标题: Sustainable and efficient stabilization/solidification of Pb, Cr, and Cd in lead-zinc tailings by using highly reactive pozzolanic solid waste

作者: Wang, HJ (Wang, Haojie); Ju, CX (Ju, Chenxuan); Zhou, M (Zhou, Min); Chen, JA (Chen, Jiaao); Dong, YQ (Dong, Yiqie); Hou, HB (Hou, Haobo)

来源出版物: JOURNAL OF ENVIRONMENTAL MANAGEMENT 卷: 306 文献号: 114473 DOI: 10.1016/j.jenvman.2022.114473 出版年: MAR 15 2022

摘要: Lead-zinc tailings (LZTs) are industrial by-products containing a large number of heavy metals that seriously harm the ecological environment and human health. This study was performed to propose a sustainable and efficient method for immobilizing Pb, Cr, and Cd in LZTs by using solid waste. To better assess the immobilization performance and mechanism, the leaching toxicity, fraction distribution, unconfined compressive strength, environmental risk assessment, and hydration products were explored. The LZTs were mixed and molded with different constituents of ground granulated blast furnace slag (GGBFS) and rice husk ashes (RHAs) at different curing temperatures. Results suggest that >= 99% of the Pb, Cr, and Cd were immobilized mainly in the form of residual fractions in the LZTs. The amounts of Pb, Cr, and Cd in the bioavailable fractions notably decreased by approximately 99.83%, 99.58%, and 97.05%, respectively. After stabilization/solidification (S/S) disposal, Pb, Cr, and Cd showed low to even no risk. The RHAs were effective to stabilize Pb, and GGBFS was effective to stabilize Cr. However, both materials showed almost equal effects to Cd. Ettringite, C-S-H gel, and portlandite were the main hydration products to immobilize Pb, Cr, and Cd, and these hydration products provided a source of strength. Honey-comb or reticular network C-S-H gel possessed higher specific surface area, higher pore volume, and bigger pore size than the other materials. The proposed method could explain the sustainability and efficiency of the S/S of Pb, Cr, and Cd in LZTs by using RHAs. This study opens up new perspectives for disposing heavy metal by using accessible agricultural solid waste (i.e., RHAs) in rural areas, and the solidified block shows certain economic benefits.

作者关键词: Lead-zinc tailings; Stabilization/solidification; Heavy metal; Fraction distribution; Rice hush ashes; Ground granulated blast furnace slag

KeyWords Plus: RICE-HUSK ASH; HEAVY-METALS; PORTLAND-CEMENT; RISK-ASSESSMENT; SEDIMENTS; STABILIZATION; SPECIATION; PHASES

地址: [Wang, Haojie; Ju, Chenxuan; Zhou, Min; Chen, Jiaao; Dong, Yiqie; Hou, Haobo] Wuhan Univ, Sch Resource & Environm Sci, Wuhan 430072, Peoples R China.

[Zhou, Min; Hou, Haobo] Hubei Environm Remediat Mat Engn Technol Res Ctr, Wuhan 430072, Peoples R China.

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

电子邮件地址: houhb@whu.edu.cn

影响因子：7.968