标题: Multiple environmental risk assessments of heavy metals and optimization of sludge dewatering: Red mud-reed straw biochar combined with Fe2+ activated H2O2

作者: Li, H (Li, He); Chen, JA (Chen, Jiaao); Zhang, JX (Zhang, Jiaxing); Dai, TL (Dai, Tenglong); Yi, H (Yi, Han); Chen, FY (Chen, Fangyuan); Zhou, M (Zhou, Min); Hou, HB (Hou, Haobo)

来源出版物: JOURNAL OF ENVIRONMENTAL MANAGEMENT 卷: 316 文献号: 115210 DOI: 10.1016/j.jenvman.2022.115210 出版年: AUG 15 2022

摘要: In this study, Fe-rich biochar (RMRS-BC) was prepared from red mud and reed straw to improve sludge dewatering and transformation of heavy metals (HMs, including Cd, Cr, Cu, Pb, and Zn). The optimal concentrations of RMRS-BC, Fe2+, and H2O2 to promote sludge dewaterability were identified by response surface methodology (RSM). The optimal dosages of RMRS-BC, Fe2+, and H2O2 were 74.0, 104.9, and 75.7 mg/g dry solids (DS), respectively. The corresponding capillary suction time (CST) and water content of sludge cake were 14.3 s and 51.25 wt%. For the improvement mechanism, heterogeneous and homogeneous Fenton reactions occurred due to RMRS-BC and Fe2+ activating H2O2. The extracellular polymeric substances (EPS) decomposed into dissolved organic matter (proteins and polysaccharides), thereby promoting the transformation of bound water to free water and further reducing the water content of the sludge cake. The research quantitatively assessed the environmental risk of heavy metals in the conditioned sludge cake based on bioavailability and ecotoxicity, pollution levels and potential ecological risks. Compound conditioning using RMRS-BC, Fe2+, and H2O2 could significantly improve the solubility and reduce the leaching toxicity of HMs. In general, RMRS-BC combined with Fe2+ to activate H2O2 provided an effective method to enhance sludge dewaterability and reduce HMs risk.

作者关键词: Red mud -reed straw biochar; Heavy metals; Sludge dewatering; Response surface methodology; Environmental risk assessment

地址: [Li, He; Chen, Jiaao; Zhang, Jiaxing; Dai, Tenglong; Yi, Han; Chen, Fangyuan; Zhou, Min; Hou, Haobo] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Hubei, Peoples R China.

[Yi, Han] Anqing Normal Univ, Coll Resources & Environm, Anqing 246011, Anhui, Peoples R China.

通讯作者地址: Hou, HB (通讯作者)，Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Hubei, Peoples R China.

电子邮件地址: houhb@whu.edu.cn

影响因子：8.91