透水混凝土对地表径流水中Pb^(2+)的吸附性模拟试验

Adsorption of heavy metal Pb^(2+)in surface water of high performance pervious concrete

为提高透水混凝土对雨水中Pb^(2+)的吸附能力,该文采用优化浆骨比(VRPA)参数的方法设计制备可以兼顾透水性和强度的高性能透水混凝土,并以Pb^(2+)的去除率为指标,研究分析不同VRPA、早期碳化养护条件对透水混凝土Pb^(2+)吸附能力的影响。结果表明:SEM扫描电镜和能谱分析表明,透水混凝土中水化产物中均含有一定量的Pb^(2+)。其中该实验设计的透水混凝土在浆骨比参数为0.39时对雨水中Pb^(2+)的吸附性最优。结果还发现,在相同浆骨比条件下,早期碳化养护会明显降低透水混凝土的实时吸附量和累积总吸附率,这表明早期碳化养护粗化了透水混凝土孔隙结构,降低了可以吸Pb^(2+)的水泥浆体的吸附表面积。

The goal of this study is to increase the adsorption capacity of pervious concrete to Pb^(2+)in rainwater.This study utilizes the approach of optimal volume ratio of paste to aggregate(VRPA)parameters to develop and prepare high-performance pervious concrete that can achieve the desired balance between permeability and strength.In addition,the influence of varying VRPA and early carbonation curing conditions on the Pb^(2+)adsorption capacity of pervious concrete was examined using the Pb^(2+)removal rate as an index.The findings of the study demonstrated:SEM scanning electron microscopy and energy spectrum analysis revealed that all of the hydration products in pervious concrete contained Pb^(2+).When the paste to aggregate ratio parameter was set to 0.39,the pervious concrete used in this experiment has the best Pb^(2+)adsorption from rainwater.It was also discovered that early carbonation curing substantially lowered the real-time and cumulative total adsorption rates of pervious concrete under identical paste to aggregate ratio conditions.This suggests that early carbonation curing coarsens the pore structure of pervious concrete and decreases the adsorption surface area of cement paste that can absorb Pb^(2+).