Removal of volatile organic sulfur compounds by aeration during algae-induced black blooms in shallow lakes

Abstract

High levels of volatile organic sulfur compounds (VOSCs) have frequently been detected during algae-induced black blooms, which pose an ecological threat to water bodies and their surrounding residents. In this study, aeration was applied to remove the VOSCs after the outbreak of a black bloom. The removal efficiencies under different aeration rates (A1 (0.06 m3-air min−1 m−3), A2 (0.18 m3-air min−1 m−3), and A3 (0.54 m3-air min−1 m−3)) were compared. For treatments A2 and A3, the level of dissolved oxygen (DO) and the oxidation-reduction potential (Eh) increased sharply after 1 h of aeration, and about 70% of the VOSCs were removed from the water columns; however, for treatment A1, the increases in DO and Eh and the rate of removal of VOSCs were slower. The ultimate removal rate of VOSCs was >99% for all the aerated treatments after 24 h. The alteration of the oxidation-reduction conditions, induced by the aeration, could be the primary reason for the removal of the VOSCs. Thus, aeration treatment might be a feasible technique for the removal of VOSCs after the outbreak of black blooms in waterworks and some shallow lakes.