Application Of Chladophora Glomerata Biofilm System In The Treatment Of N&P Of Eutrophic Water

The topic used Chladophora glomerata biofilm system to treat N&P of eutrophic water. The study of the Chladophora glomerata biofilm system was researched further by design experiment, then specific conclusions were drawn as follows:（1） Concrete block, wood block, expanded plastic and glass were chosen to do the contrast experiments. Results show that after synthetic analysis Biofilm colonization of concrete block was the best. Compared three ways of Biofilm colonization, which were Hanging open, wet hang wete, alternative wet methods of hanging, the results show that：the last method was the best. Finally, temperature, luminous intensity and biomass were taken as three factors to find the relationship between them on bristles algae growth and hang membrane effect. Results show that: when temperature is25℃，the luminous intensity is4000lux and the biomass is1.2g/L，then both of them reach the optimum.（2） In natural environment, when the temperature was18³0℃and the illumination intensity was2000⁵000lux, adopt static test method and used Chladophora glomerata biofilm system of continuous treated eutrophication of nature water5days. The result of removal rate of TN,NH₄⁺-N,NO₃^--N,NO₂^--N,TP and PO₄^3--P was best in the fourth day, respectively reaching77.51%,96.81%,99.74%,83.01%,94.87%and98.68%.（3） In natural environment, with the temperature was18³0℃and the illumination intensity was2000⁵000lux, adopt dynamic test method and used Chladophora glomerata biofilm system of continuous treated N&P of eutrophic water with hydraulic retention time of four days. Compared to the inlet and outlet content of TN, NH+-4-N, NO₃^-N, TP and PO₄^3--P, the average removal rate was77.32%、89.86%、85.20%、82.66%、71.47%, the content of NO₂^--N in test of inlet and outlet water, changes amplitude was bigger, the average removal ratewas36.23%.（4） The study of appropriate parameters of the Chladophora glomerata biofilm system treating N&P of eutrophic water used the Box-Benhnken center composite design for this experiment. Temperature （20℃,25℃,30℃）, biomass liveweight （0.8mg/L,1.2mg/L,1.6mg/L）, illumination intensity （2000lux,4000lux,6000lux） and processing time （1d,4d,7d） were taken as four factors, the removal rates of TN, NH₄⁺-N, NO₃^-N,NO₂^--N, TP and PO₄^3--P were taken as response value by the response surface analysis, appropriate parameters were given as follows:a. When temperature is26.0℃, biomass liveweight is1.36g/L, illumination intensity is4330lux, the processing time is5.13d, the removal rate of TN is the highest, about89.44%.b. When temperature is25.13℃, biomass liveweight is1.42g/L, illumination intensity is4270lux, the processing time is4.62d, the removal rate of NH₄⁺-N is the highest, about97.79%.c. When temperature is24.6℃, biomass liveweight is0.99g/L, illumination intensity is5684lux, the processing time is4.75d, the removal rate of NO₃^--N is the highest, about91.39%.d. When temperature is25.9℃,biomass liveweight is1.25g/L, illumination intensity is5002lux, the processing time is5.42d the removal rate of NO₂^--N is the highest, about100%.e. When temperature is20.9℃, biomass liveweight is0.98g/L,illumi nation intensity is5497lux, the processing time is5.49d,the removal rate of TP is the highest, about91.33%.f. When temperature is23.2℃, biomass liveweight is1.29g/L, illumination intensity is4307lux, the processing time is5.20d,the removal rate of PO₄^3--P is the highest, about100%.Combined with the appropriate parameters of the response surface analysis of the Chladophora glomerata biofilm system, conclusions were drawn that when temperature is24℃, biomass liveweight is1.3g/L, illumination inte nsity is4500lux, the processing time is5days, it will get the best results. The feasibility and scientificalness of the experiment was proved clearly from the data stated below. The removal rate of TN is86.26%, NH₄⁺-N is98.34%, NO₃^--N is90.19%, NO₂^--N is98.63%, TP is and PO₄^3--P is100%.（5） In addition, the value of PH also showed the trend of rise, and verified the conclusion referred before. So, more attention should paid to it to prevent the physicochemical property caused by rising PH value. Besides higher PH value also change the algae microorganisms in membrane system of community structure. And it prevent negative effects of eutrophication in the process of water treatment.