Experimental Study On Treatment Of High Turbidity And Flea Water By Coagulation Pre-oxidation/Filtration

In view of the main problems such as the increase of turbidity in winter and the increase of fleas in water from a water plant in Panjin of Dahuofang Reservoir,the combined treatment process of coagulation pre-oxidation and coal sand filtration was put forward.The water quality of Dahuofang reservoir with high turbidity and flea was studied.In this paper,the coagulation test of high turbidity and flea water was carried out firstly.PAC(polyaluminum chloride),PAM(polypropylene phthalamine)was added to the water.FeCl3(Ferric Chloride)three kinds of coagulants were used to investigate the coagulants with the best coagulation effect for the water quality of high turbidity flea and flea.The results showed that PAC had the best effect on turbidity of high turbidity and high flea water,and the results showed that PAC had the best effect on the turbidity of high turbidity and high flea water.In addition,PAC had certain inactivation effect on Daphnia Sagittarius.The death causes of Swordaphnia had two kinds of death caused by hydraulic agitation(agitation oar)and capped by flocculating body.The inactivation rate of 60min was up to that of 60min by adding PAC to Daphnia swordaphnia.The removal rate of flea by PAC to 26%.20mg/L was 29.1%,but the flocculant formed by 20mg/LPAC was unstable,and the activity of Daphnia was restored after 2 hours.Therefore,PAC of 15mg/L was the best dosage of coagulant in this experiment.In this paper,the beaker preoxidation test was carried out for Daphnia flea.Two different oxidants,ClO2(chlorine dioxide),NaCIO(hypochlorite),were added to investigate the optimum inactivation effect of preoxidizer for the water quality of Daphnia albicans,and the results showed that the preoxidizer had the best inactivation effect.The results showed that the oxidation effect of NaClO was not obvious,and the removal rate of flea increased with the increase of concentration of ClO2.The CI02 of 1mg/L could completely inactivate the flea in 30min,and the removal rate of flea increased gradually with the increase of dosage concentration.The removal rate can reach 100%.Then it simulates the actual operation of the water plant by using the dosing tank and the sedimentation tank device.The removal rate of fleas was reduced from 100%to 80%in the period from 0.5 to 15 hours after administration.The analysis is that the part of the sword water flea can not be fully contacted with the oxidizing agent,and then flows into the sedimentation tank and is propagated in a large amount at the bottom.By comparing the traditional sand filter media and coal sand filter media for turbidity reduction and flea removal,the better filter media types are determined and the grading parameters of the filter media are optimized.The experimental results show that the coal sand filter media shows a better ability to resist impact load in terms of turbidity reduction,and the results show that the coal sand filter media has a better anti-impact load capability in terms of turbidity reduction and flea removal.Even in the case of high turbidity water,stable effluent turbidity can be guaranteed,while the traditional sand filter medium has poor ability to resist impact load.When the turbidity of incoming water is increased,it can not guarantee stable effluent turbidity,and filter cake is formed on the surface of filter layer at the later stage of filtration.The filtration performance of filter material is seriously affected.In the aspect of flea removal,the concentration of flea in effluent increased in the late stage of filtration with traditional sand filter medium.Coal sand filter material in the first 24 hours Flea-free penetration of filter beds.However,the thickness of anthracite and the particle size of quartz sand are the key factors affecting the turbidity of filtered effluent,but the thickening of anthracite has no effect on the time of flea penetrating through the filter bed,and there is no positive correlation between filtration rate and turbidity of filtered water and flea.The thickness of anthracite and particle size of quartz sand are the key factors affecting turbidity of filtered effluent.The particle size of quartz sand is the factor that affects flea penetration.When the particle size of quartz sand is 0.5mm,the particle size of quartz sand is 0.7mm,the particle size of quartz sand is prolonged to prevent flea from penetrating for 12 hours.Under the condition of 12m/h filter speed,filter material gradation of filter column C has better filtration performance.Finally,the treatment effect of high turbidity Gao is investigated by the combined process of coagulation pre-oxidation and coal sand filter material filtration,and the test results show that the traditional water backwash can not effectively remove the impurities and organic matter left in the filter after filtration,and the concentration of ClO2 at the bottom of the sedimentation tank is small,and the daphnia is easy to breed at the bottom The following problems were found in the trial operation of three consecutive filtration cycles of the combined process,the length of three filtration cycles was shortened in turn,the phenomenon of flea penetrating filter layer occurred in the latter two filtration cycles,and the distribution of head lines was uneven.The combined backwash of gas and water can wash out and eliminate the impurities in the surface and filter layer of the filter material by rubbing each other through the filter material,which has more obvious advantages.After filtration water turbidity in three filtration cycles stable maintenance of up to 0.5NTU,pre-filtration water flea removal rate in three cycles not less than 85%,basically maintained at about 90%,after the filter water did not find the survival of fleas,the distribution of the head line is uniform and the filtration period to maintain about 72h unchanged.