The Research Of Synthesis And Congulating Capability On Poly-Silicate-Ferric

Coagulation is one of important water treatment methods, now coagulating technics used aluminum-related coagulants. aluminum-related coagulants is used widely as nowaday's common coagulation technics.when used as a kind of coagulants, residual aluminum of treated water would increase. Overseas studies proved that aluminum can lead to senile dementia, so the ferric-related coagulants are more and more focused in international.Synthesis method of the new coagulant poly-silicate-ferric (PSF) was studied in the article, various analytic means was also used to attribute the PSF. The PSF belongs to inorganic macromolecular coagulants, and the synthesis is to load trivalent ferric into poly-silicic-acid, which make it holding the advantages of poly-silicic-acid and ferric-related coagulants, and leading to the trend of research of inorganic macromolecular coagulants in water treatment field in future.Active pH value of soluble silicate, consistent of SiO₂ and affection to synthesis of polymeric silicic acid from temperature were referred in this article. An active pH value of 2³, and consistent of SiO2 equaling 6⁷%, the temperature 25℃were chosen to form the optimistic synthesis condition. Through researches done on affection to coagulating performance of PSF by checking various Fe/Si mol ratios and aging time, it was proved a successful condition when Si/Fe=1/1, and aging time beyond 35min.Through stirring experiments, coagulating performance comparison was done among polymeric ferric sulfate(PFS)and poly-aluminum ferric chloride(PAF). The result indicated that the optimistic dosage of PSF was 0.22 mmol/L, and best dosage of PAF and PFS were 0.27 mmol/L,0.32 mmol/L. The CODMn removal rate by PSF outnumbered which PFS and PAF did for 43% and 24%, furthermore, the UV254 removal rate outnumbered 22% and 31%, the TOC 30% or higher. PSF got a good performance of turbidity removal when pH value ranged from 5 to 13. After treated by PSF, the content of residual aluminum and ferrum were low, with the number of 0.10mg/L and 0.15 mg/L, which were enough to fulfill the requirement of Drinking Water Quality Standards.