废旧阴极射线管(CRT)显示器玻壳进入土壤后铅的释放及转化  

Release and Transform of Lead from the Glass of Cathode Ray Tube(CRT) Following Its Entrance in the Soil

作　　者：王喆[1] 刘少卿[1] 陈晓民[1] 李艳霞[1] 何孟常[1] 林春野[1] 

机构地区：[1]北京师范大学环境学院,水环境模拟与污染控制国家重点联合实验室,北京100875

出　　处：《环境科学》2009年第6期1855-1859,共5页Environmental Science

基　　金："十一五"国家科技支撑计划重大项目(2006BAJ05A08);国家自然科学基金项目(40671002);北京师范大学本科生科学研究基金项目

摘　　要：通过室内模拟试验,采用土壤连续提取法,探究废旧CRT显示器玻壳进入土壤环境后铅的释放及迁移转化过程.结果表明,土壤原始Pb总含量为28.4 mg/kg;按1∶20的玻壳/土壤质量比加入玻壳后土壤中Pb总含量为8 634.4 mg/kg,其中,溶解态和可交换态Pb（EXC-Pb）的含量为0.20-0.98 mg/kg,与碳酸盐结合的Pb（CARB-Pb）为20.1-103.6 mg/kg,与铁锰氧化物结合的Pb（RO-Pb）为26.7-54.3 mg/kg.上述3种形态Pb的总和为48.6-155.2 mg/kg.在EXC提取步骤中,直接从玻璃颗粒表面溶解的Pb含量为（0.038±0.025）mg/kg;而在CARB和RO提取步骤中,直接从玻璃颗粒表面溶解的Pb含量为（7.55±3.13）mg/kg.因此,CRT显示器玻壳进入土壤后,玻壳中的Pb释放并主要与土壤中CARB和RO矿物结合.加酸处理使土壤原位测定的pH值从8.0-8.3降低到7.1-7.5,但对土壤中Pb的形态没有产生显著影响.废旧CRT玻壳颗粒中的Pb向CARB、RO、EXC形态释放速率分别为21.1/t、3.8/t、0.15/tmg.（kg.d）-1（t为处理时间,单位为d）.当土壤pH或Eh值降低时,与CARB或RO结合的Pb可能转变为溶解与可交换态.因此,CRT玻壳颗粒进入土壤后Pb的释放会导致潜在的环境风险.The objective of this study was to investigate the release and transform Pb from the CRT glass following its entrance into the soil environment. A long-term incubation of soil mixed with CRT glass particles and sequential selective dissolution technology were used. Results indicated that the addition of CRT glass particle to the soil led to the increase in the total concentration of Pb in the soil from 28.4 mg/kg to 8 634.4 mg/kg. In details, the concentrations of Pb in the soluble and exchangeable form （EXC-Pb） and bound to the carbonate minerals （CARB-Pb） and manganese and iron oxides （RO-Pb） were 0.20-0.98 mg/kg, 20.1-103.6 mg/kg, and 26.7-54.3 mg/kg,respectively. The sum of these three fractions of Pb was 48.6-155.2 mg/kg. In the EXC, CARB, and RO dissolution steps, the concentrations of Pb directly released from the surface of the CRT glass particles were only （0.038 ± 0.025）, （7.55 ±3.13）, （7.55 ± 3.13） mg/kg,respectively. Hence, the released Pb from the CRT glass was mostly bound to the carbonate minerals and manganese and iron oxides in the soil. The decrease of pH from 8.0-8.3 to 7.1-7.5 did not signifieantly affect the chemical forms of Pb in the soil. The release rates of Pb from the CRT glass to the EXC,CARB,and RO forms were 0.15/t,21.1/t,and 3.8/t mg·（kg·d）-l ,respectively （t is incubation time in unit old）. The CARB-Pb or RO-Pb might transform to EXC-Pb when pH or Eh of soil decreases, thus entrance of CRT glass particles in the soil environment may pose an ecological risk.

关 键 词：铅 CRT显示器玻壳 释放 土壤 连续分级提取 形态 

分 类 号：X131.3[环境科学与工程—环境科学]