| Title |
Effect of Preozonation to the Raw Water Quality and Its Coagulation Characteristics in the Nak Dong River |
| Authors |
류동춘 ; 정형숙 ; 양병수 ( Dong Choon Ryou ; Hyung Sook Chung ; Byung Soo Yang ) |
| Abstract |
In advanced water treatment, it has been reported that pre-ozonation attributed to the preceeding processes through the enhancement of coagulation by the oxidation of algae, organic, and inorganic matters in the raw water as well as it enhanced the quality of the treated water by preventing the formation of the disinfection by-products. In this research, in order to find the effects of the pre-ozonation on the conventional water treatment system with raw water from the Nak-dong River and to get the optimal design factors and the operational conditions of ozone, the followings were concluded from the batch experiments. 1. The variation of DOC and UV-254 concentrations during ozone oxidation of raw water were not much at the ozone dosage of 2 to 3㎎/ℓ and contact time of 3 to 5minutes, while the disinfection efficiency for algae based on chlorophyll-a concentration was increased according to the increase of ozone dosage and contact time. 2. At the coagulation-sedimentation test followed by pre-ozonation, turbidity removal efficiency was not improved apparently independent from ozone contact time. But the capability of coagulation was increased compared to the case without preozonation. 3. Optimal ozone dosage to the raw water will increase the DOC and UV-254 removal efficiencies through the coagulation improvement. 4. The optimal operational conditions for pre-ozonation to improve the efficiency of the coagulation -sedimentation process in the existing water treatment plant were found to be ozone dosage of 2 to 3㎎/ℓ and contact time of 3 to 5 minutes. 5. Based on this experiment, the pre-ozonation may improve the raw water quality in the Nak Dong River. |