INVESTIGATING THE PERFORMANCE OF MOVING BED OR BIOFILMREACTOR IN THE REMOVAL OF OIL AND GREASE FROM BESATHOSPITAL WASTEWATER

Background and objective: Hospital wastewater is a special significance in terms of health when compared with other types of wastewater due to the presence of hazardous agents. If this wastewater is introduced into wastewater collection system by treating it incompletely, it causes of several problems like imbalance of biological systems for urban wastewater treatment plant. Oil and grease are among the main compounds of wastewater and can cause overflowing of wastewater from sewers. The aim of this study is to investigate the efficiency of moving bed biofilm reactor (MBBR) system in removing oil and grease from hospital wastewater. Materials and Methods: This study was carried out at pilot scale with a continuous hydraulic flow of hospital wastewater and the effect of filling percentage of K1 media, hydraulic retention time, MLSS concentration and COD was investigated with the results analyzed by SPSS 19. Findings: Based on the results, the greatest efficiency of oil and grease removal as well as COD via K1 media, with a retention time of 24 h and filling percentage of 70%, was 98.9 and 95.6%, respectively. Interpretation and Conclusion: The MBBR system with K1 media can decrease the concentration of oil and grease in wastewater down to standard levels.