Research On MWCNT Modified Electrode Degrading Biochemical Treated Coking Wastewater

Biochemical treated coking wastewater containing a number of refractory organic pollutants is a big threat to the environment. The electrochemical treatment with the advantages of mild conditions, simple operation, compatibility with the environment etc, is an advanced oxidation technology with great potential. Seeking proper electrode material and suitable treatment helps to increase the electrocatalytical activity as well as improve long-term stability.In this dissertation, biochemical treated coking wastewater was taken for analysis. GC/MS was used to carry out the organic compositions in waste water. On this basis, a kind of modified electrode with higher over potential was proposed. Typical oxide was chosen to modify the electrode. A designed electrode with metallic oxide and commercial electrodes were compared to prove the design idea. Study on aniline's degradation mechanism further proved that metallic oxide modified electrode was effective in treating refractory organics.Carbon nanotube modified electrode using for refractory pollutants treatment was studied. Two kinds of carbon nanotube modified electrode based on organic and inorganic were proposed. The CNT modified electrode was proved effective by experiment. Process scheme for a kind of electrode device was proposed to provide reference. Besides, for the need of scale and low cost, transfer after absorption on activated carbon fibers was proposed. The absorption and desorption of ACF were studied systematically.The results showed that coking wastewater contains a lot of organic compounds such as polynuclear aromatic hydrocarbons, heterocyclic compounds , phenolic compounds etc. Compared with commercial electrodes, the designed metallic oxide modified electrode had a higher degradation rate of coking wastewater, and it also degraded the benzene ring structure in aniline after a time of electrolysis. After an electrolysis for 120min, PTFE-CNTs modified electrode decreased COD of the waste water for 51%. The PTFE-CNTs modified electrode showed high electrochemical reactivity of phenol and aniline with reaction peaks of 0.12A and 0.18A. Electrochemical degradation is the major fact of the degradation of organic pollutants. Mechanical milling made CNTs evenly dispersed in sodium silicate. Clusters and winding were decreased. Etching process exposed CNTs on the surface of the electrode. Fractures and dislocations may become sensitive positions of the electrode.ACF showed high adsorption rate for aniline and quinoline. Adjusting pH and electrochemical desorption both presented good effect in regenerating ACF.