Transforming pollution into solutions: A bibliometric analysis and sustainable strategies for reducing indoor microplastics while converting to value-added products.

Microplastics (MPs), as emerging indoor contaminants, have garnered attention due to their ubiquity and unresolved implications for human health. These tiny particles have permeated indoor air and water, leading to inevitable human exposure. Preliminary evidence suggests MP exposure could be linked to respiratory, gastrointestinal, and potentially other health issues, yet the full scope of their effects remains unclear. To map the overall landscape of this research field, a bibliometric analysis based on research articles retrieved from the Web of Science database was conducted. The study synthesizes the current state of knowledge and spotlights the innovative mitigation strategies proposed to curb indoor MP pollution. These strategies involve minimizing the MP emission from source, advancements in filtration technology, aimed at reducing the MP exposure. Furthermore, this research sheds light on cutting-edge methods for converting MP waste into value-added products. These innovative approaches not only promise to alleviate environmental burdens but also contribute to a more sustainable and circular economy by transforming waste into resources such as biofuels, construction materials, and batteries. Despite these strides, this study acknowledges the ongoing challenges, including the need for more efficient removal technologies and a deeper understanding of MPs' health impacts. Looking forward, the study underscores the necessity for further research to fill these knowledge gaps, particularly in the areas of long-term health outcomes and the development of standardized, reliable methodologies for MP detection and quantification in indoor settings. This comprehensive approach paves the way for future exploration and the development of robust solutions to the complex issue of microplastic pollution.

Taguchi approach for assessing supercritical CO2 (sCO2) fluid extraction of polyhydroxyalkanoate (PHA) from Chlorella Vulgaris sp. microalgae.

This research explicitly investigates the utilization of Chlorella Vulgaris sp. microalgae as a renewable source for lipid production, focusing on its application in bioplastic manufacturing. This study employed the supercritical fluid extraction technique employing supercritical CO2 (sCO2) as a green technology to selectively extract and produce PHA's precursor utilizing CO2 solvent as a cleaner solvent compared to conventional extraction method. The study assessed the effects of three extraction parameters, namely temperature (40-60 °C), pressure (15-35 MPa), and solvent flow rate (4-8 ml/min). The pressure, flowrate, and temperature were found to be the most significant parameters affecting the sCO2 extraction. Through Taguchi optimization, the optimal parameters were determined as 60 °C, 35 MPa, and 4 ml/min with the highest lipid yield of 46.74 wt%; above-average findings were reported. Furthermore, the pretreatment process involved significant effects such as crumpled and exhaustive structure, facilitating the efficient extraction of total lipids from the microalgae matrix. This study investigated the microstructure of microalgae biomatrix before and after extraction using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Fourier-transform infrared spectroscopy (FTIR) was utilized to assess the potential of the extracted material as a precursor for biodegradable plastic production, with a focus on reduced heavy metal content through inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis. The lipid extracted from Chlorella Vulgaris sp. microalgae was analysed using gas chromatography-mass spectrometry (GC-MS), identifying key constituents, including oleic acid (C18H34O2), n-Hexadecanoic acid (C16H32O2), and octadecanoic acid (C18H36O2), essential for polyhydroxyalkanoate (PHA) formation.

Bioconversion of fruit waste and sewage sludge mixtures by black soldier fly (Diptera: Stratiomyidae) larvae.

Bioconversion of fruit waste (FW) and sewage sludge (SS) sludge mixtures into valuable products was investigated using black soldier fly (Hermetia illucens) larvae (BSFL) under a lab-scale trial. For that, five different setups of FW and SS mixtures (100FW; 100SS; 70SS+30FW; 50SS+50FW; 70FW+30SS) were prepared and changes in larval biomass, feed loss, and residual waste physicochemical properties were estimated until the emergence of fly in all waste mixtures. BSFL caused a significant decrease in total organic carbon (11.71-34.79%) and carbon-to-nitrogen ratio (C/N ratio) while the increase in total nitrogen (8.35-123.30%), total phosphorus (17.02-143.36%), and total potassium (19.40-48.87%) contents in the feedstock. The germination index and C/N ratio of frass were below the standards decided for manure quality in a few setups suggesting the non-stability of frass for agronomic applications due to the short duration (20 d) of composting. Larval biomass yield, feed conversion ratio and nutrient mineralization were found to be higher in 50SS+50FW and 70FW+30SS feedstock combinations suggesting their suitability as ideal feedstock for optimal BSFL cultivation. The impact of toxic substances in sewage on BSFL survival, growth and waste stabilization processes, and frass metal enrichment could be investigated in future studies.

Utilization of cockle shell powder as an adsorbent to remove phosphorus-containing wastewater.

The paper demonstrates the capability of using cockle shells as an adsorbent for phosphorus removal from simulated petrochemical wastewater, focusing on the actual condition of the petrochemical facultative pond. In this study, the physicochemical properties of shell powder were determined, such as the functional groups, surface morphology, crystalline structure, and surface area using FTIR, SEM, EDX, XRD, and BET. It was observed that the optimum conditions for effective phosphorus removal are under the presence of rotational speed (125 rpm), higher dosage (7 g/L), and larger surface area (smaller particle size) of the shell powder. Fine powder achieved up to 52.27% of phosphorus removal after 40 min compared to coarse powder which could only give 16.67% removal. Additionally, calcined shell powder demonstrated a higher phosphorus removal rate, i.e., up to 62.37%, compared to raw shell powders. The adsorption isotherm was studied using Langmuir and Freundlich models, but the isothermal data fit better for the Freundlich model (R2 = 0.9836). Overall, this study has successfully generated a greener and low-cost adsorbent.

Graphene and biochar-based cathode catalysts for microbial fuel cell: Performance evaluation, economic comparison, environmental and future perspectives.

Microbial fuel cells (MFCs) have been the prime focus of research in recent years because of their distinctive feature of concomitantly treating and producing electricity from wastewater. Nevertheless, the electrical performance of MFCs is hindered by a protracted oxygen reduction reaction (ORR), and often a catalyst is required to boost the cathodic reactions. Conventional transition metals-based catalysts are expensive and infeasible for field-scale usage. In this regard, carbon-based electrocatalysts like waste-derived biochar and graphene are used to enhance the commercialisation prospects of MFC technology. These carbon-catalysts possess unique properties like superior electrocatalytic activity, higher surface area, and high porosity conducive to ORR. Theoretically, graphene-based cathode catalysts yield superior results than a biochar-derived catalyst, though at a higher cost. In contrast, the synthesis of waste-extracted biochar is economical; however, its ability to catalyse ORR is debatable. Therefore, this review aims to make a side-by-side techno-economic assessment of biochar and graphene-based cathode catalyst used in MFC to predict the relative performance and typical cost of power recovery. Additionally, the life cycle analysis of the graphene and biochar-based materials has been briefly discussed to comprehend the associated environmental impacts and overall sustainability of these carbo-catalysts.

Valorisation of Fruits, their Juices and Residues into Valuable (Nano)materials for Applications in Chemical Catalysis and Environment.

One of the most abundant wastes from all around the world is nutrient resources. Among them, fruits, their extracts, and residues comprise a major portion, which contain many valuable components that get lost during disposal or become burden on the shrinking landfills. These concerns are addressed by seeking sustainable processing methods that would have a minimal environmental impact. The crops contain renewable chemicals which are useful for catalysis, wastewater treatment, or preparation of nanomaterials; there has been an upsurge for the industrial applications of (nano)materials as their environmental and catalytic appliances is a fascinating subject to design cheaper and safer catalytic systems. Due to the excellent chemical properties of the fruit extracts, they have garnered attention as cost-effective catalysts and support materials. This review focuses on the preparation of (nano)materials and their catalytic and environmental applications and highlights the potential appliances and industrial benefits derived from these low-cost renewable and sustainable greener sources thus essentially converting waste into wealth.

New process for conversion of hazardous industrial effluent of ceramic industry into nanostructured sodium carbonate and their application in textile industry.

Increase in industrialization as a tool to become global leader has led to an exponential rise in environmental pollution. The present study describes a process developed to extract nanocrystalline sodium carbonate from chemical industry effluents, which contributes to wealth creation from hazardous waste. Sodium carbonate is a high demand product because of its applications in detergents, dyeing, glass, and paper manufacturing. In the present work, we have extracted nanostructured sodium carbonate using industrial waste (alkaline solution of silicates, obtained from ceramic industry) and carbon dioxide (a major component of flue gas effluent from power plants). Here we have collected waste from ceramic industries, which is highly corrosive (pH 13-14) and disposal of such waste is dangerous to the environment and needs to be taken special care. Pure carbon dioxide has been purged in collected industrial waste to get nanoparticles and flakes structure of sodium carbonate at room temperature. The use of the nanostructured sodium carbonate in the dyeing of textiles was encouraging. Significantly, higher dyeing efficacy was observed compared to the fabric dyed in the absence of sodium carbonate (Na2CO3). The nanocrystalline particles show much better color strength than bulk sodium carbonate when K/S value was compared. Na2CO3 with the minimum particle size (26 nm) results in the maximum color strength (K/S = 14.49).

Recycling waste thermoplastic for energy efficient construction materials: An experimental investigation.

A large stream of research has studied the performance of waste plastics impregnated concrete, reporting multiple benefits and advocating its use in construction works. But no study has reported the merits of bricks impregnated with waste plastics. The present paper reports the results of experiments done on bricks made up of varying percentages of waste thermoplastics (0 - 10% by weight) and sand (60 - 70% by weight), holding percentages of fly ash and ordinary Portland cement constant at 15% (by weight) each. Three types of waste thermoplastics were used, forming three separate batches of bricks. The plastics were polycarbonates, polystyrenes, and mixed plastics. The bricks were cured under water for 28 days. Some of the batches were baked at temperatures ranging from 90 °C to 110 °C for 2 hours in order to melt the plastics to form voids. The bricks made with the above-stated compositions were found to possess low thermal conductivity and adequately high compressive strength. The compressive strength of these bricks is observed to be more than 17 MPa, which lies within the upper half of the range of strengths specified for bricks in the IS 1077:1992 standard. The waste plastics impregnated bricks display high thermal resistance, a feature that can add economic value to the brick manufacturers, motivating them to establish the necessary logistics for collection and use of all types of waste thermoplastics. The paper also presents a regression model to predict the compressive strength of bricks at varying plastic contents. The study, thus, introduces a new strand of research on sustainable recycling of waste thermoplastics in the context of the circular economy.

Waste chicken feather biofiller reinforced bioepoxy resin based biocomposites - A waste to wealth experimental approach.

Utilizing poultry wastes, particularly chicken feathers, in biopolymer composites is seen as an important aspect in lowering the environmental pollution and paving a new path to sustainability. The main objective of this experimental study is to develop polymer composites reinforced with waste chicken feather fillers and evaluate their physical, mechanical, and thermal characteristics. The composites were fabricated through an open mold casting process using bio epoxy (SR-33 Greenpoxy) as the matrix and chicken feather filler as a reinforcement in three distinct weight fractions (2.5, 5, and 7.5 wt%). To evaluate the effects of filler content on the mechanical properties of the fabricated bio-epoxy composites, they were subjected to tensile, flexural, impact, and hardness tests. The findings from the experimental studies demonstrated that the composites containing 2.5 wt% of chicken feather filler had improved mechanical properties, thermal stability, and crystallization behaviour. The thermal attributes of samples included a greater melting point, lower recrystallization temperature, higher glass transition temperature, and quicker crystallization rates. The Scanning Electron Microscope analysis of the fracture surface morphology of the biocomposites showed a better interfacial adhesion between the filler and matrix. It could be concluded from the results that the waste chicken feather can be used as potential filler reinforcements for begetting natural composites for various low- and medium-density structural and non-structural applications.

A study on production of hydrogen using Al scrap feedstock.

A sustainable future, concerning the energy transformation of a country, heavily relies on the availability of energy resources, particularly renewables such as solar, wind, hydropower, and clean hydrogen. Among these, hydrogen is the most promising energy source due to its high calorific value, ranging between 120 and 140 MJ/kg. It has the potential to lead the market in various industries such as power generation, steel, chemical, petrochemical, and automotive. Significant research has been going on in hydrogen production technologies to reduce costs and improve competitiveness with fossil fuels. One such potential approach includes the use of metal-water reactions, which offer unique opportunities for producing clean hydrogen and other valuable byproducts. However, the quantity of hydrogen produced varies depending on the metal feedstock, type of electrolyte, and the activator or catalyst, used in combination with water. This latest work discusses recent progress on hydrogen production and the effects of variations in different parameters on the process, with a focus on aluminum (Al)-water reactions. Investigations have been conducted and reported on the effect of various activators with different concentrations, the quantity of aluminum scrap feedstock, and the volume of the electrolyte on the kinetics of the metal-water reactions and hydrogen production. Sodium hydroxide (NaOH) was observed to be more effective than potassium hydroxide (KOH) in promoting metal-water reactions. These activator-assisted metal-water reactions help produce clean hydrogen, along with other value-added products such as hydroxides. This work clearly sheds light on the potential utilization of industrial aluminum scrap as feedstock for producing clean hydrogen.

A critical review on the vermicomposting of organic wastes as a strategy in circular bioeconomy: mechanism, performance, and future perspectives.

To meet the current need for sustainable development, vermicomposting (VC), a natural, eco-friendly, and cost-effective technology, can be a wise selection for the bioconversion of organic wastes into value-added by-products. However, no one has tried to establish the VC technology as an economically sustainable technology by exploring its linkage to circular bioeconomy. Even, no researcher has made any effort to explore the usability of the earthworms (EWs) as a protein supplement while assessing the economic perspectives of VC technology. Very few studies are available on the greenhouse gas (GHG) emission potential of VC technology. Still, the contribution of VC technology towards the non-carbon waste management policy is not yet explored. In the current review, a genuine effort has been made to inspect the contribution of VC technology towards the circular bioeconomy, along with evaluating its capability to bioremediate the organic wastes generated from domestic, industrial, and agricultural premises. The potential of the EWs as a protein source has also been explored to strengthen the contribution of VC technology towards the circular bioeconomy. Moreover, the linkage of the VC technology to the non-carbon waste management policy has been comprehensively demonstrated by highlighting its carbon sequestration and GHG emission potentials during the treatment of organic wastes. It has been observed that the cost of food production was reduced by 60-70% by replacing chemical fertilizers with vermicompost. The implication of the vermicompost significantly lessened the harvesting period of the crops, thereby helping the farmers attain higher profits by cultivating more crops in a single calendar year on the same plot. Furthermore, the vermicompost could hold the soil moisture for a long time, lessening the water demand up to 30-40%, which, in turn, reduced the frequency of irrigation. Also, the replacement of the chemical fertilizers with vermicompost resulted in a 23% increment in the grapes' yield, engendering an extra profit of up to 110000 rupees/ha. In Nepal, vermicompost has been produced at a cost of 15.68 rupees/kg, whereas it has been sold to the local market at a rate of 25 rupees/kg as organic manure, ensuring a net profit of 9.32 rupees/kg of vermicompost. EWs embraced 63% crude protein, 5-21% carbohydrates, 6-11% fat, 1476 kJ/100 g of metabolizable energy, and a wide range of minerals and vitamins. EWs also contained 4.11, 2.04, 4.43, 2.83, 1.47, and 6.26 g/kg (on protein basis) of leucine, isoleucine, tryptophan, arginine, histidine, and phenylalanine, respectively, enhancing the acceptability of the EW meal (EWM) as the protein supplement. The inclusion of 3 and 5% EWM in the diet of broiler pullets resulted in a 12.6 and 22.5% increase in their feed conversion ratio (FCR), respectively after one month. Similarly, when a 100% fish meal was substituted by 50% EWM and 50% fish meal, the FCR and growth rate of Parachanna obscura were increased substantially. The VC of maize crop residues mixed with pig manure, cow dung, and biochar, in the presence of Eisenia fetida EWs, yielded only 0.003-0.081, 0-0.17, and 130.40-189.10 g CO2-eq.kg-1 emissions of CO2, CH4, and N2O, respectively. Similarly, the VC of tomato stems and cow dung ensured 2.28 and 5.76 g CO2-eq.kg-1 CO2 emissions of CH4 and N2O, respectively. Additionally, the application of vermicompost at a rate of 5 t/ha improved the soil organic carbon proportion and aggravated carbon sequestration. The land application of vermicompost improved micro-aggregation and cut down the tillage, reducing GHG emissions and triggering carbon sequestration. The significant findings of the current review suggest that VC technology potentially contributes to the concept of circular bioeconomy, substantially negotiates potential GHG emissions, and complies with the non-carbon waste management policy, reinforcing its acceptability as an economically sound and environmentally benevolent organic waste bioremediation alternative.

3D Printing Approach to Valorization of Agri-Food Processing Waste Streams.

With increasing evidence of their relevance to resource recovery, waste utilization, zero waste, a circular economy, and sustainability, food-processing waste streams are being viewed as an aspect of both research and commercial interest. Accordingly, different approaches have evolved for their management and utilization. With excellent levels of customization, three-dimensional (3D) printing has found numerous applications in various sectors. The focus of this review article is to explain the state of the art, innovative interventions, and promising features of 3D printing technology for the valorization of agri-food processing waste streams. Based on recent works, this article covers two aspects: the conversion of processing waste streams into edible novel foods or inedible biodegradable materials for food packing and allied applications. However, this application domain cannot be limited to only what is already established, as there are ample prospects for several other application fields intertwining 3D food printing and waste processing. In addition, this article presents the key merits of the technology and emphasizes research needs and directions for future work on this disruptive technology, specific to food-printing applications.

Composting of limed fleshings generated in a tannery: sustainable waste management.

In tanneries, limed fleshing is an unavoidable waste generated in beamhouse operation. Proper management of limed fleshing with protein, fat, lime, and sulfide will help to protect the natural environment and at least reduce the pollution that ends up in it. In this study, excluding any pretreatment, limed fleshing is used for compost production. Chopped and mixed limed fleshing with chicken manure, cow dung, and sawdust was heaped onto a horizontal bamboo frame. Three composting heaps were fabricated weighing 720, 700, and 760 kg. The turning of composting materials in the heaps causes temperature changes in the thermophilic range. The thermophilic temperatures in these heaps were 69.07 °C (heap 1), 69.9 °C (heap 2), and 69.19 °C (heap 3) which ensured the death of the pathogenic organism. The quality of compost was assessed based on the nutrients-nitrogen (N), phosphorous (P), potassium (K), and sulfur (S) content. NPKS in the compost fulfils the requirements of the investigated materials as compost. The largest amounts of metals- zinc (Zn), copper (Cu), chromium (Cr), lead (Pb), and nickel (Ni) of the compost detected in the heaps were, respectively, 200.3, 37.4, 20.3, 12.0, and 3.9 mg/kg. Cadmium (Cd) in the compost was below the detection limit. Scanning electron microscope (SEM) photographs show the decomposing of composting materials. This study indicates that limed fleshing can be converted into nutrient-enriched compost without any pretreatment. Using an easy, simple, and adaptable technique could reduce the volume of solid waste generated in the tannery to reduce environmental pollution.

Cultivation of Navicula sp. on rice straw hydrolysate for the production of biogenic silica.

Rice straw hydrolysate (RSH) prepared at room temperature was found to be rich in silica (140 ± 4.1 mg L-1) and other nutrients (nitrate-N: 160 ± 4.3 mg L-1, total dissolve phosphate: 164 ± 6.7 mg L-1, ammoniacal-N: 439.8 ± 17 mg L-1). The aim of this work was to study four RSH dilutions (10, 30, 50, 70% v/v) to cultivate Navicula sp. with modified ASN-III as a control. The best result was achieved in 30% RSH in terms ofdoubling time (d = 1.49 days) and growth rate (µmax = 0.46 day-1). Compared to control, specific growth rate and biomass productivity were increased by 2.93 folds and 1.85 folds, respectively. Cultivation in 5 L reactor with optimized 30% RSH yielded frustule (54.2 ± 1.9%), carbohydrate (12.4 ± 1.2%), lipid (18.9 ± 1.4%), and protein (8.2 ± 0.6%). The residual solid fraction showed 18.99% increased theoretical methane yield than raw rice straw. Overall, the present process offers a sustainable solution to manage rice straw residue and recover nanoporous silica.

Emerging waste valorisation techniques to moderate the hazardous impacts, and their path towards sustainability.

Due to the recent boom in urbanisation, economy, and global population, the amount of waste generated worldwide has increased tremendously. The World Bank estimates that global waste generation is expected to increase 70% by 2050. Disposal of waste is already a major concern as it poses risks to the environment, human health, and economy. To tackle this issue and maximise potential environmental, economic, and social benefits, waste valorisation - a value-adding process for waste materials - has emerged as a sustainable and efficient strategy. The major objective of waste valorisation is to transit to a circular economy and maximally alleviate hazardous impacts of waste. This review conducts bibliometric analysis to construct a co-occurrence network of research themes related to management of five major waste streams (i.e., food, agricultural, textile, plastics, and electronics). Modern valorisation technologies and their efficiencies are highlighted. Moreover, insights into improvement of waste valorisation technologies are presented in terms of sustainable environmental, social, and economic performances. This review summarises highlighting factors that impede widespread adoption of waste valorisation, such as technology lock-in, optimisation for local conditions, unfavourable regulations, and low investments, with the aim of devising solutions that explore practical, feasible, and sustainable means of waste valorisation.

MEUF for removal and recovery of valuable organic components present in effluents: A process intensified technology.

In recent years, the domain of the research space in novel separation process has been led by membrane systems as a panacea providing multifarious benefits of high separation efficiency, elimination of extreme process conditions, sustainability, and environment friendliness coupled with high operational flexibility. In this niche area, often, ultrafiltration is touted as a robust separation technique due to its high separation efficiency, membrane stability, and lower operating costs. The only drawback of relatively large pore size can be overcome by combining surfactant addition, leading to development of integrated processes termed as Micellar Enhanced Ultrafiltration. MEUF processes isolate and selectively separate valuable organics present in effluent streams. The process characteristics fit the bill as a typified example for process intensification Technology interventions for recycling of surfactants can enhance the cost-competitiveness of the process. This has the potential to develop into a broad-spectrum effluent treatment option with a change of surfactants for target contaminants. Here, in this review, we attempt to critically examine the unique features of this technology, development of spin-offs with wide-ranging applications. Specifically applications in removal of hazardous, and persistent components like dissolved organics have been critically studied. The focus was to highlight the crux of the novel technologies highlighting the efficacy and the underlying concept of process intensification. PRACTITIONER POINTS: Role of MEUF as a sustainable process intensifying separation technique for removal and recovery of organics. Novel process development using MEUF. Comparative performance analysis to assess efficacy. Discussions on future integrative process development. Sustainability aspect of MEUF with possibility of byproduct recovery.

A comprehensive review on textile waste valorization techniques and their applications.

An increase in population compels the textile industry to expand production to fulfill the apparel requirement, resulting in huge textile waste. These wastes are managed either by landfilling or incineration processes, which negatively contribute to the environment. Converting waste into value-added products is essential to reducing environmental pollution and thereby achieving a circular economy through proper waste management practices. This paper provides a comprehensive overview of different categories and forms of textile waste, their source of generation, the reusing capability of the textile industry, other valorization potentials in different fields, and various challenges associated with their valorization practices. This review presents textile wastes as the raw material source for preparing different value-added products such as in manufacturing textiles, packaging materials, plastics, composites, construction applications, energy generation, chemical additives, composting, and several other applications.

Removal of phosphate from water by paper mill sludge biochar.

Biochar modification by metals and metal oxides is considered a practical approach for enhancing the adsorption capacity of anionic compounds such as phosphate (P). This study obtained paper mill sludge (PMS) biochar (PMSB) via a one-step process by pyrolyzing PMS waste containing ferric salt to remove anionic P from water. The ferric salt in the sludge was transformed into ferric oxide and zero-valent-iron (Fe0) in N2 atmosphere at pyrolysis temperatures ranging from 300 to 800 °C. The maximum adsorption (Qm) of the PMSBs for P ranged from 9.75 to 25.19 mg P/g. Adsorption is a spontaneous and endothermic process, which implies chemisorption. PMSB obtained at 800 °C (PMSB800) exhibited the best performance for P removal. Fe0 in PMSB800 plays a vital role in P removal via adsorption and coprecipitation, such as forming the ≡Fe-O-P ternary complex. Furthermore, the possible chemical precipitation of P by CaO decomposed from calcite (CaCO3; an additive of paper production that remains in PMS) may also contribute to the removal of P by PMSB800. Moreover, PMSBs can be easily separated magnetically from water after application and adsorption. This study achieved a waste-to-wealth strategy by turning waste PMS into a metal/metal oxide-embedded biochar with excellent P removal capability and simple magnetic separation properties via a one-step pyrolysis process.

Sustainable processing of food waste for production of bio-based products for circular bioeconomy.

Sustainable development of circular bioeconomy concept is only possible upon adopting potential advanced technologies for food waste valorization. This approach can simultaneously answer resources and environmental challenges incurred due to capital loss and greenhouse gases accumulation. Food waste valorization opens new horizons of economical growth, bringing waste as an opportunity feedstock for bio processes to synthesize biobased products from biological source in a circular loop. Advanced technologies like Ultrasound assisted extraction, Microwave assisted extraction, bioreactors, enzyme immobilization assisted extraction and their combination mitigates the global concern caused due to mismanagement of food waste. Food waste decomposition to sub-zero level using advanced techniques fabricates food waste into bio-based products like bioactive compounds (antioxidants, pigments, polysaccharides, polyphenols, etc.); biofuels (biodiesel, biomethane, biohydrogen); and bioplastics. This review abridges merits and demerits of various advanced techniques extended for food waste valorization and contribution of food waste in revenue generation as value added products.

Circular Economy across Australia: Taking Stock of Progress and Lessons.

Australia has intensified its circular economy (CE) efforts that demonstrate designing out waste while creating wealth. It has developed eco-industrial parks in metallurgy/metal industries, eco-cities and small-scale waste-to-wealth creation strategies. Mining has taken the lead in CE development with the eco-industrial areas at Kwinana, Western Australia, and Gladstone, Queensland. Easing up the waste burden, eco-efficiency and value addition are the direct benefits of circularizing the economy. Shortsightedness in looking up for opportunities across the supply chain, technological constraints, lack of policy coordination for business innovation, economic recession induced by the COVID-19 pandemic and lack of incentives to change behavior from linear to circular economy are among the barriers pointed out. A systematic review of published literature in Australian context was conducted to assess the state-of-the art circular economy development. We have found that Australia has to look into overcoming the barriers by putting in place policies and guidelines to nurture the current synergies, business relationships and trust among the firms in partnership, and more R & D to meet the demand for complementing technologies and to have cohesion over the current CE strategies, among others.