地下水阻截墙材料的配制及对污染物铬的吸附性

Preparation of Groundwater Barrier Wall Materials and Its Adsorption to Pollutant Chromium

寻找一种适用于阻截地下水铬污染的阻截墙。以水泥为主要材料,分别与膨润土、粉煤灰和硅灰石粉以不同比例配比,进行渗透试验;通过最佳配比试验材料做固化体静态试验,研究对重金属Cr^(6+)的吸附试验。渗透试验结果显示,1-3(水泥86.0%、膨润土6.5%和硅灰石粉7.5%)、2-3(水泥62.9%、膨润土2.1%和粉煤灰35%)、3-2(水泥70.1%、硅灰石粉4.9%和粉煤灰25.0%)和3-3(水泥62.9%、硅灰石粉2.1%和粉煤灰35%)的渗透系数较为合适,满足阻截材料防渗性能的要求。固化体静态试结果显示,5 h左右固化体吸附了溶液中36%左右的Cr^(6+)。综合试验结果表明,水泥(86.0%)、膨润土(6.5%)和硅灰石粉(7.5%)组成的污染物阻截墙材料对水体中重金属Cr^(6+)具有较好的阻截性能。

A barrier wall that is suitable for blocking chromium pollution from groundwater was Found. Cement was used as the main material,and the bentonite,fly ash and wollastonite powder were tested in different proportions. The adsorption test of heavy metal Cr^6＋ was carried out by the best ratio test material. The permeation test results show that the permeability coefficients of 1-3（ cement 86. 0%,bentonite 6. 5% and 7. 5% wollastonite powder）,2-3（ cement 62. 9%,bentonite 2. 1% and 35% fly ash）,3-2（ cement 70. 1%,wollastonite powder 4. 9%and 25. 0% fly ash） and 3-3（ cement 62. 9%,wollastonite powder 2. 1% and 35% fly ash） are more suitable to meet the requirements of impermeability of barrier materials. The results of the static test of the solidified body show that the solidified body adsorbs about 36% of Cr^6＋ in the solution within 5 h. The results of two experiments show that the pollutant barrier material composed of cement（ 86. 0%）,bentonite（ 6. 5%） and wollastonite powder（ 7. 5%） has good blocking performance for heavy metal Cr^6＋ in water.