Research On The Cyanobacteria's Rotting Character And The Flocculation,Condense And Sediment Effect After Being Pressured

In order to improve the concentration efficiency of cyanobacteria slurry,the additional pressure was exerted on the cyanobacteria cell to make the loss of buoyancy so that it would be easily removed by sedimentation.This paper mainly studied the cyanobacteria's rotting character and the flocculation,condense and sediment effect after it was pressurized.Based on which the dynamic test of the pressurization technology with the flocculation of the agglomeration,condense and sediment of cyanobacteria was conducted.Finally,a safe,effective and economical separation process of water with cyanobacteria was made.(1)The different temperatures were studied the rotting process of cyanobacteria slurry,cyanobacteria slurry paste are placed in the 25 ?,30OC,35 ? constant temperature incubator training,interval time observing algae traits,determining the amount of residual chlorophyll cyanobacteria slurry,used to characterize the degree of cyanobacteria slurry rotting.Determination of TOC in algae filter,TN,TP and other water quality indicators,characterization of cyanobacteria slurry rotting,algal cells release pollutants into the water after the poor indirectly reflects the extent of cyanobacteria slurry rotting.The targets of cyanobacteria slurry remained the same in the first 108 hours with the culture temperature of 25 ?,however,in the next 96 hours,decay and release of pollutants began gradually increasing,Whole decomposed more slowly and require 7.5d to completely decay;With the temperature of 30?,the targets started to change obviously after 12 hours and became flat with the speed of decay slowed down in the next 36 hours,within 36h after the changes reduce the subsequent cyanobacteria slurry rotting and pollutant emissions increased again,the whole rotting process quickly only need 3.5d well rotted;When the temperature is 35 ?,cyanobacteria slurry rotting and release of pollutants after the start on the rapid increase in the 24h until the stability rotting process quickly as a whole only 1d was completely rotten.(2)The static experimental study on coagulation properties of different decay levels cyanobacteria slurry pulp,cyanobacteria slurry paste are placed in the 25?,30?,3 5 ? constant temperature incubator training,take a certain time interval algae concentrate was subjected to pressure coagulating sedimentation experiments.The supernatant was measured turbidity,TN,TP,CODcr and residual amounts of chlorophyll and algal toxins and other water quality indicators,the final optimum dosage in varying degrees of decay.Static experiments found that when dealing with fresh algae pulp(decay of less than 30%)with increasing dosage of fresh algae slurry after coagulation sedimentation each pollutant release and residual amount of chlorophyll and algal toxins is gradually reduced,finalized when PAC dosage and dry algae mass ratio of 1/15 and PAM dosage and dry algae mass ratio of 1/1000 for the best dosage;when the cyanobacteria slurry slurry started to decompose(decay of 30%to 60%),the PAC will ultimately determine the dosage of dry algae mass ratio is adjusted to 1/5 and the PAM dosage and dry algae mass ratio is adjusted to 1/800 can significantly improve water quality;in dealing with banal algae pulp(decay of above 60%),the final determination when the best dosage PAC dosage and dry algae mass ratio of 1/1.6 and PAM dosage and dry algae mass ratio of 1/667.(3)The process and effect of condensing fresh and scouring cyanobacteria slurry by flocculation sedimentation were studied by dynamic experiments.The double-tank parallel pressurization device was used to pressurize the algae slurry and then flocculated sedimentation tank,remove the water of the sample after a period of time measured turbidity,chlorophyll a,TN,TP,potassium permanganate index and moisture content of the sediment.During the dynamic test,the economic cost and remove efficiency of cyanobacteria should be considered when dealing with the fresh cyanobacteria slurry,and the best dosage of PAC and PAM were 1/20 and 1/1500 of the mass of dry cyanobacteria respectively.Continued the test within such dosage,we found out that the concentrations of every targets were better than those in the stable test with the concentrations of turbidity,chlorophyll-a and moisture content of cyanobacteria slurry in effluent generally less than 6 NTU,7mg/m3 and 97%respectively.Besides,the efficiency was maximized when the moisture content of the raw cyanobacteria slurry was 99.4%for the purpose of keeping the moisture content higher than 99%;When dealing with the dated rotten cyanobacteria slurry,and the best dosage of PAC and PAM were 1/1.5 and 1/300 of the mass of dry cyanobacteria respectively.Continued the test we found out that keeping the ascending velocity within 2m/h would meet the effluent requirement best.Under the same dosage,the moisture content of raw cyanobacteria slurry should higher than 99.2%and would lead to the best effluent when it was 99.4%for the purpose of the highest remove efficiency.