Study On Three-dimension Electrode Bio-Electro Reactor For High Concentrations 2, 4-DNP Aqueous Wastes

The electrode bio-film process is a novel water-treatment technology, developedin recent years. It has the good effect in the treatment of ground water and drinkingwater polluted by low density of nitrate. By combining microbial treatment andbio-electro reactor (BER), we design a kind of three-dimension electrodeelectro-chemical bio-film reactor for simultaneous denitrification and 2, 4-DNPdegradation, and a kind of new technology named electrode bio-film process forwastewater treatment was developed.First, anaerobic sludge has been developed in a sequencing batch reactor (SBR)for 90 days by increasing concentrations of influent 2, 4-DNP and nitrate in step, anddominant culture was obtained. For the growth of bio-membrane, the microbe breedon the electrode in the BER were more slow than in the control reactor, but oncedomesticated maturely, it may use for long time. Furthermore, the amount ofmicroorganism on the bio-film in the BER is far more than that in the control reactor.These microorganisms are very tightness, and not precipitate easily.Second, the operational conditions and parameters of electrode bio-film processwere studied. When temperature was 25℃, electric current was 25mA, influent C/Nwas 3.4, HRT was 8 hours, the concentration of 2, 4-DNP in the polluted water wasnot more than 120 mg/L, the BER may satisfy the demand of simultaneousdenitrification and 2, 4-DNP degradation, and the remove ratio of CODer or NO₃^--Nmore than 90% above could be achieved.Thirdly, three kinds reactors have being designed, including three-dimensionalelectrode electro-chemical bio-film reactor, active carbon-active sludge reactor andactive sludge reactor. When the sludge domesticates maturely, we operated controltext on processing the waste-water under the optimized operational condition for thethree kinds reactors. The experimental result indicated that, compared with thecontrol reactor, the removal rates of CODcr and NO₃^--N in the BER improve 7.88%and 28.21% respectively. Thus, it shows that, the BER displays the remarkableadvantage in the ability of removing NO₃^--N.