Characteristics of Sampling Sites
Sediment and river water samples were collected in April 2005 from Hua Lam Poo
Canal in Samut Prakarn Province. This canal receives discharges from an industrial
estate as well as several factories nearby. The COD, SS, VSS, and pH of media
prepared according to Chapter 3 are illustrated in Tables 4.1, 4.2, and 4.3, respectively.
The COD of raw river water from both sites were higher than the ordinary Effluent
Standard value of 120 mg/l as notified by the Department of Industrial Works, Ministry
of Industry. This implies an inadequate treatment of wastewater by nearby factories.
However, the sediments from both sites were rich in organic matters which increased
the COD of the media by more than 100 times. Yeast extract also significantly
increased the COD of the mixtures. Although Site 4 is not far away from Site 3 down
stream, the bottom sediment was quite different from each other. The VSS:SS ratio of
the mixture with sediment from Site 3 was only 0.21 as compared to those with
sediment from Site 4 of 0.77. This might due to the material distribution as a result
from different specific gravity.