Abstract
This research work aims at treating saline wastewater generated from a fish market using four Sequencing Batch Reactors (SBR) operated under different conditions. The effect of C/N ratio (3, 6) and salt concentration (0.5~2%) on organic and nitrogen removal was studied. The synthetic wastewater prepared with glucose ($C_6H_{12}O_6$) as the primary carbon source along with ammonium chloride ($NH_4Cl$) was used in the three reactors. The fill, anoxic, aeration, settle and draw conditions were 2 hr, 4 hr, 4 hr and 2 hr respectively. The fourth reactor was operated at different conditions to investigate the practical feasibility of SBR application to handle fish market wastewater generated in Ulsan city that had fluctuating loading characteristics. Though the unacclimated sludge was initially affected by the salt concentration, the acclimated sludge removed 95% of the organics irrespective of the NaCl concentration and C/N ratio. However, the removal of nitrogen was affected more by C/N ratio than the salt concentration. While handling fish market wastewater, though the organic and nitrogen loading rate were varying between $0.009{\sim}0.259gCOD_{OH}/gVSS/day$ and 0.005~0.034 gN/gVSS/day, the effluent concentrations were far less than the effluent standard of $120mgCOD_{OH}/L$ and 60 mgN/L respectively, except when loading rates were fluctuating and 4 times higher than the average.