Research On Catalyzed Iron Inner Electrolysis Technique Pretreating Dyeing Industry Wastewater & Later Biological Treatment Technique

Iron inner electrolysis technique was widely used to treat dyeing industry wastewater. In order to overcome the disadvantage of iron inner electrolysis technique, many catalyzer mixed with iron and the running ways of technique were changed. This is catalyzed iron inner electrolysis technique. To deeply discuss the effect of treatment dyeing industry wastewater, the catalyzer, the running parameter and the mechanism of catalyzed iron inner electrolysis technique, the bench-scale and pilot-scale experimentation were done in shanghai Taopu industrial wastewater treatment plant and Shandong Huafang limited company wastewater treatment center.Firstly, the static state and bench-scale experimentation were done to study on the catalyzer and running ways. Aiming at the characteristic of dyeing industry wastewater -high pH , high chroma and high COD, On the basis of prophase production, Fe as reaction materials , Cu and C and Sn etc as catalyzer , the contradistinctive trial were done to increase the efficiency of catalyzed iron inner electrolysis technique;the influence of the parameter of technique by inflow pH was study in experimentation;The diverse running ways were compared to aggrandize the kind of removal mechanism.Catalyzed iron inner electrolysis technique and later biological treatment technique were studied through treating main kinds of dyeing industry wastewater. The results of experimentation shows that it is effective to treat dyeing wastewater , general dyeing industry wastewater, faded slurry wastewater and outflow of settling tank. For alkalescent dyeing industry wastewater, HRT of the catalyzed iron inner electrolysis technique isn't less than 3.0h, HRT of biological treatment technique is 24h, while the biodegradability and the removal of chroma are obviously increased. The removal efficiencies of chroma, COD and PO₄³- were 81.5%, 78% and 97% respectively. The concentration of total of Fe is less than 0.5 mg/L. Catalyzed iron inner electrolysis technique is also effective for faded slurry wastewater. While the pH of inflow is 6.0, the removal efficiency of COD is 40% after iron bed. The final removal efficiencies of COD and SS are 89%,95%respectively.The influence of the Catalyzed iron inner electrolysis technique to latter biological treatment was studied in this experimentation. This research concluded the role of biology in reactor and the forming of extracellular polymeric substances (EPS). The results of experimentation shows that the kinds and amount of microorganism was steady though iron was constantly consumed, and the iron reactor had the inner condition of biodegradability.The results of the contradistinctive trial show that it is advantageous for distilling EPS when there are lots of Fe ions in EPS. The new iron ions could improve the hanging film of carriers. Whether there is iron ion in waste water or not , the content of EPS is 46.1 mg/g, 17 mg/g respectively, the former is more the latter than 29 mg/g . As a annectent matter, large numbers of iron ion was adsorbed in EPS. That not only accelerated the forming of bioflim, but also largely changed the equipotential point of amino acid in bioflim. So the content of protein and enzyme are added and the removal of ability is consolidated. The results of contrastive experiment show that glucide degradability is faster than protein. The degradability velocity of former is as 3 times fast as the latter. After 3h, the concentration of iron ion was steady, but the consume of protein was added. It is obvious that glucide of EPS was consumed most easily, thus created the fall off of biofilm.To deeply discuss the effect of the Catalyzed iron inner electrolysis technique treating dyeing industry wastewater, and solve the problems of project, the pilot-scale experimentation was done in the plant. The concept of cell colander was introduced in project. Many problems of project were studied in experimentation to ensure the uniformity and intension of current, which concluded the ways of inflow and running. The pipe of discharge sludge was fixed in the bottom of iron reactor. Batch inflow and excessive aerating activated lots of iron. To increase the biodegradability, the running ways of the Catalyzed iron inner electrolysis technique adopt circle by pump or faint aerating, or else it is harmful to the biodegradability. Contrast to the bench-scale experimentation, the period of iron bed is shorter. When the reaction ability is depressed, it is good effect to aerate and ensure that pH of wastewater is 6.0-7.0.In pilot-scale experimentation, the applying of the Catalyzed iron inner electrolysis technique to the reuse of wastewater in dyeing industry plant was deeply discussed.Finally, according to the results of pilot-scale experimentation and the fact of wastewater treatment center, the reconstruct project was brought forward. After discuss, the project is feasible, and there are lots of benefit of society and economy.