Food Waste Treatment Research Articles

The Cost-Effectiveness of the Supporting Policies for Food Waste-Reducing Equipment: Purchase Subsidy vs. Rental Subsidy

However the food waste problem has been well characterized by the local government, finding the best solution is a difficult and daunting task. Although much attentionhasbeenpaid to analyze the effect of food waste treatment facilities, there have been few sophisticated comparisons of the costs and potential effects of food waste reduction equipment subsidized. In this study, an attempt was made to analyze lump-sum purchase and rental subsidies by comparing the costeffectiveness of food waste reduction equipment distribution by the local government, Jeju Special District. A set of scenarios for two kinds of subsidies were constructed and the data on the cost of financing methods was assembled after upscaling the costs over a 10-year period. The estimated costs are 6,091 million KRW for the purchase subsidies and 6,463 million KRW for the rental subsidies, which indicates that the former is more cost-effectivet hanthelatter. However, cost-effectiveness can vary with assumptions, such as technological progress, interest rate, risk premium, etc. The present approach can be adapted to establish proper food waste policy interventions or a mixture of policies by considering the regional economic conditions and environment.

Transformation of food waste to source of antimicrobial proteins by black soldier fly larvae for defense against marine Vibrio parahaemolyticus

Insect biorefinery by black soldier fly larvae (BSFL), Hermetia illucens, has emerged as an innovative technique for the valorization of food waste. However, despite BSFL being an attractive natural source of antimicrobial proteins (AMPs), there is a scarcity of research on the antimicrobial activity and transcriptome expression of AMPs derived from BSFL following waste treatment. In the present study, food waste treatment was performed by BSFL with a substrate C/N ratio ranging from 21:1 to 10:1, marine Vibrio parahaemolyticus (VP) was selected as the model aquaculture pathogen, the antimicrobial activities of AMPs in vitro and zebrafish in vivo were examined, and the molecular mechanism of the C/N-dependent AMP difference was expounded. Findings were made that the AMP extract of C/N16:1 resulted in relatively higher antimicrobial activity in vitro than that of other C/Ns. Further, the AMPs of C/N16:1 exhibited a promising in vivo defense effect for elevating the 96-h survival rate of zebrafish from 0% to 39% after VP infection, comparable to the animal antibiotic sulfamethoxidine. The results of transcriptome analysis reveal that lysozymes were the highest expressed components in the AMP gene family. The C/N16:1 BSFL significantly up-regulated 12 out of 51 lysozyme genes compared with C/N21:1, which likely contributed to the improvement of AMP antimicrobial activity. Further, C/N16:1 significantly up-regulated the expression of lysozyme, glycosyl hydrolase and muscle protein genes compared with C/N21:1, which likely enhanced the defense ability of the immune system, the utilization of the starch-like substrate, and the mobility of the larvae, thereby facilitating the larval transformation and AMP production. Overall, such results indicate that waste C/N ratio interacted with the activity and expression of BSFL AMPs through transcriptome regulation, and the BSFL AMPs derived from food waste could be used for the defense against marine pathogens to support the sustainable development of aquaculture.

Lipid production by oleaginous microorganisms using food wastes: a review

Food wastes are rich in nutrients and can be used for producing useful chemicals through biotransformation. Some oleaginous microorganisms can use food wastes to produce lipids and high value-added metabolites such as polyunsaturated fatty acids, squalene, and carotenoids. This not only reduces the production cost, but also improves the economic value of the products, thus has large potential for commercial production. This review summarized the advances in food waste treatment, with a focus on the lipid production by oleaginous microorganisms using food wastes. Moreover, challenges and future directions were prospected with the aim to provide a useful reference for related researchers.

Integrated treatment of food waste with wastewater and sewage sludge: Energy and carbon footprint analysis with economic implications

Food waste (FW) is a primary constituent of solid waste and its adequate management is a global challenge. Instead of disposal in landfills, integrated treatment of FW with wastewater (WW) can diminish both environmental and economic burdens. Utilizing steady-state modelling and life cycle assessment techniques, this study investigated the prospects of FW integration with biological WW treatment in terms of WW treatment performance, net energy and carbon footprint and economics of the process. The explored scenarios include co-disposal and treatment with WW by using FW disposers and anaerobic co-digestion with sewage sludge in Hong Kong. Compared to the existing WW and FW treatment, the integrated scenarios significantly improved the energy balance (~83–126%), net greenhouse gas emissions (~90%), and economics of operation, with permissible impact on WW treatment performance. Therefore, utilizing the surplus capacity of the existing WW treatment facilities, these integrated scenarios are a promising solution for sustainable development.

Isolation of potassium solubilizing bacteria in soil and preparation of liquid bacteria fertilizer from food wastewater

The production of food wastewater generated during the food waste treatment processes was tremendous, and large amounts of water-soluble organic matter dissolved into the food wastewater, which originate serious problems of both environmental and economic loss. However, food wastewater is abundance in organic matters without toxic substances, which is conducive to the growth of microorganisms. This study investigated the application of food wastewater after the food waste hydrothermal treatment (HT) to prepare potassium solubilizing bacteria (KSB) fertilizer. Two highly efficient KSB, Escherichia vulneris (K1) and Bacillus cereus (K2), were isolated from farmland soil and inoculated into the food wastewater, the organic matter content of which could be significantly increased after HT. In addition, pH, SCOD, and reducing sugar have significant effects on the growth of KSB. The optimal culture scheme of K2 in food wastewater was pH 8, temperature 30 ℃, table rotational speed 160 rpm, and inoculation amount 1.5%. The available K concentration of soil increased by 28.41 mg/kg as inoculated K2 fertilizer, which increased the garlic plant height by 23.53% and significantly affected plant height, maximum leaf width, maximum leaf length, fresh weight, and dry weight (P < 0.05).

Promoting the source separation of household kitchen waste based on comprehensive evaluation and economic feasibility

The source separation and treatment of food waste is urgent for sustainable municipal solid waste (MSW) management. Household kitchen waste (HKW) is relatively difficult to manage as large amounts are produced by dispersed sources. Although many countries and regions have begun to promote HKW source sorting, controversy over whether and how this approach could improve the comprehensive benefits of MSW management remains. This study constructed four most potential HKW source separation scenarios, and compared their energy efficiency, environmental impact and economic benefits were with the baseline full waste-incineration scenario to provide foundation for HKW management policy formation. The results showed that, when the amount of MSW stabilized, promoting HKW source separation had no significant advantages, while the overall benefits of HKW separation would be further expanded with continuous increases in the generation amount of MSW, and the economic cost would be acceptable. The suitable application conditions of different source separation modes vary. Centralized anaerobic digestion of HKW is a suitable choice for regions determined to promote long-term HKW separation, since it could reduce environmental impact by 3%–51% over the baseline scenario, and the comprehensive benefits would be further accentuated as the source separation rate increased. Small-scale on-site biochemical HKW treatment should not be widely utilized as it has high pollutant emissions and costs per-unit. Food waste disposers (FWDs) achieved outstanding waste reduction effect, and the government could guide the purchase of FWDs by residents according to the urban drainage system conditions. HKW source dewatering required the lowest cost and effort, and could be a suitable solution for regions that cannot promote strict HKW source separation.

Insights on dissolved organic matter and bacterial community succession during secondary composting in residue after black soldier fly larvae (Hermetia illucens L.) bioconversion for food waste treatment

Black soldier fly larvae (Hermetia illucens L. BSFL) bioconversion is a promising biotechnology for food waste treatment. However, the separated residues still do not meet criteria for use as land application biofertilizers. In this work, we investigated a full-scale BSFL bioconversion project to explore features of dissolved organic matter (DOM) and its associated responses of bacterial community succession in residue during secondary composting. Data showed that the concentrations of total nitrogen and ammonium nitrogen decreased by 11.8% and 22.6% during the secondary composting, respectively, while the nitrate nitrogen concentration increased 18.7 times. The DOM concentration decreased by 69.1%, in which protein-like, alcohol-phenol, and biodegradable aliphatic substances were metabolized by bacteria during the thermophilic phase together with the accumulation of humus-like substances, resulting in an increase in the relative concentration of aromatic compounds. The structure of the bacterial community varied at different stages of the bioprocess, in which Bacteroidetes, Actinobacteria, Proteobacteria, and Firmicutes were the dominant bacterial phyla. Lysinibacillus, Pusillimonas, and Caldicoprobacter were found to be key contributors in the degradation and formation of DOM. The DOM concentration (33.4%) and temperature (17.7%) were the prime environmental factors that promoted succession of the bacterial community. Through bacterial metabolism, the structural stability of DOM components was improved during the composting process, and the degrees of humification and aromaticity were also increased. This study depicted the dynamic features of DOM and the associated bacterial community succession in residue during secondary composting, which is conducive with the reuse of BSFL residue as biofertilizer for agriculture.

Comparative environmental and economic life cycle assessment of dry and wet anaerobic digestion for treating food waste and biogas digestate

Anaerobic digestion (AD) has proven to be a promising option for food waste (FW) management, due to the significant potential of recovering energy from waste. In this study, the environmental and economic impacts of six scenarios for FW and biogas digestate management in Shenzhen, China, were evaluated using life cycle assessment (LCA) and life cycle cost (LCC) analysis. GaBi model was employed to perform LCA on the basis of CML 2001 methodology, while LCC analysis was conducted using net present value to evaluate the economic efficiency. Results showed that dry AD coupled with biogas digestate incineration not only exhibited the best net environmental benefits with the reduction of 195 kg CO2 per ton of FW, but also appeared to be the most economically feasible option with the lowest LCC (446.223 thousand CNY). With respect to the FW treatment technology, dry AD scenarios exhibited better environmental benefits associated with global warming, human toxicity, marine aquatic ecotoxicity and photochemical ozone creation potential, compared to those in wet AD. Regarding post treatment for biogas digestate, incineration appeared to be the best option compared to the landfill and compost. Moreover, sensitivity analysis indicated that dry AD coupled with biogas digestate incineration exhibited least vulnerable to the change in biogas production environmentally. The outcomes of this study will contribute to developing the optimal FW management strategy for mitigating the environmental and economic impacts in terms of both environmental and economic sustainability.

Introducing new monitoring indices from the headspace of biogas digester via e-nose: A case study

This study focused on the monitoring of a biogas digester (BD) for treatment of food waste using an e-nose system. The e-nose system along with Principal Component Analysis (PCA) were applied to monitor the gaseous headspace of a mesophilic BD. In this method the digester was allowed to feed based on monitoring indices, i.e. “recovery time” and “position of sensors”, using e-nose data analysis. The results showed that the digester can be kept under the steady-state condition and good performance during evaluation phase, as organic acids to total alkalinity (FOS/TAC) was 0.2–0.3, pH was stabilized near to 8, the mean of volatile solids reduction and the daily methane production rate were 82% and 1.24 Nm3/m3 d, respectively. This study presents a robust monitoring of BD based on an adaptable reference point and graphical monitoring on plots of PCA that make it more flexible than the classical parameter monitoring with determined threshold.

Life cycle assessment of food waste anaerobic digestion with hydrothermal and ionizing radiation pretreatment

Extensive research has been conducted on the life cycle assessment of anaerobic digestion of food waste. However, few studies have evaluated the environmental impact of anaerobic digestion from a technical perspective. This study focuses on the environmental impact of using ionization radiation pretreatment technology in the anaerobic digestion of food waste and compares it with that of traditional hydrothermal pretreatment. Model construction, environmental impact assessment, and Monte Carlo simulation calculations were performed using the OpenLCA software. Data for the analysis were obtained from an actual plant in China, experiments, literature, and databases. The results show that the introduction of the proposed ionizing radiation pretreatment causes the treatment of food waste via anaerobic digestion to have the lowest environmental impact in 14 of the 18 categories analyzed. Pretreatment was found to be the most energy-consuming unit in food waste treatment, accounting for 71–75% of the total energy consumption. This research has an important guiding role in the development and application of ionizing radiation pretreatment technology for food waste.

Effects of organic loading rates on high-solids anaerobic digestion of food waste in horizontal flow reactor: Methane production, stability and mechanism

To maximize the methane production efficiency of high-solids anaerobic digestion (HSAD) of food waste (FW), a horizontal flow reactor was operated under mesophilic, semi-continuous condition at organic loading rates (OLRs) ranging from 1.00 to 13.80 kg-VS/(m3 d). The gas production, substrate transformation, and microbial community characteristics of the horizontal flow HSAD reactor were evaluated. The results indicated that the methane yield (0.173–0.516 L/(g d)) fluctuated with the increasing OLR, volumetric methane production rate (0.25–5.69 L/(L d)) increased with increasing OLR, and the volatile solids (VS) reduction rate ranged between 83.30% and 93.05%. The relationship of biogas or methane production with OLR and HRT in the horizontal flow HSAD reactor were characterized with an empirical equation. The concentrations of soluble COD and volatile fatty acid exhibited significant fluctuations, and free ammonia-nitrogen peaked at the OLR of 13.80 kg-VS/(m3 d). Microbial community analysis revealed that the methanogenic metabolic pathway changes along the propelling direction of the horizontal flow HSAD reactor from CH3COOH and H2/CO2 pathways to CH3COOH, H2/CO2, and H2/methyl co-dominant pathways. These results provide theoretical support for stable methane production from FW and deeper insight into horizontal flow HSAD for FW treatment.

“Food waste-wastewater-energy/resource” nexus: Integrating food waste management with wastewater treatment towards urban sustainability

Sustainable food waste management is a global issue with high priority for improving food security and conserving natural resources and ecosystems. Diverting food waste from the solid waste stream to the wastewater stream is a promising way for food waste source separation, collection, treatment, and disposal. Given the advances in wastewater treatment, this integrated system has great potential for the concurrent recovery of water, resource, and energy. To this end, many efforts from lab-scale to full-scale studies have been devoted to evaluating the feasibility and associated impacts on both solid waste and wastewater systems. This paper summarizes the current status of food waste diversion from the aspects of principle and application. The impacts of food waste diversion on solid waste treatment, sewer system, wastewater treatment, and environmental benefits have been comprehensively reviewed and analysed. In the context of the critical review, this paper further identified the challenges of food waste diversion in unified definitions of the field, sewer network assessment, emerging wastewater treatment technologies, scale-up studies, and policy drivers. Perspectives on the contribution of food waste diversion to a food waste management hierarchy were discussed for initiating the nexus of “food waste-wastewater-energy/resource”. We conclude that food waste diversion could facilitate sustainable urban development, but the area-specific factors (e.g., household practices, water resource, sewerage system condition, and treatment techniques) require adequate evaluations to determine the implementation. The outcomes of this study could contribute to the practice and policy-making of food waste management towards urban sustainability.

Analysis of raw materials and products characteristics from composting and anaerobic digestion in rural areas

Chinese food waste (FW) production is enormous which brings many economic and environmental benefits. There is an urgent need for proper and efficient treatment technology. Anaerobic digestion (AD) is a popular technology for centralized large-scale treatment of FW. Composting technologies including static composting (SC), forced aerated composting (FC), and machine composting (MC) have been applied in rural areas owing to their low cost and simplicity. The characteristics of products in different FW treatment are still unclear, preventing agricultural use of the products. In order to elucidate the properties of different samples and to realize the resource utilization of products, compost samples (FC, SC and MC) and AD biogas residue samples were collected on site. By analyzing the physicochemical properties (pH, moisture content, maturity, salinity, lignocellulose, etc.) and phytotoxicity, the quality of different products was evaluated to determine the most appropriate rural FW treatment technology. MC products showed poor performance in maturity, salt concentration and plant toxicity. SC products cannot be used due to phytotoxicity. High moisture content limited the prospects of AD products utilization. FC products were of good quality with 32.91% in organic matter loss, good performance in lignocellulose degradation, 6.76% in water-soluble salts, and 79.61% in germination index. FC technology is worth promoting in rural areas of China.

Environmental sustainability of an integrate anaerobic digestion-composting treatment of food waste: Analysis of an Italian plant in the circular bioeconomy strategy

In light of the adoption of recent global policies and strategies for a more sustainable food waste management system and a greater control of environmental impacts, this study describes a circular bioeconomy plant model, currently operating in South Italy, for treatment and enhancement of organic fraction of municipal solid waste. The key basis for plant activity is dry anaerobic digestion of separately collected organic fraction of municipal solid waste (SC-OFMSW) followed by digestate composting process. Biomethane for use in the transport sector is obtained by biogas cleaning and upgrading, while high-quality compost for organic farming is produced by digestate composting. Plant activities are completed by the transformation of part of the produced waste into refuse derived fuel (RDF) to be allocated to waste-to-energy plants and the treatment of odour emissions which allows the recovery of ammonium sulphate as a fertilizer. A rooftop photovoltaic system supplies most of electric energy needed by the plant. For plant activities relative to 2020, carbon footprint was equal to −112 kg CO2eq. for Mg of organic waste, while depletion of fossil resources was estimated at −89.6 kg oil eq. Mg−1 of waste. Primary energy demand of food waste treatment system was −2.66 GJ Mg−1 of input waste. Replacement of natural gas with biomethane for transport sector provided the greatest improvement contribution for all the examined categories.

Physicochemical Properties of Torrefied and Pyrolyzed Food Waste Biochars as Fuel: A Pilot-Scale Study

Food waste is an important constituent of municipal solid waste, and research has been conducted to develop various methods for treating food waste and recycling it (e.g., fuel, landfilling, composting, conversion into animal feed, drying, and carbonization). Among these, the drying and carbonization techniques can change food waste into fuel; however, they need more energy than fermentation and anaerobic digestion procedures. In this study, we investigated the physicochemical properties of food waste biochar produced under torrefaction (270 °C) and pyrolysis (450 °C) conditions to establish its applicability as fuel by comparing temperatures, residence times, and conditions before and after demineralization. The higher heating value increased after the demineralization process under both temperature conditions (270 °C and 450 °C), and the chlorine level was lower at 270 °C temperature demineralization than at 450 °C. During the demineralization process, Na and K were better removed than Ca and Mg. Additionally, Cr, Hg, Cd, and Pb levels were lower than those according to the European Union and Korean domestic bio-SRF recovered fuel criteria, confirming the applicability of biochar as fuel.

Treatment of Food Waste Contaminated by Bioplastics Using Bsf Larvae: Impact and Fate of Starch-Based Bioplastic Films

Treatment of Food Waste Contaminated by Bioplastics Using Bsf Larvae: Impact and Fate of Starch-Based Bioplastic Films

Optimal Control Analysis of Food Waste Treatment Methods Based on Improved Pressure Sensors

With the rapid development of the economy and society, people's overall living standard continues to rise, and food waste generated by various industries is becoming a major part of domestic waste, how to dispose of waste in a real-time and resourceful manner is a major test for urban environmental maintenance. This paper focus on the weight perception of solid food waste after pre-treatment and proposes an optimisation strategy for the first time. The core structure of the traditional sensor is improved from three perspectives: temperature, capacitance value and external stress, thus building an improved capacitive pressure sensor to accurately detect the weight of waste and trim the measured data more accurate. Secondly, based on the remote monitoring system, the multi-level control enables the collected food waste to be eliminated in a timely manner, which helps the resource utilization of food waste.

An Integrated Selection Framework Using an Extensible Complex Spherical Fuzzy Aras Approach for the Food Waste Treatment Method

An Integrated Selection Framework Using an Extensible Complex Spherical Fuzzy Aras Approach for the Food Waste Treatment Method

유기성 폐기물 처리기용 고효율 미생물제제 제조법 개발

Organic waste including agricultural or food waste is generated in various processing processes, and environmental pollution problems caused by wastewater and odor generated during the process of processing food waste are becoming serious social problems. Accordingly, research for effectively recycling food waste has been actively conducted based on the experiments that the treatment of food waste using rice bran, rice husk, and sawdust is effective, a microbial agent was prepared. As a result, the activity of the microbial agent was high, and even through the results of physicochemical analysis, the harmful substances were below the standard value. The maturity, C / N value, and organic value exceeded the standard value. Thus final by-product could be used as compost or feed.

Food waste treatment option selection through spherical fuzzy AHP

In line with the increase in consciousness on sustainability in today’s global world, great emphasis has been attached to food waste management. Food waste is a complex issue to manage due to uncertainties on quality, quantity, location, and time of wastes, and it involves different decisions at many stages from seed to post-consumption. These ambiguities re-quire that some decisions should be handled in a linguistic and ambiguous environment. That forces researchers to benefit from fuzzy sets mostly utilized to deal with subjectivity that causes uncertainty. In this study, as a novel approach, the spherical fuzzy analytic hierarchy process (SFAHP) was used to select the best food treatment option. In the model, four main criteria (infrastructural, governmental, economic, and environmental) and their thirteen sub-criteria are considered. A real case is conducted to show how the proposed model can be used to assess four food waste treatment options (composting, anaerobic digestion, landfilling, and incineration). Also, a sensitivity analysis is generated to check whether the evaluations on the main criteria can change the results or not. The proposed model aims to create a subsidiary tool for decision makers in relevant companies and institutions.