Study On The Removal Of Nitrogen And Phosphorus In Aquaculture Water By Immobilized Algal Pellets

The discharge of untreated aquaculture water into the original ecological waters of lakes and other waters is extremely easy to cause deterioration of water quality.Although the amount of aquaculture water cannot be limited,it has the characteristics of easy centralized treatment and is a renewable water resource.Compared with the limited coverage of physical treatment methods,chemical treatment methods will have an uncontrollable impact on water quality.The overall cost of biological purification is lower,and it can be used as a part of the aquatic ecosystem to complement each other with farmed animals.In this experiment,the composite carrier PVA-SA is used for immobilization of the immobilized algal gelatin ball.The influence of SA concentration,CaCl₂ concentration,boric acid concentration,and crosslinking time on the gel ball indicates that the mechanical strength and mass transfer effect of the gel ball are present.With a positive correlation trend,the optimal formulation of immobilized rubber balls is:2%SA,2%CaCl₂,3%boric acid,and co-treatment for 12 h.Compared with 1:1 and 1:10groups,the ratio of 10:1 of the algae bacteria in the immobilized algae gel pellets has obvious advantages in purifying NH₄-N,NO₂-N,NO₃-N and TP.The dominant group is immobilized algae The maximum removal rates of NH₄-N,NO₂-N,NO₃-N and TP with a ratio of 10:1 of algae in the glucococcus were 86.44%,95.57%,79.16%and 82.62%.Compared with the control group,the test group that put immobilized algae gum balls into the circulating water of grass goldfish basically maintained a stable state of nitrogen and phosphorus in the first week.After a week,the ammonia nitrogen concentration gradually increased with the increase of days.There is no need to change water during the cycle,which improves the utilization rate of tail water.