生物炭—生石灰对西番莲种植土壤重金属镉的阻控效应

为了探究生物炭—生石灰对西番莲种植土壤重金属镉(Cd)的阻控效应,以黄果西番莲Passiflora edulis f.flavicarpa Degener和紫果西番莲P.edulis Sims 1年生种苗进行盆栽试验,设置7.65、16.00 mg/kg Cd重金属污染土壤处理,及分别添加10 g/kg生石灰+10 g/kg生物炭、10 g/kg生石灰+20 g/kg生物炭复合钝化剂处理,测定西番莲的形态特征、各器官Cd含量以及种植土壤有效态Cd含量,计算植株各器官生物富集系数(BCF)和转运系数(TF)。结果表明,添加不同比例复合钝化剂均显著降低西番莲种植土壤的有效Cd含量,降低Cd的毒害,改善土壤养分状况,促进西番莲生长;同时降低西番莲对Cd的吸收、富集及转运,果实中Cd含量低于0.04 mg/kg。综合来看,种植黄果西番莲土壤添加生物炭∶生石灰=1∶1复合钝化剂对土壤重金属Cd阻控效果较佳;种植紫果西番莲低浓度Cd污染土壤采用生物炭∶生石灰=1∶1复合钝化剂效果较优,高浓度Cd污染土壤则采用生物炭∶生石灰=1∶2复合钝化剂效果较佳。

超声波对镉冲击下的短程硝化污泥特性影响

本文旨在探讨超声波对短程硝化性能及镉(Cd)抑制下污泥特性的影响。通过6个SBR装置实验,发现超声辐照能显著降低出水氨氮浓度,提升氨氮去除率。在特定声能密度下,污泥TB-EPS蛋白质含量增加,AOB脱氮速率提升,而NOB活性降低。添加重金属镉后,SAOR(氨氧化)与SNOR(亚硝酸盐氧化)速率均受抑制。随着声能密度增加,AOB活性增强,NOB活性减弱。本研究揭示了超声辐照对污泥处理中硝化过程的调控作用,并发现其在重金属镉抑制下对硝化细菌活性具有选择性影响,有助于优化短程硝化工艺。

腐植酸对土壤重金属镉的淋溶效果及吸附解吸机制研究

为了揭示腐植酸对土壤重金属镉(Cd)的淋溶效果及吸附解吸机制,本研究采用土柱模拟淋溶方法和吸附解吸试验方法,开展不同腐植酸用量对土壤重金属Cd的淋溶试验,以及p H变化对土壤Cd吸附解吸效应。结果表明,不同腐植酸用量导致土壤淋溶液中Cd含量有别,淋溶液中Cd含量并不随土壤腐植酸用量的增加而减少,而是当腐植酸的用量达到一定浓度时,淋溶液中Cd含量减少趋稳。在酸性条件下,各处理腐植酸对Cd的吸附性显著;在碱性条件下,当p H=11时,各处理土壤对Cd的吸附量达到最大且基本稳定。解吸试验显示,随着p H增加,各处理的解吸量不断减小,当p H=11时,各处理土壤对Cd的解吸量最小,处理间差异不显著。

Effects of Waterborne Cu and Cd on Anti-oxidative Response, Lipid Peroxidation and Heavy Metals Accumulation in Abalone Haliotis discus hannai Ino

The aim of this study was to compare the effects of waterbome copper （Cu） and cadmium （Cd） on survival, anti-oxida- tive response, lipid peroxidation and metal accumulation in abalone Haliotis discus hannai. Experimental animals （initial weight： 7.49 g±0.01 g） were exposed to graded concentrations of waterborne Cu （0.02, 0.04, 0.06, 0.08 mg L-1） or Cd （0.025, 0.05, 0.25, 0.5 mgL-1） for 28 days, respectively. Activities of the anti-oxidative enzymes （catalase, CAT; superoxide dismutase, SOD; glutathione peroxidases, GPx; glutathione S-transferase, GST）, contents of the reduced glutathione （GSH） and malondiadehyde （MDA） in the hepatopancreas, and metal accumulation in hepatopancreas and muscles were analyzed after 0, 1, 3, 6, 10, 15, 21, 28 days of metal exposure, respectively. Results showed that 0.04 mg L-1, 0.06 mg L-1 and 0.08 mgL-1 Cu caused 100% death of abalone on the 21st, 10th and 6th day, respectively. However, no dead abalone was found during the 28-day waterborne Cd exposure at all experimental concentrations. Generally, activities of SOD and GST in hepatopancreas under all Cu concentrations followed a decrease trend as the exposure time prolonged. However, these activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Activities of CAT in all Cu exposure treatments were higher than those in the control. These activities were firstly increased and then decreased to the control level and increased again during Cd exposure. Contents of MDA in hepatopancreas in all Cu treatments significantly increased first and then decreased to the control level. However, the MDA contents in hepatopan- creas were not significantly changed during the 28-day Cd exposure. The metals accumulation in both hepatopancreas and muscles of abalone significantly increased with the increase of waterborne metals concentration and exposure time. These results indicated that H. discus hannai has a positive anti-oxidative defense against Cu or Cd. In conclusion, anti-oxidative mechanism in abalone to resist waterborne Cu did not follow the same pattern as that for waterborne Cd.

镉离子快速检测方法的研究进展

简述了重金属镉(Cd)污染现状以及传统镉离子检测技术及其优缺点,着重阐述了镉离子快速检测技术的原理、技术及存在的问题.针对镉离子快速检测方法中存在的灵敏性和专一性不足的问题,提出利用镉离子敏感菌株筛选高效、低毒、专一性强、经济的镉离子螯合剂,为建立新型镉离子快速检测方法提供了理论和应用基础.

Assessment of Trace Metal Contamination of Sediments in the Lubumbashi River Basin, Kafubu, Kimilolo and Kinkalabwamba Rivers in Lubumbashi City, Democratic Republic of Congo

Arsenic （As）, Barium （Ba）, Cadmium （Cd）, Cobalt （Co）, Chromium （Cr）, Copper （Cu）, Iron （Fe）, Manganese （Mn）, Lead （Pb） and Zinc （Zn） concentrations were investigated in sediments collected from sixteen sampling sites in the Lubumbashi river basin and five sites in Kafubu, Kimilolo and Kinkalabwamba rivers during February, March and April 2016. Analyses of the samples were carried out using a portable X-RFS （X-Ray Fluorescence Spectrometer）. Water pH and OM （Organic Matter） content of the sediments were also determined. Trace metal toxicity risk to aquatic organisms was assessed using SQGs （Sediment Quality Guidelines）---TELs （Threshold Effect Levels） and PELs （Probable Effect Levels）---for freshwater sediments. Mean values ofpH and OM ranged from 4.2 to 7.8 and from 1.27% to 6.22%, respectively. The highest mean levels of trace metals in sediments were 5,438 mg·kg-1·dw and 902.5 mg·kg-1·dw for Cu and Co, respectively in Lubumbashi river 1.45 kilometer downward the Lubumbashi Slag heap, 1,534.5 mg·kg-1·dw and 342 mg·kg-1·dwdw for Zn and Pb, respectively at the confluence of Lubumbashi and Kafubu rivers, 108,900 mg·kg-1·dw, 547 mg·kg-1·dw and 174.5 mg·kg-1·dw for Fe, Ba and Cr, respectively in Kinkalabwamba river, 531 mg·kg-1·dw and 22 mg-kgl＇dw for Mn and Cd, respectively in Kimilolo river, and 37 mg·kg-1·dw for As at the confluence of Tshondo and Lubumbashi rivers. The mean concentrations of As, Cd, Cr, Cu, Pb and Zn in the sediments exceeded the corresponding SQGs＇ PELvalues and could have adverse effects on aquatic organisms of those rivers. Trace metal contamination of the studied sediments might he partially attributed to natural processes, unplanned urbanization and poor waste management and mostly to abandoned and ongoing mining and ore processing activities in Lubumbashi city.

Transfer of Heavy Metal Contaminants from Animal Feed to Animal Products

Study was conducted to assess the possible transfer of heavy metals from livestock feeds to animal products. In experiment-l, samples （n = 503） collected from conventional farms in Central Greece were analysed for heavy metal Copper （Cu）, Zinc （Zn）, Cadmium （Cd）, Lead （Pb）, Nickel （Ni） and Chromium （Cr） contents in muscle tissues, livers, kidneys, excremental and basic mixtures in livestock such as cows and sheep. Results showed that transfer of heavy metal contaminants from feed to animal products fluctuated below the permissible risk levels. In experiment 2, samples （n = 440） of feedstuffs used in different feeding regimens and seasons at different livestock farms [sheep （n = 140）, dairy cows （n = 180）, pigs （n = 120）] were collected. Results showed that relatively high concentration of Cu in the excrements of pigs （155 ＋ 9.13） and Zn in the excrements of sheep （144.56 ＋ 5.78） are explained by the use of Cu in the diet of developing piglets and sheep. Ovine showed higher concentration ofNi, Cr, and Pb in their excrements, while, the concentration of heavy metals in forages was under the allowed range to the EU legislation.

Effect of Moisture on Partitioning of Heavy Metals in Incineration of Municipal Solid Waste

The effect of moisture in municipal solid waste (MSW) on partitioning of lead (Pb), zinc (Zn), copper (Cu) and cadmium (Cd) was studied in a laboratory tubular furnace by using simulated MSW. The moisture in MSW influences heavy metals in following ways, to increase the moisture in flue gas and decrease the combustion temperature, to prolong the combustion time, and to prolong the releasing time of volatiles with the furnace temperature decreased by increasing the moisture. The volatilization of Pb, Zn and Cd was enhanced by increasing the moisture in MSW because of the prolonged combustion time. For Pb and Zn, the combustion time was important at higher temperature, while for Cd, it was important at low temperature. The moisture content showed slight effect on Cu partitioning. When extra chlorine was added to MSW, such as 1%PVC + 0.5%NaCl, the volatilization of Pb, Zn and Cu was enhanced by increasing the moisture because water evaporation reduced the temperature and increased devolatilization time. At higher temperature, NaCl tends to decompose and generates more free chlorine, producing more metal chlorides. Since Cd is a strong volatile heavy metal in MSW, the effect of moisture content on its volatilization is less than that of Pb, Zn or Cu during the MSW incineration.

Intercropping with Solanum nigrum and Solanum photeinocarpum from Two Ecoclimatic Regions Promotes Growth and Reduces Cadmium Uptake of Eggplant Seedlings

Soil contamination by heavy metals is a serious environmental problem worldwide, and reduction of heavy metal accumulation in vegetables grown on contaminated land is a matter of urgency. A pot experiment was conducted to study the effects of intercropping with the Cd hyperaccumulators Solanum nigrum and Solanum photeinocarpum from two ecoclimatic regions, Ya＇an and Chengdu, Sichuan Province, China, on the growth and cadmium （Cd） uptake of eggplant （Solanum melongena L.）. The biomass, photosynthetic pigment contents, and activities of antioxidant enzymes of eggplant were enhanced by intercropping. The biomass of eggplant was the highest after intercropping with S. photeinocarpum from Ya＇an, but did not differ significantly from that after intercropping with S. nigrum from Chengdu. The shoot Cd content of eggplant was significantly reduced by intercropping with the hyperaccumulators, which ranked as follows： S. nigrum from Chengdu 〉 S. nigrum from Ya＇an 〉 S. photeinocarpum from Chengdu 〉 S. photeinocarpum from Ya＇an, with the decreases being 19.60%, 14.36%, 9.66%, and 6.42%, respectively, as compared with the control. The lowest shoot Cd content and translocation factor of eggplant were attained after intercropping with S. nigvum from Chengdu. Therefore, it was feasible to intercrop eggplant with S. nigrum and S. photeinocarpurn on Cd-contaminated soil.