Sustainable Approach Research Articles

Strategic Analysis for Developing Tourism in Toba Regency: A Sustainable Management Approach

Toba Regency, located in North Sumatra, Indonesia, offers vast potential for tourism development, thanks to its natural beauty, cultural heritage, and historical significance. This study analyzes the strengths, weaknesses, opportunities, and threats (SWOT) related to tourism in Toba Regency, utilizing a sustainable management approach to enhance the region's tourism sector. By conducting a SWOT analysis and evaluating both internal and external factors, the study identifies key strategies for boosting tourism, including improving infrastructure, increasing local community involvement, and promoting the region’s unique cultural and natural attractions at national and international levels. The findings suggest that leveraging Toba Regency's natural and cultural resources, while addressing limitations in infrastructure and community engagement, can significantly enhance its tourism potential. The strategic recommendations provided focus on sustainable practices that will benefit the local economy, preserve cultural and environmental assets, and foster long-term tourism growth.

Industry 5.0 Research in the Sustainable Information Systems Sector: A Scoping Review Analysis

Industry 4.0, centered on cyber-physical production systems, has been criticized for prioritizing profit over social and environmental concerns. In contrast, Industry 5.0 emphasizes AI efficiency while promoting human-centric, resilient, and sustainable approaches, integrating economic, social, and environmental systems. Previous research has often focused solely on conceptual frameworks and technologies, overlooking Industry 5.0's sector-specific impacts. This study addresses that gap by conducting a scoping review to map research findings, identify trends, and highlight knowledge gaps and future research opportunities. By systematically analyzing literature from the Scopus database (2016-present), the study refined a large dataset to focus on Industry 5.0's relevance. The analysis revealed significant attention to sectors like Industry and Producer Services, while Agriculture and Retail, particularly natural resource-based sectors like agriculture and fisheries, are often neglected. Key findings indicate that Industry 5.0 is likely to be driven by the industrial sector, followed by product services and financial industries. The study also highlights the strong connection between IoT and AI in optimizing operations with real-time data and automation and identifies blockchain as a promising technology for enhancing transparency and security, despite existing implementation challenges. This research not only serves as a foundational record of Industry 5.0's implications across various sectors but also provides valuable insights into its role in Information Systems (IS). It lays the groundwork for future exploration of Industry 5.0 in diverse sectors and industries.

Socialization of mangrove planting among coastal communities: A collaborative approach for conservation and ecosystem sustainability

Socialization of mangrove planting among coastal communities: A collaborative approach for conservation and ecosystem sustainability

An environmentally sustainable ultrasonic-assisted exfoliation approach to graphene and its nanocompositing with polyaniline for supercapacitor applications

In the present work, a green high-yielding method for the preparation of graphene is introduced via ultrasonic-assisted liquid phase exfoliation (LPE) of graphite in a green solvent medium, since the common preparation method of graphene via graphite oxide is hazardous. A high concentration of 3.2 mg/ml graphene is achieved here in a comparatively short duration of 3 h ultrasonication. By using a mixed solvents strategy (acetophenone and isopropyl alcohol, 1:19 V/V), surface energy requirements needed for the exfoliation of graphite are satisfied here with acetophenone, where isopropyl alcohol further facilitated the exfoliation via non-conventional CH-π and OH-π interactions. Turbostratic graphene in high-yield (16 %) in a simple means of ultrasonic assisted LPE is the added attraction of the present procedure. The less-defective structure of graphene, its few-layered turbostratic nature, and edge functionalization of the sheets are evident from the material characterization via Raman spectroscopy, XRD, TEM-SAED, and XPS analyses. Here, we report a combination of the attractive conducting polymer polyaniline (PANI) with the as-prepared graphene for supercapacitor applications, where the PANI/graphene nanocomposites with different aniline concentrations (PANI1.125/G, PANI4.5/G, and PANI9/G) have been prepared via in-situ polymerization of aniline in the graphene dispersion. The structure and morphology of the nanocomposites are investigated using different characterization techniques which revealed that the molecular structure of the PANI is retained in the nanocomposites even with a strong interaction with graphene. FESEM and TEM images revealed the good coverage of graphene sheets with PANI that limit the volume change of PANI during the repeated charge-discharge processes. Electrochemical studies showed that PANI4.5/G has the highest specific capacitance of 126.16 mF/cm2 at a current density of 1 mA/cm2, resulting from the perfect combination of the pseudocapacitance behavior of the PANI along with the electrical double layer capacitance of graphene. A symmetric supercapacitor device is also fabricated with PANI4.5/G, which showed the highest areal capacitance of 116.38 mF/cm2 similar to that with three-electrode studies and also good cycling stability with 87 % capacitance retention in the specific capacitance after 6000 cycles. It also exhibited an energy density of 16 µWh/cm2 (0.29 Wh/kg) and a power density of 3.99 mW/cm2 (72.72 W/kg).

Enhancing nitrogen removal in low C/N wastewater with recycled sludge-derived biochar: A sustainable solution

Denitrification is an important biological process in wastewater treatment plants (WWTPs). However, a low carbon-to-nitrogen (C/N) ratio limits the availability of organic carbon, potentially reducing denitrification efficiency. This study investigates the impact of sludge-derived biochar on the nitrogen removal of activated sludge for low C/N ratio municipal wastewater. Sludge-based biochar was characterized by its physicochemical properties, revealing that biochar prepared at 400 °C exhibited the highest specific surface area and the most favorable surface functional groups for electron transfer. The results from batch tests showed that adding 4 g/L of biochar dosage enhanced denitrification rates and total nitrogen (TN) removal efficiency the most. Sequencing batch reactors (SBRs) experiments further confirmed that biochar dosgae improved the removal efficiencies of COD, NH4+-N, and TN, achieving stable values of 97.2 ± 1.2 %, 99.2 ± 0.6 %, and 83.8 ± 2.4 %, respectively. Metabolic and electrochemical analyses revealed that biochar addition enhanced the activity of denitrification enzymes, increasing the ammonia oxidation rate by 12.9 ± 0.7 %, nitrite oxidation rate by 14.7 ± 1.2 %, nitrate reduction rate by 36.9 ± 1.5 %, and nitrite reduction rate by 16.4 ± 0.8 %. The relative abundance of denitrification functional genes (amoA, nirS, nirK, narG, nosZ) increased, and the activities of the corresponding enzymes (AMO, NXR, NAP, NIR) rose by 23±6 %, 53±5 %, 260±15 %, and 55±7 %, respectively. This increase in enzyme activity suggested enhanced denitrification processes, which was further supported by the 60.1 ± 3.7 % increase in electron transfer system activity (ETSA), indicating that biochar acted as an electron shuttle. This study proposes a potential sustainable approach for sludge recycling and enhanced wastewater nitrogen removal under low C/N conditions.

Enzyme‑assisted extraction of cashew nut (Anacardium occidentale L.) testa

Enzyme-assisted extraction (EAE) has been successfully applied to extract polyphenols from various food materials and by-products. Hence, the present research aimed to valorize the cashew nut (Anacardium occidentale L.) testa by EAE method using an enzyme cocktail of cellulase and pectinase. The effects of different processing parameters, including the pH (3.0 - 6.0), temperature (30 - 70°C), extraction time (60 - 150 min), solid -to-solvent ratio (1/5 - 1/85), and enzyme concentration (0.1 - 0.4% v/v) on the total polyphenol content (TPC) and antioxidant capacity of the testa extracts were investigated. The results showed that the TPC of the testa extracts positively correlated with the antioxidant capacity. The EAE performed at pH 4.0, a temperature of 50°C, an extraction time of 60 mins, a solid-to-solvent ratio of 1/55, and an enzyme concentration of 0.2% (v/ v) resulted in the highest TPC (168.84 g GAE/kg DW) with DPPH and ABTS antioxidant activity of 885.56 and 1513.60 (mmol TE/kg DW), respectively. The EAE technique holds significant promise as a sustainable approach to mitigate the underutilization and undervaluation of cashew nut testa waste, which could otherwise contribute to environmental pollution.

Residents’ Perceived Benefits as Determinants of Sustainable Tourism Development

ABSTRACT This study explores how the benefits residents perceive influence their support for tourism and sustainable practices in nature-based tourism. It highlights the importance of community involvement and local support in achieving sustainable tourism. The study uses Partial Least Squares Structural Equation Modeling (PLS-SEM) analysis to test the proposed hypotheses. The research is conducted in Arribes del Duero Natural Park, a protected natural area spanning Spain and Portugal. Data were collected through an online survey with convenience sampling, resulting in 401 usable questionnaires. The findings demonstrate that community involvement has a positive and significant influence on perceived benefits, support for tourism, and sustainable market-oriented approaches. Perceived benefits also positively and significantly impact support for tourism and sustainable market-oriented approaches. Furthermore, support for tourism is found to have a positive and significant influence on sustainability.

How can a cost-effective method for industrial wastewater treatment be developed in India?

Wastewater treatment and repurposing will be pivotal for growing economies as demand for water increases. A sustainable approach toward economic development in India would be treating industrial wastewater for agricultural applications, reducing overall water consumption, and feeding one sector of the Indian economy with effluent from another. To achieve this, a cost-effective and sustainable treatment process needs to be developed. This paper provides a comprehensive analysis of the available methods and equipment for wastewater treatment through a brief literature review. A four-stage treatment was considered, including pretreatment, primary and secondary chemical treatment, and post treatment. The overall process features screening, oil skimming, coagulation, flocculation, sedimentation, aeration, and gravel filter. The most important specifications suitable for India include using spent poly-aluminum chloride as a coagulant and flocculant (CPCB, 2022) and using vertical shaft aerators (Drewnoski, et. al., 2019) and high-efficiency blowers (Bell, et. al., 2011) in the aeration process.

Synthesis of Pyrrolo [2,1-a]isoquinolines using Cu NPs decorated microcrystalline cellulose in 2-Methyl-THF: A biodegradable heteregeneous nanocatalyst for the sustainable cascade approach

Copper nanoparticles (Cu NPs) supported on microcrystalline cellulose (MCC) serve as an efficient and biodegradable heterogeneous nanocatalyst for the synthesis of pyrrolo [1,2a] isoquinoline under mild and sustainable reaction conditions through a cascade reaction involving condensation, addition, oxidation, and cyclization events. The catalyst underwent thorough characterization via various techniques, including FT-IR, PXRD, XPS, FE-SEM, EDX, TEM, and HR-TEM analysis. Optimized reaction conditions facilitated high-yield production of a diverse range of pyrrolo [1,2a] isoquinolines in 2-Me THF solvent, and the method demonstrated scalability with successful gram-scale synthesis. Notably, the catalyst exhibited reusability for up to five cycles without a significant decrease in activity. This approach aligns with eco-friendly principles, as evidenced by favorable green chemistry metrics for compound 4a, including low process mass intensity (7.83), a minimal environmental impact factor (6.83), a substantial atom economy (67.56 %), efficient reaction mass efficiency (60.76 %), high chemical yield (92.37 %), low mass intensity (1.64), notable mass productivity (60.97 %), considerable carbon efficiency (69.15 %), and optimum efficiency (89.93 %). These results highlight the sustainable and environmentally conscious nature of the developed synthetic methodology.

Phosphorus-loaded coconut biochar: A novel strategy for cadmium remediation and soil fertility enhancement

The management of cadmium (Cd) contamination in soils poses a significant environmental challenge. This study investigates the effectiveness of phosphorus (P)-loaded coconut biochar, synthesized at various pyrolysis temperatures (450°C, 500°C, 550°C, and 600°C), in immobilizing Cd and enhancing P availability in soil environments. The biochar underwent a series of treatments including activation and P enrichment, followed by incubation trials to evaluate its performance in Cd immobilization and P bioavailability enhancement across varying soil concentrations (0.5 %, 1.0 %, and 2.0 %) over time periods of 15, 30, and 45 days. Remediation progress was monitored using phytotoxicity assessments with radish (Raphanus sativus) root length as a bioindicator, supplemented by urease activity analyses. Notably, the activation process increased the P loading capacity of biochar produced at 450°C, 500°C, and 550°C by 54.6 %, 72.4 %, and 51.8 %, respectively, while reducing the P retention capacity of biochar prepared at 600°C by 31.0 %. The biochar activated at 550°C presented the highest efficiency in remediating Cd-contaminated soils. Key findings indicate that the enhanced specific surface area and oxygenated functional group content of the activated biochar facilitated Cd adsorption and P uptake. The P-loaded biochar exhibited a substantial adsorption capacity for Cd, particularly effective at lower concentrations, rendering it highly suitable for soil remediation purposes. Additionally, the study revealed that the application of biochar led to an increase in soil pH, resulting in precipitation of Cd as hydroxide species and formation of insoluble complexes with phosphate ions, thereby reducing its bioavailability. In summary, incorporating P-loaded biochar into soil significantly improved soil quality and enhanced Cd passivation in contaminated soils. The utilization of biochar produced at 550°C, which exhibited optimal performance, suggests a practical and sustainable approach for soil remediation. Future research endeavors should prioritize the refinement of the biochar production process to enhance cost-effectiveness while maintaining high P loading efficiency.

Optimizing Convolutional Neural Network Architectures

Convolutional neural networks (CNNs) are commonly employed for demanding applications, such as speech recognition, natural language processing, and computer vision. As CNN architectures become more complex, their computational demands grow, leading to substantial energy consumption and complicating their use on devices with limited resources (e.g., edge devices). Furthermore, a new line of research seeking more sustainable approaches to Artificial Intelligence development and research is increasingly drawing attention: Green AI. Motivated by an interest in optimizing Machine Learning models, in this paper, we propose Optimizing Convolutional Neural Network Architectures (OCNNA). It is a novel CNN optimization and construction method based on pruning designed to establish the importance of convolutional layers. The proposal was evaluated through a thorough empirical study including the best known datasets (CIFAR-10, CIFAR-100, and Imagenet) and CNN architectures (VGG-16, ResNet-50, DenseNet-40, and MobileNet), setting accuracy drop and the remaining parameters ratio as objective metrics to compare the performance of OCNNA with the other state-of-the-art approaches. Our method was compared with more than 20 convolutional neural network simplification algorithms, obtaining outstanding results. As a result, OCNNA is a competitive CNN construction method which could ease the deployment of neural networks on the IoT or resource-limited devices.

Integrated Pest Management: An Update on the Sustainability Approach to Crop Protection.

Integrated Pest Management (IPM) emerged as a pest control framework promoting sustainable intensification of agriculture, by adopting a combined strategy to reduce reliance on chemical pesticides while improving crop productivity and ecosystem health. This critical review synthesizes the most recent advances in IPM research and practice, mostly focusing on studies published within the past five years. The Review discusses the key components of IPM, including cultural practices, biological control, genetic pest control, and targeted pesticide application, with a particular emphasis on the significant advancements made in biological control and targeted pesticide delivery systems. Recent findings highlight the growing importance of genetic control and conservation biological control, which involves the management of agricultural landscapes to promote natural enemy populations. Furthermore, the recent discovery of novel biopesticides, including microbial agents and plant-derived compounds, has expanded the arsenal of tools available for eco-friendly pest management. Substantial progress has recently also been made in the development of targeted pesticide delivery systems, such as nanoemulsions and controlled-release formulations, which can minimize the environmental impact of pesticides while maintaining their efficacy. The Review also analyzes the environmental, economic, and social dimensions of IPM adoption, showcasing its potential to promote biodiversity conservation and ensure food safety. Case studies from various agroecological contexts demonstrate the successful implementation of IPM programs, highlighting the importance of participatory approaches and effective knowledge exchange among stakeholders. The Review also identifies the main challenges and opportunities for the widespread adoption of IPM, including the need for transdisciplinary research, capacity building, and policy support. In conclusion, this critical review discusses the essential role of IPM components in achieving the sustainable intensification of agriculture, as it seeks to optimize crop production while minimizing adverse environmental impacts and enhancing the resilience of agricultural systems to global challenges such as climate change and biodiversity loss.

Novel 3D FRP system used for more effectively and readily strengthening of precast concrete elements

The burgeoning precast concrete market necessitates innovative strengthening solutions to ensure the durability and safety of precast elements. This study presents a 3D Fiber Reinforced Polymer (FRP) system designed to reinforce precast concrete elements, providing a more effective and efficient method compared to traditional Externally Bonded (EB) and Near Surface Mounted (NSM) FRP techniques. The system utilizes extended FRP strips that function as bent anchorages, U-wraps for anchorage protection, and additional FRP patches to prevent anchorage cutoff at bent corners. A comprehensive experimental campaign involving 33 specimens assessed the system's performance, demonstrating significant improvements in flexural and shear capacities with minimal surface preparation requirements. The experiments included varying strip widths and anchorage configurations to optimize the system's effectiveness. Numerical models were developed to simulate the flexural behavior of the 3D FRP reinforced elements, accurately predicting load-deflection responses and failure modes. Both experimental and numerical results suggest that the 3D FRP system not only enhances the load capacity and structural integrity of precast concrete elements but also simplifies the installation process, offering a promising solution for the construction industry. The findings also offer practical guidelines for the design and fabrication of 3D FRP reinforced concrete elements, contributing to a more sustainable and economical construction approach.

Development and validation of a survey instrument for reusable sanitary products toward sustainable menstrual hygiene.

The predominant use of disposable, non-organic menstrual products has significant environmental impacts due to waste and resource depletion. Concerns over the environmental, economic, and health implications of menstrual hygiene management (MHM) have highlighted the need to explore sustainable options like reusable sanitary pads (RSPs). Despite their benefits, the adoption of RSPs is limited by a lack of awareness, availability, cost, and research. This study emphasizes the need for the development of an instrument that can capture the effectiveness, safety, and user satisfaction of RSPs, addressing a significant gap in the literature. Using a convenient sampling method, data were collected through a structured offline survey and the sample comprised 446 South Asian women of reproductive age. The instrument included 15 items designed to measure factors such as comfort, hygiene, convenience, and environmental consciousness. The instrument's reliability and validity are thoroughly assessed using reliability and factor analysis to ensure its effectiveness in capturing the multifaceted dimensions of MHM product choices. The study revealed that the overwhelming majority of women would prefer the option of RSPs that are comfortable, accessible, and easy to use and dispose of. The findings aim to provide a validated tool for manufacturers, policymakers, and researchers to evaluate reusable pads, promoting their broader acceptance and adoption of a sustainable and equitable approach to menstrual hygiene.

Exploring sustainable livelihood options for COVID-impacted rural communities in Bangladesh

The COVID pandemic paralyzed all economy-generating sectors of Bangladesh, putting abrupt pressure on livelihood-making. In this study, two sequential surveys were conducted in the Mymensingh district of Bangladesh to gain a deep understanding of the impacts of COVID on job status and post-COVID job preference. The effectiveness of preferred occupations in livelihood resilience within the Sustainable Livelihood Approach (SLA) framework was also empirically analyzed and people-driven policies were recommended for sustaining livelihoods. About 35.96 % of respondents experienced short-to long-term unemployment and migrated to rural areas. The groups most severely affected were predominantly engaged in both formal and informal employment, characterized by lower levels of education, older age brackets, and predominantly female (45 out of 114). In the COVID situation, a large portion of respondents adopted agriculture (18.42 %), aquaculture (10.53 %), livestock farming (5.26 %), and small businesses (13.27 %) as their means of livelihood. However, for post-COVID preferences, respondents remained limited to only 13 job categories, considering aquaculture (22.02 %), agriculture (19.90 %), and livestock farming (26.22 %) as their most desired sectors. Considering all five capitals within the SLA framework, aquaculture and livestock farming were found to be more effective in bringing livelihood resilience within COVID-affected rural communities than agriculture. However, the greater advantages that aquaculture offers in achieving post-COVID livelihood led the authors to consider aquaculture as a decisive choice for policy recommendation. Therefore, the study proposed 28 people-oriented policies under four broad categories (financial support, technical assistance, marketing and logistics, and governance and institutional) in making sustainable livelihoods from aquaculture where financial support takes precedence as their top priority.

Potent and selective ‘genetic zipper’ method for DNA-programmable plant protection: innovative oligonucleotide insecticides against Trioza alacris Flor

Chemical insecticides increased the chemical burden on natural ecosystems posing environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, including eco-friendly ‘genetic zipper’ method (or CUAD platform) based on contact oligonucleotide insecticides. Oligonucleotide insecticides have enjoyed success recently on many sternorrhynchans showing highly adaptable structure for distinct insect pest species and selective mode of action. In this article, we describe the efficiency of the oligonucleotide insecticides (briefly, olinscides or DNA insecticides) Alacris-11 and Laura-11, as well as their combined use in mixture (1:1), designed for control of bay sucker (Trioza alacris Flor), an important psyllid pest of noble laurel (Laurus nobilis L.). These olinscides are based on short unmodified antisense DNA oligonucleotides that target ITS2 between 5.8S rRNA and 28S rRNA in pre-rRNA (Laura-11) and 28S rRNA region in mature 28S rRNA and pre-rRNA (Alacris-11). The maximum pest mortality, observed on the 14th day of the experiment, comprised 95.01 ± 4.42% for Alacris-11, 97.16 ± 2.48% for Laura-11, and 98.72 ± 1.14% for their mixture (1:1). The control oligonucleotide CTGA-11 did not cause any significant mortality (9.38 ± 0.57%), emphasizing selectivity in the action of oligonucleotide insecticides. The results show potent and specific nature of oligonucleotide insecticides for pest control and open up new frontiers in control of economically important psyllids in agriculture and forestry, including Asian citrus psyllid (Diaphorina citri Kuwayama) and many others. Scientists can easily adopt ‘genetic zipper’ method for plethora of insect pests because DNA is a programmable molecule and provides game-changing characteristics for plant protection.Graphical

Quaternary layered double hydroxides from spent battery as electrocatalysts for the oxygen evolution reaction

Quaternary layered double hydroxides (LDHs) are emerging as effective oxygen evolution reaction (OER) electrocatalysts for alkaline water splitting. In this work, NiCoMnFe-LDH has been successfully fabricated using leachate from recycled battery cathodes, demonstrating a sustainable approach to resource utilization. By incorporating varying amounts of Vulcan XC72 carbon as a support, we improved the conductivity of the NiCoMnFe-LDH. Our results indicate that the addition of Vulcan XC72 enhances the electrocatalytic performance of the nanocomposites. Notably, the NiCoMnFe-LDH/C-50 sample exhibited superior OER activity, with an overpotential of 329 ± 10 mV at a current density of 10 mA cm⁻2 and stable performance over 15 h. Detailed characterization confirmed the advantages of the carbon support in improving both the structural stability and catalytic efficiency. This work may pave the way to a sustainable method for repurposing spent battery cathodes, advancing the development of cost-effective and environmentally friendly electrocatalysts for clean energy applications.

A sustainable approach for efficient ammonium recovery, and simultaneous TOC removal from aqueous solutions by vesicle-like iron phosphate-based carbon nanomaterials

NH4+ is an ion with versatile potential; however, the release of wastewater containing this component, regardless of its high or low concentration, causes severe eutrophication in aquatic systems and contaminates numerous manufacturing processes. Thus, this study developed a sustainable method that can simultaneously remove, recover NH4+, polish water, oxidize organic matter, and yet release a material that can still be used as fertilizer. Regarding NH4+ removal, FeP400 rapidly exhibited an exceptional NH4+ uptake capacity (343.5 mg g-1) within 8 min, even in dairy processing wastewater with high NH4+ concentrations and diverse co-existing components. FeP400 could oxidize organic compounds spontaneously to remove TOC, indirectly enhancing its NH4+ uptake up to 33.5 % through charge balance mechanisms. The adsorption process involved both chemical (i.e., double-salt precipitation) and physical mechanisms (i.e., H-bonding and electrostatic interaction), as confirmed by thermodynamics, FT-IR, and XPS analyses. Regarding recovery, FeP400 can be reused for over 10 cycles with high removal (81 %) and NH4+ recovery (88 %), a significant improvement over conventional options. FeP400 also performed efficiently under flowing conditions using low-range NH4+ and TOC samples over 10 cycles, polishing not only 34.1 L of water with undetected NH4+, neutral pH, and extremely low TOC but also effectively recovering the NH4+ uptake at an economical cost. Lastly, its environmentally friendly nature, which contains essential nutrients for plant growth, further enhances its recyclability after release. Thus, FeP400 is believed to offer a transformative, sustainable, and highly efficacious solution to the NH4+contamination and critical ultrapure water issues that industries urgently address.

Pollution control and biodiesel production with microalgae: new perspectives on the use of flat panel photobioreactors regarding variation in volume application rate.

In the present study, the microalga Arthrospira platensis DHR 20 was cultivated in vertical flat-plate photobioreactors (FPBRs) to bioremediate anaerobically digested cattle wastewater (ACWW) and used as a growth substrate. The final objective was to evaluate the properties of the oil extracted from this biomass to determine its potential for biodiesel production. The process was divided into five phases, varying the volume of the applied substrate: 1 L (Phase I), 5 L (Phase II), 10 L (Phase III), 15 L (Phase IV), and 20 L (Phase V). Dry biomass reached a maximum of 5.7g L-1, and productivity peaked at 0.74g L-1d-1. The highest rate of CO2 biofixation was 1213.5mg L-1day-1, showing good potential for purifying the air. The highest specific maximum growth rate (μmax) and the shortest doubling time (Dt) were found during Phase I. The removal of pollutants and nutrients during the experimental phases ranged from 65.8% to 87.1% for chemical oxygen demand (COD), 82.2% to 85.8% for total organic carbon (TOC), 91% to 99% for phosphate (PO43-), 62.5% to 93% for nitrate (NO3-), 90.4% to 99.7% for ammoniacal nitrogen (NH4+), and 86.5% to 98.5% for total nitrogen (TN). The highest lipid production recorded was 0.172g L-1day-1. The average cetane number recorded in Phase IV of 51 suggests that the fuel will ignite efficiently and consistently, providing smooth operation and potentially reducing pollutant emissions. The analysis of fatty acids revealed that the produced biodiesel has the potential to be used as an additive for other low-explosive biocombustibles, representing an innovative and sustainable approach that simultaneously offers bioremediation and carbon sequestration.

Innovative high-performance and energy-positive Co-treatment of organic kitchen waste and domestic wastewater using a fluidized bed ceramic membrane bioreactor

The aim of the study was to efficiently treat organic kitchen waste (FW) and domestic wastewater (DWW) together in an anaerobic fluidized bed bioreactor equipped with a ceramic membrane (AnFCMBR) through a sustainable approach considering energy recovery. The system operated continuously for 519 days at room temperature, and different filtration fluxes (1.7 and 5 L/m2/h), hydraulic retention times (HRTs) (22 h and 7 h), and organic loading rate (OLRs) (0.46, 1.52, 3.42, 6.08 kg/m3.d) were tested. The amount of organic matter in DWW may be insufficient for feasible gas production, but this challenge can be resolved through the addition of food waste. Influent chemical oxygen demand (COD) of 500 ± 143 mg/L gradually increased to 2000 ± 196 mg/L by increasing the portion of FW. The COD removal ranged from 92 to 98% throughout the study, with the membrane and the cake layer contributing 5–8% to the performance. Average supernatant SMP and EPS concentrations increased from 5 ± 1 to 45 ± 5 mg COD/L and from 54 ± 7 to 254 ± 26 mg COD/g VSS, respectively, when the highest amount of FW was added to the synthetic wastewater. This significant increase in SMP and EPS concentrations due to the addition of FW negatively impacted the filtration performance. SRF and CST values also increased with rising OLR, especially with the supplementation of synthetic wastewater with FW.After FW started to be mixed with DWW, the methane production increased approximately 5.5 times. With the use of AnFCMBR for the co-treatment of FW and DWW, it is possible to achieve energy-positive treatment with high-quality effluent that can be reused for various applications, such as irrigation. The methane produced provided 12 times more energy than was needed to operate the bioreactor.This is the first study evaluating the co-treatment of FW and DWW in AnFCMBR under varying operational parameters.