Study On Treating The Coking Waste Water By Flocculation-absorption Process

Coking Waste water is formed in the process of caol in high-temperature pyrolysis, gas purification and chemical products refining. This Waste water containing tar, phenol, ammonia, cyanide, benzene, quinoline and indole dozens of other pollutants, it is very complex and is high concentrations of pollutants, it is color, toxicity and stable, after biological treatment, there are still a large number of non-degradable organic pollutants, it is a typical example of intractable industrial wastewater.Currently, the domestic wastewater treatment including biological treatment, flocculation, activated carbon adsorption treatment and Wet oxidation treatment and so on. Among them, the coking wastewater after a separate biochemical processing and flocculation treatment is often excessive color, it is difficult to satisfy the wastewater discharge standards, and the catalytic oxidation process is expensive.We adopt the flocculation-adsorption to treat Coking Waste water. The experiment chooses three kinds of flocculants, which is Polyaluminium Chloride(PAC), Polyferric Sulfate(PFS) and Polyacrylamide(PAM). The Adsorbent is activated carbon fiber. Then we adopt the flocculation-adsorption to treat Coking Waste water, experiments on the influence of pH, the addition of coagulate, coagulant kind and the addition of actived carbon fiber and so on.The result shows that pH in PFS flocculation is about 5, the best dosage is about 800mg/L, the best pH in PAC flocculation is about 8, the best dosage is 1500mg/L, the best dosage of PAM+PFS is 15mg/L+800mg/L, and the PAM+PAC is 20mg/L+1500mg/L, in activated carbon adsorption the best dosage is between 3g/L and 5g/L. Adopt the method of flocculation-absorbtion to deal with the Coking Waste water, the removal of turbidity is 95.03%, the removal of chromaticity is 100%, and the removal of NH3-N and CODcr is 95% and 87.32%. After treatment, the wastewater becomes clear and can be recycled.