Characteristics of Thallium(Ⅰ)adsorption by ferric/aluminum-based unburned ceramiste water treatment residuals
Inorder to explore the feasibility of using unburned ceramsite water treatment residuals(UC-WTR)as adsorbent to treat thallium-containing wastewater,aluminum-based unburned ceramiste water treatment residuals(UCWTR-Al)and ferric-based unburned ceramiste water treatment residuals(UCWTR-Fe)were prepared by the burning-free method for the study of Tl(Ⅰ)adsorption in wastewater.The adsorption characteristics of the two ceramsites for Tl(Ⅰ)in wastewater were analyzed by batch adsorption,improved BCR method for hierarchical extraction,FT-IR and XPS,and the adsorption mechanism of Tl(Ⅰ)was explored.The results show that the quasi-second-order kinetic model is more suit-able to describe the adsorption process of Tl(Ⅰ)by two kinds of ceramsite.The maximum adsorption ca-pacities of UCWTR-Al and UCWTR-Fe fitted by Langmuir model are 5.360 mg·g-1 and 5.421 mg·g-1,respectively,and the adsorption capacity is positively correlated with pH value.Coexisting ion experiment shows that K+has the most significant inhibitory effect on Tl(Ⅰ).After adsorption,the existing forms of Tl in UCWTR-Al and UCWTR-Fe are mainly reducible.FT-IR and,XPS characterization analysis show that Al/Fe—O,Si—O—Si,O—Ca—Oand—OH groups contained in UCWTR-Al and UCWTR-Fe can chemically adsorb with Tl(Ⅰ),forming Fe/Al—O—Tl complexes and chelated products of C—S—H gel combined with Tl.The research results confirmed that UCWTR-Al and UCWTR-Fe are efficient adsorbents for the stable removal of Tl(Ⅰ),which provided scientific basis and technical support for their practical ap-plication in the treatment of thallium-containing wastewater.
Tl(Ⅰ)aluminum-based unburned ceramiste water treatment residualsferric-based unburned ceramiste water treatment residualsadsorption