This research investigates the use of biochar modified with Ordinary Portland Cement (OPC) as an adsorbent for heavy metal removal and evaluates the impact of competing ions and nutrients on the adsorptive removal process. The cement-modified biochar composites, featuring functional groups from biochar and hydrated OPC, exhibited significantly enhanced adsorption capacities for Cu, Pb, and Zn, approximately 3.3, 2.4, and 6 times higher, respectively, compared to unmodified biochar upon introducing 1.5 % (v/v) OPC. The Langmuir monolayer adsorption model accurately described the adsorption data, with heavy metals binding to functional groups like CC and CO, CO3–2, silanols (Si-OH), siloxanes and calcium silicate hydrate. The cement-modified biochar composite exhibited notable adsorption capacities for Cu, Pb, and Zn at 28.82 mg/g, 38.76 mg/g and 26.53 mg/g, comparable to commercial activated carbons. There were negligible effects from NO on the removal of Cu, Pb and Zn, PO ions enhanced Pb removal, and NH ions slightly reduced the removal of all three metals, while humic acid increased removal. The findings indicate that using OPC boosts heavy metal adsorption, and insights into the influence of competing ions and nutrients apprise strategies for using OPC-modified biochar in practical applications.

中文翻译：

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评估水泥改性生物炭吸附剂去除城市雨水中铜、铅和锌的性能


本研究研究了使用普通波特兰水泥（OPC）改性的生物炭作为重金属去除吸附剂的用途，并评估了竞争离子和营养物对吸附去除过程的影响。水泥改性生物炭复合材料具有来自生物炭和水合 OPC 的官能团，在引入 1.5%（ v/v)OPC。 Langmuir 单层吸附模型准确地描述了吸附数据，其中重金属与 CC 和 CO、CO3-2、硅烷醇 (Si-OH)、硅氧烷和硅酸钙水合物等官能团结合。水泥改性生物炭复合材料对 Cu、Pb 和 Zn 表现出显着的吸附能力，分别为 28.82mg/g、38.76mg/g 和 26.53mg/g，与商业活性炭相当。 NO 对 Cu、Pb 和 Zn 的去除影响可以忽略不计，PO 离子增强了 Pb 的去除，NH 离子略微降低了所有三种金属的去除，而腐殖酸则增加了去除。研究结果表明，使用 OPC 可以促进重金属吸附，并且对竞争离子和营养物质影响的深入了解为在实际应用中使用 OPC 改性生物炭提供了策略。