Research On The Carbon And Nitrogen Removal Of The Advanced Treatment Of Printing And Dyeing Wastewater By Iron Carbon Micro Electrolysis-Biological Coupling Process

Printing and dyeing wastewater has the characteristics of large amount of water, high strengthand complicated compositions, high turbidity, deep color and high pH value, which belongs totypical refractory industrial wastewater. At present, the majority of printing and dyeingwastewater using biological treatment process such as A/O and A/A/O, it is difficult to reach thefirst discharge standard and sometimes it can not reach the second emission standards. At the sametime, with the continuous progress of printing and dyeing technology, new dyes and dyesintermediates continue to occur, resulting in ammonia nitrogen exceeding standard. On the otherhand, with the continuous improvement of the national energy saving and emission reductionrequirements and the increasing attention to the environment, the emission standards ofwastewater are also continuously improved.. Taking the main indicator COD as an example, theemission standards generally raised to the the first discharge standard A (50mg/L) and B (60mg/L)of the Discharge standard of pollutants for municipal wastewater treatment plant (GB18918-2002). For printing and dyeing enterprises, low cost of printing and dyeing wastewater dischargestandards of the problem to be solved, sewage treatment plant gradually eyes into the depth ofprocessing.In this paper, biochemical effluent from a printing and dyeing plant in Zhejiang province wasstudied as the research object, and the carbon and nitrogen removal of the iron carbon microelectrolysis-biological process was carried out. The optimum reaction conditions was studied foriron carbon micro electrolysis, iron carbon biological filter and anoxic tank.The main conclusionsof the research were as follows:(1) The study of the iron carbon micro electrolysis: the effect of the iron filling, Fe/C massratio, the DO, the pH value, the reaction time on the degradation of organic compounds wasstudied.. The research shows that the main effect of the Fe/C mass ratio is oxidation or reductionunder aeration condition.. When the carbon mass ratio is high, the oxidation reaction is the main and the carbon mass ratio is lower, and the reduction reaction is the main. Under the optimumoperating conditions, the iron carbon micro electrolysis can make the effluent COD reach60mg/Lbelow.(2) The experiments on reduction of toxicity studies and biochemical studies showed that,iron carbon micro electrolysis based on the open loop and chain breaking role, degrade toxicorganic compounds in the water, such as bisphenol A, carbitol etc., and make the wastewaterbiochemical improvement for the following biological nitrogen removal and provide a theoreticalbasis.(3) The iron ion was put into iron carbon biological filter, and to explore the effect of iron ionon microbial, studies have shown that, iron ion did not cause microbial iron poisoning, after6h ofaerobic nitrification,2.0h anoxic denitrification, the TN of35mg/L below9mg/L, the removalrate was up to75%.(4) Iron ion in the system has an important role. During the process of micro electrolysis, theorganic compounds were removed by disoxidation; in anoxic stage, the use of electronic transferto promote microbial denitrification rate, reduce the dosage of carbon source for denitrificationbacteria, the eventual formation of Fe(OH)3can accelerate the sludge settling velocity.(5) The OA process strengthen by iron has obvious removal effect for organic compoundscontaining carbonyl and hydroxyl.