A novel strategy of tannery sludge disposal–converting into biochar and reusing for Cr(Ⅵ)removal from tannery wastewater  

作　　者：Zhiwei Li Di Yu Xingdong Wang Xuejiao Liu Zhen Xu Yin Wang 

机构地区：[1]CAS Key Laboratory of Urban Pollutant Conversion,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control,CAS Haixi Industrial Technology Innovation Center in Beilun,Ningbo 315830,China [4]Key Laboratory of Urban Environment and Health,Ningbo Observatio

出　　处：《Journal of Environmental Sciences》2024年第4期637-649,共13页环境科学学报（英文版）

基　　金：supported by the Alliance of International Science Organizations(No.ANSO-CR-KP-2021-08);the STS Plan Supporting Project of the Chinese Academy of Sciences in Fujian Province(Nos.2020T3036,2021T3102,2021T3073,2021T3049,and 2022T3065);the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23030301);the Social Development Leading Key Projects of Fujian Province(No.2022Y0080)。

摘　　要：Tannery sludge with high chromium content has been identified as hazardous solid waste due to its potential toxic effects.The safety disposal and valorization of the tannery sludge remains a challenge.In this study,the chromium stabilization mechanism was systematically investigated during chromium-rich tannery sludge was converted to biochar and the removal performance of the sludge biochar(SBC)for Cr(Ⅵ)from tannery wastewater was also investigated.The results showed that increase in pyrolysis temperature was conductive to the stabilization of Cr and significant reduction of the proportion of Cr(Ⅵ)in SBC.It was confirmed that the stabilization of chromium mainly was attributed to the embedding of chromium in the C matrix and the transformation of the chromium-containing substances from the amorphous Cr(OH)_(3)to the crystalline state,such as(FeMg)Cr_(2)O_(5).The biochar presented high adsorption capacity of Cr(Ⅵ)at low pH and the maximal theoretical adsorption capacity of SBC produced at 800°C can reach 352 mg Cr(Ⅵ)/g,the process of which can be well expressed by Langmuir adsorption isotherm and pseudo second order model.The electrostatic effect and reduction reaction were dominantly responsible for the Cr(Ⅵ)adsorption by SBC800.Overall,this study provided a novel strategy for the harmless disposal and resource utilization for the solid waste containing chromium in leather industry.

关 键 词：Chromium-rich tannery sludge PYROLYSIS BIOCHAR Stabilizationmechanisms Cr(Ⅵ)adsorption 

分 类 号：X794[环境科学与工程—环境工程]