15. Assessment of surface water quality changes in Ong Chuong canal, An Giang province 2020 - 2022

Abstract

The research objective was to assess the changes in surface water quality in the Ong Chuong canal, An Giang province, during the period 2020 - 2022. Analysis of surface water samples taken at three points (beginning, middle, and end the Ong Chuong canal) showed pH values ranging from 6.85 - 7.32, DO from 4.01 - 5.02 mg/l, TSS from 44 - 103 mg/l, COD from 12 - 390 mg/l, BOD₅ from 8 - 254 mg/l, total Nitrogen (TN) from 0.018 - 0.336 mg/l, total Phosphorus (TP) from KPH -0.064 mg/l, Ammonium (NH₄⁺) from KPH -1.46 mg/l, and total Coliform from 1500 - >240000 MPN/100 ml. Overall, the surface water quality of Ong Chuong canal has pH, total nitrogen, and total phosphorus values that are still within the permissible limits. However, parameters such as DO, TSS, COD, BOD_5, and total Coliform have increased beyond the permissible limits. The pollution is caused by the impact of organic matter and microbial decomposition, especially Ammonia, which exceeded the permissible limit in 2021 - 2022, and the remaining parameters also exceeded the standards (QCVN 08:2023/BTNMT, level A), negatively affecting aquatic life and human health if Ong Chuong canal water is used directly without treatment.