Characteristics of Surface Water Quality in the Areas of Agriculture and Aquaculture in An Giang Province, Vietnam

Abstract

The study was carried out to evaluate surface water quality in
agricultural production and aquaculture areas in An Giang province,
Vietnam. Water samples were collected at 42 monitoring locations (23
locations in agricultural areas, 19 locations in fisheries) with 10
surface water quality indicators including temperature, pH, total
suspended solids (TSS), dissolved oxygen (DO) biochemical oxygen
demand (BOD), chemical oxygen demand (COD), nitrate (N-NO3
-
),
ammonium (N-NH4
+
), orthophosphate (P-PO4
3-
) and coliforms. Water
quality was assessed using national technical regulations on surface
water quality (QCVN 08-Mt:2015/BTNMT). The results show that
surface water at agriculture and aquaculture areas were
contaminated with organic matters (low DO and high TSS, BOD,
COD), nutrients (high N-NH4
+
, P-PO4
3-
), and microorganisms
(Coliform), in which surface water in the agricultural production area
tended to be more polluted than that of aquaculture area. The causes
of water pollution could be fertilizer residues, wastewater, and
untreated solid waste that are discharged directly into the water
source. There is urgent need to find out appropriate measures for the
management of wastewater from agriculture and aquaculture to
improve surface water quality.