Study On The Phenol 、NH₄⁺-N And NO₃^--N Degradation By Electrochemical- Biofilm Coupling Technology

The study of phenolic wastewater treatment has been a hot topic in the field of environmental engineering for a lot of researchers because the phenolic compounds have a serious impact on the human body, animals and plants and the ecological environment. Electrochemical-biofilm coupling technology, with the characteristics of simple equipment, high efficiency, low operation cost, has broad application prospects in the field of industry wastewater treatment.In this paper, the promoting effect of initial phenol concentration, electric voltage,electric field intensity and electrolysis time on phenol degradation was investigated in a biofilm reactor affected by induced electric field. The results showed that: the degradation rate of phenol was related to above mentioned factors in the “induced electric field”-biofilm reactor. However, compared with biofilm reactor, the treatment efficiency dropped with adding the induced electric field. Meanwhile, the result in this reactor is also quite different from that in electrochemical-activated sludge reactor.Finally, we can see that electric field treat the microbial community with different growth patterns, such as fixed growth and suspended growth in different ways, along with the difference between charging process and discharging process.Then, the treatment of phenol, ammonia nitrogen and nitrate nitrogen in simulated wastewater was carried out by using the electrochemical-cathode biofilm reactor. In this new reactor, the influence of electric voltage, electrolysis time and microbial growth state on phenol and NO3- degradation was detected and finally the optimal processing conditions for the coupling technique was optimized. From the result it is seen that:compared with the “induced electric field”-biofilm reactor, the treatment effect has been improved significantly in this new reactor, along with lower operating voltage and more energy saving. The cause of this phenomenon may be closely related to the effect of theelectric field in the two reactors, and also related to the transformation process of the electron in the pollutant : in the “induced electric field”-biofilm reactor, microorganisms can not directly use the power of the transmission of electronic; microorganisms can be directly used for the continuous flow of electronic in the electrochemical-cathode biofilm reactor.At the same time, specific oxygen uptake rate(SOUR), the damage of cytomembrane and the concentration of EPS, protein and polysaccharide was discussed to investigate the effect on microbial community.