11. Application of water quality index to assess the surface water quality in Phuoc Đong - Boi Loi industrial zone, Go Dau district, Tay Ninh provice

Abstract

Phuoc Dong - Boi Loi industrial zone is one of the largest industrial zones with multi-products in Tay Ninh province. Currently, the amount of wastewater of this industrial zone is around 45,490m³/day.night and it is estimated to reach 160,000m³/day.night in 2035. Therefore, the assessment of surface water quality of Cau Duc and Ba Tuoi streams where receiving wastewater discharged from this industrial zone is essential. Surface water samples were collected at 3 sites, including: Cau Duc stream, Ba Tuoi stream, and the effluent gate of the water treatment plant of this industrial zone. Water quality index (WQI) was calculated for 2 studied times (June 2020 and October 2020) and the result showed that the WQI at Cau Duc stream increased from 56.2 to 78. This means that the water quality was changed from the grade "water for irrigation and other equivalent purposes" to "water for daily use purposes but require appropriate treatments". However, at Ba Tuoi stream, the WQI decreased from 84.1 to 67.1 at studies times and this means that the water quality changes from the grade "water for daily purposes but require appropriate treatments" to "water for irrigation and other equivalent purposes". This research also proposed a framework for building WQI in water quality assessment under the socio-economic context of the industrial zone until 2035.