In this study, kaolinite, carbon black (CB), iron sulfide (FeS), hydroxyapatite (HAP), and oyster shell powder (OSP) were selected as potentially ideal amendments to immobilize metals in sediment, including Ni, Cr, Cu, Zn, and Hg. In aqueous batch experiments, the five adsorbents were tested for capturing the five potential toxic metals individually at various concentrations. HAP and OSP showed the largest removal efficiencies towards Ni (OSP: 76.47%), Cr (OSP: 100.00%), Cu (HAP: 98.39%), and Zn (HAP: 64.56%), with CB taking the third place. In contrast, FeS and CB played a more significant role in Hg removal (FeS: 100.00%; CB: 86.40%). In the modified six-column microcosm experiments, five mixing ratios based on various considerations using the five adsorbent materials were tested; the water samples were collected and analyzed every week for 135 days. Results showed that caps including CB could immobilize the release of Hg and methylmercury (MeHg) better than those with FeS. More economical caps, namely, with a higher portion of OSP in the mixed capping, could not reach comparable effects to those with more HAP for immobilizing Ni, but performed almost the same for the other four metals. All columns with active caps showed greater metal immobilization as compared to the controlled column without caps.

中文翻译：

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使用混合活性封盖修复多种潜在有毒金属污染的沉积物以降低环境风险

在本研究中，高岭石、炭黑 (CB)、硫化铁 (FeS)、羟基磷灰石 (HAP) 和牡蛎壳粉 (OSP) 被选为固定沉积物中金属（包括镍、铬、铜、锌）的潜在理想改良剂，和汞。在水性批次实验中，测试了五种吸附剂以分别捕获不同浓度的五种潜在有毒金属。HAP 和 OSP 对 Ni（OSP：76.47%）、Cr（OSP：100.00%）、Cu（HAP：98.39%）和 Zn（HAP：64.56%）的去除效率最高，CB 位居第三。相比之下，FeS 和 CB 在去除 Hg 方面发挥了更重要的作用（FeS：100.00%；CB：86.40%）。在改进的六柱微观实验中，基于各种考虑使用五种吸附材料测试了五种混合比例；每周收集和分析水样，持续 135 天。结果表明，含 CB 的帽比含 FeS 的帽能更好地固定 Hg 和甲基汞 (MeHg) 的释放。更经济的盖帽，即在混合盖帽中具有更高比例的 OSP，无法达到与具有更多 HAP 的固定 Ni 的效果相当的效果，但对其他四种金属的表现几乎相同。与没有盖子的对照柱相比，所有带活性盖子的色谱柱都显示出更高的金属固定化。但其他四种金属的表现几乎相同。与没有盖子的对照柱相比，所有带活性盖子的色谱柱都显示出更高的金属固定化。但其他四种金属的表现几乎相同。与没有盖子的对照柱相比，所有带活性盖子的色谱柱都显示出更高的金属固定化。