Valorization of food waste: A comprehensive review of individual technologies for producing bio-based products.

BACKGROUND: The escalating global concerns about food waste and the imperative need for sustainable practices have fuelled a burgeoning interest in the valorization of food waste. This comprehensive review delves into various technologies employed for converting food waste into valuable bio-based products. The article surveys individual technologies, ranging from traditional to cutting-edge methods, highlighting their respective mechanisms, advantages, and challenges. SCOPE AND APPROACH: The exploration encompasses enzymatic processes, microbial fermentation, anaerobic digestion, and emerging technologies such as pyrolysis and hydrothermal processing. Each technology's efficacy in transforming food waste into bio-based products such as biofuels, enzymes, organic acids, prebiotics, and biopolymers is critically assessed. The review also considers the environmental and economic implications of these technologies, shedding light on their sustainability and scalability. The article discusses the role of technological integration and synergies in creating holistic approaches for maximizing the valorization potential of food waste. Key finding and conclusion: This review consolidates current knowledge on the valorization of food waste, offering a comprehensive understanding of individual technologies and their contributions to the sustainable production of bio-based products. The synthesis of information presented here aims to guide researchers, policymakers, and industry stakeholders in making informed decisions to address the global challenge of food waste while fostering a circular and eco-friendly economy.

Additive facilitated co-composting of lignocellulosic biomass waste, approach towards minimizing greenhouse gas emissions: An up to date review.

Although the composting of lignocellulosic biomass is an emerging waste-to-wealth approach towards organic waste management and circular economy, it still has some environmental loopholes that must be addressed to make it more sustainable and reliable. The significant difficulties encountered when composting lignocellulosic waste biomass are consequently discussed in this study, as well as the advances in science that have been achieved throughout time to handle these problems in a sustainable manner. It discusses an important global concern, the emission of greenhouse gases during the composting process which limits its applicability on a broader scale. Furthermore, it discusses in detail, how different organic minerals and biological additives modify the physiochemical and biological characteristics of compost, aiming at developing eco-friendly compost with minimum odor, greenhouse gases emission and an optimum C/N ratio. It brings novel insights by demonstrating the effect of additives on the microbial enzymes and their pathways involved in the degradation of lignocellulosic biomass. This review also highlights the limitations of the application of additives in composting and suggests possible ways to overcome these limitations in the future for the sustainable and eco-friendly management of agricultural waste. The present review concludes that the use of additives in the co-composting of lignocellulosic biomass can be a viable remedy for the ongoing issues with the management of lignocellulosic waste.

Treatment Options for Municipal Solid Waste by Composting and Its Challenges.

Recovery and recycling of municipal solid waste biodegradable fraction (50-55%) are essential for attaining sustainability and a circular economy. Among organic waste treatment methods, composting is used to recycle organic fractions of waste. However, only 10-12% of municipal solid waste is utilized for composting treatment due to a lack of segregation practices and process challenges, including long process periods, odorous and greenhouse gas emissions, nitrogen loss, and low compost quality, which hinders large-scale practice. The current review paper discusses the challenges of composting treatment and its possible solutions. Various strategies were explored to address these challenges, such as utilizing microbial inoculum, additives, and optimization of physicochemical parameters. It also emphasizes the application of metagenomics for exploring key species. The knowledge about the microbial community and biochemical pathways (genome mining) can be exploited for the improvement of treatment efficiency. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01087-4.

Municipal Solid Waste Management using Geographical Information System aided methods: a mini review.

Municipal Solid Waste Management (MSWM) is one of the major environmental challenges in developing countries. Many efforts to reduce and recover the wastes have been made, but still land disposal of solid wastes is the most popular one. Finding an environmentally sound landfill site is a challenging task. This paper addresses a mini review on various aspects of MSWM (suitable landfill site selection, route optimization and public acceptance) using the Geographical Information System (GIS) coupled with other tools. The salient features of each of the integrated tools with GIS are discussed in this paper. It is also addressed how GIS can help in optimizing routes for collection of solid wastes from transfer stations to disposal sites to reduce the overall cost of solid waste management. A detailed approach on performing a public acceptance study of a proposed landfill site is presented in this study. The study will help municipal authorities to identify the most effective method of MSWM.

Integrated analytical hierarchy process-grey relational analysis approach for mechanical recycling scenarios of plastics waste in India.

Mechanical recycling is an indispensable tool for plastic waste (PW) recycling and has the highest share in the PW recycling sector in India. The transition to the circular economy of plastics (CEoP) needs a systemic perspective on the mechanical recycling processes. Nevertheless, the assessment of multiple parameters influencing the mechanical recycling of PW is a complex decision-making problem for the development of triple-bottom-line mechanical recycling. A systemic perspective of various mechanical recycling scenarios was performed by employing a multi-criteria decision-making approach to examine the complexity of interlinked factors in the present investigation. Analytical hierarchy process (AHP) integrated with grey relational analysis (GRA) was used to evaluate the criteria that directly influence quality-oriented mechanical recycling. Data were collected by conducting semi-structured interviews using a framed questionnaire in stakeholder engagement with mechanical recyclers of PW. The first level hierarchy included economy, technical, resource consumption and environmental criteria. These criteria were further categorized into various significant indices such as quality of recyclate, recyclability, water and energy consumption during recycling. The results of the integrated grey relational analysis indicated that the technical parameters including quality of recyclate, resource efficiency, PW processing rate and recyclability have a significant influence on mechanical recycling. Based on AHP-GRA, scenario MR6, i.e. manufacturing of PET strap from recycled PET flakes, was ranked the optimal mechanical process amongst the various scenarios. MR6 was followed by Straps and Films at the second and third rank. The lowest ranking was observed for polymer blend recycling. These processes with higher ranks produced good quality recyclate with better efficiency and recyclability. Moreover, these processes consumed optimal resources during manufacturing. These processes also exhibited less maintenance cost, high production rate, low chemical consumption and waste generation as well as implemented pollution control practices.