铅锌选厂尾矿库生态系统中铅镉污染现状调查及对策

分析昭通市铅锌选矿厂尾矿库生态系统中铅镉等重金属污染现状，针对尾矿库闭库后的生态恢复中存在的问题，提出尾矿库闭库后的生态恢复措施及建议。     

利用玻壳厂铅尘生产三盐基硫酸铅的研究

介绍了由玻壳厂铅尘生产三盐基硫酸铅的原理，工艺流程及操作条件，该法充分 铅尘的有效成份，产品质量好，工艺简单易行，无二次污染，经济效益显著，为充分利用含铅废为和减少污染提供了一条有效途径。     

Preliminary Evaluation of the Use of Phosphogypsum for Reef Substrate. I. A Laboratory Study of Bioaccumulation of Radium and Six Heavy Metals in an Aquatic Food Chain

Phosphogypsum (PG), a solid by-product of phosphoric acid production, contains radionuclides and trace metals in concentrations which may pose a potential hazard to human health and the environment. to investigate the possibility of bioaccumulation of radium and six heavy metals over time when aquatic organisms experience both trophic and environmental exposure to PG, we designed a laboratory experiment representing three levels of an aquatic food chain. During the 135 day experiment, a meiobenthic copepod species (Amphiascoides atopus) was cultured in the presence of PG. the copepods were subsequently fed to grass shrimp (Palaemonetes vulgaris and P. pugio) which were in turn fed to gulf killifish (Fundulus grandis); both the grass shrimp and the killifish also experienced an environmental PG exposure. Other than elevated radium levels in the experimental grass shrimp, the experiment demonstrated little effect of environmental or trophic exposure to PG on microinvertebrates, macroinvertebrates, or fishes that could be attributed to PG. in all cases where increased concentrations were indicated within the experimental group, roughly equivalent increases in metal concentrations also occurred in the control group.     

海带对镉、铅的吸附作用及其机理

利用大型海藻海带(Laminaria japonica)作为可降解性生物吸附材料,对有害重金属镉离子和铅离子的吸附作用和机理进行了研究.结果显示,通过电位差滴定法,得到海带的酸性基数量为1.25mmol.g-1,其解离常数为0.18 mmol.l-1.对平衡吸附量与pH的关系进行了模型模拟.海带对于金属离子的吸附为Bidentate型,吸附平衡常数分别为5.72×103L.mol-1,6.28×104L.mol-1.同时,采用拟二次速度模型对镉离子和铅离子的吸附速度进行了模拟,得到的吸附速度常数分别为0.010 min-1,0.014min-1.结论,海带对二价镉、铝离子的吸附量大于很多其它藻类吸附剂,对它的研究可为重金属化湖泊水质的改善和生态修复提供参考依据.     

Procedure for the determination of 2,4‐D and dicamba in inhalation,dermal, hand‐wash,and urine samples from spray applicators

Abstract

Analytical procedures for the simultaneous determination of residues of 2,4‐D and dicamba from polyurethane foam plug air samplers, ethylene glycol impregnated glass‐fiber filter paper dermal samplers, 1% sodium bicarbonate hand wash solution, and urine are presented. Residues were derivatized with diazomethane and quantitated using electron capture gas chromatography. Recoveries were greater than 80% at the limit of detection in all substrates. The limits of detection for both herbicides were 0.1 μg/foam plug and 0.5 μg/filter paper, and in the urine, 1.7 μg/100 mL and 5.0 μg/100 mL for dicamba and 2,4‐D, respectively.     

Elemental uptake by edible herbs and lettuce (Latuca sativa)

The total concentration of toxic elements (aluminum, cadmium, chromium and lead) and selected macro and micro elements (iron, manganese, copper and zinc) are reported in six leafy edible vegetation species, namely lettuce, spinach, cabbage, chards and green and red types of Amaranth herbs. Although spinach and chards had greater than 125 mv of iron, both the amaranthus herbs recorded > than 320 μ g g^{? 1} dry weight. In both the spinach and chard species, the Mn and Zn levels were appreciable recording > 225 μ g g^{? 1} and 150 μ g g^{? 1} dry weight, respectively. Aluminum concentrations were (in μ g g^{? 1} dry weight) lettuce (10), cabbage (11), spinach (167), chards (65), amaranthus green (293) and amaranthus red (233). All the micro and macro elements and the toxic elements (Ni, Cr, Cd and Pb) elements analyzed, were below the recommended maximum permitted levels (RMI) in vegetables. Further the elemental uptake and distribution of the nine elements, at three growth stages of the lettuce plant grown on soil bed under controlled conditions are detailed. In the soil, except for iron (16%), greater than 33% of the other cations were in exchangeable form. Generally in the lettuce plant, roots retained much of the iron (> 224 μ g g^{? 1}) and aluminum (> 360 μ g g^{? 1}), while leaves had less than 200 μ g g^{? 1} of iron and 165 μ g g^{? 1} of Al. Although the concentrations of elements marginally decreased with growth, the lettuce leaves had significant amounts of Mn (30 μ g g^{? 1}), Zn (50 μ g g^{? 1}) and Cu (3.6 μ g g^{? 1}). Some presence of lead in leaves (2.0 μ g g^{? 1}) was noticed, but all the toxic and other elements analyzed were well below the RMI values for the vegetables.     

Ascorbic acid, β-carotene,sugars, phenols,and heavy metals in sweet potatoes grown in soil fertilized with municipal sewage sludge

Municipal sewage sludge (MSS) used for land farming typically contains heavy metals that might impact crop quality and human health. A completely randomized experimental design with three treatments (six replicates each) was used to monitor the impact of mixing native soil with MSS or yard waste (YW) mixed with MSS (YW +MSS) on: i) sweet potato yield and quality; ii) concentration of seven heavy metals (Cd, Cr, Mo, Cu, Zn, Pb, and Ni) in sweet potato plant parts (edible roots, leaves, stem, and feeder roots); and iii) concentrations of ascorbic acid, total phenols, free sugars, and β-carotene in sweet potato edible roots at harvest. Soil samples were collected and analyzed for total and extractable metals using two extraction procedures, concentrated nitric acid (to extract total metals from soil) as well as CaCl₂ solution (to extract soluble metals in soil that are available to plants), respectively. Elemental analyses were performed using inductively coupled plasma mass spectrometry (ICP-MS). Overall, plant available metals were greater in soils amended with MSS compared to control plots. Concentration of Pb was greater in YW than MSS amendments. Total concentrations of Pb, Ni, and Cr were greater in plants grown in MSS+YW treatments compared to control plants. MSS+YW treatments increased sweet potato yield, ascorbic acid, soluble sugars, and phenols in edible roots by 53, 28, 27, and 48%, respectively compared to plants grown in native soil. B-carotene concentration (157.5 μg g^?1 fresh weight) was greater in the roots of plants grown in MSS compared to roots of plants grown in MSS+YW treatments (99.9 μg g^?1 fresh weight). Concentration of heavy metals in MSS-amended soil and in sweet potato roots were below their respective permissible limits.     

Evaluation of an activated carbon filter for the retention of selected pesticide vapours

Abstract

An activated charcoal bed unit (ACBU) was constructed using teflon stock. The unit duplicated the flow and bed design of a commercially available tractor mounted filter for removing pesticides from the air.

Eight pesticides (4 herbicides and 4 insecticides) were used to test the retention efficiency of ACBU over a 12–48 h period with the ACBU in place. Polyurethane foam (PUF) plugs in series trapped any residual pesticide that came through the ACBU.

The ACBU retained 93–100% of the pesticides tested. The unit thus provides an efficient mechanism for removing airborne pesticides.     

Key airborne concentrations of chemicals for emergency response planning in HAZMAT road transportation- margin of safety or survival

The release of chemicals due to road transportation accidents could have adverse consequences such as fatality, physical and financial loss and environmental damage. The purpose of this study was to determine the suitable margin of safety/survival of individuals in HAZMAT road transportation accidents for use in Emergency Response Planning (ERP). In this study, at first, the safety margin and survival margin were defined and proposed. Then, as a case study, the chemical tanker trucks in Iran's road transport fleet were investigated and the full bore rupture of the tanker trucks was considered as the selective scenario. Eventually, safety margin and survival margin were determined using ALOHA and PHAST software and the Chemical Exposure Index (CEI). The results showed that using the CEI, among the selected chemicals, ammonia, chlorine and 1,3-butadiene had the highest chemical release potential with the exposure indices of 597, 548 and 284, respectively, and need further investigation. The possible safety margin obtained in this study was distances over 5100 m (using ALOHA software for ammonia) and 10,983 m (using PHAST software for chlorine). On the other hand, the survival margin was distances over 980 m away from the accident area (using ALOHA software for ammonia) and 620 m away from the accident area (using the PHAST software for chlorine). The results of this study indicate that determining the safety and survival margins surrounding the tanker trucks and containers of chemicals is a critical issue for the emergency response planning and determining the standards of road's safety and survival margins. On the other hand, due to the obtainment of different results by various methods and software, in road accidents, the highest hazard distance is suggested to be considered to determine the safety margin (distances longer than 10,983 m) and survival margin (distances longer than 980 m) for ERP, regardless of the type of used material and software.     

从银铅锌废渣中回收硝酸银的研究

介绍了用灼烧、浸取、沉淀、溶转和离子交换等方法,从银铅锌废渣中直接回收硝酸银,收率可达80.12%,AgNO3纯度为99.9%。考察了试料粒度、FeCl3质量浓度、溶液酸度、固液比,反应温度及浸取时间对银浸出率的影响。