High performance and mechanism of Tl(I) removal from solution by synergetic application of nanowire γ-MnOOH@biochar and free radicals: Implications to AMD treatment

Thallium (Tl) is a rare heavy metal with extreme toxicity, and Tl pollution in water bodies has frequently emerged globally. It is a challenge to effectively remove the predominant monovalent thallium from acid wastewater. In this study, highly efficient Tl(I) removal from aqueous solution was realized through synergetic application of nanowire γ-MnOOH@biochar and free radicals (·OH and SO4−) generated via activating persulfate. This method exhibited an overall robust Tl removal capacity in a wide pH range, even can remove over 97% of Tl at pH = 2, and maintain generally stable in the presence of coexisting ion and organic matter. The Tl removal capacity at low initial pH of the solution was up to 20% higher than that at alkaline conditions and fast adsorption realized in the first 10 min. This study offers a novel alternative of Tl-bearing wastewater treatment with facilely engineered composite that combines advanced oxidation and adsorption techniques, thus potentially serving as a promising method towards Tl removal from challenging acid mine drainage.