苯酚对生物硝化过程的抑制

硝化细菌由于其特殊的生理生态特性,容易受环境因素和共存有毒有害物质的影响,使硝化过程不稳定,脱氮效率降低.采用批式试验,研究了苯酚对生物硝化过程的抑制效应.结果表明,苯酚对硝化有抑制作用,该抑制属非竞争性抑制,是可逆的.苯酚与2,4-二氯酚共存时产生叠加抑制效应.且抑制剂存在时,温度对硝化速率影响更大.因此含酚废水生物脱氮处理时需引起注意.

Phenol inhibition to biological nitrification process

Nitrifying bacteria are easily affected by the surrounding factors and toxic compounds due to their physiological and ecological characteristics. The nitrification inhibition will in turn influence the stability of nitrification process and reduces nitrification efficiency, which may confine the application of denitrification in industrial wastewater treatment. This paper aims to present the author's investigation into the nitrification inhibition of phenol by batch experiments, which can commonly be seen in the industrial wastewater with nitrifying bacteria enriched by the special cultural medium. The results indicate that the phenol concentration was 20 mg/L if calculated in the nitrification inhibition formula under the condition that the extent of inhibition was about 50%. Since the inhibition of phenol to nitrification is by nature non-competitive and reversible, the inhibition can be eliminated through washing and dilution. Furthermore, if the temperature coefficients of phenol are free and the phenol-contained (the extent of nitrification inhibition was 50%) nitrification reaction were 1.09 and 1.15 respectively. Nitrification rate will be more sensitive to temperature change in phenol-contained wastewater, and as a result, proper control of temperature can also promote the counteraction of the inhibition to some extent. In addition, it is also necessary to add heterotrophic bacteria in a specific proportion to pure the nitrifying bacteria, which may produce the similar effect because heterotrophic bacteria help to degrade the phenol and protect the nitrifying bacteria by floc. And finally, the coexistence of phenol and 2,4-dichlorophenol might probably result in the superposition effect. That is perhaps one of the reasons why the treatment efficiency of industrial wastewater be worsening in contrast to the municipal sewage. Thus the nitrification of the industrial wastewater should be paid more attention to.