Research On Toxicity Test Of Important Pollutants In The Pharmaceutical Wastewater To Paramecium Caudatum

With the rapid domestic development of pharmaceutical, chemical, and healthproducts industries, pharmaceutical wastewater from the manufacturing process isnegatively affecting the health of the general public; thus, the development ofdetoxification processing yields great urgency. Nowadays, organic wastewater from thepharmaceutical production process has been recognized as one of the worst source ofpollution because of its potential toxicity. However, the study of pharmaceuticalwastewater’s impact on ecosystems is still in its infancy and lacking proper testingmethodology and environmental risk warning technology. Domestic research andmonitoring system relies mostly on the content and type of pollutant compound;nonetheless, these methods neither shows the overall effect of the compounds and thedirect effects of toxic biological populations, nor can they detect real-timeenvironmental hazards and their effects.As the representative species of Ciliata of Protozoan, the paramecium becomes thekey research carrier of water quality biological monitoring. At present, internationalscholars have conducted a vast amount of research yet few combine acute toxicologicalexperiments, chronic toxicity experiments, and changes in paramecium antioxidantenzyme activities under pollutant stress research for uses in the monitoring ofenvironmental risk posed by single pollutant in pharmaceutical wastewater. Accordingto these, this paper records the research of four important pollutants Zn²⁺、Cd²⁺、Hg²⁺、HCHO in pharmaceutical wastewater and their acute lethal effects of parameciumcaudatum, population growth inhibition, and changes in paramecium caudatum’santioxidant enzyme activity in different concentrations of pollutant stress in order toinvestigate these types of pollutants in the early environmental risk threshold.Ultimately, this research provides a reference for the monitoring and improvement ofthe relevant pharmaceutical wastewater discharge standards.From laboratory research, after24hours, the medial lethal concentration （LC50） offour pollutants Zn²⁺、Cd²⁺、Hg²⁺、HCHO to paramecium are0.974mg/L,3.532mg/L,0.345mg/L,0.332mg/L. The results show that Hg²⁺、HCHO、Zn²⁺、Cd²⁺are in descending order of acute toxicity.According to the medial lethal concentration, the research determines the chronictoxicity concentration and tests the four pollutants’ effects on the growth curve ofparamecium caudatum. For all four pollutants, test results show that with increasingconcentration, the restrain on the population quantity becomes heavier. It should benoted that when Zn²⁺is in low concentration, the average density of the population isgreater than that of the control group, which shows a gradual increase as concentrationincreases.This test researches the pollution stress of four pollutants’ effects on the activeincidence of SOD, POD, CAT of paramecium antioxidant enzyme systems in the body,and primarily explores the mechanism of toxication. The test results show that all of thefour pollutants’ stress to the paramecium will change its enzymatic activity, which canlead to excessive accumulation of free radicals thus produce peroxidation damage. Inthe duration of the test, POD has no obvious pattern of change, and SOD, CAT show atrend of falling after rising initially. In the research, the pollutants concentration has nosignificant cause-effect relationship with the change of activity of antioxidant enzymes,suggesting the differences in the mechanism of action between paramecium andmulti-cellular animals.