•The drying characteristics of moringa leaves using MD method were investigated.•14 mathematical models are used to evaluate the drying kinetics of moringa leaves.•The Midilli Kucuk model showed the ...best results of the drying kinetics.•Energy consumption and CO2 emission due to the effect of MD are investigated.•MD drying method is more effective than oven drying.
The objectives of this moringa leaf drying research are: (i) evaluating moringa leaf drying using fourteen mathematical models, (ii) analyzing EC, CO2 emissions, and SEC in drying moringa leaves using microwave and oven. Moringa leaf drying in the microwave uses 2 microwave powers, namely 136 W and 264 W. Moringa leaves used for drying contain an average of 73.65–74.10 % water. Non-linear regression methods are used to estimate drying coefficients with fourteen mathematical models. Seven error function were used to evaluate fourteen models used. With the lowest AICCorrected values of -201.3585 and -67.7706, the Midilli Kucuk model is known to be the best model for all microwave power varieties. There are four parameters of the Midilli Kucuk model at a microwave power of 136 W of “k” value of 0.00012 and a microwave power of 264 W of “k” value of 0.00024. This “k” value will be used as the amount of drying rate of moringa leaves with MD method. EC, CO2 Emission, and SEC calculations were carried out to determine the effectiveness of MD method rather than the conventional method. EC values of 0.0202–0.0289 kWh, CO2 emission of 0.0161–0.0231 kg, and SEC of 2.7091–3.9017 kWh/kg water for MD method were obtained. The results show that MD is more effective than conventional drying with EC values of 14.4000 kWh, CO2 emission of 11.5200 kg, and SEC of 196.6289 kWh/kg water. Therefore, MD is a method that is more environmentally friendly than the conventional method (oven drying).
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Basil (Ocimum sanctum) leaves, commonly known as holy basil, have various health benefits due to their rich phytochemical content. However, fresh basil leaves face challenges related to their ...perishability and short shelf life. This study explores the use of edible coating, specifically chitosan, to extend the shelf life of basil leaves. Then basil leaves with chitosan coating were dried using microwave-assisted drying (MAD) method with variations of microwave power (136, 264, 440, and 616 W), mass of basil leaves (5, 10, and 15 g), and chitosan concentration (0, 2.5, and 5 %). The purpose of this study is to analyze the color, effective moisture diffusivity, and drying kinetics. Five mathematical models and seven error functions were used. The Avhad and Marchetti Model was identified as the most suitable model to describe the drying kinetics of basil leaves with chitosan coating. The Deff value increased with decreasing mass of basil leaves, decreasing chitosan concentration, and increasing microwave power. Deff values ranged from 0.001 to 0.002 m2/s. The thickness of the basil leaves also played a role in the fluctuation of Deff values. The highest ΔE value was obtained by 5 % concentration of chitosan. The chitosan coating, especially at a concentration of 2.5 %, showed discoloration indicating better preservation of the original color of basil leaves. In conclusion, this study shows that chitosan coating and MAD are effective strategies to extend the shelf life of basil leaves and can provide valuable insights for future applications in leaf drying or thin layer drying processes.
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•First study on drying basil leaves with chitosan coating using MAD•The Avhad and Marchetti model showed a good fit for drying chitosan-coated basil leaves.•At 2.5 % chitosan concentration showed better color change for preservation of basil leaves.•The Deff value increased with increasing MP and decreasing leaf mass and chitosan concentration.•The highest ΔE value was obtained by 5 % concentration of chitosan.
The rapid development of the industrial world causes wastewater containing dyes to continue to increase. Even in recent years, the food, textile, cosmetic, plastic, and printing industries have ...developed the use of dyes. Methylene blue (MB) is one of the cationic dyes widely used in dyeing silk, wood, and cotton because of its absorbency and good fastness to materials. The adsorption process is the best technique and preferred in removing dyes from wastewater due to excellent selectivity, high efficiency from high-quality treated effluent, flexibility in design, and simplicity. Therefore, there is a growing interest to identify low-cost alternative adsorbents that have reasonable adsorption efficiency, especially natural materials such as leaves. In this study, research on MB adsorption using leaves was analyzed using bibliometric analysis. Information of bibliometric is extracted from the Scopus database with the keyword “Methylene Blue”, “Adsorption or Desorption”, and “Leaves or leaf”. The results showed that India, Desalination and Water Treatment, and SASTRA Deemed University were the country, journal, and institution that contributed the most publications on this topic. Therefore, it is expected that with the use of bibliometrics, the use of leaf-based MB adsorption processes in their potential for MB dye removal can be investigated especially for large-scale development.
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•Adsorption is more promising for large-scale development than photocatalytic degradation.•Adsorbent based on leaves needs further research, especially from a techno-economic perspective.•The first bibliometric study on MB adsorption using leaves was reported.•The high frequency of “adsorption” and “methylene blue” for the research hotspot.
Increased industrialization led to a large amount of wastewater being generated. Heavy metals (HMs), especially mercury, are one of the toxic and harmful contaminants in wastewater. Therefore, it is ...essential to develop sustainable ecotechnology that can purify wastewater. Microalgae have recently been employed as an alternative to conventional methods for removing HMs because they are renewable resources designed to treat wastewater and produce useful products. In addition, microalgae have high selectivity in binding metal ions and removing harmful substances. This review mainly focused on removing mercury from wastewater by bioremediation of microalga (Chlorella vulgaris) and utilization of microalgae biomass in several applications. The review is helpful to support sustainable natural resource development for scientists, freshwater management facility managers, wastewater treatment facility operators, and industrial communities.
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•Chlorella vulgaris has been used as an alternative for mercury removal in wastewater.•Bioremediation is a potential method for removing mercury.•Chlorella vulgaris biomass can be utilized for biodiesel production and catalysts.
