活性污泥的光电化学特性及其光电反硝化潜力

Photoelectrochemical Characteristics of Activated Sludge and Its Potential for Photoelectrochemical Denitrification

为了深入了解活性污泥的光电化学特性及其光电反硝化潜力,以活性污泥为研究对象,分析了在不同光强下活性污泥光生电流的变化情况,以及在有无碳源、有无光照条件下污泥反硝化活性的响应。此外,通过双室光电反硝化试验进一步探究了活性污泥的光电反硝化能力,并利用三维荧光光谱(EEM)对胞外聚合物(EPS)和溶解性微生物产物(SMP)进行了分析。结果显示,活性污泥具有光电化学特性,且其光生电流能力与辐照强度呈正相关。在有碳源条件下光照反硝化速率达1.470 mg(/gVSS·h),显著高于无碳源无光照组[0.093 mg(/gVSS·h)]、无碳源有光照组[0.201 mg(/gVSS·h)]和有碳源无光照组[1.018 mg(/gVSS·h)]。在双室光电反硝化装置中,EPS和SMP被认为是光敏物质,其主要成分包括色氨酸、酪氨酸类蛋白质和胡敏酸类腐殖质,并验证了活性污泥的光电反硝化能力。

To gain a deeper understanding of the photoelectrochemical characteristics of activated sludge and its potential for photoelectrochemical denitrification,this paper conducted an analysis on the variations in photogenerated current of activated sludge under different light intensities,as well as the response of denitrification activity under conditions with or without carbon source and illumination.Furthermore,the photoelectrochemical denitrification capability of activated sludge was further examined through a two-chamber photoelectrochemical denitrification test,while extracellular polymeric substances(EPS)and soluble microbial products(SMP)were analyzed using excitation-emission matrix(EEM)spectroscopy.The activated sludge exhibited photoelectrochemical characteristics,and its ability to generate photocurrent was positively associated with the irradiation intensity.Under carbon source conditions,the photoelectrochemical denitrification rate reached 1.470 mg/(gVSS·h),which was significantly higher than that in the groups without both carbon source and illumination[0.093 mg/(gVSS·h)],without carbon source but with illumination[0.201 mg/(gVSS·h)],and with carbon source but without illumination[1.018 mg/(gVSS·h)].EPS and SMP were identified as photosensitive substances in the twochamber photoelectrochemical denitrification device,with their primary components being tryptophan,tyrosine protein,and humic acid.This finding confirmed the photoelectrochemical denitrification capability of activated sludge.