University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa.
University of Johannesburg, PO Box 524, Auckland Park 2006, South Africa.
J Hazard Mater. 2017 Feb 5;323(Pt B):641-653. doi: 10.1016/j.jhazmat.2016.10.027. Epub 2016 Oct 14.
This paper presents a column study conducted to investigate the potential use of pervious concrete as a reactive barrier for treatment of water impacted by mine waste. The study was done using acid mine drainage (AMD) collected from a gold mine (WZ) and a coalfield (TDB). Pervious concrete mixtures consisting of Portland cement CEM I 52.5R with or without 30% fly ash (FA) were prepared at a water-cementitious ratio of 0.27 then used to make cubes which were employed in the reactor columns. It was found that the removal efficiency levels of Al, Fe, Mn, Co and Ni were 75%, 98%, 99%, 94% and 95% for WZ; 87%, 96%, 99%, 98% and 90% for TDB, respectively. The high rate of acid reduction and metal removal by pervious concrete is attributed to dissolution of portlandite which is a typical constituent of concrete. The dominant reaction product in all four columns was gypsum, which also contributed to some removal of sulphate from AMD. Formation of gypsum, goethite, and Glauber's salt were identified. Precipitation of metal hydroxides seems to be the dominant metal removal mechanism. Use of pervious concrete offers a promising alternative treatment method for polluted or acidic mine water.
本文介绍了一项柱研究，旨在研究透水混凝土作为一种反应性屏障用于处理受矿山废物影响的水的潜力。该研究使用了来自金矿 (WZ) 和煤田 (TDB) 的酸性矿山排水 (AMD) 进行。在水胶比为 0.27 的条件下，制备了含有或不含有 30%粉煤灰 (FA) 的波特兰水泥 CEM I 52.5R 透水混凝土混合物，然后将其用于制作反应器柱中的立方体。结果表明，WZ 的 Al、Fe、Mn、Co 和 Ni 的去除效率水平分别为 75%、98%、99%、94%和 95%；TDB 的分别为 87%、96%、99%、98%和 90%。透水混凝土具有高的酸还原率和金属去除率，这归因于波特兰石的溶解，波特兰石是混凝土的典型成分。四个柱子中的主要反应产物都是石膏，石膏也有助于从 AMD 中去除一些硫酸盐。鉴定出石膏、针铁矿和 Glauber 盐的形成。金属氢氧化物的沉淀似乎是主要的金属去除机制。使用透水混凝土为受污染或酸性矿山水提供了一种有前途的替代处理方法。
