废物水泥窑共处置产品中Cd释放的pH影响  

Impact of pH on the release of Cd in cement product from co-processing waste in cement kiln

作　　者：杨昱[1] 黄启飞[1] 杨玉飞[1,2] 张霞[3] 王琪[1] 

机构地区：[1]中国环境科学研究院,北京100012 [2]浙江工业大学浙西分校化学与制药工程系,浙江衢州324000 [3]河南城建学院环境工程系,河南平顶山467044

出　　处：《环境污染与防治》2009年第7期5-9,共5页Environmental Pollution & Control

基　　金：国家"十一五"科技支撑计划项目(No.2007BAC16B03;No.2006BAC02A19)

摘　　要：用高温电炉模拟煅烧试验制取水泥熟料后再制作混凝土,参考EANEN7375:2004浸出试验,设定5种不同pH的浸取液对混凝土进行长期浸出试验,研究了pH对水泥窑共处置混凝土中Cd释放量以及释放过程的影响。结果表明:(1)pH为2.00、3.50、5.00、7.35和10.00的浸取液中,Cd的累积释放量分别为0.4080、0.0058、0.0007、0.0004、0.0012mg/kg。在酸性条件下,随pH的增大,Cd的累积释放量减小。在碱性条件下,随pH的增大,Cd的累积释放量增大。(2)pH为7.35的浸取液中,Cd累积释放量的释放曲线与斜率为0.5的直线拟合最佳。pH为7.35的浸取液中,混凝土中Cd的释放机制为扩散控制;pH为2.00和5.00的浸取液中,Cd的释放在前期为扩散控制,后期发生了耗竭作用;pH为3.50和10.00条件下,Cd的释放在前期发生了延滞作用,中期为扩散控制,后期发生了耗竭作用。Clinker was produced by simulating cement calcination test, and concrete samples were also prepared. The impact of pH on the release of Cd in the concrete samples was studied using EA NEN 7375：2004 leaching method. The results showed that pH impacted the Cd release significantly. In the different leachants with pH of 2.00, 3.50,5.00,7.35 and 10.00, the correlated cumulative release amount of Cd in the concrete was 0. 408 0,0. 005 8, 0. 000 7,0. 000 4,0. 001 2 mg/kg, respectively. In the acid condition, the cumulative release amount decreased with the increase of pH,while in the alkaline condition,the Cd release presented different tendency. In the leachant with pH of 7.35,the release process was diffusion controlled,the Cd release curves was well fitted by standard line （rc= 0.5）,and slopes of different increments ranged from 0.35 to 0.65. In the leachants with p H of 2.00 and 5.00, the Cd release was diffusion controlled at earlier stage,while,the depletion occurred at the later stage. In the leachants with pH of 3.50 and 10.00,delayed diffusion occurred at the early stage of release process,and then the process was diffusion controlled in the middle stage,finally depletion presented at the last stage.

关 键 词：水泥产品 CD 释放量 释放机制 水泥窑共处置 

分 类 号：X781.5[环境科学与工程—环境工程]