Desalination, Vol.272, No.1-3, 246-253, 2011
Removal of a disperse red dye from synthetic wastewater by chemical coagulation and continuous electrocoagulation. A comparative study
The effectiveness of chemical coagulation (CC) was compared to electrocoagulation (EC) with aluminium electrodes for decolourization purpose of a synthetic textile wastewater containing a disperse red dye. For CC, ferric chloride FeCl3 and aluminium sulphate Al-2(SO4)(3) as the coagulant were compared: the respective effects of initial pH, coagulant dosage, initial dye concentration, ionic strength and mixing conditions were investigated in order to maximize decolourization yield. The comparison between CC and EC is based on recently published data on EC by the same authors. Experimental results showed first that Al-2(SO4)(3) was far more effective than FeCl3 for colour removal using CC, regardless of operating conditions. A removal yield higher than 90% could be achieved with a 40 mg/L dose of Al-2(SO4)(3) 18H(2)O in a large range of pH from 4 to 8 and for a dye concentration up to 235 mg/L The removal yield could however be enhanced up to 95% using EC for pH values between 6 and 9 at the expense of higher operating costs. Nevertheless, EC presented the additional advantages to be more robust against pH change and to reduce simultaneously equipment costs in comparison to CC. (C) 2011 Elsevier B.V. All rights reserved.