Cafeteria Waste Research Articles

Biogas production from cafeteria waste by anaerobic digestion

Biogas production from cafeteria waste by anaerobic digestion

Physicomechanical behavior of agro waste-filled polypropylene composites materials

For many applications, polymers are modified by adding reinforcements so that the mechanical behavior becomes optimal. Mixing lignocellulosic waste with polymer composites has gained wide consideration due to their weak price, biodegradability, and availability [1–3].Natural fillers are composed of hydrophilic lignocellulosic materials. These fillers are therefore incompatible with nonpolar polymers and have a low resistance to moisture. This leads to obtaining composites with weak properties. To improve adhesion between the filler and the matrix, it is necessary to modify the surface of these materials by the physical or chemical treatment, to enhance the mechanical properties of the composites [4].This work aims to prepare and characterize new composite materials based on polypropylene (PP) filled with either treated or untreated coffee husk waste (WCHT, WCHUT) collected from cafeteria waste. The effect of chemical treatments on the crystallinity and thermal stability of filler and PP / WCH composites were analyzed. Tensile properties were investigated. The treatment has enhanced the compatibility between PP and WCH, which is confirmed by the improvement of the tensile properties by the introduction of treated filler.

Performance evaluation of yeast-assisted microalgal microbial fuel cells on bioremediation of cafeteria wastewater for electricity generation and microalgae biomass production

In this work, microalgae–microbial fuel cell (MMFC) was used as an alternative method to treat cafeteria waste in Indonesia to produce electricity and microalgal biomass simultaneously. The organic contents from cafeteria waste were used as substrates by Saccharomyces cerevisiae. Spirulina platensis acted as an oxygen producer for oxygen reduction reaction on the cathode side. A salt bridge was used as a separator and ion exchanger. Yeast (Saccharomyces cerevisiae) was used as an anode biocatalyst because of its availability, resistance to extreme weather, and ease of culture and incubation. A voltage of 0.17 V and current density of 400 mA m−2 were obtained using the MMFC system. Meanwhile, the power density and maximum power density (MPD) reached 73 and 98 mW m−2, respectively. The MMFC systems can easily reduce the chemical oxygen demand to 60% and the total dissolved solid to 82.83%. Meanwhile, the microalgae growing on the cathode side reached 0.74 g L−1 by utilizing CO2 from the anode side. The MPD of the MMFC system was 2.38 folds higher than that of the MFC system (without microalgae) and 1.58 times higher than that of the MMFC system that used a commercial membrane. These advantages make the MMFC system for cafeteria waste highly suitable for use in countries with large populations or developing countries.

Acetate Production from Cafeteria Wastes and Corn Stover Using a Thermophilic Anaerobic Consortium: A Prelude Study for the Use of Acetate for the Production of Value-Added Products.

Efficient and sustainable biochemical production using low-cost waste assumes considerable industrial and ecological importance. Solid organic wastes (SOWs) are inexpensive, abundantly available resources and their bioconversion to volatile fatty acids, especially acetate, aids in relieving the requirements of pure sugars for microbial biochemical productions in industries. Acetate production from SOW that utilizes the organic carbon of these wastes is used as an efficient solid waste reduction strategy if the environmental factors are optimized. This study screens and optimizes influential factors (physical and chemical) for acetate production by a thermophilic acetogenic consortium using two SOWs—cafeteria wastes and corn stover. The screening experiment revealed significant effects of temperature, bromoethane sulfonate, and shaking on acetate production. Temperature, medium pH, and C:N ratio were further optimized using statistical optimization with response surface methodology. The maximum acetate concentration of 8061 mg L−1 (>200% improvement) was achieved at temperature, pH, and C:N ratio of 60 °C, 6, 25, respectively, and acetate accounted for more than 85% of metabolites. This study also demonstrated the feasibility of using acetate-rich fermentate (obtained from SOWs) as a substrate for the growth of industrially relevant yeast Yarrowia lipolytica, which can convert acetate into higher-value biochemicals.

Microbes Associated With Black Soldier Fly (Diptera: Stratiomiidae) Degradation of Food Waste.

Black soldier fly (Hermetia illucens L.) larvae are capable of valorizing waste by converting it into insect biomass that can be used as animal feed, leaving undigested residue that can be used as soil enrichment. Evidence is conflicting over whether larvae fed substrate containing pathogenic microbes emerge uncontaminated. Studies also differ on which clades comprise the species' gut microbiome, and on whether and how diet affects these microbes. Using culturing and metabarcoding, the bacterial microbiota of black soldier fly larvae reared on two different kinds of food waste (postproduction soy pulp and postconsumer cafeteria waste) were analyzed, along with the microbes of their substrates. Little to no overlap was found between the wastes, the larvae, and the residues, but the larvae fed different foods had a significant percentage of their microbes in common. The data, in line with other works on this species, suggest the larvae have a conserved microbiota whose components vary geographically.

Anaerobic Digestion of Vegetable, Fruit and Cafeteria Wastes with Cow Dung by Chemical Pretreatment for Biogas Production in Batch Digester

Co-processing of organic product, vegetable and cafeteria squander with cow manure by mean of pretreated chemically under anaerobic condition for research facility scale creation of biogas was under taken. The pH and temperature ranges for this investigation were 5.5 – 7.1 and 40°C-50°C, respectively under hydraulic retention time of 42 days. The objective of this research work was to fructify the execution of biological products, vegetable and cafeteria waste in batch anaerobic digester for biogas production.

Waste Separation in Cafeterias: A Study among University Students in the Netherlands.

Recycling waste is important to reduce the production of greenhouse gasses. The aim of this project was to understand determinants of cafeteria waste separation behavior among university students. First, the determinants of waste separation behavior among university students (n = 121) were explored using an online questionnaire. In study 2 (pre-/post-test design), the effect of a small intervention (based on study 1) on actual waste sorting behavior was observed. Finally, a semi-qualitative study in 59 students was conducted as process evaluation of the intervention. The following results were revealed: (1) Students have limited knowledge about waste separation, have a high intention to separate waste, are positive about waste separation in general, and believe that they can separate waste correctly. (2) Just over half of the waste is correctly recycled. An intervention with extra information had no significant effect on improving recycling behavior. (3) Students evaluated the intervention positively. Some students suggested that more information should be available where the actual decision making takes place. Ultimately, this paper concludes that although students have a positive attitude and are willing to behave pro-environmentally, there is a gap between intention and actual behavior. These results may also apply to other organizations and members of those organizations. New interventions are needed to trigger students to make correct waste separation decisions where the actual decision making takes place.

Effects of food substrates and moxidectin on development of black soldier fly, Hermetia illucens

AbstractBlack soldier fly is a common and widely distributed saprophagous species that has an excellent potential for being used for biological conversion of organic wastes on an industrial scale. The main goal of the reported study was expanding the list of wastes suitable for utilization by this species. We compared larval growth on cull potatoes, horse manure and cafeteria food waste in 100‐L bins in a greenhouse. We also conducted laboratory experiments to investigate whether black soldier fly larvae are affected by the presence of moxidectin, a common endectocide used to treat an array of domestic animals and readily excreted in faeces, in their food substrates. Feeding on potatoes resulted in slower growth, and the final size of potato‐fed larvae was smaller compared to the larvae fed on cafeteria waste. Nevertheless, potatoes supported substantial biomass accumulation, and could be a valuable option for rearing fly larvae for commercial feed production. Larvae feeding on horse manure gained very little weight and eventually failed to pupate. Moxidectin had a strong negative effect on larval survivorship; however, ca. 30% of larvae reared in the substrate containing a realistic field concentration of moxidectin still survived to adulthood. Our findings confirm that using black soldier fly larvae is a promising technology for recycling organic wastes, including those of plant origin.

Isolation and screening of cellulase producing bacterial strains from Cafeteria waste

Cellulases are a group of enzymes that are involved in the breakdown of cellulose into simpler sugars. These enzymes have tremendous application in the production various products like pulp and paper, textiles etc. Plants, animals and various microorganisms like protozoans, bacteria and fungi naturally produce these enzymes. Since most industrial applications utilize fungi and bacteria for fermentation, this study was also designed to isolate cellulose producing bacterial strains. In this study, food waste was collected from cafeteria and used for isolation of cellulase producing bacterial strains. The waste was pulverized using mortar and pestle subsequently used for making serial dilution, followed by the spreading of diluents on nutrient agar plates. Morphologically distinct colonies were selected and streaked to obtain single colonies. Cellulase production potential of the selected 8 isolates was tested by streaking each strain on agar plates enriched with different concentration of carboxymethylcellulose (as the sole carbon source). The plates were incubated for 72-120 hours followed by staining with 1% (v/v) Congo-red dye. Further the plates were decolourised by 1M Sodium chloride solution. A zone of clearance was observed around the bacterial strains capable of cellulase production because of their ability to hydrolyze cellulose. Further, the ability of the isolates to utilize varying concentration of CMC was tested in order to ascertain. The study resulted in isolation of 3 cellulase producing bacterial strains from cafeteria waste which can be utilized in cellulase production in the industries and also in agricultural waste management.

Cafeteria Waste Reduction Programs in Three Southern Maine Elementary Schools: A Waste Audit Analysis

Solid waste is a serious environmental problem in the modern world. School cafeterias are one source of food and packaging waste that must be dealt with. Reducing the amount of cafeteria waste disposed of as trash through source reduction, recycling, and composting will not only improve environmental outcomes, but will also teach students about sustainability and save schools money. Waste audits at three elementary schools in southern Maine reveal that there are major differences in how effectively waste is sort­ed and the types and quantity of waste generated per student. Overall waste diversion was measured at 67 percent or greater at all three schools, with an average of 69 percent among the two schools where organics were measured. While there is still work to be done at all three schools, the programs have a major impact even in their current state.

Methane enrichment of biogas by carbon dioxide fixation with calcium hydroxide and activated carbon

Although, Biogas generated from anaerobic digestion process is a clean, carbon neutral and environmental friendly energy alternative, raw biogas needs to be purified necessarily before using. The removal of CO2 from raw biogas ensures its better applications in engines, heating purposes and electricity generation. Reduction of CO2 content also enhances the calorific value. Biogas generated from vegetable, fruit and cafeteria wastes for duration of 30 days with the average concentration for CH4 and CO2 as 62 and 34%, respectively have been observed. The CO2 content was possible to reduce significantly by treating the raw biogas with purifying agents as: solid CaO, CaO solution and activated carbon. Purifying agent's mass and concentration and treatment time dependent biogas upgradation profile reveals that these novel purification processes are effective and affordable.

Food Waste Auditing at Three Florida Schools

School cafeterias are a significant source of food waste and represent an ideal opportunity for diverting food waste from landfills. In this study, cafeteria waste audits were conducted at three Florida schools. Food waste comprised the largest fraction of school cafeteria waste streams, ranging from 47% to 58%, followed by milk, paper products (tissue, milk cartons, pasteboard, paper plates, and cardboard), and plastics (plastic wrap, packaging, and utensils). Metal and glass comprised the smallest fraction of the waste stream. Average total waste generation ranged from 50.5 to 137.6 g·student−1·day−1. The mean generation rates for food waste ranged from 24.7 to 64.9 g·student−1·day−1. The overall average for cafeteria waste generation among all three schools was 102.3 g·student−1·day−1, with food waste alone contributing 52.2 g·student−1·day−1. There are two primary approaches to diverting school food waste from landfills: reduction and recycling. Food waste can be reduced through educating students and staff in order to change behaviors that cause food waste. Food waste can be collected and recycled through composting or anaerobic digestion in order to generate beneficial end products, including soil amendments and bioenergy. Over 75% of the cafeteria waste measured in this study could be recycled in this manner.

Production of Biomethane from Cafeteria, Vegetable and Fruit Wastes by Anaerobic Co-Digestion Process

Alleviate energy crisis and global climate change, the world is need of a green, efficient, carbon-neutral renewable energy source to replace fossil fuels. This study was designed to determine the optimal mixing ratio of cafeteria, vegetable and fruit wastes in biogas production and methane yields using batch anaerobic digesters at mesophilic (25 to 34℃) temperature. The mixing ratio used were CW:VW:FW (0.5:1.0:1.5, 1.0:1.5:0.5, 1.5:0.5:1.0 and 1.0:1.0:1.0) for cafeteria waste (CW), vegetable waste (VW) and fruit waste (FW) respectively. The fermentation was carried out in 200 L polypropylene digesters. The results showed that the co-digestion significantly affected the biogas production rate. At four mixing ratio tested, after 35 days of digestion, the biogas yield was determined to be CW:VW:FW (0.5:1.0:1.5, 1.0:1.5:0.5, 1.5:0.5:1.0 and 1.0:1.0:1.0) were 13.38, 15.85, 17.03 and 19.43 L/day, respectively. The cumulative average biogas productions from CW:VW:FW (0.5:1.0:1.5, 1.0:1.5:0.5, 1.5:0.5:1.0 and 1.0:1.0:1.0) were 225, 279, 305 and 332 L/day, respectively. The biogas yields obtained in the work for the cafeteria (CW), vegetable (VW) and fruit wastes (FW) mixture were in the order of (1.0:1.0:1.0 > 1.5:0.5:1.0 > 1.0:1.5:0.5 > 0.5:1.0:1.5). The higher methane contents and yields were obtained from the CW:VW:FW (1.0:1.0:1.0) mixture ratio than those from the CW:VW:FW (1.5:0.5:1.0, 1.0:1.5:0.5, and 0.5:1.0:1.5). Thus, optimum mixing ratio suggested by the study which gave maximum yields within 35 day hydraulic retention time without inoculums added. 

Glucoamylase production from food waste by solid state fermentation and its evaluation in the hydrolysis of domestic food waste

In this study, food wastes such as waste bread, savory, waste cakes, cafeteria waste, fruits, vegetables and potatoes were used as sole substrate for glucoamylase production by solid state fermentation. Response surface methodology was employed to optimize the fermentation conditions for improving the production of high activity enzyme. It was found that waste cake was the best substrate for glucoamylase production. Among all the parameters studied, glucoamylase activity was significantly affected by the initial pH and incubation time. The highest glucoamylase activity of 108.47 U/gds was achieved at initial pH of 7.9, moisture content of 69.6% wt., inoculum loading of 5.2×105 cells/gram substrate (gs) and incubation time of 6 d. The enzyme preparation could effectively digest 50% suspension of domestic food waste in 24 h with an almost complete saccharification using an enzyme dose of only 2U/g food waste at 60°C.

Production of Biomethane from Cafeteria, Vegetable and Fruit Wastes by Anaerobic Co-Digestion Process

Production of Biomethane from Cafeteria, Vegetable and Fruit Wastes by Anaerobic Co-Digestion Process

Visual Inspection of Cafeteria Waste by Quarter Servings Rivals the Accuracy of Weighing

ObjectiveWeighing plate waste is the gold standard measure of determining what is eaten in school cafeterias, but it is costly and time consuming. Four common methods of analyzing tray waste – percentage estimates, quarter serving estimates, top-down photographs, and angled photographs – are compared to determine their accuracy.Theory, Prior Research, RationaleNo prior research has compared all of the leading plate waste estimation methods to determine which is most accurate and efficient to use in large scale operations.Study Design, Setting, Participants, and InterventionTray waste from 233 K-12 lunchroom trays in Lansing, New York were measured in each of 5 different ways: weighing, percentage estimates, quarter serving estimates, top-down photographs, and angled photographs.Outcome, Measures and AnalysisEstimation accuracy compared with weighing.ResultsBoth methods of photography tended to underestimate the amount of wasted food by approximately 12%. Percentage estimation showed a bias of 6% but had the lowest retest reliability. Quarter serving estimation (0, 25, 50, 75, or 100%) most accurately approximated actual weight (-3.2%). This is largely because most items are either in total, uneaten or only have 1to 2 bites (25%) out of them.Conclusions and ImplicationsThe new USDA focus on reducing plate waste will make plate waste analysis important on a large-scale basis. This research suggests that using the quarter serving estimate method can be used quickly, widely, and inexpensively to approximate how much has been eaten when weighing is not possible.FundingNone. ObjectiveWeighing plate waste is the gold standard measure of determining what is eaten in school cafeterias, but it is costly and time consuming. Four common methods of analyzing tray waste – percentage estimates, quarter serving estimates, top-down photographs, and angled photographs – are compared to determine their accuracy. Weighing plate waste is the gold standard measure of determining what is eaten in school cafeterias, but it is costly and time consuming. Four common methods of analyzing tray waste – percentage estimates, quarter serving estimates, top-down photographs, and angled photographs – are compared to determine their accuracy. Theory, Prior Research, RationaleNo prior research has compared all of the leading plate waste estimation methods to determine which is most accurate and efficient to use in large scale operations. No prior research has compared all of the leading plate waste estimation methods to determine which is most accurate and efficient to use in large scale operations. Study Design, Setting, Participants, and InterventionTray waste from 233 K-12 lunchroom trays in Lansing, New York were measured in each of 5 different ways: weighing, percentage estimates, quarter serving estimates, top-down photographs, and angled photographs. Tray waste from 233 K-12 lunchroom trays in Lansing, New York were measured in each of 5 different ways: weighing, percentage estimates, quarter serving estimates, top-down photographs, and angled photographs. Outcome, Measures and AnalysisEstimation accuracy compared with weighing. Estimation accuracy compared with weighing. ResultsBoth methods of photography tended to underestimate the amount of wasted food by approximately 12%. Percentage estimation showed a bias of 6% but had the lowest retest reliability. Quarter serving estimation (0, 25, 50, 75, or 100%) most accurately approximated actual weight (-3.2%). This is largely because most items are either in total, uneaten or only have 1to 2 bites (25%) out of them. Both methods of photography tended to underestimate the amount of wasted food by approximately 12%. Percentage estimation showed a bias of 6% but had the lowest retest reliability. Quarter serving estimation (0, 25, 50, 75, or 100%) most accurately approximated actual weight (-3.2%). This is largely because most items are either in total, uneaten or only have 1to 2 bites (25%) out of them. Conclusions and ImplicationsThe new USDA focus on reducing plate waste will make plate waste analysis important on a large-scale basis. This research suggests that using the quarter serving estimate method can be used quickly, widely, and inexpensively to approximate how much has been eaten when weighing is not possible. The new USDA focus on reducing plate waste will make plate waste analysis important on a large-scale basis. This research suggests that using the quarter serving estimate method can be used quickly, widely, and inexpensively to approximate how much has been eaten when weighing is not possible.

Waste to Energy: A New Dimension in Generating Electricity in Bangladesh

The conventional fuels required for production of electricity is decreasing day by day and it is very important to find out alternative sources which can be used as the fuel for the production of electricity especially for developing countries like Bangladesh. With a population of 160 million Bangladesh produce enough amount of waste per day to ponder about this topic. So, we felt that it is worth working on this field and it is high time to inject the concept of Waste to Energy in Bangladesh. First, a base line survey was conducted for independent research to accumulate the data of total waste generation in Bangladesh. During this Endeavour it was found some local poultry farms are using poultry waste to generate electricity. These case studies encouraged to carry forward the Endeavour and to generate electricity from Municipal Solid Waste (MSW), cafeteria waste, and different composition of different wastes at the university campus to make the technology locally appropriate. A model for community based small and medium waste to energy power plant is being developed for proper waste management and possible solution of energy crisis in Bangladesh.

Waste water recycling technology using a rotary disk module

Rotary disk modules developed for the separation of highly concentrated activated sludge can be used in place of biological settling ponds to efficiently recycle sewage or waste water. Applied to sewage treatment, the rotary disk module allowed us to consistently obtain recycled water of T-N < 5 mg/l, BOD < 2 mg/l, SS trace. When the module was applied to cafeteria waste water treatment, we were able to obtain recycled water of BOD < 2 mg/l, SS trace. In both cases flux through the module was maintained at 1.5 m3/m2/d while filtering liquid of 10–15 gl/l MLSS.

Heavy metal contents of some solid wastes in Ibadan, Nigeria

The heavy metal contents of some solid wastes produced in residential areas, a market, a cafeteria and the composts in lbadan, Nigeria, were measured. The solid wastes produced in low density areas with higher per capita income showed higher levels of heavy metals. The cafeteria waste showed low levels of some of these metals. The significance of the heavy metal status on Nigerian environment is discussed.