| Phenols is a kind of persistence organic compounds which has the characteristicsof high biological toxicity, wide pollution surface, excessive emission and criticaldanger. They are widely used in the fields of coking, oil refining, synthetic resin and soon. Phenolic compounds can interfere with the reproduction of aquatic, damageagricultural production and affect the safety of drinking water. Therefore, the study ofphenolic wastewater treatment has been a hot topic in the field of environmentalengineering.Electrochemical-activated sludge coupling technology, with the characteristics ofhigh efficiency, easy to realize automation, low operation cost, has broad applicationprospects in the field of industry wastewater treatment. In this paper, the promotingeffect of electric field on phenol degradation was investigated by comparing the phenoldegradation rate of electrolytic process, active sludge method and electrochemical-activated sludge coupling method. The results showed that: compared with electrolyticprocess and activated sludge method, the phenol degradation rate of couplingtechnology increased by67.76%and87.81%respectively at the electric field intensityof4.0V/cm, electrolysis time of4.0h. While, the influence of electric field intensity,electrolysis time and initial phenol concentration on phenol removal was detected. Fromthe result it is seen that phenol was degraded quickly and efficiently byelectrochemical-activated sludge coupling technology and the degradation rate ofphenol was associated with both electric field intensity and electrolysis time. At theinitial phenol concentration of100mg/L, electric field intensity of4.0V/cm, electrolysistime of4.0h, the phenol removal rate of coupling system was95.55%. The possiblepathway of phenol degradation of electrochemical-activated sludge coupling system was put forward.At the same time, specific oxygen uptake rate(SOUR), settleability and the damageof cytomembrane was discussed to investigate the effect of electric field intensity,electrolysis time and initial phenol concentration on microbial community. Resultsshowed that electric field with appropriate intensity can promote the bioactivity ofactivated sludge and improve the defense capability of microbial to toxic substances,while electric field with high intensity will be harmful to the microbial.Combined the effects of electric field intensity, electrolysis time and the initialphenol concentration on phenol degradation rate with the SOUR of activated sludge, theoperating conditions of the electrochemical-activated sludge coupling technology wasput forward to provide experimental basis for the risk management of microbes to toxiccompounds in the practical wastewater treatment process. |
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