Energy and water are two basic resources that are intricately connected, and hence, they become a vital component to the functioning of regional, national, and international economies. Water is a finite resource, and many regions around the world are already experiencing water scarcity. About a quarter of the world’s population are living in water-scarce countries. If the same trend continues, by 2040 the world would not be able to meet the demands of ensuring safe drinking water for all people and generating energy for the growing population at the same time. Hence, an innovative is to be devised and implemented in the energy sector so that the water and energy demands can be met to ensure water and energy availability to the global citizens. This chapter focuses on the innovative approach of water footprint throughout the various energy production sectors critically focusing on the renewable energy sector. Moreover, to overcome the excess water consumption, few strategies to overcome the excessive water usage and comparative analysis on water consumption between bioenergy and other renewable energy sectors are also discussed.

The need for a green and sustainable nanomaterial sourced from biomass in the form of nanochitin has raised interest in paving the way towards incorporating biological resources for the production of functional materials. Nanochitin as nanofibers and nanocrystals/whiskers have attractive features like their ability to self-assemble into multidimensional biomaterials while retaining their intrinsic characteristics. Herein, the review discusses chitin's molecular association and hierarchical assemblies and gives an overview of the extraction methods adopted to produce nanochitin. Recent progress in the development of advanced functional nanochitin-based materials/composites and their current application in agriculture and environmental remediation are reviewed to gain a better understanding of their applicability for forthcoming research and improvement. Furthermore, the environmental impact assessment of chitin has been discussed, followed by the techno-economic analysis, thus providing scope for improvement in manufacturing and perspectives on the potential of nanochitin in the context of sustainable material and their role in circular bioeconomy.

Anaerobic digestion (AD) plays a crucial role in sustainable waste management, converting biowaste into biogas while generating digestate as a nutrient-rich by-product. This review explores innovative digestate valorization strategies based on the principles of green chemistry, focusing on resource efficiency and waste minimization through reutilization routes involving environmentally benign processes. The study examines the physicochemical characteristics of digestate and highlights its applications in sustainable agriculture, bioprocessing for enzyme production, algal biorefineries and hydroponic systems. Advanced valorization pathways, including bio-based polymer synthesis, biochar production and recovery of high-value chemicals such as volatile fatty acids, lactic acid and humic substances for commercial viability are critically analyzed through technoeconomic feasibility and life cycle assessment insights. Inorganic nutrient recovery techniques, including ammonia stripping, struvite precipitation and membrane separation, were also explored for their potential to enhance resource utilization. Thus, by integrating digestate valorization within a circular bioeconomy framework and industrial symbiosis, this study underscores its role in reducing the environmental impact, improving the carbon footprint and contributing to net-zero emissions. Our discussion further highlights the challenges in digestate processing, regulatory considerations and future research directions to optimize sustainable valorization strategies by integrating green chemistry principles.

Bioremediation is an effective and sustainable method for removing xenobiotic pollutants from the environment, utilizing microorganisms and plants to metabolize harmful chemicals into harmless compounds like CO2 and water. Among various bioremediation strategies, mycoremediation stands out due to the unique enzymatic capabilities and metabolic diversity of fungi, enabling them to degrade persistent and toxic pollutants under harsh environmental conditions. This review specifically addresses the application of mycoremediation to emerging contaminants pharmaceuticals and personal care products (PPCPs) which pose significant environmental challenges due to their persistence, bioaccumulation potential, and ecotoxicity. This article provides a comprehensive overview of fungal-based strategies for PPCP remediation, documenting the fate, distribution, and impacts of these contaminants in soil. It highlights the enzymatic mechanisms and fungal species involved in PPCP degradation, with an emphasis on their ecological resilience and pollutant-specific adaptability. Additionally, the review explores under-discussed factors influencing fungal efficacy, such as pH, temperature, and contaminant concentration, alongside innovative advancements like myco-nanotechnology and enzyme engineering that enhance remediation efficiency. By integrating these aspects with policy perspectives and sustainable development goals, this review contributes novel insights into the potential of mycoremediation as a cutting-edge approach for mitigating PPCP contamination. It underscores the role of fungi in advancing circular economy principles and offers a foundation for future research and practical applications in environmental management.

The transition toward sustainable biofuel systems requires a multidimensional approach that integrates policy frameworks, sustainability assessment, and environmental performance analysis. Studies on biofuel development often focus on individual aspects such as feedstock optimization, life cycle emissions, or blending mandated. Few have attempted a comprehensive synthesis bridging these critical domains. This review addresses that gap by systematically examining global and regional biofuel policy instruments, evaluating sustainability metrics across environmental, economic, and social dimensions, and assessing environmental impacts using life cycle assessment, indirect land use change, and biodiversity frameworks. Additionally, the study explores integrative tools such as the water–energy–food–biodiversity nexus, industrial symbiosis, and multi-criteria decision analysis as pathways to optimize trade-offs and enhances stakeholder participation. Drawing from different articles and policy documents, this work develops a unified analytical framework and policy research roadmap to guide decision-making in the biofuel sector. The findings highlight the need for harmonized certification, expanded social LCA, circular bioeconomy integration, and adaptive governance strategies that align national goals with global sustainability targets.

Potato is among the most widely cultivated and consumed food crops worldwide, with production steadily rising to meet global food demands. Alongside this growth, industrial processing of potato-based products generates substantial amounts of waste streams, including peels, mash, pulp, and process water, that are often discarded without commercial utilization. These residues are rich in carbohydrates, proteins, and bioactive compounds, making them attractive substrates for extraction and bioconversion into a wide range of value-added products. Emerging studies demonstrate their potential for producing biofuels, organic acids, enzymes, carotenoids, lipids, nutraceuticals, fertilizers and bioenergy-related products. Valorization of potato residues not only enhances resource efficiency but also supports circular economy principles and reduces environmental burden. This review synthesizes current advances through a bibliometric and systematic analysis of SCOPUS-indexed publications (2015–2025), complemented by keyword co-occurrence mapping using VOSviewer to capture research hotspots, technological pathways, and sustainability linkages. The findings highlight that potato waste valorization contributes significantly to Sustainable Development Goals (SDGs), particularly by promoting responsible production and consumption (SDG12), enabling clean and renewable energy generation (SDG7), and mitigating negative environmental impacts (SDGs 6, 11, 13, 14, and 15). Furthermore, integrating potato residue valorization into industrial symbiosis strengthens innovation, infrastructure, and economic growth (SDGs 8 and 9). Overall, potato waste represents a versatile feedstock for biorefinery applications, offering a holistic model that integrates circular economy strategies with sustainable development objectives.

Bioremediation can help reduce and remove the pollution we produce, to provide clean air, water, and healthy soils for future generations. Pollution damages our health and the environment, affecting wildlife and the sustainability of our planet, as summarised in our policy briefing on food security. Under controlled conditions, bioremediation is the process of biologically degrading organic wastes, typically to a state of innocuousness or to concentration levels that remain within particular concentration limits set forth by the controlling authority. In bioremediation, it is possible to do it either ex situ or in situ, depending on a number of factors, such as the type and concentration of pollutants, cost, and/or site characteristics. As a result, ex situ is generally more expensive than in situ, since excavation results in additional expenses. Biological processes are the most effective and economical way to remediate a polluted site. Though bioremediation is not a new technique, our understanding of the mechanisms behind it is growing, enabling us to use it more effectively. Frequently, bioremediation uses fewer resources and less energy than conventional technologies and doesn't produce waste products that can be hazardous bioremediation has both technical and cost advantages, though it can sometimes take longer to complete than traditional methods.

Water pollution stands as a critical worldwide concern, bearing extensive repercussions that extend to human health and the natural ecosystem. The sources of water pollution can be diverse, arising from natural processes and human activities and the pollutants may range from chemical and biological agents to physical and radiological contaminants. The contamination of water disrupts the natural functioning of the system, leading to both immediate and prolonged health problems. Various technologies and procedures, ranging from conventional to advanced, have been developed to eliminate water impurities, with the choice depending on the type and level of contamination. Assessing risks is a crucial element in guaranteeing the safety of drinking water. Till now, research is continuing the removal of contaminates for the sake of supplying safe drinking water. The study examined physical, inorganic, organic, biological and radiological contaminants in drinking water. It looked at where these contaminants come from, their characteristics, the impact they have and successful methods used in real-world situations to clean the contaminated water. Risk assessment methodologies associated with the use of unsafe drinking water as future directives are also taken into consideration in the present study for the benefit of public concern. The manuscript introduces a comprehensive study on water pollution, focusing on assessing and mitigating risks associated with physical, inorganic, organic, biological and radiological contaminants in drinking water, with a novel emphasis on future directives and sustainable solutions for public safety.

Ionic liquids (ILs) are next generation solvents which are synthesized by organic salts, possess negligible vapour pressure and have low flammability. They possess high thermal and electrochemical stability, can be reused for multiple cycles, and its properties can be tuned according to the components used in its synthesis. Hence, ILs are considered to be potential alternatives for the conventional organic solvents for numerous applications such as environmental remediation, nanoparticles synthesis, as catalysts in various chemical reactions, as solvents for the extraction of biomolecules from recalcitrant lignocellulosic biomass, etc. In this review article, the holistic approach of ILs starting from various techniques adopted for its synthesis along with its critical review has been discussed followed by detailed discussion on the mechanism involved for the remediation of environmental pollutants using ILs. Further, in depth documentation of various environmental pollutants remediated till date using ILs has been done. One of the major drawbacks of solvents application is the reusability factor, and hence in this review article, techniques adopted to recycle/reuse of ILs has been discussed. Further, the adverse effect of using ILs for environmental remediation has been comprehensively discussed to present a holistic view. Future studies should focus on synthesis of environment friendly ILs and their field-scale applications for environmental remediation.

With an increase in the world's economy and the human population, there's a growing need for drinking water suitable for consumption. Water management might inevitably become the top priority on a global scale. The rapidly evolving bioremediation landscape is a major driver for the development of sustainable solutions that can provide value beyond just environmental remediation. Phycoremediation or algae-mediated remediation is attracting the most attention because of its captivating sustainability characteristics, its ability to eliminate odors, fouling, and toxins, its ability to eliminate many common as well as emerging contaminants from the gaseous and aqueous environment, and its ability to produce biomass for a variety of value-added products. Algae-based wastewater treatment plants like bioreactors are gaining more attention than traditional membrane reactors as they are environmentally friendly and sustainable. Due to the non-function of traditional municipal wastewater treatment plants, emerging pollutants such as personal care products, pharmaceuticals, antibiotics, and mono- and polyaromatic hydrocarbons are discharged into the waterbody regularly causing harmful effects to aquatic lives. Algae-based membrane bioreactors (AMBRs), are the most advanced technology used to remove emerging contaminants (ECs) found in wastewater. Furthermore, mixed algae-MBRs become more popular than unialgal MBRs due to mutualistic synergism. Advancements in cylindrical and rectangular-shaped AMBRs were also found better for the bioremediation of ECs. In conclusion, various ECs and their remediation mechanisms by different algal strains and sustainable technologies are discussed in the present communication. Most importantly, modifications of AMBRs with microfiltration membrane or osmotic membrane or integrated with activated sludge have been considered in this research.

Scientists have been working on developing a green bio-TENG for portable remote devices, including wearables in the biomedical sector. The process involves obtaining pectin, a green material with anti-microbial properties, as a Triboelectric material. This study focuses on the extraction of essential oil (EO) and pectin from Assam lemon peel simultaneously. A single-step strategy was optimized using a central composite design-based response surface approach. The extracted pectin yielded 4.19 ± 0.31 % and 11.53 ± 0.11 %, respectively. GC-MS analysis revealed 52 volatile components in the Assam lemon EOs, with limonin being 94.47 % and β-Bisabolene being 1.26 %. Only khusilal was found in the EOs, a rare discovery in the scientific domain. The extracted pectin showed good purity and antimicrobial properties. The in vitro activities of the citrus EO against microbial cultures revealed its activity in controlling and eradicating bacterial and fungal growth. Hydro distillation followed by enzyme treatment is a promising approach that combines two separate extraction procedures. The produced biopolymer showed the generation of electrical signals under minimal pressure and stretching and prevented microbial degeneration when applied to a nanogenerator.

Search for alternatives to synthetic plastics led to the development of eco-friendly degradable polymers of natural origin termed ‘bioplastic’ which is a sustainable option to reduce the reliance on fossil fuel resources and address the needs of pressing environmental problems. Food packaging has become an important aspect of supply chain management that not only governs the food from spoilage but also contributes to a sensible biocompatible material, safe for human consumption as there is a recent concern on microplastic leaching. Polyhydroxyalkanoates (PHAs), derived from microorganisms, are extensively used as a polymeric base for packaging applications in food industries as they offer advantages such as biodegradability, non-toxicity, hydrophobicity, thermoplasticity, and superior barrier properties, thereby making them a promising alternative to conventional synthetic plastics. However, challenges related to material properties, performance, and cost of the product must be addressed for PHA to make it an economical and feasible packaging material. Recent developments in PHA formulations in terms of technology, additives, and production factors have led to improvement in the polymer properties and beaconed the advent of active packaging. PHA-based packaging systems can redefine food industry packaging, turning it from a passive physical entity into an active solution that sustainably ensures food quality and safety. This review examines the sustainable microbial production of PHA from waste resources, recent advancements in PHA formulations, and their impact on material properties. It highlights emerging trends in active food packaging with PHA, such as controlled-release, antimicrobial and antioxidant properties, advanced barrier properties and spoilage indicators.

The use of algae for value-added product and biorefining applications is enchanting attention among researchers in recent years due to its remarkable photosynthetic ability, adaptability, and capacity to accumulate lipids and carbohydrates. Algae biomass, based on its low manufacturing costs, is relatively renewable, sustainable, environmentally friendly and economical in comparison with other species. High production rate of algae provides a unique opportunity for its conversion to biochar with excellent physicochemical properties, viz. high surface area and pore volume, high adsorption capacity, abundant functional groups over surface, etc. Despite several potential algal-biochar, a detailed study on its application for removal of emerging contaminants from wastewater is limited. Therefore, this technical review is being carried out to evaluate the specific elimination of inorganic and organic pollutants from wastewater, with a view to assessing adsorption performances of biochar obtained from various algae species. Species-specific adsorption of emerging pollutants from wastewater have been discussed in the present review. The promising methods like pyrolysis, gasification, dry and wet torrefaction for the production of algae biochar are highlighted. The strategies include chemical and structural modifications of algae biochar for the removal of toxic contaminants have also been considered in the current work. The overall aim of this review is to confer about the synthesis, technological advancements, delineation and application of algae biochar for the treatment of wastewater.

Landfill mining is the prominent solution for the recovery of resources from legacy waste. The bio-earth recovered from landfill mining is being utilized for a variety of applications like application as fertilizer. The presence of microplastic in the recovered bio-earth disrupts its usefulness. This study investigated the composition and microplastic pollution in bio-earth derived from landfill mining at the Bhandewadi landfill, Nagpur, India. Results provided insights into its characterization and presence of microplastic. The average moisture content of the bio-earth was 25.2 ± 1.1% with total organic carbon of 14.3 ± 0.6%. The bio-earth exhibited a C:N ratio of 16.9 ± 5.0, volatile solid content of 24.6 ± 1.0%, and ash content of 75.4 ± 1.0%. Bulk density was 434.3 ± 37.2 kg/m3, pH value 6.91 ± 0.28, and electrical conductivity 4.6 ± 0.7 dS/m. Total nitrogen content was 0.9 ± 0.3%, available phosphorus 2.1 ± 0.3 g/kg, and potassium and sodium contents of 12.7 ± 0.4 g/kg and 3.9 ± 0.3 g/kg, respectively. Heavy metals detected included Fe, Zn, Mn, Cu, Pb, Ni, Cr, and Cd. Microplastics in the bio-earth samples were assessed using attenuated total reflectance–Fourier-transform infrared spectroscopy (ATR-FTIR). The amount of microplastics averaged 100,150 ± 29,286 items per kg (dry basis). Additionally, five specific polymer types were prominent as microplastics. Further research and mitigation strategies are necessary to ensure the safe and sustainable use of bio-earth in agriculture and horticulture.

In a globalized world, energy remains a critical driver of development. The reliance on non-renewable fossil fuels has led to pollution, health concerns, and accelerated climate change due to greenhouse gas emissions. As fossil fuel reserves diminish, biofuels derived from biomass present a promising and sustainable alternative. Biomass, being abundant and renewable, has the potential to replace fossil fuels, with advances in technology and a focus on green synthesis enabling more efficient and environmentally friendly production processes. Heterogeneous catalysts play a crucial role in biofuel production, significantly impacting the development of more sustainable energy solutions. These catalysts, which operate in a different phase from the reactants, are crucial for achieving high conversion efficiency, recyclability, and minimal environmental impact in biofuel production. Specifically designed to break down lignocellulosic biomass, these catalysts are essential for a carbon-neutral biofuel production process and for driving sustainable development. This article explores the historical development and evolving role of these catalysts in biofuel technology along with a categorization of various catalysts used in biofuel production. The discussion includes an examination of biomass sources and its structural and chemical compositions vital for conversion processes. The application of heterogeneous catalysts in producing diverse biofuels—such as bioethanol, biobutanol, biogas, biodiesel and biohydrogen are analyzed, highlighting recent advancements and improvements in efficiency. Insights and recommendations for future research underscore the indispensable role of heterogeneous catalysts in advancing sustainable energy practices and securing our energy future.

The electrical and electronic waste, commonly known as “E-waste,” has come into the limelight from mid-1970s. A large amount of E-waste was transported from the developed countries and dumped in the developing countries due to availability of large area and labor force. It has been documented that 95% of the total E-waste generated is recycled by the informal (unauthorized) sector but at the cost of environment and human health. The informal sector has a well-established network for collection of E-waste from various parts of the country, but, in comparison to the formal (authorized) sector, they lack financial and technological support. For example, in India, there are 472 registered recycling centers having a capacity of 1,426,685.22 MTA but the generation rate is much higher than the recycling amount. In view of the adverse impacts resulted from mishandling of E-waste, research studies have been conducted and technologies developed to combat the problems of E-waste. Today, there is immense opportunity to establish start-ups and enhance the business opportunity to recycle and recover resources from E-waste to increase the economic growth of the country. The informal and formal sectors can coordinate and initiate a great prospect in the management of E-waste in an environment-friendly manner. Through their coordination, the concept of circular economy can be achieved, leading to the sustainable development. The present chapter covers the challenges faced by the society and environment due to the generation of E-waste, as well as business opportunities associated with E-waste management options.

E-waste management has become a global concern because of the enormous rise in the rate of end-of-life electrical and electronic equipment's (EEEs). Disposal of waste EEE directly into the environment leads to adverse effects on the environment as well as on human health. For the management of E-waste, numerous studies have been carried out for extracting metals (base, precious, and rare earth) following pyrometallurgy, hydrometallurgy, and biometallurgy. Irrespective of the advantages of these processes, certain limitations still exist with each of these options in terms of their adoption as treatment techniques. Several journal publications regarding the different processes have been made which aids in future research in the field of E-waste management. This review provides a comprehensive summary of the various metal recovery processes (pyrometallurgy, hydrometallurgy, and biometallurgy) from E-waste, along with their advantages and limitations. A bibliometric study based on the published articles using different keywords in Scopus has been provided for a complete idea about E-waste with green technology perspective like bioleaching, biosorption, etc. The present study also focussed on the circular economic approach towards sustainable E-waste management along with its socio-economic aspects and the economic growth of the country. The present study would provide valuable knowledge in understanding E-waste and its different treatment processes to the students, researchers, industrialists, and policymakers of the country.

Since the enactment of the Clean Water Act (1972), which was supplemented by increased accountability under Resource Conservation and Recovery Act (RCRA) Subtitle D (1991) and the Clean Air Act Amendments (1996), landfills have indeed been widely used all around the world for treating various wastes. The landfill's biological and biogeochemical processes are believed to be originated about 2 to 4 decades ago. Scopus and web of Science based bibliometric study reveals that there are few papers available in scientific domain. Further, till today not a single paper demonstrated the detailed landfills heterogenicity, chemistry and microbiological processes and their associated dynamics in a combined approach. Accordingly, the paper addresses the recent applications of cutting-edge biogeochemical and biological methods adopted by different countries to sketch an emerging perspective of landfill biological and biogeochemical reactions and dynamics. Additionally, the significance of several regulatory factors controlling the landfill's biogeochemical and biological processes is highlighted. Finally, this article emphasizes the future opportunities for integrating advanced techniques to explain landfill chemistry explicitly. In conclusion, this paper will provide a comprehensive vision of the diverse dimensions of landfill biological and biogeochemical reactions and dynamics to the scientific world and policymakers.

Face masks, a prime component of personal protective equipment (PPE) items, have become an integral part of human beings to survive under the ongoing COVID-19 pandemic situation. The global population requires an estimated 130 billion face masks and 64 billion gloves/month, while the COVID-19 pandemic has led to the daily disposal of approximately 3.5 billion single-use face masks, resulting in a staggering 14,245,230.63 kg of face mask waste. The improper disposal of face mask wastes followed by its mismanagement is a challenge to the scientists as the wastes create pollution leading to environmental degradation, especially plastic pollution (macro/meso/micro/nano). Each year, an estimated 0.15–0.39 million tons of COVID-19 face mask waste, along with 173,000 microfibers released daily from discarded surgical masks, could enter the marine environment, while used masks have a significantly higher microplastic release capacity (1246.62 ± 403.50 particles/piece) compared to new masks (183.00 ± 78.42 particles/piece). Surgical face masks emit around 59 g CO2-eq greenhouse gas emissions per single use, cloth face masks emit approximately 60 g CO2-eq/single mask, and inhaling or ingesting microplastics (MPs) caused adverse health problems including chronic inflammation, granulomas or fibrosis, DNA damage, cellular damage, oxidative stress, and cytokine secretion. The present review critically addresses the role of face masks in reducing COVID-19 infections, their distribution pattern in diverse environments, the volume of waste produced, degradation in the natural environment, and adverse impacts on different environmental segments, and proposes sustainable remediation options to tackle environmental challenges posed by disposable COVID-19 face masks.

Carbon dioxide (CO2) emissions from a variety of sources, such as transportation, fossil fuel burning, and cement manufacturing facilities, are widely regarded to be the root cause of global warming. The rising CO2 levels call for immediate improvements in CO2 capture, extraction, and utilization technology. Methods for capturing and converting CO2 into useful products have included the use of microbial enzymes, nonporous materials, metal-organic frameworks (MOFs), chemicals, and hybrid membranes. However, these methods possess limitations that make the scale up and commercialization challenging. Scientists are concentrating on maximizing CO2 utilization by incorporating CO2-philic components into enzyme-chemical-material combinations, due to the high solubility of CO2. Here, the focus is on the chemistry of CO2-phillic materials, enzymes and biomolecules engaged in CO2 conversion, and the hybrid micro-reactors that contain material and enzymes integrating together to convert the CO2 into value-added products (organic acids, bioelectricity, carbonates, carbamates, methane, methanol, etc.). The difficulties and obstacles inherent in creating and sustaining such systems have also been highlighted.

Bio-hythane has attracted increasing attention recently and emerged as a promising alternative to fossil-based fuels due to cleanliness, carbon dioxide (CO2) neutrality, high calorific value, and environment-friendly nature. It is a blend of hydrogen–methane, with typical mixture of 10%–15% hydrogen (H2), 30%–40% CO2, and 50%–55% methane (CH4). The hydrogen concentration in hydrogen–methane blend sometimes can reach up to 30% v/v. Bio-hythane is generally produced from a wide variety of feedstock materials by two-stage fermentation technique, i.e., dark fermentation followed by anaerobic digestion. However, the bio-hythane yield is regulated by several factors, such as co-digestion of substrates, pretreatment methods, biomass type, organic loading rate, pH, temperature, microbial consortium, and type of fermenter (single/dual stage) used. Firstly, this book chapter discussed the possibility of co-digestion to improve the bio-hythane yield in state-of-the-art manner. Secondly, the role of different pretreatment strategies adopted for feedstock for improving the bio-hythane yield are addressed independently and in combination. Generally, pretreatment method choice (mechanical/physical, chemical, thermal, and biological) depends on type of feedstock materials. Additionally, pretreatment methods are compared with regard to energy efficiency, yield, and environmental sustainability. Further, the major advancement of improving yield due to organic loading rate, biomass type, pH and temperature changes, microbial consortium, and fermenter type has been reviewed. Finally, the challenges and perspectives of bio-hythane production will be addressed. The outcomes of the present book chapter will provide valuable information to researchers and scientific community, and stakeholders for effective policy implementation.

The rapid growth in population has increased the demand for potable water. Available technologies for its generation are the desalination of sea water through reverse osmosis, electrodialysis etc., which are energy and cost intensive. In this context, microbial desalination cell (MDC) presents a low-cost and sustainable option which can simultaneously treat wastewater, desalinate saline water, produce electrical energy and recover nutrients from wastewater. This review paper is focussed on presenting a detailed analysis of MDCs starting from the principle of operation, microbial community analysis, basic architecture, evolution in design, operational challenges, effect of process parameters, scale-up studies, application in multiple arenas and future prospects. After thorough review, it can be inferred that MDCs can be used as a stand-alone option or pre-treatment step for conventional desalination techniques without the application of external energy. MDCs have been used in multiple applications ranging from desalination, remediation of contaminated water, recovery of energy and nutrients from wastewater, softening of hardwater, biohydrogen production to degradation of waste engine oil. Although, MDCs have been used for multiple applications, still a number of operational challenges have been reported viz., interference of co-existing ions during desalination, membrane fouling, pH imbalance and limited potential of exoelectrogens. However, the re-circulation of anolytes with electrodialysis chamber has led to the maintenance of optimal pH for favourable microbial growth leading to improvement in the overall performance of MDCs. In future, genetic engineering may be used for improving the electrogenic activity of microbial community, next generation materials may be used as anode and cathode, varied sources of wastewater may be explored as anolytes, life cycle analysis and exergy analysis may be carried out to study the impact on environment and detailed pilot scale studies have to be carried out for assessing the feasibility of operation at large scale.

Biological carbon sequestration gaining more impetus day by day, where algae is the main backbone as a biological agent. Thus, the present study focused on the evaluation of algal biomass growth, collected from the polysheet wall of green house chamber, along with its carbon capture potentiality. The experiment were conducted in three different atmospheric conditions viz. (i) inside the green house chamber where temperature and carbon dioxide concentration was higher; (ii) in the normal atmospheric condition under full sunlight, and (iii) in closed room condition where light intensity was fixed. Maximum carbon accumulation was found (834.59±2.09 mg C/g) inside the green house chamber where mean temperature and carbon dioxide concentration were 41 °C and 705 ppm respectively. Collective effect of temperature and carbon dioxide concentration also facilitate in the maximum growth of the algal biomass (8693.68 mean number of cell/mL) in the greenhouse chamber.

Limitation in the availability of natural resources like water is the main drive for focussing on resource recovery from wastewater. Rapid urbanization with increased consumption of natural resources has severely affected its management and security. The application of biotechnological processes offers a feasible approach to concentrating and transforming wastewater for resource recovery and a step towards a circular economy. Wastewater generally contains high organic materials, nutrients, metals and chemicals, which have economic value. Hence, its management can be a valuable resource through the implementation of a paradigm transformation for value-added product recovery. This review focuses on the circular economy of “close loop” process by wastewater reuse and energy recovery identifying the emerging technologies for recovering resources across the wastewater treatment phase. Conventional wastewater treatment technologies have been discussed along with the advanced treatment technologies such as algal treatment, anammox technology, microbial fuel cells (MFC). Apart from recovering energy in the form of biogas and biohydrogen, second and third-generation biofuels as well as biohythane and electricity generation have been deliberated. Other options for resource recovery are single-cell protein (SCP), biopolymers as well as recovery of metals and nutrients. The paper also highlights the applications of treated wastewater in agriculture, aquaponics, fisheries and algal cultivation. The concept of Partitions-release-recover (PRR) has been discussed for a better understanding of the filtration treatment coupled with anaerobic digestion. The review provides a critical evaluation on the importance of adopting a circular economy and their role in achieving sustainable development goals (SDGs). Thus, it is imperative that such initiatives towards resource recovery from wastewater through integration of concepts can aid in providing wastewater treatment system with resource efficiency.

Microplastics (MPs) have attracted wide attention all over the world as a remarkable pollutant. While MPs are spreading throughout several complex environmental matrices, various experiments till date have been preliminary concentrate on aquatic ecosystems. Terrestrial sources namely solid waste-origin have remains unexplored, although they contribute largely for aquatic microplastics origin. Simultaneously, terrestrial systems under human activity, like healthcare units, are likely to be polluted by various plastic ingredients. Solid waste MPs sources primarily include sanitary landfilling, food waste, wastewater treatment end-product (sludge), tire wear, textile washing and paint failure. These microplastics caused adverse impacts on ecosystem, environment, and health. Accordingly, the present study addressed solid waste MPs’ occurrence and sources, identification, quantification, characterization, fate, and degradation pathways for developing comprehensive management strategies following the principles of circular economy. In particularly, this paper critically demonstrated solid waste MPs sources, solid waste MPs sampling followed by identification and quantification by adopting combined chemical (e.g., spectroscopy viz., Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy), physical (e.g., microscopy such as transmission or scanning electronic microscopy, TEM or SEM) and thermal analyses. Additionally, the strengths and limitations of each analytical technique are discussed critically with practical aspect. Further, the MPs related national and international regulations or laws and their subsequent relevance to solid waste MPs management with future challenges are discussed very critically. Finally, the outcomes of the review paper will be valuable to different stakeholders for effective policy implementation.

In an aquaculture system, estimates were made of soil organic carbon content, carbon burial rate, soil structure and algal productivity with the intention of examining the synergistic effects of both greenhouse gas (GHG) induced temperature and manure-driven carbon reduction potentials in sediments that depend on productivity as well as tilapia spawning responses under greenhouse mimicking conditions during winter. Different manure treatments such as cattle manure and saw dust (T1); poultry droppings and saw dust (T2); vermi-compost and saw dust (T3); mixture of cattle manure, poultry droppings, vermi-compost and saw dust (T4); iso-carbonic states maintained with vermi-compost (T5); and with poultry droppings (T6) were applied three times (frequency of application) in the tank during the course of investigation. Different parameters like soil organic carbon, carbon burial rate, algal productivity and water quality were examined in aquaculture system. GHG effect impacted on the enhanced carbon reduction potential (44.36-62.36%) which was directly related with soil organic carbon (38.16-56.40 mg C/g) dependent carbon burial rate (0.0033-0.0118 g/cm2 per 100 days). Average carbon burial rates for different manure treatments at GHG impacted temperature (0.0071 g/cm2 per 100 days) was as high as 27.90% than at ambient air temperature (0.0054 g/cm2 per 100 days). Residual carbon or sink in soils has been increased by 8.49 to 43.11% in different treatments or 23%, on an average attributed to almost 6 °C rise in GHG mediated atmospheric temperature. The low carbon footprint potential in different treatments was conspicuous inside the polyhouse (maximum 62.36%) due to greenhouse driven temperature compared. As a positive impact of the study, breeding of tilapia occurred where in T3 100% survival occurred in close polyhouse and also exhibited maximum carbon burial rate. In this study it has been observed that one degree rise in atmospheric temperature resulted in a ~ 4% rise in residual carbon in the experimental tank. However, future work can be conducted on other different treatments and large scale application. Graphical Abstract: Graphical representation of greenhouse-temperature induced manure driven carbon accumulation in aquaculture mesocosm.[Figure not available: see fulltext.]

The present study comprises valorization of Assam lemon waste through anaerobic digestion. The uniqueness of the study lies in its process of substituting cow dung with a mixed anaerobic culture (MAC) and in evaluating the effect of graphene oxide (GO) on the fermentation process. A sequential improvement of biomethane yield was observed to be 93.86 ± 0.31, 216.54 ± 1.63, 219.64 ± 0.14 and 231.55 ± 0.27 ml/g VSfed in presence of single variable such as substrate concentration, time, GO and inoculum volume, respectively. Further optimization was carried out adopting central composite design (CCD) based response surface methodology (RSM). The maximum biomethane yield of 243.23 ± 1.99 ml/g VSfed was achieved when the solid loading was kept at 25 g TS/L, 0.06% (w/v) concentration of GO, incubated for 30 days at 37 °C which has resulted into 19.04% enhanced methane yield. Kinetic analysis exhibited lowest deviation with experimental cumulative methane yield, lowest value of λ (4.37 days) and RMSE (5.85) in modified Gompertz model. Digested biomass characterization revealed 18.46% reduction in crystallinity along with a major change in FTIR peaks. Materials and energy flow of the underlying process show 70.88% efficiency of the process with 4.96 kJ/g net energy gain. The report on AD of generated Assam lemon waste to biomethane with the intervention of GO is rare. Thus the result obtained from the current study will encourage the scientific community to improve the biomethane yield by the addition of conductive materials.

Laccase pretreatment of yard waste (YW) was conducted for improving its anaerobic biodegradability. The optimum pretreatment condition based on response surface methodology for maximum delignification was: solid loading 19.7% (w/v) of total solid, treatment duration 9 h, and pretreatment temperature 44.5 °C. The mechanism of biomass delignification was further investigated by the change in physical and chemical properties. Specifically the increase in water retention value (2.05 times), specific porosity (1.72 times), and crystallinity index (1.25 times) in pretreated YW indicates the capability of laccase pretreatment to remove lignin selectively. The methane yield after 30 days of anaerobic digestion for untreated YW was 294 ± 12 mL/g volatile solid (VS) and for laccase pretreated yard waste at the optimum condition was 405 ± 15 mL/gVS. The Modified Gompertz model showed the best fit for untreated yard waste however for pretreated YW logistic function model was the best. The energy balance analysis of the studied method confirmed a positive energy gain of 1.6 kJ/g VS indicates further validation in field scale studies.

Assam lemon, Kachai lemon and Pomelo are the three different types of abundantly available lemons in North-East India. The present article emphasizes on the debittered juice production from these three citrus fruits followed by optimization studies adopting Simplex centroid mixture design (SCMD) based approach. Moreover, optimization of simultaneous debittering and clarification has been carried out by response surface methodology (RSM). A maximum debittering (51.87±1.84%) and clarification (95.69±1.15%) have been observed at 42.66°C when the bitter lemon juice was incubated for 1.73 h with 38.51 IU and 6.13 IU tannase and polygalacturonase, respectively. The quantification of released gallic acid and naringin were estimated through HPLC analysis. The obtained results exhibited that the treated juice released 0.46 mg/mL of gallic acid while naringin was reduced from 0.19 mg/ml to 0.0019 mg/ml. Biochemical analyses of the treated juice exhibited significant increase in reducing sugar, total sugar and antioxidant property (p ≤ 0.001) than that of the untreated juice while other biochemical and elemental compositions remain unaltered.

Bioethanol from lignocellulosic biomass is a promising alternative to petroleum-based fuels to alleviate greenhouse gas emissions and reduce the dependency on fossil fuels. The lignocellulosic biomass is exploited for ethanol production due to its sustainability and abundance. Sugarcane tops, an agricultural residue, was employed in the present investigation to assess its potential as a feedstock for bioethanol production by adopting different fermentation approaches, namely separate fermentation, simultaneous saccharification and fermentation (SSF) and partially consolidated bioprocessing (PCBP). The present study demonstrated the potential of mono and co-fermentation for ethanol production. Comparison between separate fermentation and SSF using S.cerevisiae showed the latter to be more efficient with ethanol production of 5.69% (v/v) in 30.67 h of fermentation time than separate fermentation with 3.76% (v/v) ethanol in 48 h. An integrated fermentation strategy stated as partially consolidated bioprocessing (PCBP) was investigated to improve fermentation efficiency. This process integrates simultaneous pretreatment and saccharification (SPS), conducted by enzyme blends of laccase and cellulase followed by co-fermentation using S. cerevisiae and xylose-fermenting yeast AKBR 212. This approach resulted in a 7.57% (v/v) maximum ethanol concentration in 24.30 h. The different fermentation strategies involved enzymes and yeasts only, thus offering a green biotechnology approach towards converting sugarcane tops into bioethanol.

Digested Assam lemon waste was subjected to biomanure production with appropriate concern on carbon emission through biocircular economy concept. For the biomanure production digested waste was treated with different cyanobacterial cultures such as Anabaena variabilis, Aulosira fertilissima, Cylindrospermum muscicola, and Fischerella muscicola. Among all the strains F. muscicola was found to be most efficient in N, P and K enrichment and bioavailability where 2.88, 2.00 and 2.16 folds increase in N, P and K content has been recorded. The produced enriched biomanure was applied solely and in combination with inorganic fertilizer to find out the best treatment condition towards soil enrichment vis a vis mung bean (Vigna radiata) production. Combination of inorganic fertilizer and produced biomanure exhibits good results where the yield of the mung seed was enhanced by 2.02 folds. Application of biomanure in the crop field could maintain the soil physico-chemical properties.

The present article deals with the processing of Assam lemon (AL), which is rare and under-explored variety and is abundantly available in North-East India. Studies on valorization of Assam lemon waste (ALW) into various value-added products are limited. During pre-processing of ALW a 4.19 ± 0.11% (v/w) essential oil and 12.67 ± 0.46% (w/w) pectin were recovered. Thereafter, the treated biomass was subjected to partial simultaneous saccharification and co-fermentation (PSSCF) for ethanol production. The maximum ethanol yield was obtained as 12.16 ± 0.15% (v/v) when solid loading, temperature, time and pentose to hexose utilizing strains ratio were kept as 30% (w/v), 35 °C, 24 h and 0.5, respectively. Model was found to be significant having R2 and R2(adj.) of 99.93 and 99.86, respectively. Fermented biomass showed a drastic reduction in crystallinity index (19.49%) along with a major change in FTIR peaks, which corroborates the improved bioconversion process. The overall process efficiency was found to be 69.17%.

Citrus waste from the processing industry, generated after juice extraction, comprises about 50% of its wet fruit mass, which constitutes about 50% of peel waste. With the increasing number of industries, colossal volumes of waste are being released constantly to the environment. Disposal of these huge aggregates of wastes is a great concern. Furthermore, wastes comprise valuable ingredients, such as sugars, lipids, organic acids, carbohydrates, flavonoids, essential oil, vitamins and minerals, and also pose economic losses. Legislation concerning organic waste and the demand for renewable biochemicals and fuel are driving industry to make a virtue out of a necessity toward sustainability, cost-effectiveness, and to meet consumer’s demands. Proficient utilization of agroindustrial wastes is deemed to be crucial for an effective bioeconomy strategy. Nowadays, the valorization of citrus waste through value-added product recovery and energy production is gaining more impetus under the umbrella of the bio-based economy. Biorefining from citrus waste facilitates the utilization of one industry’s waste to generate revenue by converting waste into wealth. This chapter highlights the potential of citrus fruit waste in terms of resource recovery and energy production and its role in the bioeconomy.

Upgradation and advancement in every field related to mankind leads to the origin of a contaminated environment. Development in science and technology enabled humans to combat the rate of contaminants by using biological agents, commonly known as bioremediation. The chapter deals with the different species of bioremediation agents viz. bacteria, fungi, algae, plants, animals and organic wastes to treat diverse environmental pollution. The extent of environmental bioremediation encompasses inorganic viz. arsenic, chromium, mercury, cyanide etc. and organics viz. Hydrocarbons, petroleum, pesticides etc. Thus, the reasons for the control of water and soil by considering bioremediation are concern on public health, protection of environment, and cost reduction of decontamination. Different case studies have been demonstrated herein to understand the enigmatic process and evaluate practical efficacy of the environment to decontaminate itself by the presence of various biological organisms.

Commercialization of citrus fruit juice is always hindered by the bitterness development in juice when stored for a significant period of time. In order to debitter citrus juice, an attempt has been taken up by treating the juice with tannase. Central Composite Design (CCD) based Response Surface Methodology (RSM) has been implemented to evaluate and optimize the effect of underlying process parameters viz., enzyme volume, temperature, incubation time and enzyme titre on debittering effect of Assam lemon juice. The significance of parameters and their interaction were assessed by analysis of variance at 95% level of confidence. Optimization study reveals that the maximum debittering (40.12 ± 0.02%) of Assam lemon juice takes place at ambient temperature (37 °C) within an incubation time of 2 h and 1.12% (v/v) enzyme volume while 30 IU/ml enzyme activity. Moreover, percentage contribution of the underlying process parameters demonstrate that the enzyme volume and enzyme titre as first and second most significant contributors in process of debittering. As part of validating the above results, experimental debittering has been performed and compared with predicted debittering percentage which showed a high coefficient value (0.971) which ensures the effectiveness of the proposed model. Biochemical analysis of the treated juice reveals improved antioxidant property after enzymatic treatment by 15.30%. Total sugar and reducing sugar content has also been enhanced by 1.38 and 1.49 folds, respectively, after enzymatic treatment of juice. Furthermore, no alteration in the elemental composition of the treated juice ensure that the quality of the final juice is retained with the enzyme applications. Sensory analysis based on nine-point Hedonic scale advocates the best organoleptic property in 1% (v/v) enzyme treated juice.

This study focused on isolation and identification of possible phosphate-solubilizing bacteria (PSB) from the sewage-fed East Kolkata Wetland (EKWL), a prospective water resource for pisciculture. In addition, different limnological parameters have been correlated with orthophosphate and seasonal variations. PSB have been isolated in Pikovskaya medium and identified morphologically and biochemically and finally analysed by 16S rDNA gene sequence. Limnological studies involving temperature (potentiometric), pH (potentiometric), dissolved oxygen (iodometric), ammonia-nitrogen (spectrophotometric) and orthophosphate (spectrophotometric) concentrations were conducted. The results of this study established the presence of Bacillus megaterium, a potential PSB in EKWL. The activity of B. megaterium is also supported by the seasonal orthophosphate variations. The changes in concentration of other limnological parameters were also prominent. The water quality parameters of temperature (r = 0.886), dissolved oxygen (r = 0.729) and ammonia-nitrogen (r = 0.396) concentrations exhibited a positive correlation with orthophosphate and a negative correlation with pH (r = −0.699). The B. megaterium obtained in this study, exhibited a significant alteration in regard to orthophosphate content and relationships with other factors. Further experiment on the soluble phosphorus solubilization potential of B. megaterium revealed the biological availability of phosphorus was increased by threefold after 120 hr of incubation, with the decreasing pH value, although the phytase activity was 0.419 U/ml. PSB have a vital function in plant nutrition in supplying phosphate, essential nutrients and its uptake results in appropriate functioning and metabolism of different aquatic plants and organisms. PSB are competent biofertilizer to amplify aquaculture production for sustainable development.

Contamination, pollution and degradation of air, water, and soil environments by geogenically and anthropogenically generated various pollutants are severe and life threatening problems globally. Recently, bioremediation has evolved as the most promising eco-friendly approach in the field of environmental remediation technology, playing a pivotal role in solving the menacing problems of environmental pollution in 2018. Several innovative and advanced bioremediation technologies have been developed using genomics and metagenomics, proteomics, transcriptomics and metabolomics in order to overcome the limitations concerning the process. The present chapter has attempted to briefly discuss the advancement of bioremediation in respect to significant biotechnological improvement for applying as green technology in order to eco-friendly cleaning the air, water, and soil environments.

Global warming and climate change are major concerns in every domain of the earth. Recently, there was an increase in global atmospheric carbon dioxide (CO2) concentration (64.05 ppm) from 1980 to 2016 due to enhancement of fossil fuel burning and alteration in land use related with population growth and industrialization. This increased atmospheric concentration can be managed by the combination of reduced emissions and mitigation strategies by enhancing natural carbon storage i.e., biosequestration of carbon. Algal carbon sequestration and carbon storage plays important role in mitigating global problem of CO2 pollution, especially microalgal carbon sequestration through the photosynthetic pathway facilitate the remarkable reduction of atmospheric CO2 and act as a promising alternative biological tool for biological carbon sequestration. Therefore, microalgae are promising organisms for bio-mitigation, because 1.83 kg of CO2 can be fixed via cultivating one kilogram of microalgae. Recently, there is a number of algal based CO2 Capture Pilot Plant that has been established around the world. Among the various alternatives to carbon capture and utilization, microalgae cultivation is currently one of the less mature and economically practicable technique. From these points of view, the present chapter focused on the algal carbon sequestration and storage mechanism, and role of microalgae in carbon sequestration and capture with pilot scale case studies on algae based carbon capture. This green technological innovation of algal carbon sequestration is important, which is one of the prime solutions in future prospect in mitigating the global CO2 problem.

In India, a variety of agricultural products such as bananas, pomegranates, apples, cashew apples, citrus, litchi, mangos, guava, apricots, pineapples, peaches, berries, grapes, watermelons, passion fruit, carrots, amlas, and tomatoes are produced in plenty. As some of the vegetables/fruits are perishable in nature, the improvement of shelf life plays an important role. An alternative strategy adopted for the proper utilization of such fruits/vegetables is juice preparation for appropriate usage of the raw material. In modern fruit juice manufacturing, industrial enzymes are major fundamental components. The functions of enzymes in juice processing are increasing juice yield, clear and visually attractive juice production, debittering of juice, and improvement of the antioxidant and nutritional properties of juice. The use of the enzymes such as pectinase, tannase, carbohydrase, naringinase, and lipase/esterase alone as well as their blends can not only give better juice yield but also help in retaining enhanced nutrition in the juice. In this chapter, the authors will emphasize not only the cost-effective production of industrial enzymes for their selection in appropriate fruit juice production in the pure as well as mixed form, but also accentuate the titer value, shelf life, appropriate enzyme selection, and nutritional upliftment of the final product. A series of enzymes involved in these processes will include laccase, tannase, pectinase, naringinase, carbohydrase, and a few oxido-reductase along with the juice quality and sensory evaluation for maximum wide acceptability of the fruit/vegetable juices.

Conventional leaching methods in metal mobilization and recovery is a troublesome process require strong acids and other associated facilities, which are not favourable and ecofriendly, posing severe hazardous threats to the environment. Discovery of microbial leaching properties opens a new avenue in metal mobilization and recovery. Various technologies have been developed concerning the application of microbes in metal mobilization and recovery from the sources employing microbial leaching mechanism. The present chapter attempted to draw an updated picture on the current advancement of bioleaching in metal mobilization considering the brief historical perspective, bioleaching mechanism, microbes in bioleaching, factores influencing the bioleaching process and its application as green technology and nanoparticle processing. The chapter summarily concluded that bioleaching is a green and environment friendly biotechnological application, has broad future prospects and its current research and advancement openning newer avenues for developing cleaner and greener environment.

Identification of tree species that can biologically monitor air pollution and can endure air pollution is very much important for a sustainable green belt development around any polluted place. To ascertain the species, ten tree species were selected on the basis of some previous study from the campus of the University of Burdwan and were studied in the pre-monsoon and post-monsoon seasons. The study has been designed to investigate biochemical and physiological activities of selected tree species as the campus is presently exposed to primary air pollutants and their impacts on plant community were observed through the changes in several physical and biochemical constituents of plant leaves. As the plant species continuously exchange different gaseous pollutants in and out of the foliar system and are very sensitive to gaseous pollutants, they serve as bioindicators. Due to air pollution, foliar surface undergoes different structural and functional changes. In the selected plant species, it was observed that the concentration of primary air pollutants, proline content, pH, relative water holding capacity, photosynthetic rate, and respiration rate were higher in the pre-monsoon than the post-monsoon season, whereas the total chlorophyll, ascorbic acid, sugar, and conductivity were higher in the post-monsoon season. From the entire study, it was observed that the concentration of sulfur oxide (SOx), nitrogen oxide (NOx), and suspended particulate matter (SPM) all are reduced in the post-monsoon season than the pre-monsoon season. In the pre-monsoon season, SOx, NOx, and SPM do not have any significant correlation with biochemical as well as physiological parameters. SPM shows a negative relationship with chlorophyll ‘a’ (r = −0.288), chlorophyll ‘b’ (r = −0.267), and total chlorophyll (r = −0.238). Similarly, chlorophyll a, chlorophyll b, and the total chlorophyll show negative relations with SOx and NOx (p < 0.005) during the post-monsoon season. Proline shows a positive relationship with SOx in the pre-monsoon season whereas in the post-monsoon season proline content shows a positive relationship with both SOx and NOx. The present study facilitates to screen eight sensitive and two moderately tolerant tree species according to their air pollution tolerance index (APTI) values.

Upgradation and advancement in every field related to mankind leads to the origin of a contaminated environment. Development in science and technology enabled humans to combat the rate of contaminants by using biological agents, commonly known as bioremediation. The chapter deals with the different species of bioremediation agents viz. bacteria, fungi, algae, plants, animals and organic wastes to treat diverse environmental pollution. The extent of environmental bioremediation encompasses inorganic viz. arsenic, chromium, mercury, cyanide etc. and organics viz. Hydrocarbons, petroleum, pesticides etc. Thus, the reasons for the control of water and soil by considering bioremediation are concern on public health, protection of environment, and cost reduction of decontamination. Different case studies have been demonstrated herein to understand the enigmatic process and evaluate practical efficacy of the environment to decontaminate itself by the presence of various biological organisms.

Escalating demand for novel biocatalysts has intensified the production of vital enzymes from microbial, plant and animal origins. Microbial sources are mostly preferred owing to their short doubling time, capacity to utilize a wide range of substrates and easy maintenance. Enzymes have a crucial role in biorefiner ies mainly due to their ability to operate under mild conditions and substrate specificity, which enables efficient raw material biotransformation with low/no inhibitor formation, thus manifesting higher product yield. In this milieu, utili zation of recalcitrant lignocellulosic feedstocks may be considered as a sustain able alternative for fuel production. Enzymatic pretreatment and hydrolysis of lignocellulosics is being increasingly pursued globally for biofuel production with an objective to alleviate the disadvantages caused by physical, chemical and physicochemical approaches on the yield of the product, process economy and environment. Therefore, this chapter focuses on the industrially imperative micro bial enzymes and their applications in biorefineries for eco-friendly lignocellulosic fuel production.

Background: Food-based technologies established itself as a vast, interdisciplinary and multifaceted research area are at crossroads of scientific and technological advancements. The review of patents reveals that growing concerns over the source of nourishment for the burgeoning population, its quality, quantity and safety, along with associated human and environmental welfare has inspired global researchers to implement several new bio-based technologies. Objective: Biotechnological interventions in food sector have been aimed at enhancing/modifying taste, aroma, shelf-life, texture and nutritional value of food products employing fermentation, enzyme technology, nanotechnology and molecular biology. The use of whole microbes as a source of nutrition and genetically modified microorganisms to be used as food or genetically modified food have been successfully attempted, which has addressed the mass population and malnutrition. Further, the processing techniques have been improved along with the proper utilization of food wastes for the generation of many useful byproducts. Conclusion: The article covers broadly the impact of biotechnological interventions in food sector. Techniques mostly discussed include not only the nutrient enriched food production but also byproduct utilization through proper improvisation of food waste into bioenergy, biomanure and other value added products, which is of great economic and environmental importance. This article reviews the overall aspects in relation to some of the recent advancements in food sector.

A relation between zooplankton periodicity and limnological parameters was studied in sewage-fed East Kolkata Wetland (EKWL), a Ramsar site for a period of one year. Physicochemical study has shown temperature, pH, conductivity and TDS ranged between 28.9 and 30.3oC, 7.4 and 8.4, 731.00 and 841.04 µS/cm, 518.5 and 595.0 mg/L respectively. Dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total hardness, chloride, ammonia-nitrogen, nitrate-nitrogen, sulphate, phosphate, iron, sodium and potassium concentrations were also studied seasonally. Among these dissolved oxygen concentration in sewage carrying channel (M4) was very less (1.7 mg/L) whereas, ammonia-nitrogen (1.01 to 2.87 mg/L) and nitrate-nitrogen (1.75 to 7.68 mg/L) exceeded the minimum permissible range. Total zooplankton population was correlated with 18 limnological parameters (2 positive, 14 negative and 2 with both positive or negative) in EKWL. Most of the zooplankton species showed negative correlation with pH, temperature, conductivity, chemical oxygen demand, biochemical oxygen demand, total hardness etc., and positive correlation with DO and Na. This in depth study on zooplankton distribution of EKWL is able to establish the relationship between its water quality and fish production, i.e., the main source of earning of the core group of people who are solely dependent on this pisciculture. It can strongly be advocated that risk assessment studies should be conducted and it is an urgent need for water quality restoration and management of EKWL.