Treatment And Utilization In Papermaking Wastewater

As to problem of low utilization value and cost experience in lignin in the papermaking wastewater teatrment, Treatment of papermaking wastewater with precipitation was studied. According to the basement of the experiment, treatment of papermaking wastewater with precipitation was proved as an effective separation method in papermaking wastewater. And the modification of lignosulfonate was studied in the article.The effects of pH-value, amount of precipitation reagent(Cca²⁺), temperature(T), and storing time(t) on lignosulfonates recovery from concentrated red liquor were discussed to determine the optimize conditions. And the mechanism of precipitation reaction was studied in the article. It was found that pH-value played an important role in complexing action between lignosulfonates and calcium. While the optimize conditions were obtained: pH=13, Cca²⁺=8g/L, T= 40℃, t=30min, and the precipitation capacity of lignosulfonate was 4.5g.According to thermogravimetic analysis and infrared spectrum analysis, the outlier and the lignosulfonate in sell were in similar structure. And the outliers were composed of a serial of molecular lignosulfonate. The sulfonation modification in lignosulfonate was studied in the article. The sulfonation process was determined by pre-oxidization and sulfonation process.The sulphoating agent was sodium and the oxidizing agent was potassium hypermanganate. In pre-oxidization, the effects of amount of the oxidizing agent, temperature (T), reaction time (t) were discussed to determine the optimize conditions. While the optimize conditions were obtained: amount of the oxidizing agent was 5%,T=90c,t=2h.In the sulfonation process, the effects of amount of the sulphoating agent, pH value, temperature(T), reaction time(t) were discussed to determine the optimize conditions. While the optimize conditions were obtained: amount of the sulphoating agent was 60%, pH=ll,T=90°C,t=3.5h.The corrosion inhibitor of lignosulfonate was studied in the article. According to binary-Multiplex experiment and orthogonal experiment, the formulation made. The ratio of Lignosulfonate: sodium: molybdate: sodium tungstate, zinc sulfate: thiocarbamide: Hexa-methylenetetraamine was. 1: 1: 0.6: 0.3: 0.8: 0.8: 0.4. According to Polarization behavior of steel in a simulated boiler solution experiment, the corrosion inhibitor was anode inhibitor compound. According to electrochemical impedance spectroscopy of steel in a simulated boiler solution, the results shown that the formulation inhibitor could resist corrosion.