Organochlorine insecticide residues in water and sediment in the Chao Phraya river
1998
Kanogwan Phiched-apha
Study on types and quantities of organochlorine insecticide residues in water and sediment in Chao Phraya River were carried out during January to October 1997. Samples collected every three months from 14 stations were investigated by Gas Chromatography for thirteen organochlorine insecticide residues. Eleven organochlorine insecticide residues detected in water samples were p,p'-DDD, p,p'-DDT, dieldrin, heptachlor, p,p'-DDE, alpha-BHC, heptachlor epoxide, gamma-BHC, beta-BHC, delta-BHC and aldrin. As in sediment samples, thirteen organochlorines found were p,p'-DDE, p,p'-DDD, beta-BHC, delta-BHC, dieldrin, p,p'-DDT, alpha-BHC, o,p-DDT, heptachlor, heptachlor epoxide, gamma-BHC, endrin and aldrin. The everage concentrations of benzene hexachloride isomers, cyclodiene compounds and DDT analogues in water were 0.0032, 0.0070 and 0.0084 ppb and sediment were 19.3085, 11.2057 and 20.8290 ppb, respectively. Amounts of organochlorine insecticide residues found in sediment as benzene hexachloride isomers, cyclodiene compounds and DDT analogues were 6,034, 1,601 and 2,480 times, respectively, higher than in water. Differences among groups are significantly different at 99 percent. Concentrations of benzene hexachloride isomers and cyclodiene compounds in water are significantly different at 99 percent for seasons (rainy and dry season). However, in sediment the diffences are not significantly at 95 percent.
显示更多 [+] 显示较少 [-]