The Bioindicating Effect Of Pseudorasbora Parva On The Purified Efficiency Of Constructed Wetland Systems

In recent years,with the fast development of industry and agriculture and the rapid increase of the population,plenty of industrial sewage and domestic sewage were poured into the Yellow River without effective control.At the same time,there were prevalent phenomena in the upstream of the Yellow River,such as water loss, soil erosion and discharging back of irrigating water,which caused serious pollution of Baiyin Section of the Yellow River(BSYR).Over the last two decades,constructed wetland systems are increasingly used to treat domestic sewage,industrial wastewater, and agricultural runoff.In this study,we chose P.parva as bioindicator to illustrate the purified efficiency of wetland by comparing physiological and genetic differences between P.parva in polluted Yellow River and purified Yellow River water by wetland controlled by HRT(Hydroli Retention Time).SOD:With the treating time extending,the activity of SOD gradually decreased. For liver,the SOD activity showed significant difference between the experiment groups and control group(P＜0.05),except for the 14-day treatment.There was no significant difference in SOD activity between 28-day treatment and 42-day treatment;however,the SOD activity of 56-day treatment was lower than any other groups(P＜0.05).For gill,only the 42-day treatment was remarkable different from the control group,and there was significant difference between 56-day treatment and 14-day treatment(P＜0.05).GPx:The situation of GPx was similar with SOD,but its activity in liver and gill, which was significant different from the control group(P＜0.05).And prominent difference existed among each treatment(P＜0.05).MDA:Although MDA in the treatment for 28,42,and 56 days increased compared with 14-day treatment,generally,the MDA in treatment groups decreased compared with the control group.For liver,each treatment showed significant difference compared with the control(P＜0.05),no significant difference existed among treatment groups.Single cell gel electrophoresis(SCGE):With the treating time prolonging,the DNA damage decreased in both liver and gill.This result was consistent with that of MDA.For liver,only the 42-day and the 56-day treatment was remarkable different from the control group,and also different from the 14-day and the 28-day(P＜0.05). For gill,the DNA damage showed significant difference between the treatment groups and control group(P＜0.05),except for the 14-day treatment.The research proved that the constructed wetland performed well in removing contaminants from domestic sewage.It is an improved technology to purify water quality and rehabilitation of aquatic ecosystems.