Environmental and Sanitary Engineering, Universidade Federal da Fronteira Sul - Campus Erechim, Erechim, RS, 99700-970, Brazil.
Graduate Program in Environmental Science and Technology, Universidade Federal da Fronteira Sul - Campus Erechim, Erechim, RS, 99700-970, Brazil.
Sci Rep. 2022 May 9;12(1):7542. doi: 10.1038/s41598-022-11529-6.
This study evaluates the use of rice husk ash (RHA)-eggshell lime (ESL) and RHA-commercial lime (CL) as alternative binders for clayey soil stabilization, as well as the performance of soil-binder mixtures under acidic attack. A central composite design was carried out to analyze the reactivity by batch tests with a sulfuric acid solution. Physical and mechanical behavior was evaluated by compaction test and unconfined compressive strength (UCS). Reactivity tests demonstrated better neutralization of contaminant acidity for mixtures with ESL. The highest compressive strength, reactivity and partial encapsulation of toxic elements are associated with application of 30% RHA and 6% ESL in the soil. A C-S-H gel is observed in poorly crystalline phases through the XRD pattern. The application of RHA-ESL in soils exposed to acidic attack has environmental feasibility. Analysis of RHA grinding processes combined with the mixture strength over time, and its application tests in impermeable barriers, in landfills, are recommended.
本研究评估了稻壳灰（RHA）-鸡蛋壳石灰（ESL）和 RHA-商业石灰（CL）作为替代黏结剂用于黏土稳定化的用途，以及在酸性侵蚀下土壤-黏结剂混合物的性能。采用硫酸溶液进行批式试验进行了中心复合设计以分析反应性。通过压实试验和无侧限抗压强度（UCS）评估物理力学性能。反应性试验表明，混合物中 ESL 的反应性更好，可以中和污染物的酸性。在土壤中应用 30%的 RHA 和 6%的 ESL 可以获得最高的抗压强度、反应性和部分有毒元素的封装。XRD 图谱显示，在非晶相中观察到 C-S-H 凝胶。在酸性侵蚀下应用 RHA-ESL 具有环境可行性。建议对 RHA 研磨工艺进行分析，并结合一段时间内的混合物强度及其在不透水屏障、垃圾填埋场中的应用测试。
