Computational study of the performance of a solar dryer for improvement in the shelf life of the food materials.

In this study, the thermal and drying characteristics of a thin layer food sample were investigated. An indirect type, simple, efficient, and economically feasible solar dryer was fabricated and used for food preservation. However, a dynamic model of a fabricated solar dryer was also presented to gain a better insight into the drying and thermal actions. This model consists of thermal modeling of the drying chamber, solar collector, and solar-dried food sample. The law of conservation of energy was applied to evaluate the temperature at different sections of the solar dryer with respect to drying time. All listed model equations were solved in the MATLAB environment. This study helps to examine the influence of solar radiation on the collector plate temperature, drying chamber temperature, food sample temperature, and performance parameters such as thermal efficiency with respect to drying time. Model data was found in good agreement with experimental data within a 4% error. It is concluded that the drying of food material is affected by air temperature, the collector temperature, mode of heat transfer, and material characteristics such as dimension and mass of the food sample.

Potable water production through a low-cost single chamber solar still in north India.

The main aim of this study is to evaluate the performance of a single slope solar still and to assess the effect of nanofluid on its performance. A single basin single slope solar still was designed and fabricated at the Department of Chemical Engineering, IET Lucknow. Its performance was assessed in terms of the yield of potable water. The effect of various climatic parameters was also studied. Al2O3 nanofluid was used to enhance the yield of the solar still. In the presence of nanofluid, the total yield of the solar still improved by 16.6%. Its economic feasibility was analyzed and reported. The portability of the small size of solar stills, its better economics, easy fabrication, and good performance make them very useful for industrial as well as household purposes.

Unlocking growth potential: Synergistic potassium fertilization for enhanced yield, nutrient uptake, and energy fractions in Chinese cabbage.

The implementation of integrated potassium management presents a viable approach for augmenting plant growth, yield, and nutrient uptake while enhancing soil nutrient availability. A field experiment was executed during the rabi season of 2020, employing a randomized complete block design encompassing eight treatments involving standard (100%) and reduced (75% and 50%) rates of the recommended dose of potassium (RDK) administered through muriate of potash (MOP). Treatments included variations in the incorporation/exclusion of plant growth-promoting rhizobacteria (PGPR), farmyard manure (FYM) at 25% of potassium recommendation, and foliar application of nano potash. The use of 100% RDK +25% K augmentation through FYM + PGPR and nano K fertilizer spray at 25 and 40 DAS (T8) exhibited significant enhancements in green fodder yield (64.0 ± 2.2 t ha-1) over control with no potassium application (47.3 ± 3.7 t ha-1) and found at par with and 75% RDK + 25% K augmentation through FYM + PGPR and nano K fertilizer spray at 25 and 40 DAS (T7). These treatments yielded maximum percent increase for plant height (34.9%), leaf count (38.5%), leaf dimensions (28.8-31.5%), stem girth (25.84%), root volume (27.0%), and root length (37.64%), observed at the harvest stage compared to control (T1-no potassium application). The treatment T8 was on par with T7 and recorded highest uptake of macro (N, P, and K) and micro (Zn, Fe, Cu, and Mn) nutrients. While soil parameters such as available nitrogen and potassium levels were notably increased through the application of treatment T7 across various treatment combinations and found significantly superiority over treatment T8. Multivariate analysis also highlighted treatment T7 is more efficient in maintaining sustainability. Hence, based on the present findings it can be concluded that application of 75% RDK +25% K augmentation through FYM + PGPR and nano K fertilizer spray at 25 and 40 DAS (T7) can be recommended for achieving enhanced productivity and soil fertility improvement within agricultural systems.

Microalgae derived honeycomb structured mesoporous diatom biosilica for adsorption of malachite green: Process optimization and modeling.

The present study investigated the removal of malachite green dye from aquifers by means of microalgae-derived mesoporous diatom biosilica. The various process variables (dye concentration, pH, and adsorbent dose) influencing the removal of the dye were optimized and their interactive effects on the removal efficiency were explored by response surface methodology. The pH of the solution (pH = 5.26) was found to be the most dominating among other tested variables. The Langmuir isotherm (R2 = 0.995) best fitted the equilibrium adsorption data with an adsorption capacity of 40.7 mg/g at 323 K and pseudo-second-order model (R2 = 0.983) best elucidated the rate of dye removal (10.6 mg/g). The underlying mechanism of adsorption was investigated by Weber-Morris and Boyd models and results revealed that the film diffusion governed the overall adsorption process. The theoretical investigations on the dye structure using DFT-based chemical reactivity descriptors indicated that malachite green cations are electrophilic, reactive and possess the ability to accept electrons, and are strongly adsorbed on the surface of diatom biosilica. Also, the Fukui function analysis proposed the favorable adsorption sites available on the adsorbent surface.

Application and functional properties of millet starch: Wet milling extraction process and different modification approaches.

In the past decade, the demand and interest of consumers have expanded for using plant-based novel starch sources in different food and non-food processing. Therefore, millet-based value-added functional foods are acquired spare attention due to their excellent nutritional, medicinal, and therapeutic properties. Millet is mainly composed of starch (amylose and amylopectin), which is primary component of the millet grain and defines the quality of millet-based food products. Millet contains approximately 70 % starch of the total grain, which can be used as a, ingredient, thickening agent, binding agent, and stabilizer commercially due to its functional attributes. The physical, chemical, and enzymatic methods are used to extract starch from millet and other cereals. Numerous ways, such as non-thermal physical processes, including ultrasonication, HPP (High pressure processing) high-pressure, PEF (Pulsed electric field), and irradiation are used for modification of millet starch and improve functional properties compared to native starch. In the present review, different databases such as Scopus, Google Scholar, Research Gate, Science Direct, Web of Science, and PubMed were used to collect research articles, review articles, book chapters, reports, etc., for detailed study about millet starch, their extraction (wet milling process) and modification methods such as physical, chemical, biological. The impact of different modification approaches on the techno-functional properties of millet starch and their applications in different sectors have also been reviewed. The data and information created and aggregated in this study will give users the necessary knowledge to further utilize millet starch for value addition and new product development.

Graphene-based functional electrochemical sensors for the detection of chlorpyrifos in water and food samples: a review.

Prolonged and excessive use of chlorpyrifos (CPS) has caused severe pollution, particularly in crops, vegetables, fruits, and water sources. As a result, CPS is detected in various food and water samples using conventional methods. However, its applications are limited due to size, portability, cost, etc. In this regard, electrochemical sensors are preferred for CPS detection due to their high sensitivity, reliability, rapid, on-site detection, and user-friendly. Notably, graphene-based electrochemical sensors have gained more attention due to their unique physiochemical and electrochemical properties. It shows high sensitivity, selectivity, and quick response because of its high surface area and high conductivity. In this review, we have discussed an overview of three graphene-based different functional electrochemical sensors such as electroanalytical sensors, bio-electrochemical sensors, and photoelectrochemical sensors used to detect CPS in food and water samples. Furthermore, the fabrication and operation of these electrochemical sensors using various materials (low band gap material, nanomaterials, enzymes, antibodies, DNA, aptamers, and so on) and electrochemical techniques (CV, DPV, EIS, SWV etc.) are discussed. The study found that the electrical signal was reduced with increasing CPS concentration. This is due to the blocking of active sites, reduced redox reaction, impedance, irreversible reactions, etc. In addition, acetylcholinesterase-coupled sensors are more sensitive and stable than others. Also, it can be further improved by fabricating with low band gap nanomaterials. Despite their advantages, these sensors have significant drawbacks, such as low reusability, repeatability, stability, and high cost. Therefore, further research is required to overcome such limitations.

Sustainable pathways for solar desalination using nanofluids: A critical review.

Water is a fundamental requirement for the survival of human beings. Although water is abundantly available across the globe, access to freshwater still remains a major concern. Most of the water available is saline or brackish, which is not fit for human consumption. Desalination is the optimum solution for production of potable water from saline water. A major shortcoming of conventional desalination technologies is their dependence on fossil fuel that results in environmental degradation, global warming, etc. Therefore, sustainable desalination technology has evolved as a need of hour. Among all renewable energy resources, solar energy is abundantly available and can be potentially harvested. Therefore, solar energy can be used to drive sustainable desalination technologies. A solar still converts saline water into freshwater in a single step using solar energy. But the major drawbacks of solar still are relatively lower efficiency and lower yield. Nanofluids are widely used to overcome these limitations due to their extraordinary and unique properties. This paper critically reviews the recent research performed on the application of nanofluids in solar desalination systems. Methods of nanofluid preparation, their types and properties are also discussed in detail. Application of nanofluids in solar desalination systems is discussed with special attention on performance enhancement of solar stills. Combinations of nanofluids with various other performance enhancement techniques are also considered. The effectiveness of nanofluids in solar stills is found to be dependent majorly on the nature and concentration of the nanofluid used.

Adsorptive removal of ciprofloxacin and sulfamethoxazole from aqueous matrices using sawdust and plastic waste-derived biochar: A sustainable fight against antibiotic resistance.

We produced carbon-negative biochar from the pyrolysis of sawdust biomass alone (SB) and from the co-pyrolysis of sawdust and plastic waste (SPB). The co-pyrolysis approach in this study was driven by several hypothetical factors, such as increased porosity, surface chemistry, stability, as well as waste management. We applied pyrolyzed and co-pyrolyzed biochars for the removal of ciprofloxacin (CFX) and sulfamethoxazole (SMX). Due to its more alkaline and amorphous nature, SB showed better removal efficiencies compared to SPB. The maximum removals of CFX and SMX with SB were observed as ∼95% and >95%, respectively whereas with SPB were 58.8%, and 34.9%, respectively. The primary mechanisms involved in the adsorption process were H-bonding, electrostatic and π-π electron donor-acceptor interactions. Homogenously and heterogeneously driven adsorption of both antibiotics followed the pseudo-second-order kinetic model, implying electron sharing/transfer (chemisorption) mediated adsorption. The work is highly pertinent in the context of emerging concerns related to drivers that promote antimicrobial resistance.

An analytical hierarchy process based decision support system for the selection of biogas up-gradation technologies.

Recent developments in biogas upgradation have opened new horizons for its utilisation because upgradation technologies are fully developed and commercially available. However, the implementation of biogas upgrading technologies is not at the scale required to harness the full potential of biogas. Therefore, it is requisite to adopt a multicriteria decision-making methodology (MCDM) to select the most appropriate biogas up-gradation technology as each technology has its own set of benefits and downside. In this multifaceted scenario, the analytical hierarchy Process (AHP), one of the most preferred MCDM methods in rational decision-making, is applied in this study to select the most appropriate biogas upgrading technology. The broader recognition of AHP is its provision for converting multifaceted problems into a simple hierarchy. The research results reveal that biogas up-gradation technologies based on water scrubbing and membrane separation rank first and second among the alternatives. This research will show a direction to researchers and the MCDM community involved in biogas upgradation technologies on a broader scale.

Sustainable rural waste management using biogas technology: An analytical hierarchy process decision framework.

Biomass is present in ample amounts in rural areas, mainly in agriculture residue and animal wastes. Biogas can be produced from rural solid waste, providing affordable clean energy for rural households and a prominent solution to solid waste management. Despite having several benefits of using biogas, the contribution of biogas in rural areas is not as much as expected. Several technical and non-technical barriers are accountable for the slow rate of biogas technology adoption in rural households. Nineteen barriers to household biogas plant adoption in four dimensions of technical, economic, market, and awareness are identified and ranked with the analytical hierarchy process (AHP) in the perspective of rural India. The outcome of the barrier dimension reveals that the economic dimension gets the highest weight of (0.350), followed by the market with a weight of (0.322). At the same time, high installation cost with a weight of (0.141) dominates in the category of barriers, followed by competition from freely available fuel with a weight of 0.105). The gap in capital cost and capital subsidy, lack of paying capacity, and lack of easy credit have positioned respectively third, fourth, and fifth in the overall ranking of barriers with weights of (0.094), (0.084), and (0.08). This paper may contribute significantly to creating greater awareness, evaluating numerous barriers, and adopting biogas technology in India more effectively and efficiently.

Uncovering the phytochemicals of root exudates and extracts of lead (Pb) tolerant Chrysopogon zizanioides (L.) Roberty in response to lead contamination and their effect on the chemotactic behavior of rhizospheric bacteria.

The chemical composition of root exudates and root extracts from Chrysopogon zizanioides (L.) Roberty cv KS-1 was determined in the presence of lead [Pb(II)]. Hitherto, no information is available in the literature concerning the phytochemical components of root exudates of C. zizanioides. Significantly higher concentrations of total carbohydrates (26.75 and 42.62% in root exudates and root extract, respectively), reducing sugars (21.46 and 56.11% in root exudates and root extract, respectively), total proteins (9.22 and 23.70% in root exudates and root extract, respectively), total phenolic acids (14.69 and 8.33% in root exudates and root extract, respectively), total flavonoids (14.30 and 12.28% in root exudates and root extract, respectively), and total alkaloids (12.48 and 7.96% in root exudates and root extract, respectively) were observed in samples from plants growing under Pb(II) stress in comparison to the respective controls. GC-MS profiling showed the presence of a diverse group of compounds in root exudates and extracts, including terpenes, alkaloids, flavonoids, carotenoids, plant hormones, carboxylic/organic acids, and fatty acids. Among the detected compounds, many have an important role in plant development, regulating rhizosphere microbiota and allelopathy. Furthermore, the results indicated that C. zizanioides exudates possess a chemotactic response for rhizospheric bacterial strains Bacillus licheniformis, Bacillus subtilis, and Acinetobacter junii Pb1.

Advances in the development of electrode materials for improving the reactor kinetics in microbial fuel cells.

Microbial fuel cells (MFCs) are an emerging technology for converting organic waste into electricity, thus providing potential solution to energy crises along with eco-friendly wastewater treatment. The electrode properties and biocatalysts are the major factors affecting electricity production in MFC. The electrons generated during microbial metabolism are captured by the anode and transferred towards the cathode via an external circuit, causing the flow of electricity. This flow of electrons is greatly influenced by the electrode properties and thus, much effort has been made towards electrode modification to improve the MFC performance. Different semiconductors, nanostructured metal oxides and their composite materials have been used to modify the anode as they possess high specific surface area, good biocompatibility, chemical stability and conductive properties. The cathode materials have also been modified using metals like platinum and nano-composites for increasing the redox potential, electrical conductivity and surface area. Therefore, this paper reviews the recent developments in the modification of electrodes towards improving the power generation capacity of MFCs.

Highly efficient bio-adsorption of Malachite green using Chinese Fan-Palm Biochar (Livistona chinensis).

The discharge of effluents from the textile industry is a multidimensional problem that affects the ecosystem in many ways. Though many new technologies are being developed, it remains to be seen which of those can be practiced in a real scenario. The current investigation attempts to absorb the Malachite Green, an effluent from textile dye using Chinese Fan Palm Seed Biochar. Accordingly, biochar was prepared using fruits of Chinese Fan Palm (Livistona chinensis) tree. The fruit also yielded a significant amount of biochar and bio-oil. 1.346 kg of fresh and cleaned fruit was fast pyrolyzed at 500 °C in a laboratory-scale Pyrolyzer resulting in 0.487 kg of biochar and 0.803 L of bio-oil. The remaining fruit matter was converted to gaseous products. The kinetics of dye removal were studied and the parameters were determined. The study advocates that the Langmuir isotherm model simulates the adsorption experiment, to a good extent. From the plot, the maximum (monolayer) adsorption capacity, Qm was determined to be 21.4 mg/g. The suitability of the Langmuir isotherm model onto biochar was established by the high correlation coefficient, R2 that was higher than 0.97.

Construction of biotreatment platforms for aromatic hydrocarbons and their future perspectives.

Aromatic hydrocarbons (AHCs) are one of the major environmental pollutants introduced from both natural and anthropogenic sources. Many AHCs are well known for their toxic, carcinogenic, and mutagenic impact on human health and ecological systems. Biodegradation is an eco-friendly and cost-effective option as microorganisms (e.g., bacteria, fungi, and algae) can efficiently breakdown or transform such pollutants into less harmful and simple metabolites (e.g., carbon dioxide (aerobic), methane (anaerobic), water, and inorganic salts). This paper is organized to offer a state-of-the-art review on the biodegradation of AHCs (monocyclic aromatic hydrocarbons (MAHs) and polycyclic aromatic hydrocarbons (PAHs)) and associated mechanisms. The recent progress in biological treatment using suspended and attached growth bioreactors for the biodegradation of AHCs is also discussed. In addition, various substrate growth and inhibition models are introduced along with the key factors governing their biodegradation kinetics. The growth and inhibition models have helped gain a better understanding of substrate inhibition in biodegradation. Techno-economic analysis (TEA) and life cycle assessment (LCA) aspects are also described to assess the technical, economical, and environmental impacts of the biological treatment system.

Silk nanodisc based edible chitosan nanocomposite coating for fresh produces: A candidate with superior thermal, hydrophobic, optical, mechanical and food properties.

This paper demonstrates the fabrication of silk nanodisc (SND) dispersed chitosan (CS) based new edible coating as a candidate for superior thermal, hydrophobic, optical, mechanical, and physicochemical properties, which further provide remarkable storage quality for banana fruits. Fabrication of SND is attained following acid hydrolysis of silk fibroin (SF), where the successful nanostructures formulations are analyzed by FESEM, FETEM and XRD analysis delivering disc shaped morphology with amplified crystallinity (~95.0%). The SF has been fabricated from waste muga cocoons using the degumming process. The superior thermal stability of SND compared to SF portray a new era in required heat resistant packaging. The effectiveness of SND is investigated on packaging properties of CS biocomposites including thermal, wettability, mechanical, color, surface morphology, and others. Wettability of SND incorporated CS biocomposite enhanced by ~ 10° suggesting improved hydrophobicity. The edible coatings are a new candidate to improve the shelf life of bananas over 7 days at 25 °C for prevailing original weight, optical property, firmness, and others.

Evaluation of seasonal variation and the optimization of reducing sugar extraction from Ulva prolifera biomass using thermochemical method.

Green macroalgae comprise significant amount of structural carbohydrates for their conversion to liquid biofuels. However, it generally relies on species characteristics and the variability in seasonal profile to determine its route for bioprocessing. Hence, this study was conducted to analyze the indigenous marine macroalgal strain (Ulva prolifera) with respect to periodic trend and reducing sugar extraction. Consequently, in our investigation, the monthly variation in sugar profile and bioethanol yield was assessed between the monsoon and post-monsoon seasons, of which relatively high reducing sugar and fermentative bioethanol yield of about 0.152 ± 0.009 g/gdw and 6.275 ± 0.161 g/L was obtained for the October-month isolate (MITM10). Thereafter, the biochemical profile of this collected biomass (MITM10) revealed carbohydrate 34.98 ± 3.30%, protein 12.45 ± 0.49%, and lipid 1.93 ± 0.07%, respectively, on dry weight basis. Of these, the total carbohydrate fraction yielded the maximum reducing sugar of 0.156 ± 0.005 g/gdw under optimal conditions (11.07% (w/v) dosage, 0.9 M H2SO4, 121°C for 50 min) for thermal-acid hydrolysis. Furthermore, the elimination of polysaccharides was confirmed using the characterization techniques scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Therefore, the present thermochemical treatment method provides a species-specific novel strategy to breakdown the macroalgal cell wall polysaccharides that enhances sugar extraction for its utilization as an efficient bioenergy resource.

Prevalence and hazardous impact of pharmaceutical and personal care products and antibiotics in environment: A review on emerging contaminants.

Antibiotic resistance is a global health emergency linked to unrestrained use of pharmaceutical and personal care products (PPCPs) as prophylactic agent and therapeutic purposes across various industries. Occurrence of pharmaceuticals are identified in ground water, surface water, soils, and wastewater treatment plants (WWTPs) in ng/L to µg/L concentration range. The prevalence of organic compounds including antimicrobial agents, hormones, antibiotics, preservatives, disinfectants, synthetic musks etc. in environment have posed serious health concerns. The aim of this review is to elucidate the major sources accountable for emergence of antibiotic resistance. For this purpose, variety of introductory sources and fate of PPCPs in aquatic environment including human and veterinary wastes, aquaculture and agriculture related wastes, and other anthropogenic activities have been discussed. Furthermore, genetic and enzymatic factors responsible for transfer and appearance of antibiotic resistance genes are presented. Ecotoxicity of PPCPs has been studied in environment in order to present risk imposed to human and ecological health. As per published literature reports, the removal of antibiotics and related traces being difficult, couples the possibility of emergence of antibiotic resistance and hence sustainability in global water resources. Therefore, research on environmental behavior and control strategies should be conducted along with assessing their chronic toxicity to identify potential human and ecological risks.

Recent advancement in remediation of synthetic organic antibiotics from environmental matrices: Challenges and perspective.

Continuous discharge and persistence of antibiotics in aquatic ecosystem is identified as emerging environment health hazard. Partial degradation and inappropriate disposal induce appearance of diverse antibiotic resistant genes (ARGs) and bacteria, hence their execution is imperative. Conventional methods including waste water treatment plants (WWTPs) are found ineffective for the removal of recalcitrant antibiotics. Therefore, constructive removal of antibiotics from environmental matrices and other alternatives have been discussed. This review summarizes present scenario and removal of micro-pollutants, antibiotics from environment. Various strategies including physicochemical, bioremediation, use of bioreactor, and biocatalysts are recognized as potent antibiotic removal strategies. Microbial Fuel Cells (MFCs) and biochar have emerged as promising biodegradation processes due to low cost, energy efficient and environmental benignity. With higher removal rate (20-50%) combined/ hybrid processes seems to be more efficient for permanent and sustainable elimination of reluctant antibiotics.

Unravelling the Role of Rhizospheric Plant-Microbe Synergy in Phytoremediation: A Genomic Perspective.

BACKGROUND: Accretion of organic and inorganic contaminants in soil interferes in the food chain, thereby posing a serious threat to the ecosystem and adversely affecting crop productivity and human life. Both endophytic and rhizospheric microbial communities are responsible for the biodegradation of toxic organic compounds and have the capability to enhance the uptake of heavy metals by plants via phytoremediation approaches. The diverse set of metabolic genes encoding for the production of biosurfactants and biofilms, specific enzymes for degrading plant polymers, modification of cell surface hydrophobicity and various detoxification pathways for the organic pollutants, plays a significant role in bacterial driven bioremediation. Various genetic engineering approaches have been demonstrated to modulate the activity of specific microbial species in order to enhance their detoxification potential. Certain rhizospheric bacterial communities are genetically modified to produce specific enzymes that play a role in degrading toxic pollutants. Few studies suggest that the overexpression of extracellular enzymes secreted by plant, fungi or rhizospheric microbes can improve the degradation of specific organic pollutants in the soil. Plants and microbes dwell synergistically, where microbes draw benefit by nutrient acquisition from root exudates whereas they assist in plant growth and survival by producing certain plant growth promoting metabolites, nitrogen fixation, phosphate solubilization, auxin production, siderophore production, and inhibition or suppression of plant pathogens. Thus, the plant-microbe interaction establishes the foundation of the soil nutrient cycle as well as decreases soil toxicity by the removal of harmful pollutants. CONCLUSION: The perspective of integrating genetic approach with bioremediation is crucial to evaluate connexions among microbial communities, plant communities and ecosystem processes with a focus on improving phytoremediation of contaminated sites.

Reusability of brilliant green dye contaminated wastewater using corncob biochar and Brevibacillus parabrevis: hybrid treatment and kinetic studies.

This work highlights the potential of corncob biochar (CCBC) and Brevibacillus parabrevis for the decolorization of brilliant green (BG) dye from synthetically prepared contaminated wastewater. The CCBC was characterized by proximate, Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis, respectively. Different parameters affecting the adsorption process were evaluated. The experimental results were analyzed by the Langmuir and Freundlich isotherm models. Kinetic results were examined by different models; pseudo-second-order model has shown the best fit to the experimental data. Anew positive values of ΔHo (172.58 kJ/mol) and ΔSo (569.97 J/K/mol) in the temperature range of 303-318 K revealed that the adsorption process was spontaneous and endothermic. The present investigation showed that the bacteria immobilized with CCBC showed better BG dye degradation. The kinetic parameters, µmax, Ks, and µ max, were found to be 0.5 per day, 39.4 mg/day, and 0.012 L/mg/day using Monod model, respectively. The adsorbent with bacteria showed good potential for the removal of cationic BG dye and can be considered for the remediation of industrial effluent.