ApplicationNo.: 2007 100250 17.2 Application Date: July 2007-10.
The invention discloses an aluminum sulfate-polydimethyl diallyl ammonium chloride composite coagulant and a preparation and use method thereof. The preparation method of coagulant is to put aluminum sulfate dry powder or solution in a mixing kettle, add water and stir to form a solution; Stir AS solution at room temperature or heating, and add PDMDAAC colloid or dry powder; Stirring or heating at room temperature until the PDMDAAC colloid or dry powder is completely dissolved to obtain a stable aluminum sulfate-polydimethyl diallyl ammonium chloride composite coagulant. Its application is to dilute or directly add aluminum sulfate-polydimethyl diallyl ammonium chloride composite coagulant in any proportion with water, which is used for the treatment of various raw water and wastewater and the dehydration of sewage and sludge. The invention has clear composition and structure, controls the impurity content, can replace aluminum sulfate to reduce the use cost of the medicament, strengthen the coagulation effect and improve the effluent quality. The composite coagulant can be stored at room temperature for a long time without changing its application performance and its performance is stable.
Applicant: Nanjing University of Science and Technology.
Claim: 1, an aluminum sulfate-polydimethyl diallylammonium chloride composite coagulant, which is characterized by being prepared by the following steps: (1) putting aluminum sulfate dry powder or solution in a mixing kettle, adding water to make aluminum salt, and the AS content is1.5% ~1/based on the mass fraction of Al2O3. (2) stirring the AS solution at room temperature or under heating conditions, and adding polydimethyl diallylammonium chloride (PDMDAAC) colloid or dry powder with intrinsic viscosity of 1.0 ~ 4.7 dl/g, so that the mass ratio of AS to PDMDAAC in the mixed solution is 20.0:1~ 2.0:1; (3) stirring or heating at room temperature until the PDMDAAC colloid or dry powder is completely dissolved to obtain a stable aluminum sulfate-polydimethyl diallyl ammonium chloride composite coagulant.