Experimental Research And Engineering Applications Of Micro-vortex Clarification Technology

Currently the water quality pollution is more and more serious,water consumption has improved,conventional clarification techniques are difficult to meet the requirements of users for water quantity and water quality sometimes.Combined with the current economic situation in China,to improve and strengthen routine clarification technology,is the most economical and practical measures to increase water rate and improve quality of effluent water.This project from the principle of clarifier,the present situation,the reconstruction situations and problems,on the basis of micro-vortex coagulation,using theory of fluid dynamics and flocculation kinetics,research and development efficient clarification technology(micro-vortex clarification technology)with low energy consumption,to improve water production capacity and water quality stability of the clarifier with lower operating costs.Through pilot model test,to verify running effect and water purification capacity of micro-vortex clarifier,to get the design parameters,such as the value of G,hydraulic retention time,the best ratio of vortex reactor,the water weir crest load,and so on.On the basis of the test,using micro-vortex clarification technology to reconstruct the hydraulic recirculation clarifier of a water plant in Yizheng City,for its present status.And through the engineering application,technical and economic analysis,then further optimize micro-vortex clarification technology: design parameters of reaction chamber,control conditions and operation parameters.Let micro-vortex clarification technology be more practicability and popularization.The main research results are as follows:1.Through micro vortex clarifier compared with hydraulic circulating clarifier water purification effect,it is concluded that the advantage of micro vortex clarification technology,water flow in 3~5 m~3/h,the effluent water of micro vortex clarifier: turbidity is less than 3 NTU,UV254 is less than 0.04 cm-1,the absolute value of zate potential is less than 5 mV,CODMn is less than 4 mg/L,the water quality indicators can meet the technological requirements of subsequent filtration process;And the effluent water quality index of hydraulic circulating clarifier,such as: turbidity,UV254,the absolute value of zate potential,CODMn,along with the increase of inlet flow rate increasing,when the traffic reaches after 5 m~3/h,the effluent water quality indicators have not meet the technological requirements of subsequent filtration process.In addition,water purification effect of hydraulic circulating clarifier is worse than micro vortex clarifier,and with the increase of water flow,the gap is growing.2.With the increase of water inflow,in micro-vortex clarifier of reaction zone,the number of micro-vortex in per volume water is increase,the absolute value of zeta potential get smaller,which is favorable to flocculation.It suggests that the water production capability of micro vortex clarifier is stronger than hydraulic circulating clarifier,and the treatment size is bigger in same volume of tank.3.The time of sludge discharge in the micro-vortex clarifier is significantly shorter than it in the hydraulic circulating clarifier.It suggests that sludge have high concentration and good settling performance.In further,the flocculation reaction effect of micro vortex clarifier is better.Because the vortex reactor can guarantee the stability of suspended sludge layer,reduce the influence of suspended sludge layer by sludge discharge,improve the clarifier the bottom sludge solid content.4.Through contrast test with clarifier water purification effects on various adding ratio of vortex reactor(with 35 mm aperture and 25 mm aperture),it is concluded that when put 30 HJTM-2 vortex reactor on the first reaction chamber of clarifier,90 HJTM-1 vortex reactor on the second reaction chamber,and 30 HJTM-1 vortex reactor on the transition of reaction chambers,the value of G in the first reaction chamber is 57.1 s-1,the value of GT is 11134.5,the value of G in the second reaction chamber is 20.3 s-1,the value of GT is 11875.5,the water purification of clarifier is best.5.Through engineering application and economic analysis of micro-vortex clarify technical in the water plant,conclusion that clarifier run stability after reconstruction,the turbidity of treated water is below 2 NTU,the other quality parameters of water are standard,the water productivity increase 50%(4800m~3/d)and the total investment is 630000 yuan,the reconstruction cost is about 130 yuan per ton water,the economic benefit is remarkable.After reconstruction,operation cost greatly reduced,coagulant dosing quantity reduction from 15.6 mg/L to 10.4 mg/L,to save coagulants about 75 kg every day;Sludge discharge cycle extend from 8 hours to 24 hours,to save dredge water 45 m~3 every day;Backwash cycle of 3 # gravity valveless filter which correspond by the clarifier extend from 12 hours to 24 hours,to save backwash water 144 m~3 per day.