【摘要】 伴生矿固体废物合理处置是当前广东需要解决的一个环境问题,本实验研究挑选锆英砂类型伴生放射性矿固体废物作为研究对象,通过浸泡实验、室内小土柱淋滤实验、室外大土柱模拟填埋实验,研究了伴生矿固体废物中的U、Th、Cd、Pb、Cr、Hg、As的浸出特性与动力学机理、污染元素向土壤的迁移规律与长时间淋滤作用下污染物的浸出分布规律。结果表明:天然雨水的浸泡实验中出现最高浸出率分别为U(0.007 9%)、Th(0.000 53%)、Cr(0.15%)、Pb(0.033%)、As(0.18%)、Cd(0.0%)、Hg(0.041%),浸出过程较多符合由多种扩散与反应过程决定的混合控制动力学模型;经过100 d室内小土柱与1 a室外大土柱填埋淋滤实验结果显示,污染物向环境中的释放速度较为缓慢或较难释放。结果可为实现伴生放射性矿固体废物安全处置提供数据依据。更多还原

【Abstract】 [Background] The proper disposal of solid wastes of mine associated with radioactivity has become an urgent environmental problem in Guangdong. [Purpose] This study aims at the leaching characteristics, kinetic mechanism, migration and leaching distribution of nuclides and heavy metals from the associated radioactivity solid wastes for properly disposing of solid wastes. [Methods] U, Th, Cd, Pb, Cr, Hg and As nuclides and heavy metals from zircon sand type associated radioactivity solid wastes were taken as objects in soaking experiment, indoor soil column leaching experiment and outdoor soil column simulated landfill experiments. Migration law of pollution elements to soil and leaching distribution law of pollutants under long-term leaching were investigated. [Results &Conclusions] Experimental results indicate that the highest leaching rates of U, Th, Cr, Pb, As, Cd and Hg from natural rainwater leaching experiment are 0.007 9%, 0.000 53%, 0.15%, 0.033%, 0.18%, 0.0% and 0.041%,respectively, and most of the elements from associated radioactivity solid wastes were fitted to hybrid control kinetic model. Results of 100-d indoor soil column experiment and one year outdoor soil column simulated landfill experiment show that the contaminants are difficult or quite slow to release to the environment, which provides basic data for the proper disposal of the associated radioactivity solid wastes.更多还原