抄録
Short-term chronic toxicity tests were conducted using a battery of three aquatic organisms (fish, daphnia, and alga) for effluents of five selected factories in Tokushima, Japan, and relatively strong toxicity was found for two factories (X and Y) for Ceriodaphnia dubia. The source water, the major processes to discharge toxicants, and their water treatment processes were examined by the interview with effluent managers. For Factory X, source water and the influent of the water treatment facility did not exert strong toxicity for C. dubia while the treated effluent was strongly toxic. As results of bio-assay for two major water additives, the inorganic additive was found to be toxic. The additional bio-assay for the major components aluminum and sulfate, and chemical analysis of these ions identified aluminum ion as a major causative agent. For Factory Y, source water was non-toxic while the influent of the water treatment facility was found to be strongly toxic. As results of interview with the effluent manager, bio-assay and chemical analysis, sulfate was found as a major causative agent. Toxicity reduction measure was under process for both factories using improvement of water treatment processes.
