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Run of the river (RoR) hydropower projects are generally considered more environmentally sustainable as compared to their reservoir based counterparts. Further, impacts of these projects are supposed to be in proportion to their installed capacity. Large numbers of this category of hydropower projects in different size ranges are coming up in Himalayan regions. Un-sustainable construction/operation practices adopted during development and/or running of these projects are posing an environmental threat to this fragile and youngest mountain range of the world. This research paper presents a public perception cum data collection study on the environmental impacts of small and large RoR hydropower projects located in western Himalayan region of India. A structured questionnaire was designed to collect the primary data pertaining to intangible impacts while secondary data was collected to analyse tangible environmental parameters. The study concludes that every environmental impact of SHPs is not 'small' as compared to LHPs. Ignoring the environmental impacts of SHPs may not be a good practice. [ABSTRACT FROM AUTHOR]

Small hydropower projects (SHPs), though generally considered more environmentally benign and socially acceptable as compared to large projects, yet their overall sustainability is under suspicion in the Himalayan regions. Almost all SHPs in this region are being developed as run of the river mode which generally causes less/no submergence and quite less displacement of people as compared to large reservoir based hydropower production mode. However, in the absence of proper planning and monitoring mechanism, these projects are causing implacable tunnelling of hills, choking of streams, conversion of streams into dry ditches and long term socio-environmental impacts. This paper presents a SHP development study from hydro rich Beas river basin of Himachal Pradesh, a state nestled in western Himalayan region of India. In depth field studies, focus group discussions with the project affected people and interaction with project proponents of five SHPs in this region suggest that sustainability issues with respect to SHPs are not small vis-a-vis size of their installed capacity. There is an urgent need to take steps to include SHPs having an installed capacity of above 10 MW into the ambit of environment clearance process which is absent in many countries of the world at present. [ABSTRACT FROM AUTHOR]

Abstract: Any hydropower project whether mega, large or small is to be weighed for sustainability at the time of its inception. Without proper sustainability assessment, the project may face many problems during its construction or/and operational phase(s). Legally also, this aspect has been made mandatory in many countries across the globe to check the feasibility of the project from sustainability point of view beforehand. This study intends to emphasise sustainability of run of the river (RoR) hydropower projects in hydro rich regions of India where these types of projects are being undertaken on a large scale. In addition, this study has compiled a list of sustainability indicators which may be of use for policy makers and designers while planning RoR projects in hydro rich regions of India and similar regions throughout the world. [Copyright &y& Elsevier]

[Display omitted] • 2D-MXenes are emerging as advanced photocatalysts to degrade water contaminants. • 2D-MXenes-based SERS sensors detecting low-level heavy metals present in water. • 2D-MXene system can monitor and manage water quality to support sustainability. • To achieve tasks, state-of-the-art challenges and prospects are also discussed. Due to their controlled and manipulative optical, electronic, mechanical, molecular, and thermal properties, 2D MXenes-based sensors are emerging as high-performance analytical tools for detecting various types of organic or pharmaceutical contaminants, including dyes such as Methylene blue (MB), methyl orange (MO) and metallic ions such as lead (Pb2+), chromium (Cr2+), copper (Cu2+), mercury (Hg2+) and many more from the waste or discharged water. The photocatalytic capabilities of 2D MXene are considered to be a practical approach to the degradation of water pollutants due to its durability, low power consumption, and environment-friendly nature. This process requires natural solar irradiation and photocatalyst such as MXene or their composites for water purification. This review addresses MXenes as an effective and efficient absorbent and catalytic material for wastewater treatment. Various synthesis schemes of MXenes and Surface Enhanced Raman Spectroscopy (SERS) substrates for photocatalytic water purification and elimination of organic & inorganic contaminations are highlighted. MXene-based SERS detection systems & stability of MXenes are critically discussed. The future perspective of MXenes-based photocatalytic and SERS-based sensing performances, limitations, and challenges for a sustainable environment are also presented, which can provide a pathway to understanding the full potential of MXenes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Lactic acid (LA) produced from pure/crude xylose under non-sterile conditions. • Crude xylose obtained from sugarcane bagasse (SCB) and olive pits (OP). • 97.8 g/L LA accumulated with 0.67 g/g yield on pure xylose. • 52–62 g/L LA titres attained with 0.50–0.60 g/g yield from SCB/OP hydrolysates. • Recovery of 80–90% LA demonstrated using aqueous two-phase system. Lactic acid (LA) is a platform chemical with diverse industrial applications. Presently, commercial production of LA is dominated by microbial fermentation using sugary or starch-based feedstocks. Research pursuits emphasizing towards sustainable production of LA using non-edible and renewable feedstocks have accelerated the use of lignocellulosic biomass (LCB). The present study focuses on the valorisation of xylose derived from sugarcane bagasse (SCB) and olive pits (OP) through hydrothermal and dilute acid pretreatment, respectively. The xylose-rich hydrolysate obtained was used for LA production by homo-fermentative and thermophilic Bacillus coagulans DSM2314 strain under non-sterile conditions. The fed-batch mode of fermentation resulted in maximum LA titers of 97.8, 52.4 and 61.3 g/L with a yield of 0.77, 0.66 and 0.71 g/g using pure xylose, xylose-rich SCB and OP hydrolysates, respectively. Further, a two-step aqueous two-phase system (ATPS) extraction technique was employed for the separation and recovery of LA accumulated on pure and crude xylose. The LA recovery was 45 – 65% in the first step and enhanced to 80–90% in the second step.The study demonstrated an efficient integrated biorefinery approach to valorising the xylose-rich stream for cost-effective LA production and recovery. [ABSTRACT FROM AUTHOR]

Municipal solid waste (MSW) disposal methods that are not under control, such as open burning, unrestricted incineration, landfilling and dumping into water bodies, pose a severe hazard to the environment and public health. As a result, the development of cheap and ecologically suitable disposal methods is currently extensively demanded by the expanding contemporary communities across the globe. However, the heterogeneous structure and variable physicochemical qualities are a key technical impediment to a total transformation in present conversion methods. Under a green biorefinery strategy, an organic-rich portion of MSW might serve as a low-cost, readily accessible substrate for making fuel and high-value chemicals. The present review examines the new issues in municipal solid waste production and management and the generation of diverse bioproducts with added value. In addition, the conversion of organic waste materials into a variety of biofuels, such as liquids, solids, gases, and power, is discussed in this paper. The most up-to-date methods for turning organic waste into high value bioproducts like compost and organic acids are thoroughly examined. The biorefinery technique is bolstered by converting organic solid waste to high value bioproducts that reduce waste, increase energy output, and provide additional healthcare commodities. As a result, it can be said that recycling MSW into high value bioproducts and biofuels will aid in reaching high levels of energy security, environmental protection, and a more robust bioeconomy. [Display omitted] • The health and environmental consequences of municipal solid waste are reviewed. • Focus on important factors, traditional techniques, issues, and disagreements. • Unlike traditional combustion, gasification is a unique alternative fuel generating technique. • Strategic innovations in dark fermentation could enable the production of clean energy. • Integration of thermochemical and biochemical technology is needed for efficient waste management. [ABSTRACT FROM AUTHOR]

[Display omitted] • Renewable biomass, microalgae have immense potential for sustainable H 2 production. • Dark fermentation and photolysis are currently emerging biotechnological routes. • Biowaste-syngas- H 2 could be a commercially adoptable process for low-cost economics. • Global warming, acidification, and eutrophication are key factors for H 2 scale-up. • Biomass recalcitrance, achieving Thauer Limit and stable H 2 production are key challenges. Biohydrogen (bio-H 2) is regarded as a clean, non-toxic, energy carrier and has enormous potential for transforming fossil fuel-based economy. The development of a continuous high-rate H 2 production with low-cost economics following an environmentally friendly approach should be admired for technology demonstration. Thus, the current review discusses the biotechnological and thermochemical pathways for H 2 production. Thermochemical conversion involves pyrolysis and gasification routes, while biotechnological involves light-dependent processes (e.g., direct and indirect photolysis, photo/ dark fermentation strategies). Moreover, environmentally friendly technologies can be created while utilizing renewable energy sources including lignocellulosic, wastewater, sludge, microalgae, and others, which are still being developed. Lifecycle assessment (LCA) evaluates and integrates the economic, environmental, and social performance of H 2 production from biomass, microalgae, and biochar. Moreover, system boundaries evaluation, i.e., global warming potential, acidification, eutrophication, and sensitivity analysis could lead in development of sustainable bioenergy transition with high economic and environmental benefits. [ABSTRACT FROM AUTHOR]

[Display omitted] • Overview of challenges and opportunities of low carbon circular bioeconomy. • Development of low carbon circular bioeconomy were discussed. • Co-evolution of ecosystems, technologies, business strategies and user practices was analyzed. • Overview of value-added products production from these substrates were review. • Metabolic pathway of acidogenic fermentation was reviewed. The development of sustainable and low carbon impact processes for a suitable management of waste and by-products coming from different factors of the industrial value chain like agricultural, forestry and food processing industries. Implementing this will helps to avoid the negative environmental impact and global warming. The application of the circular bioeconomy (CB) and the circular economic models have been shown to be a great opportunity for facing the waste and by-products issues by bringing sustainable processing systems which allow to the value chains be more responsible and resilient. In addition, biorefinery approach coupled to CB context could offer different solution and insights to conquer the current challenges related to decrease the fossil fuel dependency as well as increase efficiency of resource recovery and processing cost of the industrial residues. It is worth to remark the important role that the biotechnological processes such as fermentative, digestive and enzymatic conversions play for an effective waste management and carbon neutrality. [ABSTRACT FROM AUTHOR]

• Introduction to bioderived carbonaceous nanomaterials (Bd-CNMs). • Utilization of Bd-CNMs for biomedical applications, namely for drug delivery, tuberculosis, etc. • Current outlook, future trends and limitations of Bd-CNMs in the biomedical sector. Global concerns about energy, environment and human health have sparked research into new materials and methods for conserving energy, enhancing the sustainability of the ecosystem, and enhancing human health. As a result of the current biological and environmental crises, researchers are scrambling to find ecologically responsible ways to get cheap and sustainable resources to produce new functional materials. To combat numerous illnesses that affect people and animals, scientists from across the globe are studying new forms of bioderived nanomaterials for biomedical applications. One of the interesting possibilities for biomedical and related applications is bioderived carbonaceous nanomaterials (Bd-CNMs). The biological features of Bd-CNMs, including their facile functionalization, drug loading capacity, biocompatibility, and other attributes, have drawn the attention of many researchers. Thus, the important objective of this featured article is to summarize the most recent developments in the usage of Bd-CNMs for various biomedical applications, which will be followed by a discussion on the utility of carbonaceous nanoparticles in biomedical research to show how versatile they are in many domains. [ABSTRACT FROM AUTHOR]

[Display omitted] • Blueberry waste as potential resource for value addition end product recovery are discussed. • Sustainable resource recovery and ecofriendly approach are reviewed. • Recent trends and possibilities on blueberry biorefinery are mentioned. • Challenges in blueberry waste resource recovery and applications are appraised. • Circular bioeconomy aspects and regulatory issues of blueberry waste are discussed. Waste valorization using biological methods for value addition as well as environmental management is becoming popular approach for sustainable development. The present review addresses the availability of blueberry crop residues (BCR), applications of this feedstock in bioprocess for obtaining range of value-added products, to offer economic viability, business development and market potential, challenges and future perspectives. To the best of our knowledge, this is the first article addressing the blueberry waste valorization for a sustainable circular bioeconomy. Furthermore, it covers the information on the alternative BCR valorization methods and production of biochar for environmental management through removal or mitigation of organic and inorganic pollutants from contaminated sites. The review also discusses the ample opportunities of strategic utilization of BCR to offer solutions for environmental sustenance, covers the emerging trends to produce multi-products and techno-economic prospective for sustainable agronomy. [ABSTRACT FROM AUTHOR]