Effects of ultrasound pre-treatment on the amount of dissolved organic matter extracted from food waste

• Published in: Bioresource technology 2014-03, Vol.155, p.266-271
• Main Authors: Jiang, Jianguo, Gong, Changxiu, Wang, Jiaming, Tian, Sicong, Zhang, Yujing
• Format: Article
• Language: English
• Subjects: Anaerobiosis; Biological and medical sciences; Biological Oxygen Demand Analysis; Fatty acids; Fatty Acids, Volatile - biosynthesis; Fermentation; Food; Food industries; Food waste; Foods; Fundamental and applied biological sciences. Psychology; Hydrolysis; Lipids; Oxygen demand; Proteins; Refuse Disposal - methods; SCOD; Sound; Sugars; Ultrasound; Use and upgrading of agricultural and food by-products. Biotechnology; VFAs; Waste Products - analysis; Wastes
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.12.064

•After ultrasonic pretreatment, the total production of VFA increased markedly.•Ultrasonic significantly increased the COD and protein of supernatant of food waste.•Ultrasonic increased the amount of reducing sugars dissolved out of food waste.•Ultrasonic markedly decreased the amount of fat dissolved out of food waste. This paper describes a series of studies on the effects of food waste disintegration using an ultrasonic generator and the production of volatile fatty acids (VFAs) by anaerobic hydrolysis. The results suggest that ultrasound treatment can significantly increase COD [chemical oxygen demand], proteins and reducing sugars, but decrease that of lipids in food waste supernatant. Ultrasound pre-treatment boosted the production of VFAs dramatically during the fermentation of food waste. At an ultrasonic energy density of 480W/L, we treated two kinds of food waste (total solids (TS): 40 and 100g/L, respectively) with ultrasound for 15min. The amount of COD dissolved from the waste increased by 1.6–1.7-fold, proteins increased by 3.8–4.3-fold, and reducing sugars increased by 4.4–3.6-fold, whereas the lipid content decreased from 2 to 0.1g/L. Additionally, a higher VFA yield was observed following ultrasonic pre-treatment.