State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation, Tianjin University, Tianjin, 300072, China; Ecological Environment Bureau of Xiong'an New Area Management Committee of Hebei Province, Baoding, 071799, China.
Environ Pollut. 2024 Dec 15;363(Pt 2):125175. doi: 10.1016/j.envpol.2024.125175. Epub 2024 Oct 21.
Heavy metal sediment pollution has become an increasingly serious problem associated with industrial development, so extensive studies have been conducted concerning their removal. Biochar has recently shown good potential for in-situ remediation of heavy metal-contaminated sediments. The heavy metal adsorption capacity of inexpensive biochar can be improved by loading it with metal oxides. In this study, manganese-modified biochar (MBC) was prepared by KMnO-modified waste-activated sludge biochar and applied to immobilize Pb and Cd in sediments. Its effects on the sediment microbial community were also investigated. The Results showed that manganese modification of the biochar made it more conducive to the adsorption of heavy metals, owing to its higher specific surface area and graphitization structure, more active sites and oxygen-containing groups, and the presence of MnO crystal structure on the surface. The maximum adsorption capacities of this material for Pb and Cd in solution were 176.9 mg/g and 44.0 mg/g, respectively. The application of MBC to the remediation of heavy metal-contaminated sediments transformed Pb and Cd in the sediments from exchangeable to residual state. The F4 content of Pb in the sediments increased from 40.52%-42.36% to 49.11%-51.14% after application of 1% MBC, and to 63.94%-64.49% after application of 5% MBC. Correspondingly, the F1 content of Pb in the sediments decreased from 29.09%-30.68% to 17.43%-17.69% after the application of 5% MBC. Furthermore, MBC efficiently enriched the microbial biodiversity and affected the microbial population structure within 60 days. The relative abundance of uncultured f Symbiobacteraceae and Fonticella communities significantly increased after incubation. The results may provide empirical support for the combination of metal oxides and biochar for the remediation of heavy metal-contaminated sediments.
重金属沉积物污染已成为与工业发展相关的一个日益严重的问题，因此广泛开展了有关重金属去除的研究。生物炭最近显示出了用于原位修复重金属污染沉积物的巨大潜力。通过负载金属氧化物可以提高廉价生物炭的重金属吸附能力。本研究采用 KMnO4 改性废活性污泥生物炭制备了锰改性生物炭（MBC），并将其应用于固定沉积物中的 Pb 和 Cd。还研究了其对沉积物微生物群落的影响。结果表明，由于比表面积和石墨化结构更大、更多的活性位点和含氧基团以及表面存在 MnO 晶体结构，生物炭的锰改性使其更有利于重金属的吸附。该材料对溶液中 Pb 和 Cd 的最大吸附容量分别为 176.9 mg/g 和 44.0 mg/g。MBC 应用于重金属污染沉积物的修复，将沉积物中的 Pb 和 Cd 从可交换态转化为残渣态。应用 1% MBC 后，沉积物中 Pb 的 F4 含量从 40.52%-42.36%增加到 49.11%-51.14%，应用 5% MBC 后增加到 63.94%-64.49%。相应地，应用 5% MBC 后，沉积物中 Pb 的 F1 含量从 29.09%-30.68%降低到 17.43%-17.69%。此外，MBC 在 60 天内有效地富集了微生物生物多样性并影响了微生物种群结构。培养后，未培养的 f Symbiobacteraceae 和 Fonticella 群落的相对丰度显著增加。研究结果可能为金属氧化物和生物炭结合修复重金属污染沉积物提供经验支持。
