Research On High PH Regulation Technology Of Chloride-type Saline-alkaline Water In Fish And Shrimp Polyculture Ponds

Water quality regulation has always been a core issue in the aquaculture industry.Because the water quality of saline-alkaline soil has the characteristics of high pH and high carbonate alkalinity,it has become a factor restricting the survival rate and yield of aquaculture.saline-alkaline water is configured according to the saline-alkali water quality parameters of mixed fish and shrimp breeding ponds,and physical,chemical and biological methods are adopted to carry out algae inhibition and pH reduction research,and to explore the feasible measures of reducing the high pH of saline-alkali water quality.The main study results are as follows:1.The rise of pH in saline-alkaline ponds is closely related to cyanobacterial blooms.Taking Microcystis aeruginosa as an example,according to the difference in the absorption of different light colors by algae,the growth differences of Microcystis aeruginosa under blue light,green light,white light and control light were compared.Color has a significant effect on the growth of Microcystis aeruginosa.Among them,the growth of Microcystis aeruginosa was significantly inhibited under green light conditions,and the algal density was 1.8×10⁶cells·m L^-1on the sixth day,compared with 2.7×10⁶cells·m L^-1in the control group.Green light can inhibit the synthesis and production of chlorophyll a,reaching 1.6mg·L^-1on the sixth day,which is 88.9%of the control group.2.Chemical methods use calcium preparations to reduce the high pH of water bodies.In the experiment,three kinds of calcium preparations commonly used in aquaculture,calcium dihydrogen phosphate,calcium lactate,and calcium chloride,were used to treat and configure saline-alkaline water,and the initial pH was 8.92.The results show that the three calcium preparations have significant differences in the regulation of high pH of saline-alkaline water,calcium dihydrogen phosphate and calcium lactate have poor regulation ability,while calcium chloride has better regulation ability.Among them,the use of calcium chloride with a concentration of 1.44 mmol·L^-1has the most obvious effect on reducing the pH of saline-alkaline water,and the pH decreased to 8.8 after 5 hours;the total alkalinity of the water body decreased from the initial 18.5 mmol·L^-1to 16.8 mmol·L^-1after3 hours.L,and finally remain stable.3.Biological methods employ beneficial microbial agents to control cyanobacteria.To study the inhibitory effect and approach of Bacillus licheniformis on Microcystis aeruginosa in saline-alkali water.The results showed that Bacillus licheniformis had a good inhibitory effect on the growth of Microcystis aeruginosa in saline-alkali water environment.When the concentration reached 7.1×10⁶CFU·m L^-1,the inhibition rate could reach 71.1%,and the bacteria were sterile.The algae inhibition effect of the filtrate was more obvious,and the algae inhibition rate of the 2%cell-free filtrate addition group reached 79.5%.The active substances it contains affect the photosynthesis of Microcystis aeruginosa by inhibiting the expression of photosynthesis genes psb A1 and psb D1,and inhibit its growth4.Through non-targeted metabolomic analysis of Bacillus licheniformis cells and cell-free filtrate in saline-alkaline water,it was found that some metabolites in the sterile filtrate changed significantly,and found the inhibition of aeruginosa microbes.Some of the key metabolites in the growth of Cystis sp.,such as phenylalanine,tryptophan,lysine and syringic acid.In this paper,through the three aspects of physics,chemistry and biology to control the high pH of saline-alkaline land aquaculture water quality,three practical so lutions have been researched,and a strain-lichen suitable for saline-alkaline land aquaculture to inhibit cyanobacteria outbreaks has been found.Bacillus,providing a the oretical basis for water quality regulation in saline-alkaline soils.