Abstract:

A series of dualcoagulants used for the treatment of synthetic disperse yellow and reactive red dyeing wastewater were prepared with different basicicity (B) of PFC, different intrinsic viscosities (η) of EPIDMA and  different ratios (P) of  PFC (by weight of Fe) to dry weight of EPI-DMA. The effectsof addition methods of dualcoagulants, P value, η value and B value oncoagulation efficiency were studied. The results showed that first adding PFC and second adding EPI-DMA could achieve the maximum color removal rate for synthetic disperse yellow wastewater, whereas the reverse adding order could obtain the best color removal rate for synthetic reactive red wastewater. The coagulant with η of4200mPa·s, P of 0.5 and B of 0.3  gave the highest color removal rate in this study. 

Key words: epichlorohydrindimethylamine (EPI-DMA), polyferric chloride (PFC), color removal