Treatment Of Dye Simulated Waste Water By Pellet Coagulation

Pellet coagulation is a new flocculated technique, which can control the random growth of flocculation by improving its dosing way and hydraulic conditions to reduce the moisture content of flocculation. In this paper, the characteristics of the pellet coagulation process were expatiated, and the various technicses of pellet coagulation were compared. Three different kind dyes, direct acid-resistant red 4BS, active yellow K-4G and disperse blue 2NBL were selected as references, the corresponding experimental set was designed, the comprehensive study on the treatment of dye wastewater by pellet coagulation process was conducted. The results showed that: (1) For the treatment of simulated dye wastewater of direct acid-resistant red 4BS by pellet coagulation procession, lower dosage and higher flow rate were realized. When the flow rate was 64.1m/min, decolorization ratio was still high to 96%.(2) For the simulated dye wastewater of active yellow K-4G, drug dosage and decolorization ratio were not better than the traditional flocculation. Decolorization ratio was only 87.5%, the highest flow rate was only 47.77cm/min. (3)For the simulated dye wastewater of disperse blue 2BLN, drug dosage was close to the traditional flocculation, but the higher flow rate was not afforded by this technics. Decolorization ratio was only 90% , which was relatively lower than 95% of traditional flocculation. The flow rate was not higher than 26.5cm/min. (4) For the simulation waste water of mixed dye, drug dosage was smaller than that for the single dye, flow rate was higher, and the highest flow rate was 60cm/min.. But decolorization ratio was lower, which was 80%. (5) The three dye wastewaters were treated by the quartz sand microflocculation, the results showed that: the decolorization ratios for three dye wastewaters were about 50%, while larger drug dosage, lower water flow rate were observed. This technics has good prospects, in particular for the application and development of dye wastewater treatment, which is better the the conventional flocculation for the direct dye wastewater.