Study On Kinetics Of Chromium (Cr(Ⅵ)) Reduction By In The Wastewater Ferrous Sulfide

This paper discusses the use of FeS as reductant to reduce Cr (VI) in wastewater. High purity of ferrous sulfide is prepared by FeSO4 and Na2S which are purified.The effects on reaction includes the mole ratio of FeSO4 and Na2S,reaction temperature,reaction time and concentration of reactors.At last,the optimal condition is obtained,the purity of ferrous sulfide can reach 95.41% .In the constant temperature and the anaerobic conditions,the kinetics of chromium(Cr(Ⅵ))reduction by sulfide and its affecting factors were conducted in batch experimental systems.The results showed that the reaction displayed in two stages when solution pH (1～2)kept stable and the initial concentration of Iron sulfide was excessive.At the initial stage Cr(Ⅵ)Was consumed ranging from 60%～80%,the reaction followed the pseudo first-order and the plots of 1nC(Cr(Ⅵ)) versus reaction time(t) was linear.At the later stage,when Cr(Ⅵ)remained about 20%～40%,reaction rate Was decelerated dramatically.