The Influence of Key Elements in Black-Odor Water

Abstract

Currently, the progress for the treatment of black-odor rivers is not optimistic. One of the main reasons is that the public understanding of the influence of key elements for the formation of black-odor water still remains unclear. Studying the key elements in black-odor water is important to determine the water quality conditions, evolution process, and mechanism underlying the formation of black-odor water, as well as to quantify the degree of black-odor water. In this study, the effect of total organic carbon on dissolved oxygen (DO) and oxidation–reduction potential (ORP) values was studied by artificially simulating black-odor water. The contribution of inorganic sulfur (IS) and organic sulfur (OS) to the formation of black-odor water was discussed. The obtained results show that pure organic pollutants do not cause black-odor water. When the DO content is below 1 mg/L and the ORP value decreases to –200 mv, metal sulfides begin to appear, followed by pungent odors such as H2S and volatile organic sulfur compounds (VOSCs). Both IS and OS contribute to the black-odor water. IS is more likely to form metallic sulfides than OS; however, OS is more likely to produce pungent odors than IS.