废旧阴极射线管(CRT)显示器玻壳中铅浸出特性研究  

RESEARCH ON THE LEACHING CHARACTERISTICS OF LEAD IN CRT GLASS

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：《环境工程》2008年第S1期230-234,共5页Environmental Engineering

基　　金：国家"十一五"科技支撑计划重大项目课题:(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：CRT显示器玻壳中含有大量的铅,废旧CRT显示器玻壳被列为危险废物。采用4种浸提方法(水平振荡法(GB5086.2-1997)、翻转法(GB5086.1-1997)、硫酸硝酸法(HJ/T299-2007)、醋酸缓冲溶液法(HJ/T300-2007))研究CRT显示器玻壳中铅的浸出特性。同时探讨浸提液pH和pH缓冲能力、振荡方式、CRT玻壳颗粒粒径、液固比、浸提时间对CRT玻壳颗粒中的Pb浸出的影响。结果表明:上述4种方法浸提液中Pb的平均浓度分别为0.07、0.69、1.64、11.33 mg/L。随着醋酸缓冲液初始pH值从4.0升高到7.0,其浸提的Pb的含量呈现出逐渐下降的趋势。而去离子水的pH值低于5时,其浸提的Pb的含量才明显升高。Visual MINTEQ模型计算结果表明:在去离子水和硫酸硝酸混合液浸提过程中,主要以酸碱反应为主;而在醋酸缓冲液浸提过程中,以酸碱反应和络合反应为主。前3种浸提方法使用的浸提液类似于天然水环境或降水,其浸提的Pb浓度高于地下水环境质量III标准。第4种浸提方法模拟垃圾填埋场环境,其浸提的Pb的浓度高于工业固废最高容许浸出浓度。因此,废旧CRT玻壳无论填埋处置或直接进入土壤或水体环境,都存在环境风险。Cathode ray tube(CRT) monitor is widely used because of its good performance and low price.Because the CRT glass contains high content of lead,the retired CRTs are regarded as hazardous waste.This study investigated the leaching characteristics of lead in the CRT glass,using 4 leaching test procedures(GB5086.2-1997(I),GB5086.1-1997(II),HJ/T299-2007(III),HJ/T300-2007(IV)).In addition,this research studied the effects of pH and its buffer capacity in the leaching solutions,shaking mode,particle size of CRT glass,ratio of liquid to solid, and leaching time on the leaching of Pb in the CRT glass.Results showed the leached Pb concentrations were 0.07,0.69,1.64,and 11.33 mg/L for the I,II,III,and IV methods,respectively.With the increase in pH of CH_3COONa-CH_3COOH buffer solution from 4.0 to 7.0,the leached Pb concentration generally behaved a decreasing trend.On the other hand,the leached Pb concentration by the deionized water significantly increased only at pH<5.0.Species of Pb in the leaching solutions,calculated by Visual MINTEQ,indicated that the leaching process using the deionized water and H_2SO_4/HNO_3 mixture as leaching solution was dominated by the acid-base reactions,while it was mainly controlled by acid-base reaction and complexation reaction when employing the CH_3COONa-CH_3COOH buffer solution as leaching solution.The I,II and III methods generally simulate natural aqueous environment or raining,and the leaching Pb concentrations by them were higher than the grade III of ground water quality standard in China.The IV method generally simulates landfill environment,and the leached Pb concentration by it was higher than the permitted highest concentration leached from solid wastes in China.Therefore,the entrance of retired CRT glass in the aqueous environment and landfill site might lead to environmental risk due to the release of Pb in it.

关 键 词：CRT显示器玻壳 铅 浸提 PH 

分 类 号：X705[环境科学与工程—环境工程]