| Abstract:Coagulation experiments were performed to find out the optimum coagulant for the treatment of carbonless paper coating wastewater. Four coagulants(PAC， PFS， aluminum sulfate and ferrous sulfate） and coagulant aid(CPAM） were used in the experiments. Enhanced coagulation(EC） using anaerobic sludge in the treatment of coating wastewater was evaluated and the optimized coagulation treatments were determined， in the mean time， the particle size of the flocs produced in the enhanced coagulation treatment were investigated by using laser particle size analyzer and SEM. Results revealed that among the four coagulants， PAC presented greater efficiency in CODCr, color and SS removal， which were 69.6%, 99.1% and 98.9%， respectively when at the applied dosages of 400 mg/L for PAC and 6 mg/L for CPAM. Results of enhanced coagulation showed that removal of CODCr, color and SS were 74.6%, 97.0%和 95.9%， respectively when the dosages of PAC and CPAM reduced by 50% and 33%， respectively. The particle size analysis and SEM observation of the flocs showed that the floc size and adsorption capacity increased， and the precipitation effect was significantly enhanced． |
