LAUSR

Abstract Electrolytic manganese metal residue (EMMR) harmless treatment has always lacked a low-cost and quick processing technology. In this study, surfactants, namely tetradecyl trimethylammonium chloride (TTC), sodium dodecyl benzene sulfonate (SDBS), sodium lignin sulfonate (SLS), and octadecyl trimethylammonium chloride (OTC), were used in the solidification of Mn2+ and removal of NH4+-N from electrolytic manganese metal residue (EMMR). The Mn2+ and NH4+-N concentrations under different reaction conditions, Mn2+ solidification and NH4+-N removal mechanisms, and leaching behavior were studied. The results revealed that the surfactants could enhance the Mn2+ solidification and NH4+-N removal from EMMR, and the order of enhancement was as follows: TTC ＞ SDBS ＞ OTC ＞ SLS. The NH4+-N and Mn2+ concentrations were 12.3 and 0.05 mg/L with the use of 60.0 mg/kg TTC under optimum conditions (solid-liquid ratio of 1.5:1, EMMR to BRM mass ratio of 100:8, temperature of 20 ℃, and reaction duration of 12 h), which met the integrated wastewater discharge standard (GB8978-1996). Mn2+ was mainly solidified as Mn(OH)2, MnOOH and MnSiO3, and NH4+-N in EMMR was mostly removed in the form of ammonia. The results of this study could provide a new idea for cost-effective EMMR harmless treatment.