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Excessive food waste (nearly 1.3 billion tons per annum) has exacerbated the world hunger crisis. This comprehensive review focuses on the food waste scenario, adverse effects, food waste management, existing waste management policies, and regulations in Bangladesh. Municipalities and urban centers generate 3.78 million tons of waste each year (15.96% of total food waste). This study utilized the national database to analyze food waste generation and projected growth by the year 2050. Yearly an estimated 17215.2 thousand acres of land and a significant amount of natural resources (water, energy) are being used to produce 23691.15 thousand tons of wasted food (45% of total food production). This study critically analyzed the waste management policy gap of Bangladesh and clearly identified each stage of the food loss production supply chain. The study assessed that yearly 481.6 MW energy could be generated from food waste. Focusing on effective policy and sustainability, a national food waste management model has been proposed for Bangladesh in compliance with sustainable development goals 12.3.1 global food loss. Food accumulates 16.7% to 20% of the world economy; therefore, any measures taken to reduce the food waste will be economically beneficial and environmentally sustainable.

Waste in the food supply chain is estimated to be about 30-40% of the total food production, which aggravates the world hunger and increases waste management burden and environmental impact. Despite the dire food scarcity, majority of this food waste takes place in developing countries because of the lack of appropriate and affordable preservation techniques. Traditional open sun drying is the most popular food-reservation technique to the local farmers due to near-zero capital cost and cheap labor cost. However, this method is highly energy intensive, unhygienic, and time demanding. The high energy consumption resulting from uncontrolled simultaneous heat, mass, and momentum transfer processes in traditional drying systems highlights the necessity of pursuing sustainability in drying process targeting reduced energy consumption, environmental and social impacts. This paper presents a comprehensive review on the sustainable food drying technologies based on renewable energy sources, with emphasis on the developing countries. It was observed that the integration of thermal energy storage with heat pump makes the integrated drying system more efficient, and dries food with better quality. Likewise, advanced integrated drying systems, such as, solar with microwave, and heat pump with microwave make the drying process more cost and quality competent. Finally, impact of resource distribution and governmental incentives for renewable energy use in sustainable drying is discussed.

Internal mixing twin-fluid atomiser is known to be one of the prominent atomisers for the generation of spray or spray-like dispersion from bulk liquids. This paper designs and investigates the per...

Drying techniques reduce post-harvest food deterioration. However, conventional drying consumes 20–25% of the energy used in food processing industries. This work presents a detailed design and comprehensive numerical analysis of a hybrid geothermal-PCM flat plate solar collector, which is in effect a self-sustaining renewable energy food drying system. The applicability of the hybrid geothermal-solar dryer for developing countries with a significant underground geothermal temperature gradient is investigated. The performed numerical analysis promises high efficiency and effectivity of this near-zero hybrid energy technology. The proposed conceptual design assessed using the related mathematical model to assess the functional parameters of the hybrid geothermal PCM flat plate solar collector dryer. Numerical simulation showed that the efficiency of hybrid geothermal PA-FPSC is 20.5% higher than conventional flat plate solar collector when the mass flow rate is at 0.02 kg/s. Therefore, successful integration of this technology to the existing food processing industries of the developing countries could be a step towards the prevention of irreversible climate change achieving SDG 12 (sustainable development goals).

Food waste is an alarming issue for the modern world. Drying is one of the oldest and easiest solutions for overcoming unnecessary food waste. However, most of the conventional drying consumes a significant amount of energy to remove water from food. On the other hand, there are many sources, which cause heat waste. Smart utilization of waste heat from sources including IC engine, turbine, brick kiln and something like those would be a great solution to the energy consumption problem of food drying. There is no systematic theoretical analysis of waste-heat-based food drying system available in the literature. In this study, a comprehensive transport model of drying system using engine’s exhaust waste heat has been simulated. Utilization of a small lab-scale IC engine exhaust results in reducing about 1137.15 kg of CO2 every year that would be produced from a conventional food dryer of the same capacity. In addition, low installation cost and payback period offer a promising rational solution of drying system. The proposed system is also capable of reducing entropy to an appreciable extent. Therefore, successful implementation of this proposed technique would offer a high-energy efficient, low-cost drying system along with ensuring a green environment.

In the last 50 years, plastics has become a favorite industry for packaging materials for their ease of manufacture and excellent performance. The advancement of food, electronics, automobile, medical and agricultural industries has increased the demand for packaging and casing materials made of large hydrocarbon polymers. Since plastics show resistance to biodegradation, they pose considerable threats to the environment. Degradable plastics and biopolymers offer promising solutions to this problem. Degradable plastics can be easily absorbed in the environment while exhibiting the properties of conventional plastics. There are three types of biopolymers according to their source: biomass extracted polymers, synthesized from microorganisms and produced from bio-derived monomers. Biodegradable plastics are commonly used in one-off packaging such as crockery, food service containers and cutlery. Although biodegradable plastics can replace conventional plastics in a lot of applications, their performance and cost are sometimes problematic. This chapter analyses the growth of the degradable plastic industry and explores their potential applications.

Cow dung or cow manure is a heterogeneous substance excreted by bovine animal species as waste. It also contains water, microbiota, feed scraps and dead skin. The demand for livestock and dairy products has led to the exponential growth in cow dung generation in the past decades. Cow dung is primarily disposed in the environment, used as organic fertiliser or used as solid fuel in rural areas. However, severe environmental and ecological damage has been caused by indiscriminate disposal and improper elimination of cow dung into the surrounding. This alarming problem can be addressed by converting cow dung into biofuel via thermochemical process or be used as organic fertiliser after vermicompost treatment. Moreover, cow dung can be used for electricity production, heat, biochar and friction composites. A cow dung to biofuel conversion systems should be efficient and well controlled to offer economically feasible energy generation and limit environmental pollution. Hence, the objective of this chapter is to analyse the physio-chemical properties of cow dung and evaluate its potential for multi-utilisation as biofuel and organic fertiliser. Moreover, the chapter discusses advanced processes of thermochemical energetic conversion of cow dung to assess its potential as a sustainable renewable source.

This paper presents the state of the art of the current status, techniques used for conversion, possible future prospects, policies and challenges of biomass energy in the context of Bangladesh. It is seen that the utilization of biomass energy is increasing day by day. Biomass has the potential capacity to contribute around 400 EJ/yr in the future global energy supply by the year 2050 ensuring the adaptability of Sustainable Development Goal 7 (access to affordable, reliable, sustainable and modern energy for all). However, in many cases, lack of modern technology augmented by socioeconomic challenges is creating a tremendous hindrance to the way of extracting and utilizing the biomass energy at a higher efficacy. The authors believe if well-researched plans and techniques are adapted specifically for Bangladesh, and followed accordingly, it is possible to mitigate this hindrance to a great extent. The authors have also proposed some recent techniques that might be feasible in the context of Bangladesh.

Nowadays, the electrical and electronic products are a crucial commodity for different purposes of daily life and they are multiplying five times faster than human like mobile phones, which has reached zero to 7.2 billion in only three decades. A 5-10% yearly increase in the amount of used electrical and electronic equipment that are disposed of prudently can cause environmental hazards that have an aversive effect on human health, marine life, contamination of groundwater, and reduces soil's fertility. Management of this enormous influx of electrical and electronic waste is a challenge for developing countries like Bangladesh with barebones solid waste management infrastructure. Inadequacy of public awareness, policies and poor budget in the field of waste management are few of the key factors behind this delineating scenario. In this study, the picture electrical and electronic waste productions in Bangladesh along with the recent E-waste management systems have been presented comprehensively. Based on the study, it was concluded that most of the adapted E-waste management methods are conversational and detached from current technological capability. A set of sustainable E-waste management system has been suggested along with the challenges, which might appear during the implementation of these strategies. Successful implementation of these suggested systems would advance the quality of E-waste management in Bangladesh increasing the current 35% overall E-waste recycling rate and offer enormous energy from the waste.

Water removal rate during drying depends on the microstructural pathways of water migration from inside the food materials. The water removal rate also depends on the mechanical properties of plant tissue. There is no literature that shows the interrelationship between viscoelastic property and transport phenomena during drying. In this study, the influence of viscoelastic property of plant-based food material on transport phenomena during drying has been experimentally investigated. Granny Smith apple, pears, and beet root has been taken as the sample in this study. A 2 kN Instron universal testing machine and ImageJ software were used in order to measure and analyze the viscoelasticity of the samples. Three different fruits Granny Smith apple, pears, and beet root show different viscoelastic properties along with different energy loss due to hysteresis. A positive relationship was found between energy loss due to viscoelastic nature of materials and drying kinetics. This correlation can be explained by the nature of the cell wall stiffness that facilitates or hinders the water migration in mechanical and thermal energy applications.

Food is one of the indispensable commodities for human existence. Insufficient production and lack of efficacious preservation system of food are the main causes of deprivation in Bangladesh. Bangl...

Today, urbanised people spend most of their time in indoor environments, and the risk of exposure to toxic materials in an indoor environment is of great concern. This paper considers sources for t...

Transition to alternative energy is receiving serious attention globally and in this very way, biodiesel from inedible neem can be an alternative to conventional liquid fuels as it contains 30–45% ...

Improved cooking stoves (ICSs) advance the cooking system significantly in Bangladesh. However, the comparative performance analyses of ICSs of Bangladesh are not available in the literature. In th...

The plastic-derived product, nowadays, becomes an indispensable commodity for different purposes. A huge amount of used plastic causes environmental hazards that turn in danger for marine life, reduces the fertility of soil, and contamination of ground water. Management of this enormous plastic waste is challenging in particular for developing countries like Bangladesh. Lack of facilities, infrastructure development, and insufficient budget for waste management are some of the prime causes of improper plastic management in Bangladesh. In this study, the route of plastic waste production and current plastic waste management system in Bangladesh have been reviewed extensively. It emerges that no technical and improved methods are adapted in the plastic management system. A set of the sustainable plastic management system has been proposed along with the challenges that would emerge during the implementation these strategies. Successful execution of the proposed systems would enhance the quality of plastic waste management in Bangladesh and offers enormous energy from waste.

Monodisperse aerosols are essential in many applications, such as filter testing, aerosol instrument calibration, and experiments for validating models. This paper describes the design principle, construction, and performance of a monodisperse-aerosol generation system that comprises an atomizer, virtual impactor, microcontroller-based isokinetic probe, wind tunnel, and velocity measurement device. The size distribution of the produced monodisperse aerosols was determined by an optical particle counter. The effects of atomizer characteristics, the rates of minor and major flow, and solution criteria were investigated. It was found that all these parameters affect the generation of monodisperse aerosol. Finally, the expected geometric standard deviation (≤1.25) of monodisperse aerosol particles was obtained with the most suitable atomizer for 10% oleic acid in ethyl alcohol solution with 5%–15% minor flow, where the ratio between the nozzle-to-probe distance and acceleration-nozzle-exit diameter was 0.66. The constructed monodisperse-aerosol-generation system can be used for instrumental calibration and aerosol research.

A hybrid energy system named as SAH embraces the features of solar and thermal devices to generate electrical and thermal energies simultaneously. Recently, some SAH has developed with higher efficiency but less feasible to the developing countries due to higher installation cost. Here, a cheaper SAH with more capability of utilising the solar energy and enhanced efficiency by incorporating fin with the SAH has developed. SAH performances have been analysed experimentally by varying the air mass flow rate from 0.0132 to 0.02166 kg/s for the both fin and without fin attached condition. During mass flow rate of 0.02166 kg/s, maximum efficiency for the collector, photovoltaic cell and the overall efficiency of the system has been recorded as 34.25%, 6.48%, and 35.26% with fin and 28.07%, 4.10%, and 29.37% without fin, respectively. This study would assist the researcher for further improvement of the SAH and guide the consumer to select the appropriate SAH.

The application of the drying technique for food preservation dates back thousands of years. The simple operation and easy installation of conventional drying technologies are responsible for its ubiquitous practice in various developing countries. The people of these countries prefer inexpensive conventional dryers over advanced dryers due to their financial constraints and lack of knowledge. However, recent developments in sustainable renewable energy drying technologies have made many advanced dryers accessible to developing countries as the associated energy cost is reduced. In order to adequately integrate the sustainable drying techniques with the existing drying systems in developing countries, a proper understanding of conventional drying practice is essential. In this chapter, the five most commonly used drying techniques including, sun drying, solar drying, biomass drying, STR drying, and reversible air drying, have been discussed extensively. In each section, the basic principle of these dryers, their advantages, and disadvantages are discussed.

A universal solution for food waste may not be practical as it is related to a complex mixture of economic inequality, policy failure, and lack of awareness. On the other hand, energy costs are steadily rising. Therefore, only through sustainable renewable drying technologies the crisis of food waste can be ameliorated. The high energy requirement of drying is one of the most predominant challenges towards achieving food security and economic sustainability. Therefore, this chapter proposes some improved drying techniques that can operate on renewable energy. Extensive discussion is done on their working principle, efficiency, effectiveness, and the quality of the dried product. The chapter starts by classifying the drying technologies to put the entire drying practice into perspective. Then the chapter introduces ten sustainable drying technologies for developing countries. Feasibility analysis was performed on the drying techniques which are currently in development stage. Each developing country has its unique energy economy and geographical features. Therefore, an in-depth analytical comparison among all the proposed dryers were made at the end of the chapter.

The modern practice of drying focuses on retaining the structural and bioactive functionality of foods. In order to produce high quality dried food, it is essential to understand the properties of food that appeal to general consumers. An ideal drying process should be able to maintain quality attributes such as texture, taste, aroma, nutrients, and color. However, these drying systems are expensive, and their operating and maintenance costs are also high. Therefore, a balance between the quality of dried food and the cost of the drying systems is desirable. Developing countries with limited resources cannot afford sumptuous drying technology. As such, selected sustainable drying techniques should not only be economical but also be able to preserve the expected quality. The main purpose of this chapter is to give an overview of the quality aspects of drying, along with the required energy and time to retain these features. Additionally, a method of selecting drying techniques for developing countries, taking the cost and safety factor into consideration, has been discussed extensively at the end of this chapter.

Extensive research and rigorous experimentation can reveal critical factors that affect the performance of drying technology. However, the industrial application of any new drying technology is far more challenging. For instance, new drying system needs to compete with the existing low-cost dryers, must abide by the country policies, and convince buyers to use renewable energy-based systems in a market dominated by fossil fuel-based systems. Therefore, there are numerous potential challenges in implementing the proposed drying techniques. In order to better prepare them for the impending challenges, this chapter is dedicated to discussing the possible difficulties associated with the industrial application of sustainable drying techniques. The chapter begins by discussing the overall challenges of drying and then provides an in-depth analysis of the specific implementation challenges associated with each type of proposed sustainable drying technologies.

The world has limited stock of conventional energy sources, and therefore this finite energy reserve must be utilized wisely for their socio-economic advancement. Drying techniques are fundamentally energy extensive. Hence, in order to recommend sustainable drying techniques for different developing countries, it is essential to evaluate their current energy scenario. In this chapter, the renewable and non-renewable energy resources of low income, lower-middle income, middle income, and high-income developing countries have been analyzed and presented. The chapter also provides a general discussion on the energy requirement for drying. The potential for integrating renewable energy with drying systems is also highlighted in this chapter. Since renewable energy usage in developing countries is still in the early stages, its integration with the drying industry will be met with various barriers and challenges. A comprehensive discussion on the barriers to renewable energy integration is provided at the end of this chapter.

This paper aims to establish consumer's perception of electric waste recycling and management on a national scale in Bangladesh. The attitude, willingness to pay (WTP) and consumers' behaviour were explored by conducting a questionnaire-based survey. The conclusions are based on 915 valid responses out of 2000 online survey invitations. Interestingly, 37.9% of the respondents indicated that they would accept to pay for electronic waste recycling. Analysis also shows that the preferred WTP would cover 5–10% of the recycling cost. Factors like environmental awareness, monthly income, and education level affect the consumers' WTP. Nevertheless, most of the participants believe that the Government should share the recycling cost. The study suggests that e-waste recycling can be stimulated by promoting environmental awareness, educating the public about the benefits of recycling e-waste, and making e-waste recycling more convenient. However, additional measures will likely be needed to tackle the e-waste problem. Thus, support for environmental education is imperative in order to promote environmental awareness and increase the WTP of consumers. The study outlines key characteristics of consumer-focused e-waste management archetypes and proposes an effective road map for Bangladesh.

World Food Program reports that more than 821 million people are subjected to acute hunger despite sufficient amount of food being produced. One of the underlying reasons is the food wastage due to poor preservation techniques and the energy cost of the established processing methods. Drying techniques are an effective means for reducing post-harvest food loss. However, the existing industrial drying techniques consume 20–25% of the energy used in the food processing chain. A system that utilizes the waste heat recovered from a diesel engine exhaust flue gas is proposed and an initial prototype tested. The system requires no external energy to operate the drying process; hence no CO2 is generated as a result of this process. Furthermore, the entropy is reduced by 0.206 kJ/kg.K as the overall thermal efficiency increases by 8.46%. It is estimated that the payback period is in the range of 321 days. Drying experiments were conducted to assess the dried food quality of five different staple food products, i.e. potato, pumpkin, carrot, radish, and apple. The drying performance (moisture removal rate) and product quality (Color analysis and Vitamin C analysis) conformed to the current industry standard. The overall performance assessment suggests that the system has the potential to reduce current levels of emission in food drying process and could be a stepping stone towards the development of energy-efficient food preservation technique.

Many of the traditional food preservation techniques offer an effective solution to food waste. However, there are many challenges that can be solved easily with the incorporation of modern technology. With the advancement of technology and better understanding, food preservation techniques are being changed day by day. Incorporation of feasible innovative technique can solve the challenges and enhance the overall performance of food preservation technology in developing countries. Although modern techniques offer enormous advantages, prior viability analysis must be conducted prior to incorporation in developing countries instead of traditional ones. Different constraints such as financial, technological, and environmental need to consider preceding of changing and modifying traditional food preservation technique. Therefore, the optimization of advanced technology must be analyzed before implementing modern technology in food preservation in developing countries. In this chapter, the feasibility of some potential advanced technologies in connection with food preservation has been discussed in this chapter.

When people have surplus foods and predict potential food insecurity in the future, food preservation needs to be adapted. From early history, humans felt the necessity of food storage and preservation. Human’s inquest mind has innovated and discovered different food preservation systems throughout history. Most of the preservation techniques practiced by the early humans were based on daily experiences. Utilization of natural energy including solar, biomass, and natural phenomena such as evaporation cooling, spontaneous reactions like fermentation are some of the common features of these food preservation techniques. Many traditional food preservation techniques in developing countries still follow this approach extensively. However, a wide variation prevails in each preservation technique in different regions of the globe. This chapter attempts to present a brief on the history of some selected food preservation techniques.

Drying is one of the oldest food preservation techniques associated simultaneous heat and mass transfer in order to extend the shelf-life of food materials. However, it is an energy intensive process and consumes about 20-25% of the energy used in the food processing industries. Developing of innovative drying system such as intermittent convective microwave (IMC) and utilization of renewable energy like solar energy in drying can be the potential solution of minimizing consumption of conventional energy in drying process. In this study, an innovative solar energy driven IMC dryer has been designed and fabricated. In addition to this, the effectiveness of this dryer over conventional drying process has been performed. Overall, the developed renewable energy based IMC drying shows better performance in energy consumption and quality aspect of the finish food product.

Dramatic variation of tool temperature while machining is treated as a considerable problem because it shortens the life of cutting edge which is considered as low durability of that part resulting in an adverse effect on the production. The excessive heat generated in the local cutting zone leads to thermal deformation, noticeable tool wear and low machining accuracy as well. In general, during highly precise machining operatios, it is necessary to determine the amount of process heat and heat fluxes into the work piece, tool and chips. This differs from various physical properties of tool including tool geometry, physical properties and for different operating conditions. Therefore, for precision machining operation it is discernible that the temperature distribution and the rate of cutting heat generation during the cutting operation are important for the prediction of thermal deformation. The aim of this research is to show an explicit overview of the nature of heat generation varying with different materials and cutting speed. In this study the cutting environment was designed in Solidworks Premium 2016 software and then it was simulated through Comsol Multiphysics using thermoelastic physics interface. The analysis was observed for aluminum and cast iron as job material and high speed steel as cutting tool. The result found during analysis was more heat generation in cast iron machining compared to aluminum. It was also determined that the total temperature field of job material during cutting process changes with simultaneous change in cutting speed and feed rate. The results certified the endeavor of making a comparison between two dissimilar materials for determining the optimum condition in production aspects.

Food is one of the primary necessities of human. Consumption of any kind of food is not sufficient unless it ensures required nutrition. Safe food is indispensable for humans. The quantity of this highly valuable bounty is not uniformly distributed across the globe. Similar to having low per capita income and low urbanization growth, developing countries produce a relatively lower amount of food than developed countries do. People in developing countries encounter acute hunger on a daily basis. On the other hand, significant loss of food takes place throughout the world. However, the prime causes of food waste vary through countries. A significant amount of food is being wasted at the consumer level in developed countries. On the other hand, postharvest loss accounts for the maximum wastage of food in developing countries. In this chapter, the socioeconomic status of both developed and developing countries has been discussed extensively. Especially, the availability of food in developing countries has been focused in this chapter.