[The Preparation and Characterization of a New Solid Coagulant: Polymeric Ferric Silicate Sulfate].

As one of the most important water treatment agents, polysilicate coagulant, has been playing an important role in coagulation- flocculation, but it is prone to lose stability due to self-polymerization and the forming of silica gel. Therefore, research on the preparation of stable polysilicate coagulant has attract great attention. A new method to prepare a stable polysilicate coagulant (PSPF), was proposed in this paper.

[Determination of cationic degree in PDA with near infrared reflectance spectroscopy].

Cationic degree has been investigated as an important factor in polyacrylamide materials. Diallyl dimethyl ammonium chloride and acrylamide (PDA) was grafted by free radical polymerisation of acrylamide monomer (AM) onto the cationic monomer dimethyl diallyl ammonium chloride (DMDAAC). In the present study, near infrared reflectance spectroscopy (NIRS) was used as a rapid and accurate method to determine the cationic degree in the PDA.

[Determination of acrylamide in PDA with near infrared reflectance spectroscopy].

In the present study, near infrared reflectance spectroscopy(NIRS) was used as a rapid and accurate method to determine the residual of acrylamide monomer in the product of diallyl dimethyl ammonium chloride and acrylamide. In this experiment 38 products were used which were self-prepared in the laboratory, then near infrared spectra of the product were scanned, seven bands were selected, the characteristic peaks of each band were used as the independent variables, and the absorption peak was used as the dependent variable, using partial least squares (PLS) method to establish the mathematical conversion near infrared reflectance spectroscopy (NIRS) calibration model. In the analysis of the spectrum, using wavelet analysis as the method of reducing the noise of spectrum, and with comparison of the simulated value and measured value, the measured value was determined by using UV spectrum, the external validation determination coefficient was found to be 0.