Assessment of eutrophication status in the downstream region of The Tra Khuc River, Quang Ngai Province in 2024, using the TRIX

Abstract

The Tra Khuc River is one of the four major rivers in Quang Ngai province, providing a critical source of surface water for various purposes, including domestic use and socio-economic development activities in Quang Ngai City. Analysis of water quality parameters at survey points in the downstream region of the Tra Khuc River indicates that most water quality in this area meets the requirements of Level A according to QCVN 08:2023/BTNMT, except at sampling locations TK4 and TK5, where parameters such as DO, BOD5, COD, and TN only meet Level B or Level C standards. However, based on the TRIX index, the surface water quality across the surveyed area has been affected by eutrophication, with TRIX values ranging from 5,77 to 6,70. The limiting factor for eutrophication in the downstream region is primarily phosphorus (P), accounting for 60%.