Water quality assessment of main rivers and canals in Ben Tre Province, Mekong Delta Vietnam

Abstract

Ben Tre, a Mekong Delta Province has dense canal networks with about 6,000km in total extension. There are more than 60 canals having over 50m of width. The river system plays the important role of Ben Tre, providing water for agriculture, drainage, navigation, fisheries and restoration in local area. Data for 44 sites from the main rivers and canals of Ben Tre were collected in April and October from 2015 to 2016 to analyze for pH, total suspended solid (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), amoni (NH4+), phosphate (PO43-), and coliform. Then data were used for calculation and mapping. The ArcGIS 9.3 software, Inverse Distance Weighting (IDW) interpolation, and hydrologic variables in April and October from 2015 to 2016 were applied to build the maps of water quality for the Ben Tre. This result indicated that the water quality of many sites from the main rivers and canals of Ben Tre in April and October from 2015 to 2016 were polluted with TSS values at 75 − 304 mg/L, BOD5 from 7.0 − 25.0 mg/L; and coliform from 1.1 × 103 to 2.3 × 105 MPN/100 mL. Additionally, the results classified water quality of Ben Tre at 5 classes, as described by The Vietnam Environmental Protection Agency, good quality for water supply (1); use for water supply required appropriate treatment (2); usage for water use for irrigation (3); water use for navigation (4); and, heavy pollution (5). Last but not least, the wastewater control solutions for Ben Tre are also suggested. There were some the prior projects for environmental pollution control these have been implemented to improve the water quality for main river and canals in Ben Tre Province.