The Effect Of Deep Well Pressure Coagulation Precipitation On The Composite Cyanobacteria Water And Its Safety

In the summer,lake,reservoir,breeding pond algae blooms frequently outbreaks of algae floating on the surface of a large amount of water,a serious threat to the safety and water ecological environment,thus effectively remove of blue-green algae caused people attach great importance to.Because cyanobacteria cell contains the existence of false empty spore(airbag),has the characteristics of the floating algae,and cyanobacteria algae cell surface of afterbirth package,negatively charged,is not conducive to the coagulation precipitation,this paper chose two common single-celled cyanobacteria spirulina-Leptospira maximus and Anabaena spirals as the research object,to subvert the algal cells by the method of deep well pressure inside the balloon,make it lose the ability of buoyancy,so as to improve the removal efficiency of coagulation precipitation.The main conNaClOusions are as follows:70m deep well pressure coagulation sedimentation treatment Leptospira maximus and Anabaena spirals algae water yielded good effect to remove algae in water,and is superior to ordinary coagulation sedimentation process,preoxidation coagulation sedimentation process treatment effect is the worst.When the maximum Spirulina water was treated,when the dosage of PAC was 11 mg/L,the turbidity of the supernatant was 1.66NTU,the removal rate of chlorophyll a and CODMn was 93.12%and 77.12%,respectively,and the turbidity of the supernatant after coagulation and precipitation was 20.9 NTU,and the removal rate of chlorophyll a and CODMn was 59.89%and 46.27%respectively.When the water of Anabaena Spirulina was treated,when the dosage of PAC was 12 mg/L,the turbidity of the supernatant was 0.79NTU,the removal rate of chlorophyll a and CODMn was 92.28%and 73.84%,respectively,and the turbidity of the supernatant after coagulation and precipitation was 16.5NTU,and the removal rate of chlorophyll a and CODMn was 63.43%and 48.66%respectively.After Maximum spirulina water and Anabaena spirals water were pressurized by a 70 m deep well,DOC and algal toxin in the water were not increased,indicating that deep water pressurization would not damage the cell wall of algal cells,and the effluent water quality is safe However,after the preoxidation of 2 mg/L of NaCIO,algal toxin and DOC increased significantly,and the effluent water quality was not safe.After Maximum spirulina water and Anabaena spirals water were pressurized by a 70 m deep well,by algal cells slice observation,discover gasbag volume fraction less obviously,algal cell are cyanobacteria precipitation efficiency.There was no damage to algal cells after deep water pressurization,and after preoxidation,algal cells ruptured,which was the cause of algal toxin leakage.Deep pressure coagulation precipitation and preoxidation coagulation precipitation processing natural algae composite pollution of water,the results show that with the increase of well depth,treatment effect is becoming more and more good,obtain the best effect when 70 m depth,and deep well is obviously better than the compression process to remove algae in pre oxidation process.Under the condition of 50 mg/L Al2(SO4)3·18H2O dosage,the water turbidity of coagulation precipitate in deep well pressure process is 1.45 NTU,and the removal rates of chlorophyll a and CODMn are 89.64%and 78.79%respectively.After coagulation and precipitation,the turbidity of supernatant was 13.7ntu,chlorophyll a and CODMn removal rate were 83.72%and 75.51%respectively.There was no increase in algal toxins,DOC and so on after deep well pressurization treatment of cyanobacterium compound polluted water,and the effluent water quality was safe.Coagulation precipitation after pre-oxidation and deep well pressurization can improve the treatment effect,but the treatment effect is different with different sequence.The removal efficiency of algae by deep well pressure reoxidation is better than that by deep well pressure reoxidation.Under the condition of 50 mg/L Al2(SO4)3·18H2O dosage,the water turbidity precipitated by the deep well + preoxidation process was 0.47 NTU,and the removal rates of chlorophyll a and CODMn were 96.84%and 78.81%,respectively.The precipitated water turbidity in the pre-oxidation + deep well process was 1.43NTU,and the removal rates of chlorophyll a and CODMn were 95.02%and 69.35%respectively.The coagulation and precipitation of algal toxin and DOC in the deep-well + preoxidation process did not increase,and there was a certain degree of reduction,so the effluent water quality was safe.The concentration of algal toxin in pre-oxidation and deep-well process is 1.3 times that of raw water,and the effluent water quality is not safe.Treatment of water turbidity of cyanobacterium compound polluted water by deep well pressurization process Chlorophyll a and CODMn removal rates were 97.88%and 81.94%,respectively.The treatment effect is better than that of the preoxidation process,which has strong impact load,long filtration period and small water consumption for backwashing.It is simple to transform the combined process of deep well + preoxidation.It only needs to add a deep well with a depth of more than 70 m on the original basis.