Portion Of Waste Research Articles

A planning model for using municipal solid waste management technologies- considering Energy, Economic, and Environmental Impacts in Tehran-Iran

Municipal solid waste can be considered both an opportunity and a threat. If it is not managed properly, it will cause pollution. On the other hand, it is a significant source of raw materials and energy. This paper aims to develop a multi-period multi-objective linear programming model to design a municipal waste management planning model. Cost, air pollution, and volume of waste constitute the objectives. Incineration, gasification, anaerobic digestion, landfill with and without gas recovery, recycling, and composting are the candidate technologies. Two scenarios, including examining all technologies and removing recycling and composting from the options, are considered. Incineration and gasification with average capacities of 31.8 MW and 10.4 MW were the first scenario’s energy generation systems. On the other hand, in the second scenario, incineration, gasification, and anaerobic digestion with average capacities of 62.4 MW MW, 30.8 MW, and 59.8 MW, respectively, were the proposed options for energy production. All in all, results indicated that recycling and composting are preferable for waste management in Tehran; besides, among energy production technologies, incineration and anaerobic digestion are the best systems for the non-biodegradable and biodegradable portion of waste, respectively.

Fermentative Production of Lactic Acid as a Sustainable Approach to Valorize Household Bio-Waste

Source-sorted organic portion of municipal solid waste (bio-waste) can be fermented to lactic acid, a platform chemical widely used in the production of biodegradable polymers, green solvents and chemicals. In the present study, fermentation of bio-waste using lactic acid producing bacterium (LAB) Lactobacillus delbrueckii was investigated. Results showed that adding 10% (v/v) of L. delbrueckii as LAB inoculum along with pH adjustment to 6.2 had the highest lactic acid yield (0.65 g/g total sugars). Nevertheless, pH adjustment without bio-augmentation could also result in relatively high yield of lactic acid (0.57 g/g total sugars). Furthermore, enzymatic hydrolysis was applied to boost the lactic acid production slightly increasing the yield to 0.72 g/g total sugars. Thus, fermentative production of lactic acid can be achieved without the addition of enzymes to reduce production costs. Overall, the results indicate that bio-waste could be a suitable substrate for the production of lactic acid.

Jackfruit Waste: A Promising Source of Food and Feed

All the food sources comprise edible and non-edible waste portions. With increasing demand for food and feed the current agriculture is focusing on agro-processing to utilize the maximum portion of the plant or animal resources. This review paper aims at summarizing the present status of utilization of jackfruit (Artocarpus heterophyllus Lam, Moraceae) wastes in food, feed, and other industry. Apart from the non-edible portion like peel and axis, the edible by-products like seeds of jackfruit mostly remain underutilized worldwide including Bangladesh. This article has reviewed the works devoted to utilize different waste portions of jackfruit other than the juicy edible bulbs. There are many works which suggested that the thick peel of jackfruit can be utilized in nutrient enriched cattle feeds, extraction of bio-fuel, nano-porous adsorbent for removing dye etc. The peel and central axis of this fruit also had investigated for extraction of pectin. The seeds of jackfruit were attempted by many researches to be used in various bakery products. The starch and protein fractions were isolated from jackfruit seeds flour to make them use at a purified state in the food formulations.
 Ann. Bangladesh Agric. (2019) 23(1) : 91-102

Flexure and shear behaviour of self-compacting reinforced concrete beams with polyethylene terephthalate fibres and strips

One of the major environmental concerns is the disposal of the solid waste. The limited landfill sites intensify the issue and increase the need for alternative use of solid waste. Plastic drinking bottles made of Polyethylene Terephthalate (PET) are one of the major portions of solid waste. Beverage containers are made by PET and are intended for single use only. This study is focused on the use of PET as Fibres cut from waste drinking bottles in concrete. Long strips and Short PET fibres cut it from waste beverage bottles were used in self-compacting reinforced concrete (SCRC) beams as reinforcement. Together with the steel reinforcement in beams, the PET strips or fibres were used with, and without shear reinforcement. In SCRC beams detailed for the flexural and shear failure, the 1 percent volume fraction of short strips or fibres were used. Material properties such as compressive strength, elastic modulus were performed along with the beams tested under four-point bending. The results were analysed and compared with strips or fibres reinforced beams with a control beam. Based on the results, it was found that PET bottles as strips or fibres could be used as shear and flexural reinforcement in concrete as enhance in ductility, load capacity and shift of mode of failure were observed with strips and fibres.

Municipal Solid Waste Characterization and its Associated Vector-borne Diseases within the Vicinity of Dumpsite and Controlled Site

This paper presents the composition of municipal solid waste in Uyo and vector-borne diseases associated with municipal solid waste within the vicinity of the dumping site (less than 1 km) and controlled site (above 1 km). The compositions of municipal solid waste were determined using samples obtained from Uyo village road waste dumping site. The dumpsite receives solid waste from all the communities in Uyo local government area. In order to assess the public perception of vector-borne diseases associated with municipal solid waste, sample survey method was adopted, which involved the administration of 500 questionnaires of which 250 were administered to the residents who lived less than 1 km from the boundary of the waste dumpsite and 250 questionnaires were also administered to the communities living further away. The compositions and percentages constituent by mass revealed the following: Organic waste component constitute 53.86% and inorganic constituted a waste portion of 46.14%. For vector-borne diseases associated with municipal solid waste, the results indicated that 70.8% of the respondents attended tertiary education (OND/NCE and above), so the issues associated with municipal solid waste may not be strange to them. A significant number of respondents are aware that the origin of municipal solid waste is residential, commercial, industrial, market, street sweeping and industrial sectors. Respondents are more aware that rats, flies, mosquitoes, birds, pigs and cockroaches are vector-borne diseases associated with municipal solid waste. The findings in this study will be useful in a comprehensive solid waste management program which encompasses sweeping, storage, collection and disposal of solid waste. However, the waste can be best treated if any of these techniques are utilized composting, gasification and energy recovery in future for further reduction of waste.

Boosting landfill gas production from lignin-containing wastes via termite hindgut microorganism

Lignocellulose comprises a significant portion of municipal solid waste (MSW) − 40–70% in developed countries, including paper, wood, and yard waste. Cellulose and hemicellulose are often shielded by lignin, posing a barrier to waste decomposition and landfill gas generation. Unfortunately, lignin is resistant to microbial degradation under low-oxygen conditions that normally occur in MSW landfills.The bacterium strain TAV5, microaerophilic and member of phylum Verrucomicrobia, isolated from the hindgut of the Reticulitermes flavipes termite, the most widely distributed subterranean termite in North America. Its genome contains genes associated with methylotrophic competency which code for enzymes that structurally modify lignin. The overall goal of this research was to use TAV5 to modify lignin and boost methane production from MSW.Batch-scale reactors (125 mL) were filled with paper, yard, or wood waste, and four ratios of mixed of waste. Reactors were seeded with different ratios of TAV5 to anaerobic digester (AD) microorganisms (representing landfill anaerobic microorganisms). Based on batch tests, optimal ratios of TAV5 to AD microorganisms were used to seed wastes (mixed, yard, and wood) in 6-gallon reactors.Addition of TAV5 increased methane production from mixed waste, yard waste, and wood, by 49%, 34%, and 297%, respectively. TAV5 decreased acid soluble lignin by 7–39%, depending on waste type. TAV5 grown under aerobic conditions and room temperature (not requiring a heated anaerobic chamber) was found to remain viable and increase methane production under low-level oxygen conditions (1–2%). This finding will potentially lessen costs for growing large volumes of it for seeding landfills.

Present Scenario of Waste Management in India

In India, approach towards waste management is unscientific. Even today, large portion of solid waste is dumped indiscriminately on outskirts of places without any prior treatment leading to groundwater contamination and increase in air pollution. Resource recovery from waste and safe disposal of residual in scientifically designed landfills are grossly neglected. The present system is focused on collection and transportation of largely mixed unsegregated waste for sustainable solid waste management, but the capacity to plan and manage the system and ensure the enforcement of rules is a major challenge. This study analyses current scenario of waste management in India. Besides presenting few mitigation choices to respond to the growing challenge, it also suggests mechanisms for ensuring integrated waste management systems.

Evaluating Anaerobic Digestion Technology in Reducing the Quantity of Solid Waste: Case of Kigali Dumpsite

Biodegradable organic matter constitutes a great portion of Municipal solid waste and comprises organic material which can be broken down by bacteria like paper, card, green waste, food waste, miscellaneous items with an organic element and fine materials. This paper mainly evaluated the potential of anaerobic digestion technology in reducing the quantity of solid waste destined to the dumpsite in Kigali city. The paper evaluates the viability of using biodegradable waste meant to the land where the biogas is produced and undertaking its cost & benefit analysis for chemical, physical and biological characteristics of municipal solids waste on anaerobic digestion technology. The quantity of municipal waste generated in Kigali city was used for designing the biodigester required. The paper indicates that the organic waste in Kigali city produces 457 L/kg DM of methane and the overall assessed value of methane was 51,384,375 L with the electricity derived from the methane of 180,873 KWh which is 54% of the daily demand in Kigali city. The volume of the biodigester was found to be 58,065 m3. Based on the energy recovered, revealed that cities will benefit this research for the population demand for the increased electricity.

Rescuing imperfect produce: The effects of stigma disclosure strategies, controllability, and aesthetics

In the U.S., the foodservice industry has been responsible for significant portions of food waste. Recently, on-site foodservice industry leaders advocate for the potential use of imperfect produce. However, lack of research efforts on the use of imperfect produce limits its adoption by the industry. Thus, this study investigates ways to enhance guests’ perception of companies when they adopt imperfect produce in their operations. Grounded in stigma theory, this research conducted two studies to evaluate the application of stigma theory to imperfect produce in a foodservice setting: study one, 3 (disclosure strategies: simple vs. de-categorization vs. integration) × 2 (controllability: high vs. low) and study two, 3 (same disclosure strategies) × 2 (aesthetics: standard vs. aesthetic). Findings of this research indicate that simple disclosure strategies are not effective compared to the other two strategies. However, this depends on controllability of the stigma and environmental aesthetics of imperfect produce presentation.

Enhancing anaerobic digestion of okra waste with the addition of iron nanocomposite (Ppy/Fe3O4)

The high reactivity, adsorptive capacity and environmental stability of polypyrrole-magnetic nanocomposite (nano-PPy/Fe3O4) additive are the sterling properties that make it useful for water/wastewater treatment. PPy/Fe3O4 is akin to other previously studied iron-based additives used for improving biodeterioration of lignocellulosic substrates with their electron donation capability during anaerobic digestion process. This study examined the enhancement of anaerobic digestion of okra waste with nano-PPy/Fe3O4 additive. Portions of okra waste were treated with different dosages of PPy/Fe3O4 additives (0, 20, 75, 750, and 1000 mg/l) and digested anaerobically using the biomethane potential bioreactors at mesophilic condition and hydraulic retention time of 32 days. The morphological deformation and elemental analysis of the undigested substrate, the control and digestates of substrate supplemented with nano-PPy/Fe3O4 additive evaluated with Scanning Electron Microscopy (SEM-EDS) revealed structural decomposition in the digested samples and increased Fe ions (0.1-3.9 wt%) in the digestates. The bioreactor with 20 mg/l cumulative volumes of the PPy/Fe3O4 additives recorded the highest increase of 2.74% rise in biomethane yield. Artificial neural network (ANN) and kinetic models (first-order kinetic and modified Gompertz model) were validated with the experimental data at 95% confidence level, but ANN model showed better goodness of fit and better correlated with the experimental data.

Effect of ageing on waste characteristics excavated from an Indian dumpsite and its potential valorisation

This paper assesses the effect of ageing on physicochemical characteristics of excavated municipal solid waste from Mulund dumpsite in Mumbai, India. Based on disposal year, waste was excavated from different zones in the dumpsite. The excavated waste was screened into five different size categories and further sorted into different streams. Physicochemical characteristics, i.e., pH, bulk density, ultimate and proximate analysis, calorific value and heavy metal concentration of excavated waste were also determined. The results indicate a change in the characteristics and composition of waste with age. The particle size distribution of waste revealed that waste above 80mm was mostly plastic and textile, whereas <4mm (fine fraction) composed of soil-like material. Above 80mm fraction shows a decreasing trend with age and depth, suggesting particle size reduction with time. Parameters like volatile matter, total and organic carbon and calorific value of excavated waste also reduced with the age. A significant portion of waste was fine fraction (∼45%) emphasising on its valorisation for success of landfill mining. Furthermore, metal content in the dumpsite was <1%. The findings from this study can be used to reclaim dumpsites and suggest possible valorisation routes for excavated waste in developing countries like India.

Quantification and determination of household food waste and its relation to sociodemographic characteristics in Croatia

Every year in the EU alone, almost 90 million tonnes of food is lost. The sectors contributing the most to this amount are households, accounting for 53% of total food waste. Bearing in mind the fact those two-thirds of this amount refers to the occurrence of waste which is theoretically avoidable, the greatest attention should be paid to the generation of food waste in households. In Croatia, there is no data on the quantities of food waste produced, but only estimates on the amount of such waste. The aim of this research paper was to determine the type and amount of household food waste and the differences in production of waste relative to the socio-demographic characteristics of household members. The research was carried out by 115 Croatian households, who self-reported the amount of food waste during seven days. According to the results, on average, 2.57 portions of food waste were reported as the amount of discarded food per household member per day, equivalent to 0.21 kg of food waste mass. In general, the typical Croatian household generates 75 kg of food waste per person on average. The age of respondents positively affected the prevention of waste, while the income level and the number of children under the age of 18 in the household had an adverse impact.

Elevated biogas production from the anaerobic co-digestion of farmhouse waste: Insight into the process performance and kinetics.

The biodegradable portion of solid waste generated in farmhouses can be treated for energy recovery with small portable biogas plants. This action can be done across the Netherlands and all around the planet. This study aims to appraise the performance of anaerobic digestion of different wastes (cow manure, food waste and garden waste) obtained from a regional farmhouse. Batch reactors were established under mesophilic conditions in order to investigate the impact of ternary mixtures on the anaerobic digestion process performance. Different mixing ratios were set in the batch tests. The upshots from the experiments connoted that ternary digestion with cow manure:food waste:garden waste mixing ratio of 40:50:10 yielded higher biogas amount. The kinetics’ results showed quite good congruence with the experimental study. The results from the kinetic analysis appeared to be in line with the experimental one.

Greedy randomized adaptive search procedure to design waste collection routes in La Palma

This paper seeks to analyze application of a metaheuristic in the improvement in the design of routes for the collection of recyclable waste in the island of La Palma (Canary Islands, Spain). This work is a partial result of a technological and research transfer project aimed to analyze the route planning for collecting two portions of the recyclable waste, specifically paper and cardboard packaging and plastic packaging and cans, in this context. This scenario is modelled by an optimization problem termed Eco-efficient Vehicle Routing Problem. A mathematical model is proposed to formalize this problem. A Greedy Randomized Adaptive Search Procedure (GRASP) is applied to obtain approximate solutions in real-life scenarios. Its goal is to increase the amount of recyclable waste collected, prioritizing the collection of those containers with the highest fill level. Moreover, a fill level estimation of the containers based on an historical data analysis is also developed and integrated into the solution approach. The results obtained in the computational experiments reveal that the proposed solution approach is highly efficient and able to improve the current route planning according to eco-efficient metrics.

Effect of dry-solid content level in feeding slurry of municipal solid waste consumed by FSIG/GT power generation process; a theoretical study

The theoretical studies on Fuel Slurry Integrated Gasification/Gas Turbine (FSIG/GT) power generation process have progressed. The present focuses on the influence of dry-solid content level (DSC) in the slurry consumed by FSIG/GT process. At the present, the portion of Municipal Solid Waste (MSW)—known as LWTR (letter, wood, textile, and rubber)—fuels the unit. In such a process, the solid fuel is mixed with water to form a slurry, which is pumped into a drier. The dried fuel is fed to a gasifier and the produced gas is cleaned until reaching adequate levels of particle content and sizes, as well alkaline concentrations for injection in commercial gas turbines. Energy recovering is provided by steam cycles. The highest 1st Law efficiency became close to 32% when DSC nears 50%. The results demonstrate that power generation efficiencies are very sensitive regarding the DSC of feeding slurry. Such information might be useful at the decision-taking phase of power generation unit design.

Management of solid municipal waste as the federal ecological project

The dynamics of solid municipal waste accumulation in Russia is considered taking into account the low rate of their reprocessing and utilization, which worsens the living conditions and aggravates the social tension in the country. The necessity to create an almost new industry is noted based on the collection, sorting, temporal storage, reprocessing and disposal of the non-utilizable part of waste. The tasks arising may be divided in two groups, i.e., technological and engineering geological groups. The most important tasks of the former group include sorting waste, separation of waste portion suitable for re-use as secondary raw material and recycling of the bulk of waste with the subsequent disposal of non-utilizable part. Among engineering geological tasks, the focus is concentrated on zoning territories for the optimal allocation of sites for temporary storage, reprocessing and disposal of solid municipal waste so that the newly formed bodies not to become a new source of technogenic contamination of the environment.

Are LEED-certified healthcare buildings in the USA truly impacting sustainability?

Healthcare buildings are energy and water intensive, which remarkably impacts their sustainability. They also share a larger portion of hazardous and non-hazardous wastes. Leadership in Energy and Environmental Design (LEED) has been rating healthcare buildings under a separate category of Building Design and Construction (BD + C): Healthcare to acknowledge their role and importance. This research investigates the credit points achieved by these buildings using all versions and rating systems of LEED BD + C: Healthcare. The results report a very small number of Platinum-certified buildings as compared to other certification levels. Further, Technique for Order of Preference by Similarity to Ideal Solution is applied on credit points and certification levels according to their rating system, climate and location to reveal that buildings require a lot more effort to raise their certification level from Gold to Platinum as compared to the effort required between Gold, Silver and Certified. Based on this, a new certification level is proposed. Furthermore, buildings located in dry weather and South region of the USA have been shown to achieve better credit points. The findings can help designers in scoring better LEED points, which could help promote the culture of rating systems.

Methodology for upstream estimation of construction waste for new building projects

Construction waste includes waste arising from construction works such as new build, renovation, demolition and road works. Through waste sorting and separation, inert material can be used to fill in reclamation sites; however, the non-inert portion of the construction waste still goes to landfills. However, Hong Kong is running out of landfill space. When determining reduction and management strategies for construction waste, the Government's objectives are to reduce waste generation, maximize reusing and recycling and reduce the intake of mixed construction waste at landfills. In order to develop and implement the waste reduction and management strategies at project level, proper quantification of construction waste generation is a prerequisite. Our research reveals that limited information is currently available for understanding the magnitude and composition of construction waste and for preparing an appropriate construction waste management plan for a project on new or existing facilities. To bridge the gap, the aim of this research is to present a comprehensive and practical approach for estimating the construction waste for building projects once detail design is carried out for new build or major retrofitting works. The estimation of waste quantities is based on the actual design information available from tender or contract documentation for a project at the upstream stage (a full set of bills of quantities classified under standard format). The proposed methodology of aggregating wastages accruing to quantified elements for a complete building has its advantages over a ball park figure established through indexing or other methods as proposed in existing literature, in terms of ensuring accuracy and maximizing the use of available design information whilst the workflow is uninterrupted.Three representative case studies with different formwork and façade systems are depicted to highlight the significant effects on waste generation in otherwise similar construction projects.

Cost-benefit analysis of a circular economy project: a study on a recycling system for end-of-life tyres

End-of-life vehicles (ELV) represent a relevant waste source in Europe, even if ELV recycling is a priority of the European Union waste legislation and Environment Action Programmes (EAPs). End-of-Life Tires (ELTs) constitute a relevant portion of ELV waste. Textile fibre, which is a relevant portion of the ELT material, is considered as a special waste (European Waste Catalogue – EWC code 19.12.08). The main problem related to textile fibre is its contamination with rubber which does not allow to obtain a pure product economically and qualitatively useable.The aim of this paper is to illustrate an innovative technology for ELT fibre's recycling, which allows to transform textile fibre into a useful secondary raw material for different applications.In particular, the use of ELT fibre as additive for bituminous conglomerates has been investigated. The different processes have been analysed from an environmental point of view, applying the Life Cycle Assessment methodology. It came up there is an impact reduction in case the ELT fibre is reused as additive for bituminous conglomerates, instead of disposing it (through incineration).Moreover, the financial and economic sustainability of the related technological process has been evaluated to check whether the process is sustainable in the long term. Starting from the results of the Life Cycle Assessment, economic performance indicators have been calculated, by applying the European Commission methodology for cost-benefit analysis. According to the present cost-benefit analysis, in the medium and long term the system is financially viable, and the high economic profitability makes the process economically sustainable. Furthermore, a sensitivity analysis as well as a risk assessment have been carried out in order to identify critical variables, evaluate risks and define risk mitigation measures. According to the sensitivity analysis performed, the project is not highly risky since even in the worst scenario the possible loss is moderate.Based on the results of this analysis, it can be concluded that this ELT fibre's recycling system can be replicated across Europe, conveniently fostered by national policies (such as subsidies, value added tax etc.).

Decentralized composting of household wet biodegradable waste in plastic drums: Effect of waste turning, microbial inoculum and bulking agent on product quality

Household wet biodegradable waste (HWBW) forms a major portion of municipal solid waste (MSW) in developing nations. Its recycling at the source of generation can not only reduce waste transportation costs but also prevent harmful air emissions. Therefore, the present study was planned to investigate the performance of a decentralized household composting system for onsite recycling of source-segregated HWBW. The study was carried out in the recycled plastic drums (capacity = 100 L). The effect of waste turning and addition of microbial inoculum and bulking agent (garden waste) on the composting process was examined. The results showed that proper provisions for aeration and periodic waste turning are necessary to produce good quality compost. The addition of a suitable microbial inoculum can reduce duration of waste stabilization. During composting, the peak temperature was found greater than 55 °C for 3–6 days and the compost yield (<4 mm fraction) was 18%–20%. The phytotoxicity tests results showed that the growth of cress plants is not affected in the presence of 20% of compost mixed in soil. One-time addition of inoculum at the start of composting process was found sufficient for completion of the active decomposition period within 30 days. Based on the above results, two-drum systems can be suggested as feasible option to produce compost from HWBW.