Study On Rapid Algae Removal Of Enhanced Coagulation Sedimentation

This paper was aiming at the issues of river pollution caused by algal bloom in summer and studied on rapid algae removal of enhanced coagulation sedimentation.The author designed an efficient chute sedimentation integrated device to realize the response control of algae.It could be moved at any time.Contrast algae removal effect of different coagulants,flocculation.The results of magnetic flocculation and sand sedimentation could provide technology development and application support for emergency treatment of polluted river water.Main results:(1)Choose the species of flocculent and coagulant by small pilot test.Find PAC was better as coagulant,PAM or Diatomite were better as flocculent.The best dosage of PAM as flocculent was 1 mg/L,the best dosage of PAC as coagulant was 80 mg/L.The best dosage of Diatomite as flocculent was 60 mg/L,the best dosage of PAC as flocculent was 60 mg/L.(2)Use this efficient sedimentation integrated device to treat polluted water.The deterioration of water quality and other conditions have been better improved.Removal rates of Turbidity and Chlorophyll were over at 50% and 60%.Using of PAM as flocculent was more economical and the lowest cost of each ton water treatment was 0.13 yuan.(3)Magnetic flocculation can enhance coagulation effect,improve removal rate of pollutants,HRT could be shorten to 5 min and dosage saved over 70%.When the dosage of magnetic particle was 0.5 g/L,flocculent was PAM and coagulant was PAC,water quality achieved the best.For algae bloom water,removal rates of Turbidity and Chlorophyll were over at 60% and 80%.For malodorous black water,removal rates of Turbidity and COD were over at 50% and 75%.(4)Sand sedimentation could effectively reduce Turbidity and Chlorophyll.When HRT was 15 min and the dosage of white sand was 3 g/L,the removal of impurities achieved the best.When 80mg/L PAC and 0.5 mg/L PAM was dosed,removal rates of Turbidity and Chlorophyll were over at 66% and 85%.When 80mg/L PAC and 40mg/L Diatomite was dosed,removal rates of Turbidity and Chlorophyll were over at 88 % and 90%.(5)Compared with cyanobacteria,green algae were more likely to be processed by PAC and PAM,but more difficult to be processed by Diatomite and new adsorptional coagulant.Using conventional coagulation sedimentation technology,green algae water is easier to be treat than cyanobacteria water.Coagulation and sedimentation technology could be used to deal with malodorous black water.