Experimental Study Of Microvortex Coagulation Process On Operating Parameters And Sludge Discharge Program In Different Conditions

Through this experimental study of micro-vortex coagulation clarifier on operatingparameters and sludge discharge program in different water quality, determined its basicoperating parameters, optimized its sludge discharge program. The experiment results hasbeen applied to new water plant and renovation project, which has achieved good economicand social benefits, the experimental parameters has been verified which derived fromengineering practice. The main experimental findings are as follows:It has a good correlation between the dosage effects of micro-vortex coagulationclarifier, ξ potential and floc equivalent diameter of the reaction zone. When the clarifiedeffluent’s ξ potential changes within±5mV, or flocs is large and dense, and its equivalentdiameter is greater than0.450mm, it usual can get better clarification of the water effect.Temperature can effect the dosage of flocculant obviously. Great lake water, for example,in order to purify to3NTU, it need more4mg/L dosage in winter than in summer;composition of impurities in water will also affect the coagulation reaction, experiments forthe effluent turbidity purify to3NTU, it needs21.4mg/L flocculant dosage for small lakewater, while the great Lake water needs15mg/L flocculant dosage, small lake water needsmore6.4mg/L than great lake water; with the micro-vortex coagulation clarifier surface loadincreaseing, the equivalent to the formation of floc particle size in the reaction zone tends todecrease. By more flocculant dosing can increase the physical collisions between particles andimprove water quality.According to the traditional water cycle coagulation clarifier,when its source water isfrom the great lakes of the ECJTU,(SSinto=25mg/L, SSout=5mg/L), experimental clarifier’ssludge discharge cycle is2.4h, and the time of sludge discharge is10s, the sludge rate is0.25%, on this basis, by optimizing the micro-vortex clarifier sludge’s discharge cycle, itscycle can be extended to12h, the rate of sludge closes to1%, sludge volume reduces to25%.The concentration in sludge concentration area, SV30and sludge resistance increase as theincreasing extension period. When the experimental clarifier’s sludge discharge cycle is12h,the rate of sludge solids is0.97%, SV30increases to80%, the sludge resistance is3.07×10~9s~2/g. Let the Micro-vortex coagulation clarifier runs12h and then put it aside12h, the sludge solids will become to2.46%, SV30will increase to98%, resistance of sludge will become to6.23×10~9s~2/g, which will be double than the previous resistance. In operation of water plants,when it doesn’t need run, it could be considered to discharge Sludge before re-running themicro-vortex coagulation clarifier.It found that clarifier sludge return can increase the capacity of water production; and thesludge return can save the flocculant dosage about25%by calculating.The above results show that the micro-vortex coagulation clarifier has thecharacteristic of high quality and long sludge discharge cycle. its basic operating parametersand sludge discharge program will provide guidance for the production practices, which isgood for the promotion and applicationof the micro-vortex coagulation process.