| Title |
Determination of ORP Control Structure to control aeration period in SBR for Piggery Wastewater Treatment |
| Authors |
부경민 ( Bu Gyeong Min ) ; 전병희 ( Jeon Byeong Hui ) ; 임정훈 ( Im Jeong Hun ) ; 우혜진 ( U Hye Jin ) ; 김창원 ( Kim Chang Won ) |
| Keywords |
Piggery Wastewater; Nitrogen Removal; SBR; ORP; Control |
| Abstract |
A pilot-scale SBR (effective volume, 20 ㎥) treating piggery wastewater was operated with real wastewater in situ. The operation mode of intermittent feeding of raw water and sub-cycle with repeating anoxic-aeration conditions were adapted to avoid the high-strength nitrogen inhibition. During the sub-cycle operation, the controls of each phase such as on/off pumps, mixer, blower were performed using only ORP meter. ORP profiles were strongly dependent on influent loading rates, however, the developed control strategy was proven to be useful for the stable control throughout wide operation conditions. Differing to prior control studies such as ammonia valley in pH or bending point in ORP, dORP/dt values with range of 0-1 corresponding to the ending point of ammonia oxidation and make it possible to actually stable operation regardless of influent variation. With the ORP characteristics of rapid and sensitive response towards microbial status within reactor, operation diagnosis such as abnormal feeding of raw water by some mechanical trouble was possible. The ORP showed the characterized profiles with increasing of influent flow rate and the slope before complete ammonia oxidation (pre-slope) changed to more plateau and long time continued. As results, the ORP was effective control criteria for the stable SBR operation for the piggety wastewater treatment and increased the nitrogen removal loading rate and improve operation stability through the rapid diagnosis towards immediate influent disturbances. |