Water Quality Evaluation Method Research Of The Fresh Water Collection Pond In Nanning

To reveal the water type, contamination situation and scope, three pon ds were selected in the WuMing country, which was GuangXi province’s large freshwater fish center of the lead breeding. The main results are as follows:We routinely monitored contents of the total nitrogen(TN), total phosphorus(TP), chemical oxygen demand (CODMn), ammoniacal nitrogen (NH3-N), dissolved oxygen (DO), nitrite nitrogen(NO2-N), copper (Cu), zinc (Zn) concentrations in the water, and calculated the average value of water quality indexs, and found that the content of total nitrogen was in the range0.9～4.0mg/L, total phosphorus was0.027～0.598mg/L, chemical oxygen demand was2.91～11.1mg/L, ammoniacal nitrogen was0.045～2.03mg/L dissolved oxygen was6.45～5.32mg/L, nitrite nitrogen was0.007～0.023mg/L copper0.001～0.082mg/L, zinc was0.006～0.061mg/LBased on these data, by applicated the single factor water quality identification index method and comprehensive water quality identification index method, fuzzy comprehensive evaluation method, integrated pollution index. With the Standards of 《Environmental Quality Standards for Surface of China》.The result showed that with comprehensive water quality identification index method, we can see that the main pollutants in pond culture water were TN, TP, CODMn, NH3-N, and the contents of Cu and Zn were in the safe rang. So it was eutrophication and without caused heavy metals’pollution. The water quality was ranged between Grade Ⅱ and Grade IV of the environmental quality standards for surface of china, and the standard rate of Grade Ⅲ was94.3%; With fuzzy comprehensive evaluation method, we can see that the main pollutants in pond culture water were TNn TP、CODMn、NH3-N、DO, and the contents of Cu and Zn were in the safe rang,too. The water quality was ranged between Grade Ⅱ and Grade V of the environmental quality standards for surface of china, and the standard rate of Grade III was41.67%; With integrated pollution index, we can see that the main pollutants in pond culture water were TN、TP. The water quality was ranged between up to standard and pollution of the environmental quality standards for surface of china, and the standard rate of Grade Ⅲ was75.0%; The method of water quality from superior to inferior is comprehensive water quality identification index, integrated pollution index and fuzzy comprehensive evaluation method. Study results confirms:we can have a different results of water guality with the different method. The comprehensive water quality identification index method was simply’ used and can fully reflected the status of the water quality, the evaluation results were scientific and reasonable, can reflect the pollution situation, not affected by too high or too low of one water quality. According to the characteristics of freshwater ponds in China, recommended to choose comprehensive water quality identification index method.