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191.
含铜印刷电路板废水的处理及综合利用 总被引:16,自引:1,他引:16
采用酸性蚀刻废液与碱性蚀刻废液混合沉铜的方法,生产工业硫酸铜。对影响产品质量和产率的主要因素———沉淀时pH值、化浆用水量和浓硫酸用量进行了探讨,找到了最佳工艺条件。同时,研究了沉淀母液中残余铜的除去方法,使之再生,可回用于碱性蚀刻液的生产。 相似文献
192.
Ten male buffalo calves were randomly allotted into five groups of two each. Four groups were fed with cadmium, molybdenum, cadmium-molybdenum, and copper-cadmium-molybdenum respectively for 130 days to determine the elements' metabolic interactions in calves. These results indicated that cadmium and molybdenum could increase the accumulation of molybdenum and cadmium in liver and kidneys in buffalo calves, but copper could not. reduce to normal the levels of molybdenum and cadmium in liver and kidneys caused by cadmium-molybdenum. In addition, we found the copper concentrations in liver and kindeys was significantly greater in treatment calves than in controls. 相似文献
193.
两种金属和两种农药对草鱼不同发育阶段的毒性效应 总被引:3,自引:0,他引:3
进行了金属和农药对草鱼不同发育阶段影响的试验。结果表明,对草鱼胚胎孵化率的影响,96h的EC_(50)值分别为:Cd~(2+)0.078mg/L;Cu~(2+)0.17mg/L;丙体六六六1.0mg/L;对硫磷1.0mg/L。畸形症状呈现出草鱼胚胎卵黄囊水肿,心脏发育受阻而形成管状心脏、胚体弯曲(弯体)等。草鱼的不同发育阶段对金属的敏感性存在着差异:Cd~(2+)96h的LC_(50)值,胚胎为0.1—0.5mg/L;10日龄草鱼苗为0.34mg/L;120日龄草鱼种为8mg/L.Cu~(2+)96h的LC_(50)值,胚胎为0.3—0.5mg/L;10日龄草鱼苗为0.11mg/L;120日龄草鱼种为0.59mg/L. 相似文献
194.
用1-(2-吡啶偶氮)—2-萘酚改性硅胶富集天然水中痕量铜 总被引:1,自引:0,他引:1
用螯合剂改性硅胶富集和分离痕量金属铜离子已有报道。本文报道了用吸附1-(2—吡啶偶氮)-2-萘酚(PAN)的改性硅胶(PAN-SG)富集并测定天然水中痕量Cu~(2+)的工作。 实验部分 1.试剂和仪器 Cu~(2+)标准溶液(1.018mg/ml,0.500mg/ml);PAN的乙醇溶液(3.407×10~-_3mol/L,2.5×10~(-3)mol/L);Britton-Robison(B.R.)缓冲液(0.02mol/L,pH1.8 相似文献
195.
196.
采用OTC-1型开顶式培养箱,模拟研究了CO2体积分数升高对2种小麦的生长以及根际、非根际中Cu和Cd形态分布的影响.结果表明,CO2体积分数的升高显著提高了小麦地上部和地下部生物量,降低了小麦根际和非根际的pH值.临麦2号和宁麦8号小麦地上部干重分别增加了36.9%和25.2%,地下部干重则分别增加了55.1%和59.7%.此外,CO2体积分数升高对不同重金属形态分布的影响随小麦品种和重金属种类的不同而异.在高CO2体积分数条件下,可交换态(F1)Cu和Cd含量显著提高,其中临麦2号根际土壤可交换态Cu和Cd含量分别较对照增加10.6%和29.6%,宁麦8号根际土壤可交换态Cu和Cd分别较对照增加11.0%和20.3%;碳酸盐结合态(F2)Cu和Cd均有所降低,其中宁麦8号和临麦2号根际Cu降低均达极显著(分别降低73.6%和50.0%);铁锰氧化物结合态(F3),有机结合态(F4)和残渣态(F5)Cu和Cd在CO2体积分数升高情况下变化较小.同时CO2体积分数升高还显著增加了2种小麦地上部和地下部铜累积量,增加了临麦2号地上部和地下部镉累积量和宁麦8号地上部镉累积量,但对宁麦8号地下部镉累积量无显著影响. 相似文献
197.
198.
199.
改良剂对中国两种典型土壤铜锌有效性的影响及机理 总被引:2,自引:0,他引:2
研究了改良剂对土壤铜锌有效性的影响,以期对重金属复合污染土壤的修复有一定的指导意义。在红壤与黄泥土中施用石灰、重钙和沸石,观测土壤有效态铜锌含量及pH,并测定了不同pH值下土壤有效态铜锌含量,以阐明改良剂影响土壤重金属有效性的机理。向供试土壤中外源加入一定量的铜锌溶液,制成铜、锌污染土壤,稳定平衡30d,采用CaCl2浸提法测定土壤有效态铜锌的含量。结果表明,施用改良剂能显著降低土壤铜锌的有效性,其中石灰的效果最佳,沸石次之,重钙最差。两种土壤中,复合污染下铜锌有效态含量均高于单一污染,其中铜单一污染有效态含量与复合污染差异显著(P<0.05),而锌单一污染与复合污染差异不显著(P>0.05)。可能是因为锌比铜竞争力更强,更易于被土壤吸附固定。随着土壤pH升高,两种土壤的有效态铜锌含量均显著下降,且复合污染高于单一污染;而在相同pH值下,两种土壤中有效态铜锌含量的差异不显著。可见,pH值是影响土壤重金属有效性的关键因素。改良剂影响土壤重金属有效性的主要机理在于其能显著提高土壤pH值,致使有效态重金属含量明显下降。 相似文献
200.
Background Frequent application of Bordeaux mixture, which includes copper, as a fungicide in fruit and grape orchards may lead to copper accumulation in the soil, especially when orchard age and application times increase. The objectives of this study were: (i) to investigate the copper content and its spatial distribution in orchard soils; (ii) to identify the copper fractionation in soil and its relationship with plant uptake; (iii) to understand the characteristics of copper contamination in orchard soils. Materials and Methods Soil profile samples were taken in apple orchards with ages of 0, 5, 10, 20, 30 years and pot experiments were also carried out to study the effects of external copper input on copper fractionation. All soil samples were air-dried, ground and extracted with 0.43 mol L1 HNO3 for the total absorbed copper. Fractionation determination was conducted following Tessier and Shuman sequential extraction methods, and copper was measured with AAS. Plant samples were first dry ashed, dissolved with 6 mol L1 HCl and then copper and other elements were measured with ICP-MS.Results and Discussion Soil total Cu was higher in the apple orchards than that in non-orchard fields and was seen to have increased with orchard age. Soil Cu increased substantially with the average annual copper increase, ranging from 2.5 to 9 mg Cu kg1. The distribution of copper in the soil profile was uneven, decreasing from surface to deeper layers, and the differences were significant, but the contents in every layer were also significantly correlated with those in the next layers.
For all copper fractions, the organically bound, crystalline Mn oxide bound, and amorphous Fe bound fractions extracted with the Shuman method were much higher than the exchangeable and residual fractions. Using the Tessier method, organically bound, carbonate bound and Fe-Mn oxide bound fractions were much higher. With an increase in external copper input, the organically bound, crystalline Mn oxide bound and amorphous Fe bound fractions in the Shuman method and organically bound, carbonate bound and Fe-Mn oxide bound fractions in the Tessier method all increased significantly, while the changes in other fractions were not significant.
Soil total copper and copper fractions were found to have good correlations with apple tree uptake. Copper in fruit flesh had significant correlations with soil total content in the 010 cm layer, all the copper fractions in the 05 cm layer, and some fractions in the deeper layers. Conclusion Copper content in orchard soils increased significantly with intensive application of Bordeaux mixtures and orchard age. Copper content decreased sharply from the topsoil to deeper soil layers. The copper contents in different layers also significantly correlated with those in the next layers. Dominant fractions of the copper in soil were mainly associated with organic matter, iron and manganese oxides and carbonates. A close relationship was found between the copper content in soils and in apple tree organs (which contained 8.9 to 66mg kg1 Cu). Recommendation and Perspective Though most copper in the soil was specifically adsorbed or immobilized, and copper was mainly distributed in topsoil, which was essentially devoid of roots, the copper concentration of fruit still had significantly positive correlations with soil copper and most copper fractions. Therefore, measures must be taken to control copper accumulation in orchard soils and to make the apple fruit production sustainable. 相似文献