Study on manganese, cadmium and lead contents in stream-water and sediment from various watershed classes in lower South of Thailand
1990
Sumral Phatchara
Annual average of the dissolved contents and total contents of the three metals in water were highly significantly different among the 5 various classes of watershed, but not in sediment. The highest contents were shown in the fourth class of the watershed. The values were 148, 211 microgram/l for manganese and 0.85, 1.25 microgram/l for cadmium in dissolved contents and total contents in water respectively. The average contents in water of the three metals were highest in rainy season at the values of 94, 0.65 and 12.15 microgram/l for dissolved contents and 1370, 0.96 and 17.04 microgram/l for total contents in water for manganese, cadmium and lead respectively. But in sediment, manganese content was highest in winter season while cadmium and lead in hot season. For the types of land usage, the metals contents in non-forest area were higher than in forest area. The contents of the three metals in this study didn't exceed the maximum permissible level in surface water of NEB standard. Only manganese content was over the maximum permissible level in drinking water of WHO standard. Nevertheless the three metals contents in sediment of the lower south watershed were relatively lower than the watershed in other parts of Thailand.
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