OPTIMIZATION OF PHOSPHORUS LEACHING FROM SEWAGE SLUDGE OF BINH HUNG DOMESTIC WASTEWATER TREATMENT PLANT TỐI ƯU HÓA TRÍCH LY PHOSPHORUS TỪ BÙN THẢI NHÀ MÁY XỬ LÝ NƯỚC THẢI ĐÔ THỊ BÌNH HƯNG

Abstract

Leaching phosphorus (P) in dewatered sludge from domestic wastewater treatment plant is an important step to convert solid P compounds into a soluble form that can be separated and recovered as clean products. In addition, optimization of leaching conditions is essential to minimize the amount of chemicals used and water resources in developing P recovery processes. This study combines experimental studies and simulation calculations by using the Aqion-PRO hydrochemistry tool to determine the optimal conditions for P leaching. Type of leaching agent, liquid-solid phase ratio, agent concentration and leaching time are researched to optimize. The liquid-solid phase ratio and leaching agent concentration are correlated to the P leaching ability from the sludge. The H₂SO₄ 1.1M, phase ratio 5 and leaching time 60 minutes were determined as the most optimal parameters to leaching phosphorus, P leaching efficiency can reach about 85 ± 3%.