Title |
Performance Evaluation of Advanced Municipal Wastewater Treatment by Phased Isolation Intrachannel Clarifier Ditch |
Authors |
홍기호 ( Ki Ho Hong ) ; 장덕 ( Duk Chang ) ; 한상배 ( Sang Bae Han ) |
Keywords |
Biological nutrient removal; Municipal wastewater treatment; Oxidation ditch; Temporal phase separation; Phased isolation ditch process |
Abstract |
Phased isolation intrachannel clarifier ditch process developed in this study is an enhanced biological nutrient removal process employing two ditches with intrachannel clarifiers. Bench-scale phased isolation ditch process was used to evaluate the system performance on municipal wastewater and detailed assessment of internal behavior in a ditch and each reactions. When the system was operated at the HRTs of 6∼12hours, SRTs of 9∼31 days, and cycle times of 4hours, the system showed removals of BOD, TN, and TP as high as 88∼97%, 73∼78%, and 65∼90%, respectively. The internal behavior were well matched on each reactions such as nitrification, denitrification, and phosphorus release and uptake. As the SRT became longer, TN removal increased gradually, whereas TP removal decreased contrarily. However, the system was capable of producing an effluent TP concentration 1㎎/L or less even at longer SRTs except the case of solids discharge by malfunction of intra-clarifier occurred by its geometrical limit. The system performance slightly decreased by hydraulic shock loading(increasing of influent flowrate and decreasing of system HRT). However, the higher system performance could be achieved again after four cycles. Thus, the system reliability could be successfully achieved short-term hydraulic shock loading that occurred in medium- and small-sized wastewater treatment plants suffering fluctuation of influent quality and flowrate during wet season. |