Effect of oxide interactions on chromium speciation transformation during simulated municipal solid waste incineration  

作　　者：Guodong Zhao Chong Tian Peidong Wu Xuguang Zhang Zhikang Wang Xiaoxiang Chen Zhuo Xiong Yongchun Zhao Junying Zhang 

机构地区：[1]State Key Laboratory of Coal Combustion,School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan 430074,China [2]School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China [3]National Environmental Protection Engineering Technology Center for Trace Elements Pollution Control and Low Carbon Utilization of Coal,Huazhong University of Science and Technology,Wuhan 430074,China [4]School of Environmental Engineering,Wuhan Textile University,Wuhan 430200,China

出　　处：《Journal of Environmental Sciences》2024年第8期11-20,共10页环境科学学报（英文版）

基　　金：supported by the National R&D Program Project of China(No.2019YFC1907000);the Key Research and Development Program of Hubei Province(No.2020BCA076);the Natural Sciences Foundation of China(No.52176127);Natural Science Foundation of Hubei Province(No.2022CFB045)。

摘　　要：Chromium released during municipal solid waste incineration(MSWI)is toxic and carcinogenic.The removal of chromium from simulated MSWI flue gas by four sorbents(CaO,bamboo charcoal(BC),powdered activated carbon(PAC),and Al_(2)O_(3))and the effects of four oxides(SiO_(2),Al_(2)O_(3),Fe_(2)O_(3),and CaO)on chromium speciation transformationwere investigated.The results showed that the removal rates of total Cr by the four sorbents were Al_(2)O_(3)<CaO<PAC<BC,while the removal rates of Cr(Ⅵ)by the four sorbents were Al_(2)O_(3)<PAC<BC<CaO.CaO had a strong oxidizing effect on Cr(Ⅲ),while BC and PAC had a better-reducing effect on Cr(Ⅵ).SiO_(2)was better for the reduction of Na_(2)CrO_(4)and K_(2)CrO_(4)above 1000℃due to its strong acidity,and the addition of CaO significantly inhibited the reduction of Cr(Ⅵ).MgCrO_(4)decomposed above 700℃to form MgCr_(2)O_(4),and the reaction between MgCrO_(4)and oxides also existed in the form of a more stable trivalent spinel.Furthermore,when investigating the effect of oxides on the oxidation of Cr(Ⅲ)in CrC_(l3),it was discovered that CaO promoted the conversion of Cr(Ⅲ)to Cr(Ⅵ),while the presence of chlorine caused chromium to exist in the form of Cr(V),and increasing the content of CaO and extending the heating time facilitated the oxidation of Cr(Ⅲ).In addition,silicate,aluminate,and ferrite were generated after the addition of SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3),which reduced the alkalinity of CaO and had an important role in inhibiting the oxidation of Cr(Ⅲ).The acidic oxides can not only promote the reduction of Cr(Ⅵ)but also have an inhibitory effect on the oxidation of Cr(Ⅲ)ascribed to alkali metals/alkaline earth metals,and the proportion of acidic oxides can be increased moderately to reduce the generation of harmful substances in the hazardous solid waste heat treatment.

关 键 词：Cr(Ⅵ)reduction Cr(Ⅲ)oxidation Alkali oxides Acidic oxides Municipal solid waste incineration 

分 类 号：X799.3[环境科学与工程—环境工程]