Research On The Preparation Of The Copper-Zinc-Polysilicate And Its Application In Treating Making-paper Wastewater

Copper-Zinc-polysilicate coagulant is a new type of inorganic polymer flocculants; it's made up by adding copperion and zincion into polysilicate-sulfate, and it has not only the property of electricity neutralization of copper and zinc, but also the property of adsorption and framing of polysilicate-sulfate.The process of developing PCZSS is as follow. At first, prepare the sodium silicate solution in a definite concertration, then add the zinc(â…¡) sulfate and copper(â…¡) sulfate after the solution polymerizing in acid condition for a certain time, and then the polymerization can reach an available polymeric degree in this reaction after a period of aging time. In this work, several variables that affect PCZSS flocculation capability have been studied. Particularly, the effect of pH of the solution,the sodium silicate concentration,copper(â…¡) ion and zinc(â…¡)ion concentration,the mode of adding chemical and the adding chemical amount have been considered.In the process of paper-making wastewater treatment by flocculating, stirring rate and time, pH value, temperature and quantities of flocculation all influent the result of flocculating. At the optimum condition, CODCr of paper-making wastewater can be reduced to about 202mg/L from 1750mg/L, and turbidity reduced to about 0 NTU from 228NTU, it conform to the first rate standard of discharging. By contrast experiment we can know that the application scope of PCZSS is wider. Temperature effect lower to the CODCr but higher to the turbidity removal ratio, moreover the quantities of PCZSS is needed lesser.PCZSS'capability was evaluated in the treatment of paper-making wastewater through the comparison between PFZSS,PFSS,PZSS according to the flocculation result comparison experiment,the turbidity removal result comparison experiment.These experiments indicate that PCZSS has some advantages for wastewater treatment. On one hand, PCZSS not only has the characters of general flocculants such as electric charge neutralization and linkage of the...