Preparation And Performance Of A Novel Inorganic Polymer Flocculant-polysilicic Acid Ferrir And Zinc Sulfate Containing Boron

Coagulation was an important technology used generally in water treatment.The cost of coagulants approximately account for 50 percent of the total cost of the water treatment.a relatively new type of flocculation reagents, such as polysilicic-salt, had been recently concerned as an inorganic polymeric flocculant with good flocculation effect and low cost, which had the charge neutralizing capacity and adsorption bridging by researchers. A new type of inorganic polymer flocculant, polysilicate boron ferric and zinc sulfate (PSBFZ), was prepared through reaction of sodium silicate, ferric sulfate, zinc sulfate and sodium tetraborate. The preparation conditions,flocculation performance,practice effect and flocculation mechanism were fully investigated in this paper.1,PSBFZ, PFS, PSBF, PSFZ were synthesized by co-polymerization. the removal of the turbidity ,the chromaticity and stability were compared,By investigating the removing rate of turbidity and chromaticity and the stability, the results show that the flocculation efficiency is influenced by the concentration of Na2SiO3, polymerization time,the Fe/Si,Zn/Si and B/Si malar rate.The Optimal synthesis process and material mixture ratio were determined by Orthogonal and single-factor experiments. Experimental results demonstrated that the optimal preparation conditions were as follows: the concentration of Na2SiO3 was 0.5mol/L ; polymerization time was 120 min; activation pH value was 2.2; aging time was 48h; n(B)/n(Si), n(Fe)/n(Si), n(Zn)/n(Si) were 0.4, 1.5, 1.5, respectively. PSBFZ had a favorable stability that it will not gel within 4 months.2,Compared to those traditional inorganic polymer flocculants, such as PFS and PAC and PSF, the good efficiency was studied.(1)It has good stability effect. The form and flocculation efficiency of PSBFZ almost have no more change with the condition of haning it placed at nature. (2)The removal of turbidity at 5-40℃of PSBFZ was better than that of any othert emperatures.(3)PSBFZ dosage is more less than it of PAC and PFC, but the flocculation efficiency was better than them.(4)PSBFZ crassitude and close-grained floc was observed.3,In order to test practice effect in sewage treatment, dyeing waste water, landscape water and landfill leachate were to get disposal by using PSBFZ. The flocculation efficiency of PSBFZ was better than that of PFS,PAC,PSF。COD removal of rate and color removal of rate can attain 92.2% and 95.4% about dyeing waste water, colority of wastewater could reach to 90.1%. Remove rate of COD may get to 67.4%. PSBFZ crassitude and close-grained floc was observed.4,Mechanism Of flocculation and structure characterizations of PSBFZ were Studied.Particular analysis Was carried out with IR spectrometry for the binding mechanism of the polymeric silicic acid and metal ions.The results showed that the structure of this new flocculant was polymeric with O-and OH·bridges. By XRD instrument analysis, PSBFZ which is composed with B, Fe3+, Zn2+ and polysilicic acid is amorphous polymer. PSBFZ crassitude and close-grained floc was observed.