Experimental Study On Turbidity Removal Efficiency Of Sludge Recycle On Vortex Clarifier

At present in traditional clarifiers run energy consumption, low efficiency of coagulation, running instability, it is still a lack of in-depth research for clarifiers recycle ratio test parameters, this test using vortex clarifier to research recycle ratio turbidity removal. The test mainly includes two parts of the static tests and dynamic tests. Static test study on different coagulant dosage on turbidity removal, the preferred coagulant, and to determine the dosage in the Kongmu Lake andmimic muddy water two running conditions. Dynamic test research sludge recycle ratio of vortex to clarify the effect of the pool run by the presence or absence of sludge recycle comparative test, sludge recycle ratio of vortex clarify pool startup time impact test, different recycle ratio coagulant dosage run effect impact test, the different flocculation time under sludge recycle run effect impact test, determine the best operating conditions and test parameters.vortex clarified pool of best run workers condition and the related technical support.The main findings and conclusions are as follows:1.In the static test, the flocculation effect of PAC, Al2(SO4)3and FeCl3was studied. with the condition of lake water from18NTU Kongmu Lake, and the suitable coagulant was PAC, its best dosage was25mg/L. With the condition of180NTU mimic muddy water, the flocculation effect of PAC, A12(SO4)3and FeCl3was also studied. And the suitable coagulant was PAC, its best dosage was30mg/L.2.In the dynamic test, while the raw water was lake water from Kongmu Lake, water turbidity18NTU.(1) The study compared the presence or absence of sludge recycle clarify water quality, Close to the effluent turbidity the vortex to clarify pool influent flow5m3/h with recycle3m3/h without recycle, sludge recycle clarifiers, water production capacity can be improved, clarifier effluent turbidity external sludge recycle than those without recycle, calculation shows that the sludge recycle can save about25%of the flocculant dosage.(2) Research recycle ratio of vortex clarify pool start-up time, vortex clarifier the start-up time of the recycle ratio is1.0vortex is shorter than the sludge recycle ratio is1.3, the sludge recycle ratio is0.7starting the longest, described in the same dosage, the start of the recycle sludge ratio of1.0when vortex clarifiers optimal.(3) Research different recycle ratio of coagulant dosage run effect, vortex clarifier the effluent turbidity of the recycle ratio is1.0vortex is lower than the sludge recycle ratio is1.3, the sludge recycle ratio is0.7turbidity the highest, described in the same dosage, the effluent turbidity of the recycle sludge ratio of1.0when vortex clarifiers optimal.Different sludge recycle ratio under vortex clarifier effluent zeta potential values have experienced positive from negative to zero and then gradually increasing, and the zeta potential of the water in the same pac dosage point is basically the same. Effluent zeta potential is limited only by the impact of coagulant dosage, and in the the same pac dosage, different sludge recycle ratio under vortex clarify pool water zeta potential values did not differ significantly.Different sludge recycle ratio the next vortex clarifier floe size are presented first increases and then decreases, vortex clarifier the floc size of the recycle ratio is1.0vortex is biger than the sludge recycle ratio is1.3, the sludge recycle ratio is0.7starting the smallest, described in the same dosage, the floc size of the recycle sludge ratio of1.0when vortex clarifiers optimal.(4)Sludge recycle ratio study different flocculation time run effect, vortex clarifier the effluent turbidity of the recycle ratio is1.0vortex is lower than the sludge recycle ratio is1.3, the sludge recycle ratio is0.7turbidity the highest, described in the same dosage, the effluent turbidity of the recycle sludge ratio of1.0when vortex clarifiers optimal.3. The best operating conditions and design parameters:According to the test results, test raw water to the Kongmu Lake, coagulants PAC, dosage of25mg/L conditions, vortex current clarifier at a flow rate of10m3/h, select the sludge recycle ratio of1.0to run the best results, the corresponding design parameters for the flocculation time6.8min, precipitation zone surface load5.1m3/(m2·h).4. Engineering applications and debugging:the use of vortex current clarify the technical,"On Water Supply and Drainage Standard Drawings"320m3/h, hydraulic cycle clarifier s771(8) pipes, nozzles, the reaction chamber and the precipitation area appropriate transformation, select the appropriate recycle ratio and applied to the renovation and expansion project in Jiaxing waterworks.Upon completion, the scale of a single pool of processing up to500m3/h, clarifier effluent turbidity stability in3NTU, filtered water turbidity is less stable in the1NTU. The successful renovation of the water plant is fully illustrated vortex clarification of technical, coagulation efficiency and impact load, excellent water quality, easy maintenance and management, stable operation, etc. With a certain value of promotion and application prospects.