Study On The Coagulate Thermodynamics Of Polysilicate Aluminium (Zinc) In Wastewater Treatment

This paper introduced different kinds of waste-water treating methods, the important of flocculate-sedimentation method in waste-water treating was introduced.The development of flocculent were also infered.Two inorganic macromolecule flocculants: zinc polysilicate(PSAZ) and aluminum polysilicate(PSAA) were prepared by adding metallic ion into polymeric silicic acid solution, respectively.From the thermodynamics point of view, the coagulate and dilute enthalpy of this two flocculants which used for treating the bentonite aqueous stocks were measured by means of SRC-100 under constant temperature 298K.The interacting energy between the flocculent and the bentonite particle is also calculated.The enthalpy value is in 5J. Meanwhile, the effects of some factors such as pH, nephelomete, mol-ratio on the enthalpy are studied using Uniform Design method.The complicated process of flocculation was studied by one hypothetical model which only contains chemical reaction. The remanet Al(III) or Zn(II) and silicate concentrations were analysised using spectrophotometer. On the basis equilibrium constants of the flocculation reaction and the Gibbs free energy as well as the variety of entropy are obtained according to the second thermodynamics law.According to this model, the Gibbs free energy of this process is positive,while the entropy is negative. This results are accord with the thermodynamics of flocculation process. It shows that the model reflected the...