDMS concentrations in fish were determined by capillary column gas chromatography and gas chromatography‐mass spectrometry. In contrast to polychlorinated biphenyls (PCBs), only very small amounts of PDMS were retained by the fish after six weeks feeding.     

铬污染场地修复技术研究及应用

综述了国内外铬污染场地修复技术的研究动态,探讨了铬污染修复技术研发的需求,重点讨论了铬污染土壤的主要修复技术如:土壤清洗技术、化学解毒技术、电动修复技术和稳定化技术等。并针对这些技术存在的不足,开发了化学解毒与稳定化联合技术,对山西某铬渣堆存场地中受污染土壤进行修复。结果表明:运用化学解毒与稳定化联合技术可以降低污染土壤中总铬和六价铬的浸出浓度,稳定效果好且能在工程实际中高效应用。     

铬渣处理方法研究现状

铬元素是现代工业最重要的原材料之一,但有钙焙烧工艺产生的铬渣会对环境和人体健康产生巨大的危害。介绍和分析了国内外铬渣处理处置的主要方法及其优缺点,国外集中于铬渣的无害化处理,而国内则以铬渣的综合利用为主。在越来越注重环境效益和资源利用率的今天,铬渣的综合利用更能获得经济效益和环境效益的双赢。     

希瓦氏菌还原作用下黄钾铁矾的相转变特征及其负载铬的迁移转化规律

黄钾铁矾对酸性矿山废水中铬（Cr）等污染物有较好的固定去除作用.微生物活动对黄钾铁矾的稳定性和Cr的迁移转化特性有重要影响.因此,本研究在厌氧条件下,通过批次实验研究了希瓦氏菌MR-1还原溶解负载Cr黄钾铁矾过程中二次矿物的形成和Cr污染物的迁移转化特性.结果表明,希瓦氏菌能够促进黄钾铁矾的还原溶解.Cr负载能够增强黄钾铁矾的稳定性,抑制矿物的溶解转化.在不含Cr实验组,黄钾铁矾相转变产物为蓝铁矿和针铁矿;而在负载Cr实验组,二次矿物仅为蓝铁矿.在希瓦氏菌还原溶解负载Cr黄钾铁矾的过程中,矿物中有少量的Cr溶出,进入水体,随后又被吸附于新形成的二次矿物中.矿物中的Cr由原来的残渣态转化为不定型铁结合态,固相中Cr释放的风险增大.XPS检测结果表明,矿物表面的Cr（Ⅵ）被还原为Cr（Ⅲ）,Cr的毒性降低.研究结果对进一步理解酸性矿山废水中Fe、S和Cr的地球化学循环过程有重要意义.