| Bench-scale and pilot-plant studies were used to investigate theeffects of flocculation condition and floc size on the performance ofdissolved air flotation for two different types of output water fromoxidation ditches,encompassing two water quality seasons during 2000．The experiments result show that agglomeration(coagulation/flocculation)phase has been indicated as essential anddetermining the down stream process efficiency, hence it is a prerequisite for process improvement. Relevant process parameters havebeen addressed on a laboratory and two pilot plants scale, includingthe influence of coagulants and their dose,coagulation pH, flocculationtime,energy input (G value),and application of cationic polymer asa coagulant. The process efficiency was assessed as a function of thepreceding phase．The combination of DAF and Al2(SO4)3·18H2O has been foundto be the effective for the treatment of two water supplies and needsno any other aids．Cationic polymer (FO455O) has been found to be notfit for all the waters tested.There is no any relation between organic pollutant and turbidityof the tested water．One measurement of the air supplied was examined:percentage recycle.30% percent recycle was better to effectively treatall the waters．... |
PDF Full Text Request