Key Takeaways & Executive Findings
- •• • Hydrolysis-acidification of food waste yields net negative GHG emissions of -40.7 kg CO2-eq per tonne of food waste, outperforming incineration and anaerobic fermentation, making it a carbon-negative alternative for waste treatment. • • The process generates only 9.3% solid impurities requiring disposal, significantly lower than conventional methods, reducing landfill burden and operational costs. • • No additional wastewater treatment is required in the hydrolysis process, eliminating a major cost and environmental burden associated with other biological treatments. • • Sensitivity analysis shows that food waste moisture content critically affects solid impurity generation and energy recovery efficiency, indicating that feedstock variability must be controlled for optimal performance.
Abstract
The resource utilization of food waste contributes to reducing environmental pollution, driving nutrient cycling and biomass energy development, and promoting the resource recycling industry, achieving a win-win outcome for environment and economy. This study evaluated the resource recovery performance and environmental impacts of producing carbon sources for wastewater treatment through hydrolysis and acidification of food waste, comparing with two conventional alternatives: anaerobic fermentation and incineration. Results showed that among the three technologies, hydrolysis for carbon source production ranked middle in resource recycling efficiency, but its environmental benefits were superior to incineration and anaerobic fermentation. The hydrolysis process did not produce additional wastewater requiring treatment, and its greenhouse gas emissions and solid waste generation intensity were relatively low, at -40.7 kg CO2-eq/t and 9.3%, respectively. Carbon sources derived from food waste can replace commercial alternatives, reducing wastewater treatment costs and promoting synergies between pollution reduction and carbon mitigation. Sensitivity analysis revealed that water content in food waste significantly influences solid impurity generation and energy recovery efficiency of hydrolysis technology. In regions with high food waste generation and carbon source demand, hydrolysis technology is recommended to facilitate large-scale synergistic treatment of wastewater and food waste.
1. Introduction
Municipal solid waste management, particularly food waste, poses significant environmental and economic challenges in urbanizing China. Conventional treatment routes such as incineration and anaerobic digestion, while reducing waste volume, often entail high energy consumption, greenhouse gas emissions, and residual waste streams. The need for external carbon sources in wastewater treatment plants further exacerbates operational costs and carbon footprint, as commercial carbon sources are fossil-derived and expensive. This dual burden of waste disposal and wastewater nutrient removal calls for integrated solutions that can simultaneously address waste valorization and carbon source scarcity.
The hydrolysis-acidification of food waste to produce volatile fatty acids (VFAs) as a carbon source offers a promising pathway. This process converts organic waste into a valuable product that can substitute commercial carbon sources, thereby closing the nutrient loop and reducing reliance on fossil-based inputs. The present study provides a comprehensive life-cycle assessment comparing this innovative technology with incineration and anaerobic digestion, quantifying its resource efficiency, environmental impacts, and economic viability. By identifying key operational parameters such as moisture content, the research offers actionable insights for scaling up this technology in high-demand urban regions.
Loading authentic research manuscript (Pages 1–5)...
SHEN Guiyan, WEI Wei, XIAO Xiong, HUANG Jingjie, JIAO Xudong, DU Huanzheng, ZHANG Li, YUAN Wenyi, WANG Tao (2026). Synergistic Benefits of Pollution Reduction and Carbon Mitigation from Converting Food Waste into Carbon Sources for Wastewater Treatment Plants. Journal of Environmental Engineering Technology. https://doi.org/10.13205/j.hjgc.202604022
Research & Educational Purpose Only: The translations, structured abstracts, analytical annotations, and data reports provided by SinoGreenTechare intended exclusively for academic research, internal corporate R&D, and educational benchmarking. They do not constitute formal engineering, chemical safety, legal, or professional advice.
Copyright & Intellectual Property Notice: Original copyright of the underlying source articles and experimental data remains with the respective authors, institutions, and original publishing journals. SinoGreenTech claims intellectual property only over its proprietary translations, analytical syntheses, and AEO structured enhancements in accordance with international fair use and academic citation principles.
Frequently Asked Questions
What is the net greenhouse gas emission reduction per tonne of food waste processed via hydrolysis-acidification compared to incineration and anaerobic digestion?
The hydrolysis-acidification process achieves a net negative emission of -40.7 kg CO2-eq per tonne of food waste, whereas incineration and anaerobic digestion typically result in net positive emissions. This carbon-negative profile is attributed to the avoidance of fossil-based carbon source production and reduced energy demands.
How does the solid waste generation rate of hydrolysis-acidification compare to conventional methods, and what are the implications for landfill usage?
Hydrolysis-acidification generates only 9.3% solid impurities requiring disposal, significantly lower than incineration (which produces bottom ash and fly ash) and anaerobic digestion (which produces digestate). This reduction directly decreases landfill burden and associated disposal costs, making the process more environmentally and economically attractive.
What is the impact of food waste moisture content on the performance of hydrolysis-acidification, and how can this be managed in practice?
Sensitivity analysis indicates that higher moisture content increases solid impurity generation and reduces energy recovery efficiency. To optimize performance, feedstock moisture should be controlled, possibly through pre-dewatering or blending with drier organic wastes, ensuring consistent VFA yields and minimizing waste residues.
Can the carbon source produced from food waste fully replace commercial carbon sources in wastewater treatment, and what are the cost implications?
The study indicates that the produced carbon source can effectively substitute commercial alternatives, reducing wastewater treatment costs. However, the market demand for carbon sources varies seasonally and regionally, requiring storage or diversification strategies. The cost savings are significant, but scalability and market adaptation are key challenges.
What are the main barriers to large-scale commercialization of hydrolysis-acidification for food waste valorization?
Current operational scales are around 100 t/d, and large-scale performance remains unverified. The technology yields a single product (VFAs), limiting market flexibility. Additionally, the need for carbon source storage and potential seasonal demand fluctuations pose logistical challenges. These factors must be addressed through pilot projects and market development.
Related Chinese Research & Cross-Citations
Synergistic Regulation by Long- and Short-Chain Quorum Sensing Signaling Molecules Enhances Sulfamethoxazole Metabolism in Electroactive Biofilms within a Microbial Electrolysis Cell Coupled Anaerobic Digestion System
High-strength sulfamethoxazole (SMX) wastewater severely inhibits anaerobic microorganisms, reducing organic degradation and methane yield. This study investigated the effects of short-chain (C6-HSL) and long-chain (C12-HSL) N-acyl-homoserine lactone (AHL) signaling molecules, individually and in combination, on the construction, performance, and antibiotic resistance gene (ARG) profiles of anaerobic electroactive biofilms within a microbial electrolysis cell coupled anaerobic digestion (MEC-AD) system. Compared to the control (no AHLs), SMX removal efficiency increased by 9.26%, 7.44%, and 10.67% for C6-HSL (T1), C12-HSL (T2), and combined (T3) treatments, respectively. Methane production rates rose by 20.4%, 16.9%, and 23.1% for T1, T2, and T3, respectively. AHLs promoted extracellular polymeric substance secretion, enhancing electroactive microbe attachment to the anode. Microbial community analysis revealed increased diversity and modulated key functional genera. Notably, Georgenia abundance increased by 16.77% (T1) and 36.47% (T3) but decreased by 15.99% (T2). ARG analysis showed that single AHLs elevated intI1, sul1, and sul2 abundances, whereas combined AHLs (T3) exhibited a milder response, with sul2 abundance reduced by 4.92% relative to control. This suggests synergistic AHLs suppress ARG host proliferation. This study first demonstrates that combined short- and long-chain AHLs enhance electroactive biofilm formation, maintain microbial community stability, and modulate ARG dissemination risk, offering a quorum sensing-based strategy for antibiotic wastewater treatment and risk management.
Preparation of Solid-Phase Carbon Sources with Different Ratios and Their Carbon Release Properties
Low C/N ratios in wastewater treatment plant effluent necessitate external carbon sources for denitrification, but conventional liquid carbon sources are costly and unstable. This study prepared nine composite solid-phase carbon sources by combining PHBV with natural cellulose materials (straw, sawdust, corncob) at different mass ratios. Dynamic release experiments, DOC analysis, UV-Vis spectroscopy, and EEM fluorescence were employed to characterize carbon release. Results showed that increasing cellulose proportion in corncob-based sources led to release patterns opposite to those of straw- and sawdust-based sources. For straw and sawdust, higher cellulose ratios accelerated release rates, increased total release and duration, reduced aromaticity and molecular weight of released DOM, and promoted protein-like components (tryptophan, tyrosine), indicating enhanced bioavailability. Under identical ratios, corncob-based sources exhibited moderate total release, release durations exceeding 134 h, lower DOM aromaticity and molecular weight, and lower humic substance proportion, indicating superior bioavailability and engineering potential. Among the nine sources, JG5, MX5, and CC4 (PHBV:cellulose mass ratios of 4:5, 4:5, and 1:1, respectively) showed optimal comprehensive performance with low theoretical maximum release, long release periods, and high mass transfer coefficients. EEM-PARAFAC identified three DOM components (protein-like C1, C2; humic-like C3), with protein-like components dominating. This study validates the relationship between cellulose proportion and release kinetics and reveals synergistic regulation of DOM components, offering guidance for designing effective solid-phase carbon sources.
Enhancement of Anaerobic Digestion Operational Efficiency for Guar Gum Production Wastewater Using a Microaerobic-Biochar Coupled System
Guar gum production wastewater contains 1,2-propanediol, which in conventional anaerobic treatment causes propionate accumulation and microbial inhibition. Microaerobic conditions foster fermentative bacterial metabolism, enhancing organic substrate conversion, while biochar promotes anaerobic microbial aggregation and oxygen tolerance. This study treated actual guar gum wastewater using three configurations: blank control, anaerobic, and microaerobic-biochar (O2/BC) coupled systems. Under mesophilic conditions (37 °C), with micro-aeration at 0.2 mL/(g VS·d) and biochar dosage of 15 g/L, the O2/BC system achieved a COD removal efficiency of 90%, 10.6 percentage points higher than the anaerobic control. Effluent COD and propionate concentrations dropped to 3800 mg/L and 0.15 g/L, respectively, representing reductions of 49.6% and 98.4% versus the control. Biogas production was 1.64 times that of the control, with a maximum methane concentration of 77.2%. Fourier transform infrared spectroscopy (FT-IR) indicated increased abundance of –OH, –CH2–, and C–O functional groups on sludge surfaces, revealing biochar's adsorption enhancement. Scanning electron microscopy (SEM) showed dense microbial aggregates dominated by long bacilli, distinct from conventional anaerobic sludge. Microbial community analysis revealed increased abundance of Clostridium and Comamonas, modulating the propionate-to-acetate ratio and optimizing acidification efficiency, thereby promoting complex organic degradation. This study provides a novel technical pathway for biological treatment of alcohol-rich organic wastewater.
Occurrence Characteristics, Source Apportionment, and Ecological Risk Assessment of Pesticides in Plateau Lakes: A Case Study of Dianchi Lake
This study systematically investigated the occurrence, spatial distribution, sources, and ecological risks of 160 pesticides in Dianchi Lake, a typical plateau lake impacted by agricultural activities. A total of 37 pesticides were detected in the water, with total concentrations ranging from 64.2 to 1132.8 ng/L (average 610.0 ng/L). Fungicides, including boscalid (BOS), fluopicolide (FPC), and dimethomorph (DMM), were dominant, contributing up to 65.0% of the total concentration. Spatially, the southern lake region exhibited significantly higher concentrations (672.5 ng/L) than the north, attributed to intensive facility agriculture. Highly hydrophobic pesticides, such as penconazole (PEN), showed a tendency to enrich in bottom layers. Source apportionment identified inflowing rivers and wastewater treatment plant effluents as primary input sources, with average concentrations 7 and 9 times higher than lake water, respectively. Ecological risk assessment revealed that pesticides posed the highest risk to algae, followed by daphnia and fish. Prometryn (PMT) was identified as a high-risk factor for algae, while profenofos (PFF) and carbendazim (CBD) posed potential threats to higher trophic levels. These findings provide fundamental data and technical support for understanding pesticide pollution in plateau lake ecosystems.
Microbiome Mechanisms of Composite Carbon Sources for Enhancing Denitrification and Reducing N2O Emissions
Biological nitrogen removal in wastewater treatment plants (WWTPs) is often limited by insufficient influent carbon sources, necessitating external carbon addition to enhance denitrification. Conventional single carbon sources, such as sodium acetate, frequently fail to meet the metabolic demands of complex microbial communities, compromising nitrogen removal efficiency and stability. Composite carbon sources, by providing multiple electron donors, can improve metabolic cooperation among microorganisms, yet their underlying microbial mechanisms remain insufficiently understood. In this study, activated sludge from a municipal WWTP was used to investigate the microbial mechanisms of composite carbon sources during denitrification. Batch denitrification experiments were conducted in combination with metagenomic and metatranscriptomic analyses to systematically characterize microbial community structure and functional gene expression under different carbon source conditions. Results showed that, compared with sodium acetate as the single carbon source, the composite carbon source system (sodium acetate: sodium succinate: ethanol = 2:1:3) increased the denitrification rate from (6.822 ± 0.141) mg/(L·h) to (8.370 ± 0.186) mg/(L·h), representing a 22.7% improvement, while reducing N2O accumulation by approximately 55%. Metagenomic analysis revealed that Ottowia, Rubrivivax, Thauera, and Zoogloea were the dominant denitrifying genera. Metatranscriptomic results further demonstrated that the composite carbon sources significantly upregulated the transcription of key denitrification genes, with nirS, norB, and nosZ increasing by 37.8%, 27.4%, and 48.6%, respectively. In addition, the composite carbon sources promoted complementary carbon metabolic strategies among different microbial communities, enhancing electron donor supply and improving denitrification efficiency. These findings indicate that composite carbon sources synergistically enhance denitrification performance through regulation of functional gene transcription in complex microbial communities, providing a theoretical basis for carbon source optimization in WWTPs.
Key Environmental Behaviors and Pollution Control Strategies of Tire Wear Particles in Aquatic Environments
Tire wear particles (TWPs) are emerging pollutants and constitute the dominant type of microplastics (MPs) in urban stormwater runoff, accounting for up to 90% of MPs in some cases. They are characterized by small size, high mobility, complex composition, and significant toxicity. Current research on TWPs remains fragmented, lacking a comprehensive understanding of their environmental behaviors and pollution control in aquatic systems. This review systematically analyzes the enrichment and vectoring roles of TWPs for coexisting pollutants, and their environmental fate, including ecotoxicological impacts, detection methodologies, release of intrinsic additives, and aggregation and sedimentation behaviors. Drawing on insights from other microplastic studies, the paper explores control technologies across the pollution pathway—source, transport, and terminal treatment—and proposes feasible management strategies. Key findings indicate that TWPs can adsorb heavy metals and organic contaminants, with adsorption capacities influenced by aging processes. Their aggregation is governed by solution chemistry, with critical coagulation concentrations varying with ionic strength and pH. The release of additives such as zinc and benzothiazoles is significant, posing ecological risks. Future research should focus on real-water aggregation mechanisms, additive release under natural conditions, long-term performance of treatment facilities like constructed wetlands under TWPs stress, enzymatic degradation pathways, and integration of AI, big data, and IoT for cost-effective detection and risk modeling. This review provides a scientific basis for developing targeted pollution control measures for TWPs in aquatic environments.