Synthesis And Application Of Surface Modification Of Attapulgite And Its Polymer Composite Floculant, Assistant-coagulate

This thesis reviewed the research progress and development trends of flocculants based on polyacrylamide and surface modified Attapulgite as assistant-coagulate. According to the principle of the combination chemistry, carrying out the synthesis and characterization of Attapulgite graft flocculants based on polyacrylamide (ATT-g-PAM), modified Attapulgite hybrid flocculants based on polyacrylamide (ATT/PAM), and surface cationic Attapulgite (cation-ATT)which is use to assistant-coagulate. In order to remove COD, SS and turbidity presented in wastewater at the same time. While the relationship between composition and structure, the structure and properties of the resulting Attapulgite composite flocculants have been studied by the flocculating and adsorbtion experiments of wastewater.The thesis is mainly composed by following three parts:Partâ… The Attapulgite graft flocculants based on polyacrylamide(ATT-g-PAM) were synthesized by graft polymerization of acid-activive Attapulgite particles graft acrylamide in water solution. The process of composite reaction and polymerization was carried out using a complex initiation system of NNK. FT-IR spectrum of the resulting ATT-g-PAM flocculant showed that there are chemical bonds between Attapulgite particle and polyacrylamide chain. The morphology of Attapulgite particles and their dispersion in the PAM was analyzed by TEM and SEM. It was found that the Attapulgite particles could be homogeneously dispersed in the PAM. The results showed that the ATT-g-PAM composite flocculant hold excellent aging resistance property comparing to the PAM, and flocculating properties for wastewater from glutin, the ratios of removal Turbidity value and CODcr were 98.5% and 60.5%.Partâ…¡The modified Attapulgite hybrid flocculants based on polyacrylamide (ATT/PAM) was synthesized by in-situ composite reaction of Attapulgite particles modified in polymerization of acrylamide in water solution. The process of composite reaction and polymerization was carried out using a complex initiation system of NNK. FT-IR spectrum of the resulting ATT/PAM flocculant showed that there are chemical bonds between Attapulgite particle and polyacrylamide chain. The morphology of Attapulgite particles and their dispersion in the PAM was analyzed by TEM and SEM. It was found that the Attapulgite particles could be homogeneously dispersed in the PAM. TGA analysis indicates that the heat stability of hybrid flocculant was higher than that of the PAM. The ATT/PAM hybrid flocculant hold excellent flocculating properties for wastewater from glutin, the ratios of removal Turbidity value and CODcr were96.3% and 62.4%.Partâ…¢The assistant-coagulate of surface cationic Attapulgite (cation-ATT) was synthesized by organic-inorganic reaction. The cation-ATT cation-ATT hold excellent flocculating properties for wastewater from glutin, the ratios of removal Turbidity value and CODcr were98.6% and 58.4%.