Ippolito J A, Ducey T F, Spokas K A, Trippe K M, Johnson M G
School of Environment and Natural Resources, The Ohio State University, Columbus, OH 43210, USA.
Agricultural Research Service, Coastal Plains Soil, Water, and Plant Research Center, United States Department of Agriculture, Florence, SC 29501-1242, USA.
Int J Environ Sci Technol (Tehran). 2024 Apr 15;21:9611-9622. doi: 10.1007/s13762-024-05621-9.
Approximately 390,000 abandoned mines across the US pose considerable, pervasive risks to human and environmental health; world-wide the problem is even greater. Lime, organic materials, and other amendments have been used to decrease metal bioavailability (e.g., Cd, Cu, Mn, Ni, Zn) in contaminated mine wastes and to promote plant community establishment for tailings stabilization. Biochar properties (e.g., alkaline pH, metal sorbing capabilities, available nutrients, improved soil water retention) make it a potential amendment for remediating metal contaminated mine tailings. A three-step procedure was developed to identify biochars that were most effective at reducing heavy metal availability, retaining metals, and subsequently selecting biochars for use in a soil amendment laboratory trial to ultimately be utilized in heavy metal contaminated mine land settings: Step (1) a synthetic precipitation leaching procedure extract of mine tailings was produced, representing potentially available metals, and used to identify metal removal properties of 28 different biochars (e.g., made from various feedstocks and pyrolysis or gasification conditions); Step (2) evaluate how well biochars retained previously sorbed metals; and Step (3) laboratory evaluation of the most promising biochars that removed and did not releases metals, applied at 0, 1, 2.5, and 5% (by wt) to mine tailings for reducing metal bioavailability. The reported methodology and results from this study could be used to quickly identify specific biochars and application rates to reduce mine tailings metal availability and aid in future remediation of abandoned mine sites globally.
美国各地约有39万座废弃矿山对人类健康和环境构成了相当大的普遍风险；在全球范围内，这个问题更为严重。石灰、有机材料和其他改良剂已被用于降低受污染矿山废弃物中金属的生物有效性（如镉、铜、锰、镍、锌），并促进植物群落的建立以稳定尾矿。生物炭的特性（如碱性pH值、金属吸附能力、有效养分、改善土壤保水性）使其成为修复金属污染矿山尾矿的潜在改良剂。开发了一个三步程序来确定在降低重金属有效性、保留金属方面最有效的生物炭，随后选择生物炭用于土壤改良实验室试验，最终应用于重金属污染矿山土地环境中：步骤（1）制备矿山尾矿的合成沉淀浸出程序提取物，代表潜在可用金属，并用于确定28种不同生物炭（如由各种原料以及热解或气化条件制成）的金属去除特性；步骤（2）评估生物炭保留先前吸附金属的效果；步骤（3）对去除且不释放金属效果最显著的生物炭进行实验室评估，将其按0%、1%、2.5%和5%（重量）施用于矿山尾矿以降低金属生物有效性。本研究报告的方法和结果可用于快速确定特定的生物炭及其施用量，以降低矿山尾矿中金属的有效性，并有助于全球范围内未来对废弃矿山场地进行修复。
