Research And Application In The Process Of Pulp And Paper Wastewater With Modified Fenton+Multi-level Gradient Flocculation Advanced Treatment

Pulp and paper industry is one of the most serious polluted wastewater vocation.With the improvement of environmental quality requirement, high pollution and high use of water has restricted the development of pulp and paper industry. Technology research of high efficiency and low energy expenditure is in demanded for the healthy development of pulp and paper industry.This paper mainly treated the papermaking wastewater deeply with the technique of "modified Fenton+flocculation of multi-level gradient ".the research manily include: the modified Fenton technology research; technical research of multi-level gradient flocculation process; pilot study on deep treatment of wastewater in the pulp and paper; the demonstration project design of deep treatment of wastewater in the pulp and paper; research on the treatment effects of advanced treatment of wastewater in the pulp and paper. The study conclusions indicated that:(1) adjusted the pH in the process of Fenton reaction with waste acid generated from the process of titanium dioxide production by using ultraviolet lights. This principle is to improve the oxidation reaction of Fenton through the catalytic effect of Titanium dioxide obtained from waste acid waste acid residual to ultraviolet lights.(2) the effect whether in the results of CODCr and color processing or in the amount of dosage volume and sludge production in the advanced treatment process of pulp and paper wastewater was better compared with the coagulation process, it can not only achieve good results, but also save treatment and after-treatment cost realizing a win-win situation of the economic and environmental benefits in line with current policy and social needs of environmental pollution prevention and control in China.(3) pilot test results showed that it was feasible to use the process of modified Fenton redox+multi-level gradient flocculation to treat the papermaking wastewater advanced since the effluent COD stabilized unde the value of40mg/L and its chrominance was less than10times. According to papermaking test proved, the effluent used in the papermaking did not affect the paper whiteness, while the breaking length increased.(4) According to the running situation of demonstration project, it maintained strong anti-shocked property as its water quality stabilized in case of a severe influent fluctuation situation. The effluent CODCr was from38to60mg/L, chrominance was from10to20times and SS was for0～30mg/L.The treatment efficiency of " modified Fenton+flocculation of multi-level gradient " process was studied on the basis of the pulp and paper wastewater quality characteristics. A maturity and reliable pulp and paper wastewater treatment process was formed.This process provided a technical support for the discharge standards of national pulp and paper wastewater (GB3544-2008).and laid a solid foundation for the healthy development of pulp and paper industry.