Application of dirty-acid wastewater treatment technology in non-ferrous metal smelting industry: Retrospect and prospect.

Dirty-acid wastewater (DW) originating from the non-ferrous metal smelting industry is characterized by a high concentration of H 2 SO 4 and As. During the chemical precipitation treatment, a significant volume of arsenic-containing slag is generated, leading to elevated treatment expenses. The imperative to address DW with methods that are cost-effective, highly efficient, and safe is underscored. This paper conducts a comprehensive analysis of three typical methods to DW treatment, encompassing technical principles, industrial application flow charts, research advancements, arsenic residual treatment, and economic considerations. Notably, the sulfide method emerges as a focal point due to its minimal production of arsenic residue and the associated lowest overall treatment costs. Moreover, in response to increasingly stringent environmental protection policies targeting new pollutants and carbon emissions reduction, the paper explores the evolving trends in DW treatment. These trends encompass rare metal and sulfuric acid recycling, cost-effective H 2 S production methods, and strategies for reducing, safely disposing of, and harnessing resources from arsenic residue. [Display omitted] • The applications of three typical DW treatment technologies are summarized. • The three typical arsenic residues safe disposal and research progress are reviewed. • The new challenge of DW treatment is put forward under new environmental protection. • The future research of DW treatment technology is to realize the resource utilization. [ABSTRACT FROM AUTHOR]