Variability Of Algae And Bacterial Community In Water Source Of Heat Pump

In order to study the effects on water environment of heat pump discharges, surface water samples were collected with different time and locations, observations were made on environmental factors,bacterial and algae abundance. It was found that there were correlation between temperature and dissolved oxygen,potassium permanganate index and total phosphorus, and that bacterial and algae abundance reached maximum in August, least in January. In addition, the dominant algae was Cyanobacteria, Green algae and Diatoms. In summer tail-water discharge could accelerate eutrophication process, and it was essential to prevent water from Cyanobacteria bloom whichwas induced by large-scale water temperature increasing; The impact of cold water discharge to eutrophication of lake was uncertainty, and the relevant departments should take some measures to prevent water body from Diatoms bloom near outfall.PCR-TGGE technology was applied firstly to analyze bacterial community composition of water source of heat pump. Before applying TGGE, DNA extraction and 16S V3 gene amplification was completed firstly. Results indicated that the optimum method is SDS method, Reconditioning PCR can reduce the concentration of heteroduplex, the sensitivity of GoldView is higher, and that legible fingerprint is appeared when the gradient of temperature is 42℃—60℃, electrophoretic time is 18h and NaOH is confirmed as color reagent.Analysis of TGGE fingerprint revealed that richness of bacteria in Lake Ankang was relatively high. In the period of airconditioner's refrigerating, bacterial community structure fluctuated widely, while the fluctuation of bacterial community structure was small in the period of airconditioner's heating, indicating that the effect of warm effluent was larger than cold discharge. According to similarity and clustering analysis, the lasting time and load of heat pump operation decided the water range, especially the district of water absorption, which was impacted by tail-water of surface water heat pump system. Besides, the sequences obtained were affiliated with Proteobacteria,Firmicutes and Bacteroides.Based on TGGE bands, nonmetric Multidimensional Scaling (NMDS) and Canonical correspondence analysis (CCA) were carried out for further analysis. Seasonal changes of bacterial community structure in Lake Ankang could be confirmed based on NMDS, and there were two major types of bacterial community in Lake Ankang, including summer-autumn period and winter-spring period. Results of CCA indicated that bacterial community structure was correlated with temperature, total nitrogen and ammonia nitrogen, and there was a high degree of corelation between bacterial community composition and the phytoplankton community.Finally, the Shannon-Wiener indexs of phytoplankton and bacteria were regarded as evaluation indexs, and the water souce was evaluated simply. The evaluation result was general situation, that was to say, the influence from heat pump brought damage to the water circumstance, but the water ecosystem could keep fundamental function.