Study On Improvement Upon Removing Algae By Enhancing Coagulation-Filtration In The Treatment Of Micro Polluted Raw Water

The effect of polymerization of anions on species distribution of Polymeric Aluminum-Ferric Chloride (PAFC) is studied by modified (Al+Fe)-Ferron timed complexing spectrophotometry, and the effect of polymerization of anions on the algae removal efficiency in the coagulation is investigated by treatment of raw water in which the micro-algae, is predominant. The removal of turbidity, organics and algae cell in the filtration is enhanced by sand coated by metal oxides such as ferric oxide and titanium oxide. The results of experiments show that the effects of polymerization of anions on species distribution of PAFC solution mainly increase molecular weight of polymers and influence on algae removal efficiency in coagulation. The effect of polymerization of phosphor acid radical is best by comparison with the effect of polymerization of four anions such as sulfuric acid radical, phosphor acid radical, boric acid radical and silicon acid. The removal efficiency of turbidity and algae cell reaches to highest value, as mol rate of phosphor acid radical to metal ions is 15%. Compared the rule of species distribution of PAFC with that of variation of algae removal efficiency, it is found that adsorption-charge neutralization mechanism is most important in four mechanisms. The sand coated by both ferric oxide and titanium oxide can remarkably increase removal efficiency of turbidity, organics and algae cell in the filtration, otherwise, the sand coated by titanium oxide has more excellent ability to remove organics and algae cell in the filtration compared with ferric oxide.