The environmental effect of cadmium-rich Pb-Zn deposit, as exemplified by Niujiaotang Cd-rich Zn deposit, Guizhou, China     

《中国地球化学学报》2006,25(B08):45-45

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Kinetic research on the sorption of aqueous cadmium on carbonate hydroxyapatite     

Yu LIU Huanyan XU 《中国地球化学学报》2006,25(B08):104-105

The sorption of aqueous cadmium on carbonate-hydroxyapatite （CHap） is a complicated non-homogeneous solid/water reaction, From kinetic point of view, it can be described by two stages： at the earlier stage, reaction rate is so fast that its kinetic course is intricate, and at the later stage, the rate of reaction becomes slow and the process of reaction accords with one order reaction kinetic equation. Experimental results show that the relationship between reaction rate constant kl and temperature T accords to Arrhenius Equation, and the activation energy of sorption （Ea） is 6.075 J/mol and frequency factor （A） is 220 s^-1. At the same time, reaction rate constant kl increases with decreasing Cd^2＋ initial concentration, on the contrary, with increasing pH and CHap dosage.  相似文献   

Form changes and bio-effect of cadmium in the alkaline soil operated by inorganic salts     

Zuwei WANG Xin LIU Hui ZHANG 《中国地球化学学报》2006,25(B08):86-86

Four soluble inorganic salts were used to examine their influences upon cadmium forms in the alkaline soil and the contents of cadmium absorbed by plants. After KCl solution added in the soil, the contents of effective form of cadmium in the soil increased from 28% to 122%, carbonate form decreased from 2% to 47%, iron-manganese oxidation form increased from 20% to 150%. As to the organic combination form, when the KCl solution of lower concentration was added in the soils, the organic combination form contents of cadmium would decrease, while the KCl solution of higher concentration was added in the soils, the organic combination form contents of cadmium would increase. After CaCl2 solution was added in the soils, the contents of effective form of cadmium in the soils increased from 7% to 33%, the carbonate form contents of cadmium decreased from 10% to 60%, the contents of the iron-manganese oxidation form of cadmium increased from 5% to 90%, the organic combination form of cadmium increased from 5% to 73%. After KH2PO4 solution was added in the soils, the contents of effective form of cadmium in the soils decreased from 20% to 46%, the carbonate form contents of cadmium decreased from 14% to39%, the contents of the iron-manganese oxidation form of cadmium increased from14% to 95%, the organic combination form of cadmium increased from 5% to 65%. After K2CO3 solution was added in the soil, the effective form contents of cadmium decreased from 5% to 22%, the carbonate form contents of cadmium increased from 12% to 64%, the contents of organic combination form of cadmium in the soils were similar to those of the carbonate form, increasing by 3%-38%. The content variation of the iron-manganese oxidation form of cadmium was slight after K2CO3 solution was added in the soils.  相似文献   

EDTA滴定总硬度实验条件探讨     

匡向阳  彭群英 《水文》1998,(4):48-49

ＥＤＴＡ滴定总硬度实验条件探讨匡向阳彭群英（湖南省永州水文水资源勘测局）１前言水的总硬度包含了碱金属以外的所有金属离子含量的总和。但在一般情况下,除钙、镁离子以外,其它金属浓度都很低,所以通常在ＥＤＴＡ二钠容量法测定钙、镁离子总量后,经过换算成每升水...  相似文献   

火焰原子吸收光谱法测定仲钨酸铵中痕量镉   总被引：2，自引：0，他引：2  

和大超 《地质实验室》1998,14(2):87-88

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恩施州富硒区儿童发镉的调查     

邵器行  毛大钧  苏宏灿 《矿物岩石地球化学通报》1998,(2)

恩施州富硒区儿童发镉的调查邵器行（中国地质大学,武汉４３００７４）毛大钧苏宏灿（恩施州卫生防疫站,湖北恩施４４５０００）（恩施州妇幼保健院,湖北恩施４４５０００）关键词镉元素的组合效应儿童富硒区湖北恩施Ｃｄ是对人体有害的微量元素。在铅锌多金属硫化物矿...  相似文献   

巯基棉分离富集5—Br—PAN—S光度法测定镉的研究   总被引：2，自引：0，他引：2  

杜春  魏琴 《矿物岩石》1997,17(2):98-101

本文研究了镉与５－Ｂｒ－ＰＡＮ－Ｓ的显色条件。在ｐＨ９．５的缓冲液中，形成１∶２型的稳定配合物，配合物的最大吸收峰位于５４８ｎｍ波长处，表观摩尔吸光系数ε＝３．３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。镉量ρ（Ｃｄ２＋）／（ｍｇ·Ｌ－１）在０～１．６范围内符合比尔定律。采用巯基棉分离水中离子富集镉，提高了方法的选择性。本法用于水样分析，结果令人满意  相似文献   

山西土壤Hg,Cd,As,Pb最高允许浓度研究   总被引：1，自引：0，他引：1  

史崇文  郭新波 《华北地质矿产杂志》1996,11(2):189-192

根据国内外制订土壤染物质最高允许浓度的原则，利用山西土壤元素地球化学背景值及土壤生态效应的研究资料，初步确定了山西省土壤中Ｈｇ，Ｃｄ，Ａｓ，Ｐｂ等污染物的最高允许浓度：Ｈｇ０．５ｍｇ／ｋｇ，Ｃｄ０．８ｍｇ／ｋｇ，Ａｓ２２ｍｇ／ｋｇ，Ｐｂ５０ｍｇ／ｋｇ。  相似文献   

岩土非饱和性对毒性金属镉在包气带中迁移转化的影响   总被引：2，自引：0，他引：2  

张光辉  周素文 《水文地质工程地质》1996,23(2):16-20

本文在大量实验研究基础上，揭示了岩土非饱和性对毒性金属镉在包气带中迁移转化的影响特征，阐述了产生这种特征的作用机理，提出了岩土处于亏缺水分状态下和非亏缺水分状态下吸附作用机理不同的观点，指出了这一研究成果的应用前景。  相似文献   

KCQ1型镍镉电池快速充电器     

唐春芳 《北京测绘》1996,(3):40-40

ＫＣＱ１型镍镉电池快速充电器唐春芳中国电子器件工业总公司标准充电制是充电器常采用的一种充电标准，它以１０小时率的电流对电池充电１４至１６小时。在正常温度下以１０小时率的电流值对镍镉电池进行充电的最大优点是：电池可承受约１００小时的连续充电时间而不至...  相似文献