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Abstract:
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Assessment of water quality based on a set of physico-chemical parameters is most commonly applied in Vietnam while biological approaches have only been tested in recent years. In order to investigate the water quality of the Du Rive sub-basin, both physico-chemical approach and
BMWP VIET , ASPTVIET
and EPT indices based on macro nvertebrates were implemented. Samples of water, sediment and macro invertebrates of the Du Rive sub-basin were taken from 14 sites
of a large area in both dry and rainy seasons. Obtained data on physical and chemical parame-
ters, compared with Vietnam Environmental Standard and Flemish Environmental Standard
(Belgium), showed that water quality in the Du River watershed was evaluated as “acceptable” for aquatic organisms in the dry season. In the rainy season, the water was slightly affected by organic pollution. Water quality at sites N10 and N11, which are closed to the tin mines was
found to be heavily polluted by heavy metals and acids. According to BMWP
VIET
, ASPTVIET
and EPT indices, water quality in the Du River sub-basin was in general assessed as “slightly to moderately polluted”, but as “very heavily polluted” in the sites N10 and N11. The study suggested that biological methods based on macro invertebrates in this case-study were performed well in comparison with physico - chemical methods in terms of rapid assessment, cost - effect performance and long-term trend of environmental changes. |