Comparison of Residual Biotoxicity of Chlorine and Bromine Chloride to Copepods.

摘要

The copepod species Eurytemora affinis and Acartia tonsa showed 50to 60% mortality in cooling water with 0.5ppm Cl2or BrCl (applied dosage) when entrained in the cooling system. However,after 5min contact time,the biotoxicity was reduced to insignificant levels,hence mortalities in the mixing zone,given the applied dosage,would be negligible. There were no significant differences between residual biotoxicities of chlorinated and chlorobrominated cooling waters at either the low applied dose rates or at higher rates. The LC50values were 362 +or - 26ppb and 403 +or - 46ppb at 24hrs for bromine chloride and chlorine,respectively. Reproduction of Eurytemora was only affected at dosage rates well above those used in practice.