基于UASB反应器构建苯酚反硝化系统及性能研究

Construction and Performance of Phenol Denitrification System Based on UASB Reactor

基于异养反硝化原理,探究了上流式厌氧污泥床(UASB)反应器中反硝化颗粒污泥在连续流运行条件下以苯酚为碳源处理含苯酚和硝酸盐废水的去除效果.研究结果表明,当碳氮比(C/N)为4.0,进水苯酚浓度为333 mg/L,硝酸盐(NO_(3)^(-)-N)浓度为200 mg/L,水力停留时间(HRT)为4.0 h,NO_(3)^(-)-N和苯酚去除率均可达99.5%,化学需氧量(COD)去除率达95.3%.苯酚浓度(0~333 mg/L)的增加会刺激胞外聚合物(EPS)的分泌并且蛋白/多糖(PN/PS)由0.28增加至1.17,促使污泥表面疏水性增加,为形成稳定的颗粒污泥提供可能.苯酚反硝化系统运行过程中三磷酸腺苷(ATP)浓度水平、细胞膜通透性、电子传递系统活性(ETSA)均有显著增加,ATP含量的逐渐增加说明反应器中的微生物一直具有良好的代谢活性,细胞膜通透性的增加使细菌更容易吸收营养物质,从而促进ATP的合成以提高代谢活性,ETSA的增加使微生物代谢活性增加有助于脱氮和苯酚生物降解.苯酚反硝化系统能以苯酚作为碳源且高效处理同时含苯酚和硝酸盐的废水,系统出水水质符合《城镇污水处理厂污染物排放标准》(GB18918—2002)一级A排放标准.

Based on the principle of heterotrophic denitrification,the removal effect of denitrification granular sludge in Up-flow Anaerobic Sludge Bed(UASB)reactor with phenol as carbon source for simultaneous treatment of phenol and nitrate wastewater under continuous flow was investigated.The results showed that when the C/N ratio(C/N)was 4.0,the influant phenol concentration was 333 mg/L,nitrate(NO_(3)^(-)-N)concentration was 200 mg/L,hydraulic retention time(HRT)was 4.0 h,the removal rate of NO_(3)^(-)-N and phenol could reach 99.5%,and the removal rate of chemical oxygen demand(COD)could reach 95.3%.The increase of phenol concentration(0~333 mg/L)could stimulate the secretion of extracellular polymeric substance(EPS)and increase the protein/polysaccharose(PN/PS)from 0.28 to 1.17,resulting in the increase of sludge surface hydrophobicity,which provided the possibility for the formation of stable granular sludge.Adenosine triphosphate(ATP)concentration level,cell membrane permeability and electron transport system activity(ETSA)increased significantly during the operation of phenol denitrification system.The gradual increase of ATP content indicated that the microorganisms in the reactor had good metabolic activity.The increase of membrane permeability made it easier for the bacteria to absorb nutrients,thus promoting the synthesis of ATP to improve the metabolic activity.The increase of ETSA spurred the metabolic activity of microorganisms,which contributed to nitrogen removal and phenol biodegradation.Phenol denitrification system can use phenol as carbon source and efficiently treat wastewater containing phenol and nitrate.The effluent quality meets the first-class A discharge standard of Pollutant Discharge Standard for Urban Sewage Treatment Plant(GB18918—2002).