TY - JOUR
T1 - Energy and carbon footprint analysis of municipal wastewater treatment process integrated with food waste disposer
AU - Guan, Jianyu
AU - Zhuang, Huichuan
AU - Lau, Chun Yin
AU - Leng, Ling
AU - Yeung, Chi Shun
AU - Vuppaladadiyam, Arun Krishna
AU - Wang, Huaimin
AU - Tse, Ho Yin
AU - Leu, Shao Yuan
N1 - Funding Information:
The authors thank for the financial supports from the Hong Kong Drainage Services Department (DSD, ST1/LS/10/2018), General Research Fund (RGC/GRF 15212319) from the Hong Kong Research Grant Council, Environment and Conservation Fund (ECF 102/2021), Seed Fund Scheme of Guangdong-Hong Kong-Macau Joint Laboratory for Environmental Pollution and Control, and Research Institute for Future Food (RIFF, 1-CD53) of the Hong Kong Polytechnic University. The authors also thank Mr. W.S. Lam, Mr. Y.H. Chan and Ms. Ying Che in the Water and Waste Analysis Laboratory for sample analysis.
Funding Information:
The authors thank for the financial supports from the Hong Kong Drainage Services Department (DSD, ST1/LS/10/2018 ), General Research Fund ( RGC/GRF 15212319 ) from the Hong Kong Research Grant Council, Environment and Conservation Fund ( ECF 102/2021 ), Seed Fund Scheme of Guangdong-Hong Kong-Macau Joint Laboratory for Environmental Pollution and Control , and Research Institute for Future Food (RIFF, 1-CD53 ) of the Hong Kong Polytechnic University. The authors also thank Mr. W.S. Lam, Mr. Y.H. Chan and Ms. Ying Che in the Water and Waste Analysis Laboratory for sample analysis.
Publisher Copyright:
© 2022 Elsevier Ltd
PY - 2022/11/15
Y1 - 2022/11/15
N2 - Household food waste (FW) management has become an emerging environmental issue affecting sustainable urban development. The application of in-sink domestic food waste disposers (FWDs) have brought significant public attentions due to its simplified waste handling process and reduced household expenses. However, the potentail negative impacts of mixing FW in the sewer system, i.e., the reduction of aeration efficiency in wastewater treatment processes (WWTPs) and corresponding increase of greenhouse gas (GHG) emission, has not been quantified. In this study, real-time oxygen transfer efficiency in processing water was measured in WWTPs receiving negligible amount of FW and compared with those receiving sewage combined with FWD effluent. WWTP receiving sewage with FW had 6–10% lower oxygen transfer rate than those without FW, resulting in extra energy consumptions of 0.25–0.30 kWh/m3 and GHG emissions of 0.35–0.41 kg CO2/m3. For estimating the substantial impacts of FWD to the carbon cycle, sludge treatment scenarios were designed among anaerobic digestion (AD), incineration, and direct landfill disposal. Compared with AD (−0.07 kWh/kg) and incineration (0.112 kWh/kg), FWD/WWTP consumed more energy (0.69–0.9 kWh/kg) and most of which (∼64%) was required by aeration. The operating costs of WWTPs also increased by 1.6–2.1 times in comparison with those did not receive FW. The application of FWD, however, could reduce the overall GHG emissions by 35.2% in comparison with direct landfilling. Decision-makers should guide householders and waste management practitioners through new policies such as carbon credits and/or waste charging scheme to support more environmental-friendly disposal methods of FW, especally when the maturity of socio-economic conditions are of concerns. Compared with AD and incineration, FWD may be a compromising alternative to control GHG emissions with existing wastewater treatment facilities especially to those regions where complete FW classification and treatment are not well-established.
AB - Household food waste (FW) management has become an emerging environmental issue affecting sustainable urban development. The application of in-sink domestic food waste disposers (FWDs) have brought significant public attentions due to its simplified waste handling process and reduced household expenses. However, the potentail negative impacts of mixing FW in the sewer system, i.e., the reduction of aeration efficiency in wastewater treatment processes (WWTPs) and corresponding increase of greenhouse gas (GHG) emission, has not been quantified. In this study, real-time oxygen transfer efficiency in processing water was measured in WWTPs receiving negligible amount of FW and compared with those receiving sewage combined with FWD effluent. WWTP receiving sewage with FW had 6–10% lower oxygen transfer rate than those without FW, resulting in extra energy consumptions of 0.25–0.30 kWh/m3 and GHG emissions of 0.35–0.41 kg CO2/m3. For estimating the substantial impacts of FWD to the carbon cycle, sludge treatment scenarios were designed among anaerobic digestion (AD), incineration, and direct landfill disposal. Compared with AD (−0.07 kWh/kg) and incineration (0.112 kWh/kg), FWD/WWTP consumed more energy (0.69–0.9 kWh/kg) and most of which (∼64%) was required by aeration. The operating costs of WWTPs also increased by 1.6–2.1 times in comparison with those did not receive FW. The application of FWD, however, could reduce the overall GHG emissions by 35.2% in comparison with direct landfilling. Decision-makers should guide householders and waste management practitioners through new policies such as carbon credits and/or waste charging scheme to support more environmental-friendly disposal methods of FW, especally when the maturity of socio-economic conditions are of concerns. Compared with AD and incineration, FWD may be a compromising alternative to control GHG emissions with existing wastewater treatment facilities especially to those regions where complete FW classification and treatment are not well-established.
KW - Aeration efficiency
KW - Food waste
KW - Food waste disposer
KW - Greenhouse gas emission
KW - Sewage treatment system
UR - http://www.scopus.com/inward/record.url?scp=85138477311&partnerID=8YFLogxK
U2 - 10.1016/j.jclepro.2022.134063
DO - 10.1016/j.jclepro.2022.134063
M3 - Journal article
AN - SCOPUS:85138477311
SN - 0959-6526
VL - 375
JO - Journal of Cleaner Production
JF - Journal of Cleaner Production
M1 - 134063
ER -