Influence of Ph on The Lethal Toxicity of Phenol, Para Chlorophenol And Pentaclorophenol to Freshwater Fish Gambusia Affinis

Phenol and Phenolic compounds has several sources including industrial wastes, coal , wood distillation, road tars, petroleum refining, chemical and plastics manufacture, domestic sewage discharges, natural sources such as plant material decay and leaching from coal and oil deposits enter natural water system and affect the fish and other aquatic organisms , So the static renewal bioassays were done to study the influence of pH on the lethal toxicity of phenol, para chlorophenol and pentachlorophenol to the freshwater fish Gambusia affinis. The studies shows that phenol, para chlorophenol and pentachlorophenol decreased their toxicity as the pH increased to the said fish .The24,48,72 and 96 hours LC50 values were found to be 48.0,45.0, 43.0 and 41.0 mg/l at pH 6.0 and at pH 7.5 the 24,48,72 and 96 hours LC50 values were 50.0, 48.0, 46.0 and 44.0 mg/l respectively for the fish exposed to phenol, And at pH 6.0 the 24,48,72 and 96 hours LC 50 values were 24.0, 21.0, 19.0, 17.0 mg/l and at pH 7.5 the 24, 48, 72 and 96 hours were 30.0, 28.0, 25.0 and 22.0 mg/l respectively for the fish exposed to para chlorophenol .The LC50 values at 24,48,72 and 96 hours at pH 6.0 were 0.12, 0.10, 0.09 and 0.07 mg/l respectively and at pH 7.5 The LC50 values were 1.23, 1.19, 1.15 and 1.11 mg/l respectively for the fish Gambusia affinis.

The Contamination Effects and Toxicological Characterization of o-Chlorobenzylidene Manolonitrile

Toxicological characterization and global assessment of the toxicity of some chemicals used in the specific technique of the defense and public order system (e.g. o-chlorobenzylidene manolonitrile which enters the composition of the CS gas) is especially useful for environmental protection. Based on the results obtained, the toxicological characterization (acute lethal toxicity) and the harmful potential of some toxic substances, individual or in mixture, against euythermal sweet fish are established. The tests performed aim to change the behavior of the species studied in the presence of chlorobenzylidene manolonitrile, a substance used in the technique of defense and public order system. The tests established the toxicity values of acute lethal concentration LC50 and serve to further determine the maximum allowable concentration that inhibits the development of normal fish fauna in contaminated waters. The test results allow the toxicological characterization and measurement of the acute lethal toxicity of an inhibitor, in order to make more efficient its elimination from the contaminated environment.