Assessment of Water Quality Contamination under Municipal Wastewater in the Northwest Urban Canals, Ho Chi Minh City

Abstract

Anthropogenic pollution is a critical factor in the degradation of water quality in rivers, especially in urban and metropolitan regions of Asia and Africa, where water quality monitoring remains severely constrained by limited testing facilities and capacity. The systematic and scientific assessments on water quality contamination under municipal wastewater were extremely necessary to protecting the urban river eco-environment. In this study, surface water was monitored at five sites along from the Tham Luong – Ben Cat – Vam Thuat Canal system in six monitoring times of March and September from 2020 to 2022. Each surface sample was analysed for 3 organic pollution parameters (TSS, DO, BOD₅) and 9 heavy metals (Fe, Mn, Cr, Zn, Cu, Pb, Cd, Ni, As). Among all parameters examined in the study area, the concentrations of TSS (116 – 271 mg/L), DO (0 – 1.2 mg/L), BOD₅ (130 – 678 mg/L), and Fe (1.59 – 6.72 mg/L) were higher than these of permissible thresholds of the discharge limit standard of Vietnam on water quality for irrigation purposes. The results also revealed the contents of heavy metals as Fe, Mn, Cr, Zn, Cu, Pb, and Ni which were significant exceedances of the water quality standards of United State Environmental Protection Agency for posing severe risks to both aquatic ecosystems and agricultural production. This assessment provides a valuable foundation for policymakers and environmental managers in crafting targeted strategies for environmental protection and sustainable management of the northwest urban canals, Ho Chi Minh City.