Phosphorus Tailings Modified Biochar for the Removal of Phosphorus from Water

Abstract

Dehydrated sludge and phosphate tailings are used as raw materials, mixed in a certain proportion, and pyrolyzed in a tube furnace at a temperature of 800 ℃ to form sludge composite phosphate tailings biochar, which is then used for the treatment of phosphate containing wastewater. We investigated the adsorption efficiency and influencing factors (initial phosphorus concentration, pH value, and coexisting ions) of biochar for phosphorus in both single and mixed systems (coexistence of phosphorus, ammonia nitrogen, and paracetamol). The results showed that in a single system, when the phosphorus concentration was 50mg/L, the pH value was 7, and the concentration of coexisting ion SO₄^2- was 0.1mg/L, the removal rates were 99.88%, 80.96%, and 86.04%, respectively. Biochar had the best adsorption effect on phosphorus. In the mixed system, the removal rate was 99.86% when the phosphorus concentration was 50mg/L, and the removal rates were 99.86%, 54.98%, and 79.10% when the coexisting ion SO₄^2- concentration was 0.1mg/L at pH 8. The adsorption effect on phosphorus was the best. Phosphorus is one of the main elements causing eutrophication of water bodies, which can lead to the proliferation of algae in the water. So the removal of phosphorus from water is very important.