Preparation Of Poly Ferric Titanium Sulfate(PFTS) And Utilization In Drinking Water Treatment

With the development of the industrialization, the contamination in drinking water is becoming more and more complex, and more and more people draw attention to drinking water security. As an effective way of water treatment, coagulation can make coagulant mixed with solute, colloid, suspended solids and then subside. By this way, pollutants can be removed from water and the water get purified. Coagulant is one of the important factors which affect the effect of coagulation, and get a safely and efficiently coagulant is a crucial issue. This paper which made full use of pro-biotic characteristic of Ti and high load-diameter ratio features of Fe, developed a new, efficient, safe, multifunctional inorganic macromolecular composite coagulant-- The Poly Ferric Titanium Sulfate(PFTS).In this research, The Poly Ferric Titanium Sulfate(PFTS) coagulant was produced by industrial by-products Fe SO4·7H2O and Ti(SO4)2, and used Na H2PO4?2H2O as a stabilizer and Na HCO3 as an alkalizer. Poly Ferric Titanium Sulfate(PFTS) composite coagulant was prepared by direct oxidation method. The structure and hydrolysis product distribution form of iron of PFTS was characterized by ultraviolet-visible spectrum, FTIR(fourier transform infrared spectrometer), XRD(x-ray diffraction), SEM(scanning electron microscope) and Ferron complexation timed spectrophotometric method. It applied to source water with Mn and Fe and the actual river water based on the single-factor test designed. The main contents and conclusions of the thesis are as follows:1) The paper investigated and optimized the factors which might have effect on the results of PFTS coagulation by single-factor test. It was found that under the condition that Ti/Fe, P/Fe, OH/(Fe+Ti) and reaction temperature were 1/8, 0.3, 0.3, 60℃, respectively, the coagulation effect is best at the dosage of PFTS was 25mg/L. At this time, the residual turbidity was under 1.0 NTU, and UV278 removal rate was about 69%.2) Ferron complexation timed spectrophotometric method showed that the percentage of Fea, Feb, Fec in PFTS was 32.4%, 21.4%, and 46.2%, respectively. Ultraviolet analysis showed that the presence of titanium made an impact on the characteristics of the hydrolysis product of iron absorption, and the absorption peak shifted. TIR analysis showed that PFTS contained new polymer Ti-O-Fe, Ti-O and so on. XRD analysis showed that PFTS appeared some new phases such as [Fe2+, Fe3+, Ti]3 [P,Ti]2O5[OH]4,Fe0.2(Fe Ti)0.6SO4(OH)0.8(H2O) and some new diffraction structures such as Fe2+Ti2O5、Na3Fe5O7、Fe Al2 Si O5(OH)2. It indicated that PFTS was not prepared by simple mixing of raw materials, a series of polymerization reaction happened actually and a new kind of inorganic polymer composite coagulant was produced. Through SEM, the introduction of the titanium made PAFS coagulant structure closely. PFTS that had a fluffy and present class fold petals shaped surface structure possessed an excellent adsorption bridging role and swept volume capacity, which made the coagulation performance enhanced.3) It was found that the removal rate of Mn, Fe, turbidity, UV254 were remarkable when using PFTS in the treatment of source water with Mn and Fe. The paper investigated and optimized the factors which might have effect on the results of PFTS coagulation by single-factor test. It showed that under the condition that the dosage of KMn O4, the dosage of PFTS and p H were 1.5mg/L, 30mg/L, 7~9, respectively, and KMn O4 dosing time about 5min before the coagulant, the coagulation effect is best, and the content of Mn and Fe of effluent were below the national standard, while the residual turbidity was under 1.0 NTU, and UV254 removal rate was about 90.2%. Temperature had effect on the treatment, but the effect is not obvious. The amount of organic matter in water had effect on the treatment to some extent. So when the organic matter was heavy in raw water, we should increase the dosage of KMn O4 or PFTS to ensure the treatment effect. Fractal dimension showed that fractal dimension was big and floc was compacted when the dosage of PFTS is 30mg/L. Combining with Zeta potential analysis, the author found that coagulant worked under electrical neutralization and adsorption bridging role, but adsorption bridging was given priority.4) The treatment efficiency was evaluated by investigated the removal rate of turbidity, UV254, CODMn and ammonia nitrogen of the actual river water and PFTS with common coagulants(PFS, PAC) comparative study by using single factor. The residual turbidity, the removal rate of UV254, CODMn, and ammonia nitrogen was about 1.03 NTU, 85%, 72%, 39%, respectively. And residual iron ion met the national standard requirement. Comparing with two kinds of coagulant sold, the author found that these three coagulants could obtain well effect On the removal of turbidity,and the result was PAC > PFTS > PFS on the specific. While self-made PFTS had the best effect on the removal of organic matter.