High Food Waste Research Articles

High potential food wastes: Evaluation of melon seeds as spreadable butter

In this study, the evaluation of the use of melon seeds, which is an important waste in domestic and industrial production, as a source and ingredient for the production of spreadable butter was investigated. After the cleaning, roasting and grinding processes applied to the melon seeds, different amounts (10% and 20% sugar, glucose and honey) of were added during the sweetening phase. Physical, chemical and texture analyzes were performed for melon butter. According to the results obtained, the highest hardness (3124.76 g) and work of shear (1405.33 gs) values were obtained in the mixtures using Glucose20. The lowest hardness values were obtained in Sugar10 (261.61 g) and Honey10 (202.53 g) mixtures, which were not statistically different, and the lowest work of shear values were obtained in sugar and honey products. Considering the results, it was concluded that Sugar10 is the most suitable for the production of melon butter production. Practical applications Among the main objectives of the study was the introduction of a new type of seed butter that was healthy and non-allergenic to the industry with evaluating food waste. The spreadable butter samples produced with this study, in which the nutritional and technological properties of melon seeds were evaluated, are a major proof that melon seeds should considered be important ingredient for food industry.

Mitigating membrane fouling in a high solid food waste thermophilic anaerobic membrane bioreactor by incorporating fixed bed bio-carriers

Hybrid anaerobic membrane bioreactor (Hy-AnMBR) was developed by incorporating polyurethane sponge carriers to mitigate membrane fouling. The results showed that the membrane fouling was well controlled in Hy-AnMBR from the aspects of sludge property and membrane filtration performance. The solid concentration, including TS and MLSS in the Hy-AnMBR was reduced after introducing the fixed bed carrier, which was 13% and 20% lower than the control AnMBR (Con-AnMBR), and this resulted in improved filtration performance. The scanning electron microscope (SEM) photograph showed that membrane pores could still be observed on the Hy-AnMBR surface, indicating that the cake layer fouling of the Hy-AnMBR was less than the Con-AnMBR. The increase of the EPS and SMP promoted the acceleration of the membrane fouling rate. Analysis through confocal laser scanning microscopy (CLSM) and membrane cleaning revealed that adding sponge carriers mitigated 3.3%–9% pore-blocking, and the total membrane resistance in the Hy-AnMBR was reduced by 52% compared to the Con-AnMBR. Chemical cleaning was essential for pollutant removal, and membrane permeability recovery was more than 97%.

Supplementation of KOH to improve salt tolerance of methanogenesis in the two-stage anaerobic digestion of food waste using pre-acclimated anaerobically digested sludge by air-nanobubble water

Air-nanobubble water (NBW) was applied to pre-acclimate anaerobically digested sludge that was then used as the inoculum in the two-stage anaerobic digestion (AD) of high saline (20 g NaCl/L) food waste (FW) to optimize NBW application in the AD of high saline FW. K+ was simultaneously supplemented during the methanogenic stage to resist the inhibition of salt on methanogens. Results showed that after the second pre-acclimation cycle, the inoculum activity was increased 27% in the Air-NBW supplemented reactor in comparison to the deionized water (DW) supplemented one. In the first-stage AD, H2 yield was enhanced by 46% in the Air-NBW pre-acclimated sludge reactor compared with the DW pre-acclimated sludge reactor. Besides, supplementation of KOH in the methanogenic stage could enhance methane production by 17–25% in the DW reactors at initial pH 7.5, 8.0, and 9.0 when compared to the control reactor (using NaOH adjusted initial pH to 7.5), respectively.

Butyrate production and purification by combining dry fermentation of food waste with a microbial fuel cell

This study developed and evaluated a high-purity butyrate producing bioprocess from food waste by combining dry fermentation (DF) with a microbial fuel cell (MFC). Acclimatization of a DF reactor with an enrichment culture resulted in high food waste degradation (VS removed, %) and butyrate production. A high VS degradation of 81%, butyrate concentration of up to 24 gCODbutyrate/L and butyrate yields of 497 gCODbutyrate/kg VSadded was obtained in the DF reactor. As a result, butyrate comprised 83% of all short chain fatty acids (SCFA) in the DF broth. Acetate (10%) and propionate (7%) comprised the rest of the SCFA. The butyrate composition was further purified by feeding the DF broth to a multi-electrode MFC enriched with anode respiring bacteria (ARB) such as Geobacter sp. (>55%). The ARB in the MFC removed acetate and propionate while purified butyrate was recovered in the MFC effluent. Butyrate purity in the MFC effluent reached as high as 99% at hydraulic retention time of 72 h. Along with butyrate purification, the MFC produced electric power in a range of 0.1–0.6 Wh/gCODbutyraterecovered (or 0.01–7.85 kWh/ton of food waste), demonstrating that MFCs can be an energy-positive butyrate purification bioprocess.

Relationship of Food Leftover with Covid-19 Inpatients Recovery Speed in Palembang Indonesia

Background : Hospital nutrition services support the patient's recovery process, which the activity is feeding. One indicator of quality in food service is food leftover. The high food waste can affect the patient's health. The high food waste will pose a risk of malnutrition in hospitalized patients. The study aimed to analyze the food leftovers in COVID-19 inpatients at the Palembang referral hospital.Methods : This cross-sectional quantitative descriptive study was with a sample of 112 patients selected by purposive sampling in February-May 2021. Data were taken using the Comstock form and then translated in the form of percent leftover food. According to the Minister of Health, the minimum leftover food is less than 25 percent.Results : The results showed that more than 25 percent of the leftover food were 51 respondents; Thirty-three respondents (54.1%) have fully recovered and 28 respondents (45.9%) still in improvement. On the other hand, the leftovers food of less than 25 percent were 51 respondents; Forty respondents (78.4%) have fully cured, and 11 people (21.6%) still in treatments. The analysis of Chi-square test results shows a p-value of 0.013, showing a significant relationship between food waste and the recovery of COVID-19 patients.Conclusion : The food waste of COVID-19 patients in referral hospitals was still relatively high. It is necessary to modify the diet menu to prevent leftovers and speed up the patient's recovery.

Food Supply Chain During Pandemic: Changes in Food Production, Food Loss and Waste

The global COVID-19 pandemic of 2020 triggered disruption in almost all areas of the Food Supply Chain (FSC). During this year many confounding factors contributed to the disruption of the normal FSC and impacted the system adversely. This includes the agricultural food production system, the first phase of the FSC, to the final delivery of food to consumers. Food was lost or wasted as farmers were unable to transfer and distribute the food to retailers. Food shortages became problematic and consumers were not able to obtain necessary staples. Then consumers started to purchase too much (hoarding), as they feared shortages, which resulted in both rises in food prices and in higher food waste by consumers. Several reports indicated that food waste during this period was remarkably more than in pre-pandemic times. These situations were worsened as the pandemic continued. In this paper we define food loss as occurring mostly during the agricultural food production and food waste that mostly happening during distribution of food at the retailer and consumer levels. The food loss and waste (FLW) both have been shown to add to the diminution of the natural resources and the rise in greenhouse gas emissions. The high level of greenhouse gas in turn can harm the environment. In the United States (U.S.), similar to other countries, natural resources such as land (about 50%) and water (67%) are used for agriculture and food production. The main objective of this paper is therefore, to emphasize some of the current findings on the potential impact of the pandemic on the FSC which resulted in more FLW. Many reports suggest every stage of the FSC can be a significant contributor of FLW and environmental resource depletion. Long-term strategies must be implemented to keep the FSC robust, stable and sustainable during unfavorable circumstances and crises.

Optimized pre-treatment of high strength food waste digestate by high content aluminum-nanocluster based magnetic coagulation

Coagulation-based pre-treatment efficiency of high strength digestate of food waste (HSDFW) anaerobic digestion is negated by organic ligand-catalyzed decomposition of coagulants. In this study, an efficient HSDFW pre-treatment method, magnetic seeds (MS) coagulation, was employed by using highly stable Keggin Al30 nanocluster (PAC30), MS and polyacrylamide (PAM), and its operation was optimized by evaluating the performance of removing turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and total phosphorous (TP) phosphate. Results showed that at the optimum dosage of 4.82 g/L, PAC30 demonstrated excellent removals as high as 98.93% ± 0.1% of turbidity, 98.04% ± 0.1% of TSS, 58.28% ± 0.3% of total COD, 99.98% ± 0.01% of TP and 99.50% ± 0.01% of dissolved phosphate, respectively. Apparent molecular weight (AMW) and three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy analyses demonstrated more efficient removal of dissolved organic matter (DOM), particularly non-biodegradable and hydrophobic components by PAC30 than commercial coagulant. The sedimentation was much improved from 40 min by coagulation/flocculation to about 5 min settling by MS coagulation. The PAC30 based magnetic coagulation (MC) presents theoretical guidance on a cost-effective and much less footprint pre-treatment alternative for high strength wastewater.

Unsupervised aided investigation on the associations between municipal solid waste characteristics and socio-economic conditions

Better municipal solid waste (MSW) management can help to address environmental concerns and supports economic and social development. Because MSW characteristics can change over time, management strategies should also evolve and be applied correspondingly. However, many previous studies have focused on MSW characterization or investigated specific management strategies for a target MSW. Few studies have assessed the spatial variations of MSW characteristics and socio-economic (SE) conditions as well as their associations. This study evaluated the feasibility of using an integrated unsupervised method (cluster analysis and cross-tabulation analysis) to explore these topics for MSW management. Results suggest that the integrated method can successfully help to reveal key information. Seven jointed MSW-SE scenarios were investigated based on 259 individual observations of Taiwan. Associations between MSW compositions and SE conditions were identified statistically significant for four MSW-SE scenarios. In general, the general SE type (SE1) is very likely to generate high food wastes and other combustible, low paper, wood, and rubber wastes (MSW1). The small island SE type (SE3) is more likely to produce high paper and low wood, rubber, textile, and other noncombustible wastes (MSW2). Overall, the method applied in this study could help to reveal statistical associations between MSW and SE, which can help decision-makers comprehend underlying facts and develop effective management strategies.

Efficiency and key functional genera responsible for simultaneous methanation and bioelectricity generation within a continuous stirred microbial electrolysis cell (CSMEC) treating food waste

This study reveals the efficient treatment of high strength food waste under varying hydraulic retention times (48 h, 36 h and 24 h) in a continuous stirred tank reactor (CSTR) integrated with microbial electrolysis cell (MEC) to become a continuous stirred microbial electrolysis cell (CSMEC). COD removal efficiency in the CSMEC surpassed 92% with OLR ranging from 0.4 to 21.31 kg COD/m3·d compared to that of the CSTR. The maximum current density (based on the cathode surface area) was 1125.35 ± 81 mA/m2 in the CSMEC. Biogas yield and methane production rates increased by 16.5% and 19.3% in the CSMEC respectively compared to the CSTR. CSMEC was 1.52 times better in performance compared to the CSTR. Firmicutes, Synergistetes, Bacteroidetes, Thermotogae, Chloroflexi and Proteobacteria were the dominant phyla associated with both CSMEC and CSTR. Archaeal microbial community analysis showed Methanosaeta, Methanobacterium, Methanosarcina and Methanocorpusculum as the dominant populations associated with the CSMEC.

Performance issues of barrier systems for landfills: A review

The objective of the paper is to give an update in key topics related to performance issues of barrier systems for landfills. The objective of using barrier systems is to minimize the impact of contaminants on the surrounding environment. To achieve this goal puncture protection of the geomembrane must be ensured. An update is first given with respect to this matter. The question of the stability on slope of geosynthetic barrier systems is then discussed and an insight is given in modeling and laboratory measurement of parameters required to perform reliable modeling, especially as regards the case of piggy-back landfills. Geotechnical centrifuge modelling tests are very important for simulation of landfill stability induced by the failure of geosynthetic interfaces and validation of complicated numerical models, especially for the high food waste content landfills. The seismic design or assessment of landfill stability with respect to geosyntheics needs to be investigated. Finally, the question of transfers through bottom barrier systems is addressed, giving an update especially in the analytical solutions developed in the past 10 years in China in this matter. The breakthrough time based design method for landfill liner system was then summarized. The behaviour of double-liner system and its simplified performance-based design method should be further investigated in the high food waste landfills with high leachate level.

Impact of temperature on immediate and secondary compression of MSW with high and low food contents

Landfills in developing countries usually show municipal solid wastes (MSW) with large amount of food wastes, extraordinarily high moisture contents, and high internal temperatures. Because of these specific characteristics, significant post-closure settlements in landfills with high food waste are expected over time. This paper focused on the assessment of temperature impact on immediate and secondary compression behaviors of MSW with large contents of food, water, and plastic, comparatively to an aged low food content waste. A compression test was developed having a temperature-control system. The immediate compression index (C′c) of HFWC samples was found to be higher than those of low food waste content (LFWC) owing to the soft behavior of food content, although immediate compression was 15–30% of total strains for HFWC wastes, while for LFWC samples it was 80% of total strains. Mechanical creep was also greater in HFWC owing to the soft behavior of the wet food components intensified by temperature increases. Mechanical creep of LFWC samples was attributed to the deformation of large parcel of soft plastics, also accelerated by temperature. The HFWC waste showed a first dominant phase of biocompression with an intense and rapid biological degradation, and a second phase characterized by reduced biological activity. Temperatures higher and high compression stresses are required to provide significant impact on biocompression index magnitudes. Overall, the compressibility of high food content wastes has shown to be significantly higher and the temperature impact led to twice total settlements of the MSW with low organic content.

Compression behaviors of mechanically biologically treated wastes of Tianziling landfill in Hangzhou, China.

This study aimed to investigate the compression behaviors of mechanically biologically treated (MBT) wastes. For this purpose, the short-term compression-rebound and long-term compression tests were conducted on MBT wastes collected from Hangzhou Tianziling landfill in China. The results showed that the duration of immediate compression was obtained as 15.17-36.67h and was comparable to municipal solid waste (MSW). The immediate compression ratio was 0.233-0.247, and it was comparable to the aged high food waste content (HFWC)-MSW, fresh and aged low food waste content (LFWC)-MSW, but much lower than the fresh HFWC-MSW. The mechanical creep ratio (C'αc) was 0.012-0.018, being close to the fresh and aged MSWs. The bio-induced compression ratio (C'αb) was 0.143-0.174. The compression ratio rose exponentially with temperature (5-42°C) in both mechanical creep stage and bio-induced compression stage, and it increased much faster in the bio-induced compression stage. The resilient strains was only 2.1-3.3% of the compression strain at the same stress interval, suggesting that the compression strain consisted of mostly plastic deformation and negligible elastic deformation. The above findings can provide a reference for settlement prediction and storage capacity estimation of an MBT waste landfill.

Improved Food Waste Stabilization and Valorization by Anaerobic Digestion Through Supplementation of Conductive Materials and Trace Elements

The positive effects of conductive material supplementation on anaerobic digestion have been mainly investigated for single synthetic substrates, while its significance for real and complex organic wastes such as food waste has not been sufficiently investigated. This study investigated the effect of conductive material (biochar and magnetite) and trace metal supplementation on the anaerobic digestion of food waste by means of biochemical methane potential assays. The results indicated that the supplementation of biochar and trace metals improved both total biogas production and methane yields. A biochar dose of 2.0 and 5.0 g/L resulted in 11.2 ± 6.5 and 27.3 ± 9.5% increase in biogas and 8.3 ± 6.8 and 33.2 ± 2.8% increase in methane yield, respectively. Moreover, the same reactors demonstrated high food waste stabilization performance of over 80% chemical oxygen demand removal efficiency. These results indicate that biochar supplementation leads to more enhanced anaerobic digestion operation that could be through increased surface area for microbial growth and/or direct interspecies electron transfer mechanism. In turn, food waste will not only be stabilized but also valorized by anaerobic digestion at higher efficiencies that support sustainable waste management through both environmentally safe disposal and value-added generation.

Characterization of compression behaviors of high food waste content (HFWC) MSW and no food waste content (NFWC) MSW in China

In this paper, three sets of laboratory tests were conducted on high-food-waste-content (HFWC-), no-food-waste-content (NFWC-) and decomposed (D-) MSWs to characterize their compression behaviors. The immediate compression ratios C′c were 0.30, 0.23 and 0.18 for HFWC-MSW, NFWC-MSW and D-MSW respectively, and tended to increase with the increasing food waste content of MSW. The release of intra-particle water contained in food waste contributed over 23.6–29.2% to immediate compression for HFWC-MSW. The mechanical creep ratios C′sc were 0.02, 0.015 and 0.01 for HFWC-MSW, NFWC-MSW and D-MSW respectively. A prediction model for C′sc was proposed which incorporated the effects of moisture content, dry unit weight and organic waste content. The bio-compression ratios C′sbI, C′sbII and C′sbIII in response to degradation stage I, II and III were 0.12, 0.10 and 0.02 for HFWC-MSW, and were 0.01, 0.15 and 0.01 for NFWC-MSW. Bio-compression is dominant in stage I and II and mechanical creep is the major contributor in stage III for HFWC-MSW, but to NFWC-MSW, mechanical creep is dominant in stage I and III, and bio-compression takes the main position in stage II. The bio-compression tended to increase linearly with leachate draining rate for HFWC-MSW, and the release of intra-particle water contributed 61.9–65.6% to bio-compression. A new model was proposed that can well capture the highly non-linear behavior of bio-compression for both HFWC-MSW and NFWC-MSW. Based on the above findings, the settlement behavior of HFWC-MSW and NFWC-MSW landfills was compared, and suggestions for technique-efficient and cost-effective design of a NFWC-MSW landfill were discussed.

A degradation–consolidation model for the stabilization behavior of landfilled municipal solid waste

The stabilization behavior of landfilled municipal solid waste (MSW) plays an important role in the design, operation, and after care of landfills. The stabilization is dependent on the biological degradation and consolidation processes of landfilled MSW. A degradation–consolidation model for MSW was developed, which took biological degradation, skeleton deformation, two-phase flow, and solutes transport into consideration. In this model, the mass transformations of solid to liquid and then to gas were involved. The compression, hydraulic and solute transport material properties were related to the solid mass loss and the pore volume change. Indicators for the stabilization behavior of landfilled MSW were proposed. These indicators were calculated using the degradation–consolidation model to compare the stabilization behavior of landfilled high food waste content (HFWC) and low food waste content (LFWC) MSW. The results showed that the stabilization process of HFWC MSW landfills could be divided into rapid degradation, slow degradation, and post-stabilization stages based on the development of stabilization indicators. The normalized ratio of cellulose to lignin could be implemented to assess the stabilization stage of landfill more easily in practice.

The Impact of Gender on Food Waste at the Consumer Level

Abstract Food waste is one of the main contributors to economic disparities, social inequalities and environmental pollution. Numerous studies have sought to understand the drivers of food waste at various stages in the food supply chain, including the consumption stage. Based on a quantitative analysis of 252 Romanian consumers, the present study shows that gender is an important factor that affects the individuals’ attitudes and behaviours in regard to food and a potential factor that could affect the amount of food wasted. The study found that attitudes towards food waste evolve as individuals age, and that, at each stage, women tend to be more concerned about the negative impact of food waste on social equity or the family budget than men. In addition, women were found to display behaviours in regard to food acquisition and preparation that can result in higher food waste in a larger degree than men, even though the study found no differences in the actual amount of food wasted by the two genders. The results of the study are important because they show the need to adapt the public awareness campaigns on food waste on the particularities of each gender across several age groups.

The Evolution of Microbial Community during Acclimation for High Sodium Food Waste Anaerobic digestion

Anaerobic digestion is a promising method for treating the rapidly increasing food wastes. However, the high level of sodium salt in food waste significantly inhibited the anaerobic digestion process. In this study, acclimation was conducted to adapt to the high sodium food waste. The evolution of microbial community during acclimation process was characterized by high-throughput sequencing based on the 16S rRNA gene. The results revealed that the predominant phyla were Bacteroidetes, Firmicutes, Thermotogae, Chloroflexi, Proteobacteria and Synergistetes. The increase of functional genera Kosmtoga, Levilinea and Longilinea during the process potentially promoted the biodegradation of organics. As for the archaea community, the mixotrophic methanogens Methanosaricina was almost replaced by hydrogenotrophic methanogens Methanobacterium and Methanocorpusculum. The variations of pH and volatile fatty acid during acclimation provided additional information on the adaptation of microorganisms to the high sodium environment. The biogas production of food waste inoculated with acclimated sludge was increased by 63.6% compared with the raw sludge. The evolutions of bacterial and archaea communities during acclimation at the phylum level

Cow manure as additive to a DMBR for stable and high-rate digestion of food waste: Performance and microbial community

Cow manure (CM) was added to a dynamic membrane bioreactor (DMBR) operated under anaerobic condition for enhancing food waste (FW) digestion for over 300 days with stepwise increase of organic loading rates (OLRs) from 1.07 to 11.9 g COD/L/day. At a FW/CM ratio of 3.5:1 (based on volatile solids), the mixed liquor pH was always above 8.0 and no apparent volatile fatty acids (VFAs) accumulation occurred even at the highest OLR of 11.9 g COD/L/day (hydraulic retention time as 10 days and solid retention time as 15.5 days, correspondingly), indicating a very stable operation condition which resulted in an average CH4 yield as high as 250 mL/g COD and CH4 production as high as 2.71 L CH4/L/day. The hardly biodegradable organic components, such as cellulose, hemicellulose, and lignin, were effectively degraded by 78.3%, 58.8%, and 47.5%, respectively. Significantly high anaerobic digestion reaction ratios, especially the hydrolysis ratio which is usually the limiting factor, were calculated based on experimental results. Furthermore, the high lignocellulase contents and coenzyme F420 levels, along with the decrease of cellulose crystallinity from 72.6% to 16.4% in the feedstock, provided strong evidence of an enhanced biological activity by CM addition. By high-throughput sequencing analysis, more abundant and diverse bacterial, archaeal, and fungal genera were identified from the DMBR sludge. With CM addition, the biodegradation of lignocellulose might have produced sufficient H2 and CO2 for the hydrogenotrophic methanogens such as Methanoculleus, Methanomassiliicoccus, and Methanobacterium, which were highly tolerant to ammonium inhibition, and then the elevated ammonium level would have provided high buffering capacity in the DMBR thus ensuring a stable condition for high rate FW digestion and CH4 production.

Managing high fiber food waste for the cultivation of black soldier fly larvae

Increases in global human population are leading to increasing demands for food production and waste management. Insect biomass is a sustainable alternative to traditional animal feeds when insects are produced on lignocellulosic by-products. Resources high in lignocellulose have high carbon to nitrogen ratios and require nitrogen supplementation to accelerate bioconversion. Here we report on studies that examine the influence of nitrogen supplementation of almond hull-based feedstocks on black soldier fly larvae (Hermetia illucens L.) cultivation and composition. Decreasing carbon to nitrogen ratio from 49 to 16 increased larvae harvest dry weight, specific larvae growth, and yield by 36%, 31%, and 51%, respectively. However, the decrease in carbon to nitrogen ratio decreased larvae methionine and cysteine contents by 11% and 13%, respectively. The findings demonstrate that carbon to nitrogen ratio can be managed to enhance bioconversion of lignocellulose to larvae, but that this management approach can reduce larvae amino acid content.

Microbiome network analysis of co-occurrence patterns in anaerobic co-digestion of sewage sludge and food waste

Addition of food waste (FW) as a co-substrate in anaerobic digesters of wastewater treatment plants is a desirable strategy towards achievement of the potential of wastewater treatment plants to become energy-neutral, diverting at the same time organic waste from landfills. Because substrate type is a driver of variations in phylogenetic structure of digester microbiomes, it is critical to understand how microbial communities respond to changes in substrate composition and concentration. In this work, high throughput sequencing was used to monitor the dynamics of microbiome changes in four parallel laboratory-scale anaerobic digesters treating sewage sludge during acclimation to an increasing amount of food waste. A co-occurrence network was constructed using data from 49 metagenomes sampled over the 161 days of the digesters' operation. More than half of the nodes in the network were clustered in two major modules, i.e. groups of highly interconnected taxa that had much fewer connections with taxa outside the group. The dynamics of co-occurrence networks evidenced shifts that occurred within microbial communities due to the addition of food waste in the co-digestion process. A diverse and reproducible group of hydrolytic and fermentative bacteria, syntrophic bacteria and methanogenic archaea appeared to grow in a concerted fashion to allow stable performance of anaerobic co-digestion at high FW.