This research aims to improve the previous trench process. The modified process is consist of 3 processes; first settling tank, 3-staged second contact-filter, and last trench system. The experiments was operated by varying the HRT 8, 6 and 4 hours in trench. The results of laboratory experiments showed removal rate of 97∼99% of TBOD, 92∼98% of TKN, 91∼98% of T-P. From the results of this research, organic materials were removed in settling tank and nutrients in the trench stage. Therefore, it is recommended to replace the previous 3-staged contact-filter to 1-staged one, and to increase contact-time in trench system. |
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