Study on the treatment of phosphate wastewater with modified Kaolin

Kaolin has been modified with hydrochloric acid and calcination, and given a study on the adsorption of phosphate by modified Kaolin. The Results show that phosphate adsorption capacities of modified Kaolin were raised enormously. When P concentration is 20 mg/L,consumption of modified Kaolin is 2%(weight ratio), Amounts of adsorption of Kaolin modified with hydrochloric acid and modified with heating are 0.82mg/g and 1.98mg/g , respectively. Remainder concentration of P in water are 3.63mg/L and 0.12mg/L , respectively. Rate of removing of P were raised with amount of hydrochloric acid increase. Optimum temperature of heating modification is 500-600°C. Adsorption characteristics can be described with Langmuir equation.