하·폐수처리장 방류수가 하천수질에 미치는 영향

River water quality in Daegu city has fluctuated over the last several years. This condition requires more attention to avoid the possibility of more severe water quality degradation. This study aimed to identify temporal and spatial distribution, sources of pollutants, and the effects of wastewater treatment plant (WWTP) effluents on the Nakdong River. Water quality data from the Nakdong River and treated water from WWTPs over a 4-year-period has been collected and analyzed statistically. The results showed that river water quality went down several times at specific sites. Compared to other locations, the Habincheon experiences the most polluted conditions. This area should be carefully managed, primarily because it serves as a keywater source for two water treatment plants. Industrial WWTP contributes higher pollutant concentrations than municipal WWTP, particularly for Chemical Oxygen Demand (COD) and Total Nitrogen (TN), which is 5.21 - 9.77% of the COD and 6.86 - 15.45% of the TN into the river. The contribution rate of all WWTPs affects the river was 6.05% of Biochemical Oxygen Demand (BOD), 12.54% of COD, 2.33% of Suspended Solids (SS), 20.19% of TN, and 13.33% of Total Phosphorus (TP). Treated water from WWTPs had a low contribution as the pollutants into the river, whereas other sources likely delivered a higher amount of pollutant load.