餐厨垃圾废水预处理发酵回收溶解性碳源的研究

Pretreatment of Kitchen Waste Wastewater and Recovery of Soluble Carbon Source by Fermentation

针对餐厨垃圾废水资源化利用的问题,分别采用烷基糖苷(APG)与游离型亚硝酸(FNA)对含有较高浓度乳酸的餐厨垃圾废水进行预处理后再进行产酸发酵回收碳源,考察了发酵过程中挥发性脂肪酸(VFAs)与乳酸浓度的变化。结果表明,APG最佳投加量为0.10 g/gTS,可使溶解性COD(SCOD)浓度提高38%;FNA的最佳投加量为1.66 mg/L,可使SCOD浓度提高26%。APG的主要作用体现在提高发酵液的SCOD浓度和产乙酸、丙酸菌活性,而FNA在提高发酵液SCOD浓度的同时还促进了乳酸积累。预处理可使溶解性碳源的反硝化潜能和速率均有所提升,而FNA预处理还可以减少发酵液作为外加碳源时的亚硝酸盐积累。

To recover resources from kitchen waste wastewater, the kitchen waste wastewater with high lactic acid concentration was pretreated by alkyl polyglycoside(APG) and free nitrous acid(FNA), respectively, and then the carbon sources were recovered by acidogenic fermentation. Variations in concentrations of volatile fatty acids(VFAs) and lactic acid during fermentation were investigated. The soluble chemical oxygen demand(SCOD) increased by 38% when the APG was added at the optimum dosage of 0.10 g/gTS, and SCOD increased by 26% when the FNA was added at the optimum dosage of 1.66 mg/L. The main role of APG was to increase the SCOD concentration in the fermentation broth and the activities of acetic acid producing bacteria and propionic acid producing bacteria, while the FNA improved the SCOD concentration in the fermentation broth and promoted the accumulation of lactic acid. The pretreatment increased the denitrification potential and rate of dissolved carbon source, while the FNA pretreatment reduced the nitrite accumulation when the fermentation broth was used as the additional carbon source.