Advanced Treatment of Printing and Dying Wastewater Using Nanoscale Iron Enhanced Flocculation/Sand Filtration/UF Combined Process

Flocculation /sand filtration /UF combined process was used for advanced treatment of secondary effluent of printing and dying wastewater. The treatment efficiency and optimal operation conditions were investigated. The nanoscale iron and HPAC flocculant were added at the same time to enhance the toxic organics removal. GC / MS was used for the screen analysis of the organic compounds in the effluent. The results showed that flocculation / sand filtration as a pretreatment process could greatly reduce the subsequent ultrafiltration load and slow down the membrane fouling. The operational cycle time of this process could reach 8 h,and the effluent turbidity and COD were less than 0. 1 NTU and 25 mg / L,respectively. The effluent quality could meet the Reuse of Urban Recycling Water ― Water Quality Standard for Industrial Uses( GB / T 19923- 2005). It was concluded that dosing nanoscale iron and HPAC flocculant assisted the reduction of toxic organic substances in the advanced treatment of printing and dying wastewater.