THE EFFECT OF SULFIDE ON ACTIVATED SLUDGE PROCESS AND DETERMINATION OF KINETIC COEFFICIENTS OF MICROBIAL GROWTH AND INHIBITION COEFFICIENTS OF SULFIDE IN ACTIVATED SLUDGE PROCESS

This research aims at study of the effect of sulfide on operation of one of the aerobic biological treatment processes، activated sludge. For this purpose، two pilot plant units were designed and constructed. One of these units was run for wastewater sulfide contaminant (sample)، and the other one was run for wastewater without sulfide contaminant (Reference). First of all، in a quantities study، sample system was run with different influent sulfide concentrations، and compared with reference system. Then، concentration of influent sulfide was increased gradually until the inhibitory effect of sulfide on treatment process appeared. Finally، the concentration at which sulfide was inhibitory and resulted in process malfunction was determined. Also، the reference system was run with different influent COD and detention times. At the end، the behavior of pilot plants of the reference system and the sample system، were simulated with Contois model، and the microbial growth kinetic coefficient، and inhibiting coefficient of sulfide were defined.