SOLID RETENTION TIME (SRT) EFFECTS ON LANDFILL LEACHATE TREATABILITY BY MEMBRANE BIOREACTOR

摘要

One of the most important concerns in Tehran municipal landfill is the production of leachate and its potential risks to the surrounding water resources. Average COD of the leachate in aerobic submerged membrane bioreactor was 60000 mg/L. The dissolved oxygen (DO) concentration were maintained at 3.2 and 2.3 mg/L and For each aeration ratio, MLSS concentration were considered in base of sludge retention time (SRT). With increasing Sludge age of 55 days to infinity, the concentration of chloride and sulfate ions and electrical conductivity of the membrane is increased about 3, 2 and 2 times, respectively, in a way that the kinetic coefficients obtained showed a serious reduction in specific growth (μ) and the reaction coefficient (K), yield coefficient (Y), decay coefficient (K_d) and saturation constant (K_s) were in the about of 0.0093 day~(-1), 0.18 day~(-1), 0.085 mg VSS/mg COD, 0.036 day~(-1) and 2295 mg COD/L, respectively, than the MBR kinetic coefficients with SRT of 55 days were, 0.013 day~(-1), 0.236 day~(-1), 0.08 mg VSS/mg COD, 0.035 day~(-1) and 1065 mg COD/L, respectively, in order to increasing leachate treatability and reducing leachate treatment inhibitors, it is required that appropriate SRT with high MLSS and kinetic coefficient to be used.