PT14 Toxicity of Mixtures
Exhibit Hall
8:00 AM - Tuesday
(PT229) The simple toxicity identification evaluation of the industrial effluents.
Onikura, N.1, Kishi, K.1, Watanabe, A.1, 1 Japan pulp & paper research institute, inc., Tsukuba, Ibaraki, Japan
ABSTRACT- We have investigated the environmental impact of industrial effluents using a battery of bioassays combined with chemical analyses. Since the industrial effluents contain a variety of chemicals, it is difficult to identify the particular chemical(s) responsible for the toxicity to organisms. It is, however, possible to classify the origin of toxicity into several categories such as SS, organic substances, and metal ions by using toxicity identification evaluation (TIE) method. In this study, toxicity of several industrial effluents was characterized using a simple TIE method with the modification of the method recommended by US EPA. The toxicities were evaluated using Ceriodaphnia dubia reproduction test and Selenastrum carpricornutum growth inhibition test. The industrial effluents chosen in this study had toxic effects on both C. dubia reproduction and S. carpricornutum growth with no treatment (Step1). The effluents were first filtered to remove SS (Step2). Activated charcoals were then added to the effluents to sorb organic substances (Step3), followed by treating the supernatant with Chelex-100 resin to remove di- and trivalent cations including transition metals (Step4). For effluent A, toxic effects diminished after Step3 for both C. dubia and S. carpricornutum, suggesting that organic substances were major components of the toxicity to those organisms. Interestingly, effluent B exhibited a toxic effect on C. dubia even after Step3 treatment and no longer had the toxic effect by Step4 treatment, although the toxicity to S. carpricornutum was removed after Step3 treatment. Thus, effluent B appears to contain the cation(s) to specifically affect C. dubia reproduction but not S. carpricornutum growth, whereas the organic substances in the B effluent inhibit S. carpricornutum growth but do not affect C. dubia reproduction. Information obtained by this simple TIE method enables us to design the wasted water treatment systems for effective reduction of the environmental impact of the industrial effluents.
Key words: Activated charcoals , Chelex 100, Selenastrum carpricornutum , Ceriodaphnia dubia