Purification Mechanism And Experimental Study On The Clarifier Of High Density Reticular Flocculation

Clarification, as the method of water treatment which can meet people's water quality requirements, is more and more concerned by people. In order to minish the difference from the developed country,effluent quality of the clafier must be improved. The programming goal was come out in "development program of 2010": present process must be altered reasonably and the effect of traditional disposal should be full exerted. It is evident that overhauling present water plant and technique improving in a future time will be an important content and research task of water supply field in our country.The clarifier of high density reticular flocculation was designed,which was based on the research hotspot of high density clarifying technology and in combine with vortex diffusion,sludge suspension layer,wing sheet type inclined plates theory and material balance calculation equation. This clarifier's mechanism and effectiveness of water purification was identified by the raw water with the bed mud of Chan river,Yellow river and Wei river. And three coagulants (PAC, PAFC and PAM) were also selected to finish the experiment. The conclusions were below:(1) This clarifier completely depended on the effect of water flow to ensure the floc's stabilization of suspension,turbulence and tendencies. It's character was similar to plug-flow-reactor. The backmixing phenomenon did not exist so the clarifier could be achieved to fix the agents intensively. Besides, the contact flocculation' function was enhanced after adding the coagulant aid. And the original water could get better clarification.(2) This clarifier's high-efficient circulation was on the premise of adding the organic polymer coagulant aid. Furthermore, the experiment of motion water approved that the effect of adding PAFC and PAM was better than that of adding PAC and PAM in this equipment.(3) This clarifler was circulated in stability operation. Under the normal condition, thegeneral turbidity of effluent water could reach less than 3 NTU .And COD_Mn,ammonia nitrogen and NO₂^- -N all reached the drinking water criteria without filtration. The removal rate of UV₂₅₄ could be stabilized with more than 60%, and it was up to 95.6%. (4) Based on the effect of effluent water and agents' cost of this two combination, it could be concluded that the best economic coagulants' combination was PAFC+PAM.