Preparation Of Alkaline Rare Earth Coagulant And Application Study

The composition of the coking wastewater and coking wastewater pollution arespecial, with the high cost of existing treatment process and pharmaceutical treatment,and is still difficult to achieve the emission standards after deepen the treatment. Aimingat the status quo for coking wastewater treatment, the paper developed an alkaline rareearth coagulant, determined the optimal conditions of the coagulant preparation andcoagulation, At the same time, having comparison and analysis of four coagulantswhich using in coking wastewater treatment.Using a kind of concentrate rare earth and alkali solution mixed reaction to preparealkaline rare earth coagulant, Analysis of the concentration of alkali solution, rare earthamount, reaction time, bath time, and the water bath temperature factors in thepreparation process. Determining the treated water turbidity as evaluation of optimumpreparation conditions:3mol/L sodium hydroxide solution,100mL, rare earthconcentrate7g, reaction time5h, water bath （60℃） time2h.Taking coking wastewater which effluent water after deepen dealing thesedimentation tank has coagula tests, experimental results show that:the turbidity ishigher than98percent, COD_Crremoval rate of is70%, the pH value is the raw waterincreased from5to7, Chrominance to reduce is from83degrees to5degrees; Optimalconditions of coagulation reaction: Turbidity range is between30-300NTU,pH range is5-8, water mixing conditions for the quick stir of is300rad/min, duration is1min;medium speed of is100rad/min, duration is10min; slow stirring to is30rad/min,duration is10min; settling time of is10min.Experimentn compares and analyzes the coagulation effect of rare earth alkalinecoagulant and Polymeric ferric sulfate, PAFC, M180and LD101in the treatment ofcoking wastewater, The results show that the basic coagulant rare earth processing: theeffect of turbidity, COD_Cr, color removal rate are significantly better than the other fourcoagulant; sludge resistance smaller and sludge dewatering performance are better, itconducive to the subsequenttreatment.