When not properly treated, nitrate and phosphate present in groundwater can damage human health and environments. In this study, laboratory column experiments were performed for sequential treatment of nitrate and phosphate in groundwater. Two columns were set up and connected: one to treat nitrate with organic carbon materials (i.e., woodchips) and the other to treat phosphate with basic oxygen furnace (BOF) slag. The columns were operated for a total of 1.6 years. The results showed that nitrate was removed through denitrification and phosphate was removed by precipitation of the phosphate minerals (e.g., hydroxyapatite). BOF slag was effective at removing phosphate, though the high pH (11–12) of the system's effluent water raised a concern for the downgradient areas. Of the three subsequent experiments performed, pH was near neutral when the effluent of the BOF slag column was passed through local soil. Sparging with CO₂ and air, in contrast, resulted in pH levels that were either too low (5 in the case of CO₂) or too high (9.5 in the case of air). The study shows that sequential permeable reactive barrier (PRB) systems consisting of woodchips and BOF slag can be effective for removal of nitrate and phosphate in groundwater and they can be a long-term remedial solution for groundwater contaminated with both nitrate and phosphate.

如果处理不当，地下水中的硝酸盐和磷酸盐会损害人类健康和环境。在这项研究中，对地下水中硝酸盐和磷酸盐的顺序处理进行了实验室柱实验。设置并连接了两个塔：一个用有机碳材料（即木片）处理硝酸盐，另一个用碱性氧气炉（BOF）炉渣处理磷酸盐。这些塔总共运行了 1.6 年。结果表明硝酸盐通过反硝化去除，磷酸盐通过磷酸盐矿物（例如羟基磷灰石）的沉淀去除。转炉炉渣可有效去除磷酸盐，尽管系统出水的高 pH 值 (11-12) 引起了对降坡区域的关注。在随后进行的三个实验中，当转炉渣柱的流出物通过当地土壤时，pH 值接近中性。用 CO 喷射相比之下，₂和空气导致的 pH 值要么太低（在 CO ₂的情况下为₅），要么太高（在空气的情况下为 9.5）。研究表明，由木片和转炉炉渣组成的连续渗透反应屏障 (PRB) 系统可以有效去除地下水中的硝酸盐和磷酸盐，并且它们可以成为被硝酸盐和磷酸盐污染的地下水的长期补救解决方案。