Study On The Biological Toxicity Of Pharmaceutical Wastewater

In this thesis, static and semi-static acute toxicity method were adopted to study tocicityof the pharmaceutical wastewater to the aquatic organism (bioluminescent bacteria;phytoplankton and zebrafish) which was the representative international standard organism.The five samples were taken from five different processes directly. The acute toxicity of thewastewater which from five different process stages was represented by EC50(median effectconcentration) and LID (Lowest Ineffective Dilution). According to the the toxicologicalendpoints magnitude preliminary, qualitative discriminated the wastewater toxic to aquaticlife. There were several conclusions made as below:(1)According to the value of EC50and LID, the ground and underground regulationpool which using to mix, buff the quality and amount of the water were assessed as extremelytoxicant；on the other hand, the middle sedimentation tank which was used for segregate theactivated sludge was assessed as low toxicity. As for the drain which entered into themunicipal pipe net, had none biological toxicity.(2)The result showed that the luminosity of Vibrio fischeri, the growth rate ofPseudokirchneriella subcapitata and mortality rate of zebrafish could reflect the treatmenteffect. In addition, the toxicity evaluation results were consistent with the change of COD andammonia. The toxicity of wastewater for luminous bacteria was the most sensitive than greenalgae and fish, and the fitting effects of wastewater for luminous bacteria were better than theother two aquatic organisms.(3)The method (anaerobic-aerobic treatments) used in this pharmaceutical wastewatertreatment was in accordance with national standards. But experimental observations indicatedthat the raw wastewater had high concentration organic pollutants, complex componentsinhibited the luminous intensity, damaged the algae cells and poisoned the zebra fish, evenleaded to death. Rudimental antibiotics would have inhibition effect on organism whichamong species of different trophic levels，even they could create a potential risk for humansthrough food web structure due to their persistence, bio-reactivity, non-biodegradability, etc.(4)Experimental results showed that: through effective Biological and chemicaltreatment, the biotoxicity reduced gradually. The fact that the part of the pharmaceutical plantcould meet the national standard in terms of physicochemical parameters in their effluents。Itwas still presenting rather genotoxicity and endocrine disruptors to the aquatic organism needto be evaluated. It can be used to explain the necessity of application of aquatic organism toxicity as a supplement to the current physicochemical based test in environmentalmonitoring.