Study On Microwave Synthesis Of Starch Flocculant, Properties And Characterization

After cellulose output, starch is the most fruitful saccharide compounds in nature, is a source of rich renewable resources, development starch flocculant is a set of environmental protection and the increase of starch emerging the effective way. Value Microwave technology with its energy-saving, clean, simple etc, and has been applied in some high polymer and biological synthesis reactions, for starch flocculant research provides a new direction.Using GTA as etherifying agent and phosphate (Na2HPO4·12H2O and NaH2PO4·2H2O press mixing ratio), using corn starch as raw materials, instead of traditional baths with microwave heating, use the oven and heating dry process two step synthesis with high-substitute degree amphoteric starch. The amphoteric starch structure was characterized by IR, And with heavy metals and organic pollutants, studies its goal of adsorption performance.Synthetic experiment results indicate that the cationic starch for optimum reaction conditions is lOg in starch, etherifying agent 1.5 g, NaOH 0.5 g, microwave power is 480W, the response time of the power of 5min, the products of cationic substitution degree can achieve 0.25; The optimum reaction conditions for amphoteric starch were determined: phosphate/cationic starch= 2.0, microwave power for 600W, reaction time for 6min, we can produce amphoteric starch of DSa=0.22.Wastewater treatment process experiment was studied among methyl violet wastewater, phenol wastewater, copper ions wastewater and lead ions wastewater. The results show that amphoteric starch on dye decolorization, COD removal all has good effect, at the same time for heavy metal ions Cu2+, Pb2+ all have good adsorption effect. When pH = 11, amphoteric starch dose quantity of 0.3 g/L, For 50mg/L of concentration of methyl violet simulation wastewater removal rate can amount to 94.91%; Dosing quantity for 200mg/L COD removal rate of can reach 84.52%; In pH= 5, dosing quantity 400mg/L, for Initial concentration of 50mg/L the copper simulation wastewater heavy metal ions Cu2+ removal rate can amount to 61.83%; In PH= 6, dosing quantity 100mg/L, the adsorption efficiency of heavy metal ions Pb2+ reached up 99.94% for Initial concentration of 50mg/L the lead simulation wastewater.Infrared characterization of experimental results show that cationic starch and amphoteric starch with quaternary ammonium salt groups and phosphate group, the more important is also has starch carbon skeleton structure, it shows the starch after reaction with its specific functions and did not produce new substances in water treatment easily degraded, is a kind of new environment-friendly flocculant.The experimental results shows that microwave radiation technology could greatly decrease the reaction time and energy consumption of the reaction, improve the reaction rate. To a certain extent, microwave techniques will provide a new path for synthesis of natural organic polymer modification of flocculants.