| In this paper,in light of different problems of the seafood temporarily keeping pool at low temperature such as poor water quality and bad wastewater treatment efficiency,on the basis of the principle of biological denitrification and adsorption,this paper established a nitrification and denitrification process simple and stable low temperature bacteria domestication enrichment culture device,which was,at the same time,built with corn cob as biofilm carrier and denitrification carbon source,and combined the new adsorbent materials of corn to process water purification effect and study the mechanism.The construction of low-temperature strains with enrichment culture and water purification plant improves the quality of the water in seafood temporarily keeping pool,while seafood improved survival rate is of great significance to research the following conclusion:(1)At the condition of 15 °C,pH 7～.5,salinity 25±0.50,through acclimation and enrichment culture,the average ammonia nitrogen concentration decreased by 1.22mg/L per day,and the nitrite nitrogen concentration decreased by 0.54 mg/L per day.The concentration of nitrate nitrogen decreased by 3.32 mg/L per day on average.The strains of low-temperature and high-salt acclimation were mainly Proteobacteria,and the nitrifying bacteria were γ.-Gammaproteobacteria and Alphaproteobacteria are dominant,and denitrifying bacteria are mainly gamma-proteobacteria(Gammaproteobacteria).(2)The method of manually forcing the membrane on the surface of the corncob is not only easy to operate,but also has good effects,and it can reduce the startup time of the denitrification device system.The good nitrogen removal effect was achieved under the condition of system temperature at 15 °C and salinity 25±0.50.During the period of early three months,the total removal rate of total nitrogen,ammonia nitrogen and nitrate nitrogen in the experimental effluent could reach(63.46±0.55)%,(62.79 ±0.52)%and(65 ±0.63)%.(3)Analysis of high-throughput sequencing results showed that the surface microbial changes with corncob as the carrier of biofilm showed that the dominant species in the gate were Proteobacteria,Bacteroidetes and Spiral.Spirochaetae,Planctomycetes,etc.;the dominant species were Bacteroidia,Gammaproteobacteria,Spirochaetes,and Alphaproteobacteria Sphingobacteriia was the main species.The genus level was mainly Pseudomonas,Bacteroides,and Aeromonas.As the experiment progressed,the species and quantity of microorganisms showed a downward trend.(4)The effect of denitrifying and dephosphorization with corncob combined with corn husk showed that the removal rate of three-state nitrogen between corncob and corn husk was not much different from that of corncob,corncob + corn,corn cob and corn mai.The total nitrogen removal rate of the group was up to 72.09%,68.88%,and30.84%,respectively;the highest removal rates of ammonia nitrogen were 68.76%,67.38%,and 27.23%,respectively;the highest removal rates of nitrate nitrogen were66.56%,67.24%,and 31.71%,respectively..It shows that the corn coating has an adsorption effect on the phosphorus element,the double effect of nitrogen and phosphorus removal can be achieved combined with the corn core.The paper provided theoretical basis and technical support for the improvement of water quality in seawater low temperature holding tanks.(5)By studying the effect of defoaming,denitrifying and dephosphorizing equipment in seawater low temperature holding system,the device has the triple effect of denitrifying,dephosphorizing and defoaming,the foam is obviously reduced,the denitrification rate can reach 78.65±0.15%,and the phosphorus removal rate can be Up to 43.07 ± 0.55%.The system is of great significance for improving the value of aquatic products and environmental quality,as well as broad application prospects. |
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