分離膜에 의한 廢棄物 浸出水의 處理에 관한 硏究

Abstract

Landfill leachates contained high concentration of COD, BOD, nitrogen compounds and inorganic salts. It is very difficult to treat those recalcitrant substances by using conventional biological treatment. This study was focused on investigating the possibility of advanced treatment by membrane separation system and recycling of landfill leachate. The membrane separation systems were composed the rotating membrane separation(RMS) apparatus and reverse osmosis(RO) membrane process. The distribution of particle from raw leachate and effluent of biological treatment system were 4.85 ㎛ and 39.22 ㎛, respectively. This result indicates that the loading to the RO system with effluent of biological treatment system is lower than raw leachate. Polyetherslupone(PES) are used for UF membrane as pre treatment process. And 1st RO and 2nd RO membrane are used CP and X-20, respectively. The flow rate of permeated and concentrated water to be treated from the rotating membrane separating system for effluent of biological treatment system were 300~320 L/h and 200~220 L/h, respectively. The permeate flux was stable with 80~90% for biological treatment and 80~85 % for raw leachate after the rotating membrane separating system. We had the recovery rate 70~75% and 72~78% for effluent of biological treatment and raw leachate, respectively after the rotating membrane separating system as pretreatment. Namely, concentration of pollutants became higher and volume of feed water was less as the feed flow approached to the outlet. COD removal for effluent of biological treatment and raw leachate were 92~99% with effluent concentration 15~160 mg/l, and BOD removal for effluent of biological treatment and raw leachate were greater than 99.9% with effluent concentration below 1 mg/l. The suspended solids(SS), NH3-N, total nitrogen(T-N) and total phosphate(T-P) of the permeate were 1 mg/l, 0.5~2.0 mg/l, below 20 mg/l and 1 mg/l, which were 99.99%, 99%, 99% and 98% of removal efficiency, respectively. The concentration of Cl^(-) was 40 ㎎/l which is not only to meet of goal, but also to be available to recycling water quality. TDS was treated below 200 ㎎/l which comes under ten-hundredths as our aim quality. This RO membrane system was designed recovery rate 40%, rejection rate 96% of 1st RO and recovery rate 28%, rejection rate 98% of 2nd RO, respectively. The combination process of rotating membrane system(ultrafiltration) and reverse osmosis membrane was suitable for advanced treatment and reuse of landfill leachate.