TY - JOUR AU - Ngo, Tra Mai AU - Thi Thanh Hang, Phan PY - 2022/08/19 Y2 - 2024/03/29 TI - Assessment of water quality variations due to operation of wastewater treatment plant in Ca Mau city JF - Vietnam Journal of Marine Science and Technology JA - VJMST VL - 22 IS - 3 SE - Articles DO - 10.15625/1859-3097/16905 UR - https://vjs.ac.vn/index.php/jmst/article/view/16905 SP - 309-319 AB - <p>The wastewater treatment plant (WWTP) in Ca Mau city, which is being planned for construction, will be responsible for treating domestic wastewater with a capacity of 8,000 m<sup>3</sup>/day. After being treated by the physic-biological method, the plant’s wastewater will be discharged into the Thong Nhat canal and the Tac Thu river. As a result, this article applies the MIKE21 model to calculate the range, the distance, and the concentration of typical pollutants for domestic wastewater, including TSS, BOD<sub>5</sub>, NH<sub>4</sub><sup>+</sup>, and total Coliforms in the dry season, to provide evidence for water resource management following the plant’s construction. Two scenarios were established; in scenario 1 (<em>S</em>1), the WWTP is being operated inefficiently, and the wastewater has not been treated up to standards. Maximum calculation in case the processing performance = 0; in scenario 2 (<em>S</em>2), the WWTP is being operated efficiently. The concentration of 4 components in wastewater is lower than the critical value of QCVN 14:2008/BTNMT (column B, <em>K</em> = 1). The results show that the waste source will highly affect the water in the Thong Nhat canal both downstream and upstream due to the irregular semi-diurnal tide regime in case of the plant experiences problems (<em>S</em>1). In the case of the stable operation plant (<em>S</em>2), the pollutant concentrations at all positions will be lower than the critical value of QCVN 08-MT:2015/BTNMT (column B1) except for the TSS. Concentration variation is evident over time and distance: after about 1 hour and about 1 km from the source, the concentration of pollutants reaches the maximum value, then gradually decreases and ends at about 4 km after 7 hours.</p> ER -