Phosphorus Adsorption Characteristics of Alum and Iron Sludge from Drinking-Water Treatment Works

A lot of alum sludge (AS) and iron sludge (IS) produce in China from the drinking-water treatment works everyday. In this study, a series of batch experiments were conducted to investigate the phosphorus adsorption characteristics of alum sludge and iron sludge collected from two drinking-water treatment works in Zhengzhou, Henan, China using artificial P-rich wastewater. The results indicated that the Langmuir adsorption isotherm is fit for the description of the phosphorus adsorption on the two kinds of sludges (R2=0.9956 for AS, R2=0.9975 for IS). Many factors including reaction temperature, initial pH and phosphorus concentration of artificial wastewater have effect on phosphorus adsorption processes; high temperature, acid environment and low phosphorus concentration are favorable for the enhanced phosphorus adsorption.