Integrated food waste management with wastewater treatment in Hong Kong: Transformation, energy balance and economic analysis. (1st October 2020)

• Record Type: Journal Article
• Authors: Zan, Feixiang; Iqbal, Asad; Guo, Gang; Liu, Xiaoming; Dai, Ji; Ekama, George A.; Chen, Guanghao
• Is Part Of: Water research. Volume 184(2020)
• Publication Date: 2020-10-01
• Subjects: Wastewater treatment -- Food waste -- Plant-wide modelling -- Food waste disposer -- Solid waste; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2020.116155
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Diversion of food waste (FW) away from the solid waste stream into the wastewater stream is proved viable through the use of food waste disposers (FWDs). However, this may cause unwanted influences on the wastewater treatment system. In this context, this study has comprehensively evaluated integrated food waste and wastewater management on a city scale for the first time. A plant-wide COD-based transformation model was first established to assess the impacts of the use of FWDs on the networks of biological wastewater treatment plants (WWTPs) in Hong Kong. The biological WWTPs can remove about 78% of solids and 58% of chemical oxygen demand (COD) in FW. Moreover, the diversion of FW poses limited impacts on treatment capacity and effluent quality in WWTPs with the FWDs penetration rate up to 30%. The increases in energy consumption and operational cost are highly dependent on the treatment processes and the FWDs penetration rates, while municipal solid waste treatment can benefit from the diversion of FW. This study suggests that upgrading treatment processes (e.g., with less aeration) and optimizing the operation of WWTPs (e.g., reduce sludge retention time) may be required with the use of FWDs to achieve an energy-efficient and cost-effective goal. More importantly, this study not only provides a methodology for effectively evaluating the impacts of diverting FW into wastewater treatment in Hong Kong but also facilitates FW management in similar metropolises. Graphical abstract: Image 1 Highlights: A biological WWTP can remove 78% of solids and 58% of COD in food waste. FW diversion would require more efficient configuration and operation control of WWTP. Municipal solid waste management can benefit from the diversion of FW. The methodology can effectively assess the key impacts of FW diversion on a city scale.