废物水泥窑共处置产品中Ni释放的pH影响  

Impact of pH on Release of Ni in Cement Product from Coprocessing Waste in Cement Kiln

作　　者：杨昱[1] 杨玉飞[1,2] 黄启飞[1] 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,浙江衢州324000

出　　处：《环境科学与技术》2010年第3期18-22,共5页Environmental Science & Technology

基　　金：国家"十一五"科技支撑计划项目(2007BAC16B03);国家"十一五"科技支撑计划项目(2006BAC02A19)

摘　　要：通过模拟煅烧实验制取水泥熟料,并制取混凝土样品。参照NEN7375浸出方法,设定5种不同pH值的浸取液,研究了pH值对混凝土块中重金属Ni释放的影响.结果表明,浸取液的pH=2.00、3.50、5.00、7.35和10.0时,混凝土中Ni的累积释放量分别为1.64、0.167、0.038、0.019和0.025mg/kg;酸性范围内,累积释放量随着pH值的增大而减小,并在弱碱性条件下达到最小值,碱性范围内,随pH值的增大而呈增加的趋势。pH值对Ni的释放过程有影响,pH=3.50和7.35的浸取液中,混凝土中Ni的释放机理为扩散控制,释放曲线与斜率为0.5的直线拟合较佳,且不同区间浸出量曲线的斜率均在0.35～0.65范围内;pH=2.00和5.00的溶液中,Ni的释放在前、中期为扩散控制,后期发生了耗竭作用;pH为10.0条件下,Ni的释放在前期发生了延滞现象,中期为扩散控制,而后期发生了耗竭。Clinker was produced by simulating cement calcinations test, and concrete samples were also prepared. Impact of pH on the release of Ni in the concrete samples was studied using similar method of EA NEN 7375, with five different leachants. Results showed that the cumulative release amount of Ni in the concrete was 1.64, 0.167, 0.038, 0.019 and 0.025mg/kg when pH of leachant was 2.00, 3.50, 5.00, 7.35 and 10.0 respectively. In the acid condition, the cumulative release amount decreased with the increase of pH, and reached the minimum at weak alkaline condition. In the alkaline condition, the measured cumulative release amount increased with the increase of pH. pH could affect the release process of Ni. Diffusion control was the major release mechanism of Ni in the leachants with pH 3.50 and 7.35, and release curves fit the standard line which slope was 0.5 very well and slopes of different increments were all between 0.35 and 0.65. In the prophase and metaphase, diffusion control was the major release mechanism of Ni in the leachants with pH 2.00 and 5.00, but depletion occurred in the anaphase. In the leachants with pH 10.0, delayed diffusion occurred in the prophase, diffusion control was the major mechanism in the metaphase and depletion occurred in the anaphase.

关 键 词：水泥产品 NI 释放量 释放机理 水泥窑共处置 

分 类 号：X132[环境科学与工程—环境科学]