비료 유도용액의 정삼투를 이용한 하수처리수의 재이용 - 유도용액의 성능 평가 -

This study is to evaluate the performance of draw solutions in the water reuse of sewage discharge water using fertilizer drawn forward osmosis. Feed water used in all experiments was the effluent from secondary sedimentation tank in activated sludge process. Considering osmotic pressure, solubility, and pH, NH4H2PO4, KCl, KNO3, NH4Cl, (NH4)2HPO4, NH4NO3, NH4HCO3, and KHCO3 were screened from a comprehensive lists of fertilizer. Their performances were evaluated in terms of water permeate flux and reverse solute flux. KCl showed the highest average water flux followed by NH4Cl, NH4NO3, KNO3, KHCO3, NH4HCO3, NH4H2PO4, and (NH4)2HPO4. Using KCl as draw solution, the average water permeate flux was 13.49 LMH. There was no big difference in osmotic pressure between the effluent from secondary sedimentation tank and deionized water. NH4H2PO4 showed the lowest reverse solute flux followed by NH4Cl, (NH4)2HPO4, KNO3, NH4HCO3, and NH4NO3. Using NH4H2PO4 as draw solution, the reverse solute flux was 4.96 × 10-3 mmol/m2⋅sec.