Experimental Study on Powdered Manganese Dioxide for Dyeing Wastewater Treatment

The decolorization of dyeing wastewater prepared from rhodamine B or methyl orange with solid powdered manganese dioxide(PMN) was studied,and the influence of initial solution pH value and contact time on the decolorization efficiency was investigated.The results show that pH value is the key factor influencing decolorization efficiency.The lower pH value and adequate contact time is favorable for the wastewater decolorization.The decolorization efficiency is 81.9%(rhodamine B) and 92.8%(methyl orange) when pH is 1.2.It can reach the highest decolorization efficiency when contact time is 15 min and pH is 1.5.At acid condition,the removal of dye by PMN is the combined result of oxidation and adsorption.