The Research About A New Kind Of Flocculant For Paint Wastewater Treatment

With the development of the technology of modern painting, the dosage of spray paint is increasing. If the wastewater containing paint of paint spraying process were not properly solved, it would heavily pollute the atmosphere around and environment. Adding high-efficiency flocculating agents to the circulate water, can effectively solve the above-mentioned problem. Quaternary ammonium cationic starch can keep cationic state in acidic, neutral or alkali conditions. As for its ascendant performance, quaternary ammonium cationic is applied to papermaking, textile industry, oil field, mining, water treatment and other industries extensively. The research focus in the field of cationic starch are the development of new cationic reagent of quaternary ammonium cationic starch, the improvement of synthesis process, the expansion of the application field, and so on. As a kind of liner polymer, APAM has negative groups (-COONa) and positive groups (-CONH2), can adsorb and bridging these suspended particles scattered in solution. As for the effect of flocculation, APAM are widely used in water treatment and metallurgy, paper making, petroleum, chemical industry, textile, mineral processing, and so on.In this thesis, we prepared a new kind of flocculant for wastewater containing paints, using high DS quaternary ammonium salt cationic starch as detackifier and using high molecular weight anionic polyacrylamide as floatation agent. First of all. high DS cationic starches were prepared using etherifying reagent,3-chloro-2-hydroxyl propyl three methyl ammonium chloride (CTA), by hemi-dry process. And the cationic starche were mixed with Arabic gum and polymerization (PAC). Then, acrylamide was chosen as the experiment’s raw materials for its extensive sources and low prices. Synthetized high molecular weight anionic polyacrylamide by dual water phase synthesis. Finally, we chosed two waterborne paints to test the performance of self-prepared flocculant, while compared with the performance of a kind of traditional flocculant.During our experiment, the resulting polymers were characterized by infrared spectroscopy (FT-IR), Kjeldahl nitrogen analyzer, scattering turbidimeter, Chemical oxygen demand (COD) speed measuring devices, rotating viscometer and other means. Experimental results show that we set up the optimum synthesis conditions via a series of orthogonal tests. (1)The synthesis of etherifying agent:n(NMe3·HCl):n(ECH)=1.2:1, reaction temperature was40℃, reaction time was4h, c(NMe3·HCl)=60%.(2) The optimum proportion of detackifier:The mass fraction of cationic starch was1%, Arabic gum was5%, and PAC was50%.(3) The optimum synthesis conditions of anionic polyacrylamide:APS/NaHSOs0.01/0.05%, MBA=0.03%, CTA=0.01%, reaction temperature was50℃, reaction time was2.5h, m((NH4)2SO4)=10g, m(PVP)=1.0g. The final testing of flocculation effects show that, just as50%-70%dosage as traditional flocculation agent (SM-9920series), the homemade flocculant can achieve a similar effect.