This study aimed to evaluate biochar produced from eggshells to remove water-polluting substances and to apply it on clayey soil to improve physical properties. CCRD was used to determine the influence of biochar concentration and contact time in water-polluting substance removal. Bacteria removal efficiency and genotoxicity effects were evaluated. Compaction and compressive strength tests were performed after the application of biochar to clayey soils. The removal efficiency of aluminum, fluoride, manganese, zinc, and iron were 52.8, 69.8, 78.9, 96.7, and 96.4%, respectively. After 6 h of contact time, E. coli was completely removed. The water did not demonstrate genotoxic residual after biochar application. The maximum compressive strength obtained demonstrated an increase of 29.7% if compared to control. The biochar production from eggshell waste to remove water-polluting and stabilization of clayey soil provides a very simple, low-cost, effective and environmental friendly of this waste.

Graphical abstract

中文翻译：

---

蛋壳废料生产的生物炭用于去除水污染物质和稳定粘土：一种环境友好型应用

本研究旨在评估从蛋壳中生产的生物炭以去除水污染物质并将其应用于粘土以改善物理性质。CCRD 用于确定生物炭浓度和接触时间对去除水污染物质的影响。评估了细菌去除效率和遗传毒性效应。在将生物炭应用于粘土后进行压实和抗压强度测试。铝、氟、锰、锌、铁的去除率分别为52.8%、69.8%、78.9%、96.7%、96.4%。接触 6 小时后，大肠杆菌被完全删除。应用生物炭后，水没有显示出遗传毒性残留。与对照相比，获得的最大抗压强度增加了 29.7%。从蛋壳废物中生产生物炭以去除水污染和稳定粘土为这种废物提供了一种非常简单、低成本、有效和环保的方法。

图形概要