College of Natural Resources and Environment, South China Agricultural University/Key Laboratory of Agro-Environment in the Tropics, Ministry of Agriculture of China, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Eco-Circular Agriculture/Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture, Guangzhou 510642, China.
Centre for Regional and Rural Futures, Faculty of Science, Engineering and Built Environment, Deakin University, Burwood, VIC 3125, Australia.
Sci Total Environ. 2022 Oct 20;844:157062. doi: 10.1016/j.scitotenv.2022.157062. Epub 2022 Jul 7.
The use of commercially sourced dopants for synthesizing biochar-based composites could be economically undesirable. The current work aimed to explore the possibility of making low-cost biochar-based composites using red mud (an industrial waste from alumina production) as dopants. Two types of red mud were used: one from a Bayer process and another from a sintering process. Different techniques (wet chemical, magnetic, SEM-EDS, FTIR, XPS and XRD analyses) were adopted to characterize the synthesized red mud-biochar composites, along with the pristine biochar. The composites were superior to the pristine biochar in terms of acid neutralizing capacity, specific surface area, and degree of magnetization. Two laboratory simulation experiments were conducted to assess the improved efficacy of the composites on the treatment of acidic mine water and mine water-contaminated soils. In general, application of the composites resulted in a significantly higher removal rate of mine water-borne trace elements compared to the pristine biochar treatment. The composites also had better effects on immobilizing the soil-borne trace elements and weakening the uptake of trace elements by the test vegetable plant species grown in the composite-treated soils, as compared to the pristine biochar-treated soil. By comparison, the sintering red mud-biochar composite had a generally better performance compared to the Bayer red mud-biochar composite.
使用商业来源的掺杂剂来合成基于生物炭的复合材料可能在经济上不可取。本研究旨在探索使用赤泥（氧化铝生产过程中的工业废料）作为掺杂剂来制造低成本基于生物炭的复合材料的可能性。使用了两种类型的赤泥：一种来自拜耳法，另一种来自烧结法。采用不同的技术（湿法化学、磁性、SEM-EDS、FTIR、XPS 和 XRD 分析）对合成的赤泥-生物炭复合材料以及原始生物炭进行了表征。与原始生物炭相比，复合材料在中和酸能力、比表面积和磁化程度方面具有优势。进行了两项实验室模拟实验，以评估复合材料在处理酸性矿山废水和受矿山废水污染的土壤方面的改进效果。总的来说，与原始生物炭处理相比，复合材料在去除矿山水中痕量元素方面的效果显著提高。与原始生物炭处理的土壤相比，复合材料对固定土壤中痕量元素和减弱受测试蔬菜物种对复合处理土壤中痕量元素的吸收也有更好的效果。相比之下，与拜耳法赤泥-生物炭复合材料相比，烧结赤泥-生物炭复合材料的性能通常更好。
