Synthesis of activated carbon from agricultural waste using a simple method: Characterization, parametric and isotherms study

Preparation of carbonaceous materials from flotation-sludge of the poultry industry and its application in the methylene blue adsorption

In this work, different carbonaceous materials based on floated sludge from a poultry industry wastewater treatment plant (PI-WTP) were synthesized. These materials were characterized and investigated in methylene blue dye (MB) adsorption. The influences of the initial pH solution, adsorbent dosage, kinetics, equilibrium, and thermodynamics were evaluated in the adsorption experiments. A simulation of a real textile effluent was also carried out to evaluate the adsorbent. The results of the adsorbents' characterization demonstrated that adding ZnCl₂ + lime, followed by pyrolysis and acid leaching, significantly improved the material's properties, leading to abundant porosity and high surface area. The adsorption experiments indicated that the natural pH of the solution (8.0) and the AC-II dosage of 0.75 g L^-1 are optimal for MB removal. Elovich and Sips' models (with a maximum adsorption capacity of 221.02 mg g^-1 at 328 K) best fitted the experimental kinetic and equilibrium data, respectively. The adsorption process is spontaneous and endothermic according to thermodynamic parameters. The discoloration efficiency of the simulated effluent was 67.8%. In conclusion, the floated sludge, a residue produced on a large scale that needs to be disposed of correctly, can be converted into a value-added material (carbonaceous adsorbent) and applied to treat colored effluents.

Nano-Structured Carbon: Its Synthesis from Renewable Agricultural Sources and Important Applications

Carbon materials are versatile in nature due to their unique and modifiable surface and ease of production. Nanostructured carbon materials are gaining importance due to their high surface area for application in the energy, biotechnology, biomedical, and environmental fields. According to their structures, carbon allotropes are classified as carbon nanodots, carbon nanoparticles, graphene, oxide, carbon nanotubes, and fullerenes. They are synthesized via several methods, including pyrolysis, microwave method, hydrothermal synthesis, and chemical vapor deposition, and the use of renewable and cheaper agricultural feedstocks and reactants is increasing for reducing cost and simplifying production. This review explores the nanostructured carbon detailed investigation of sources and their relevant reports. Many of the renewable sources are covered as focused here, such as sugar cane waste, pineapple, its solid biomass, rise husk, date palm, nicotine tabacum stems, lapsi seed stone, rubber-seed shell, coconut shell, and orange peels. The main focus of this work is on the various methods used to synthesize these carbon materials from agricultural waste materials, and their important applications for energy storage devices, optoelectronics, biosensors, and polymer coatings.

Production and characterization of bamboo-based activated carbon through single-step H3PO4 activation for CO2 capture

Bamboo is the fastest-growing plant and is abundant in Malaysia. It is employed as a starting material for activated carbon production and evaluated for its potential in CO₂ capture. A single-stage phosphoric acid (H₃PO₄) activation is adopted by varying the concentrations of H₃PO₄ between 50 and 70 wt.% at a constant temperature and holding time of 500°C and 120 min, respectively. The bamboo-based activated carbons are characterized in terms of product yield, surface area, and porosity, as well as surface chemistry properties. Referring to the experimental findings, the prepared activated carbons have BET surface area of >1000 m² g^-1, which implies the effectiveness of the single-stage H₃PO₄ activation. Furthermore, the prepared activated carbon via 50 wt.% H₃PO₄ activation shows the highest BET surface area and carbon dioxide (CO₂) adsorption capacity of 1.45 mmol g^-1 at 25°C/1 bar and 9.0 mmol g^-1 at 25°C/30 bar. With respect to both the characterization analysis and CO₂ adsorption performance, it is concluded that bamboo waste conversion to activated carbon through H₃PO₄ activation method is indeed promising.

Optimizing the two-stage adsorber of NaOH-activated coconut shell carbon for methylene blue removal

This work was aimed at optimizing the adsorbent mass and contact time and evaluating the performance of two-stage batch adsorber of NaOH-activated coconut shell carbon for methylene blue removal. To decrease the dye concentration from 1000 to 89.4 mg/L at any effluent volumes, the two-stage adsorber displays a small mass saving of 0.33% because of the high adsorbent affinity towards methylene blue at 1.80 L/mg. Meanwhile, the contact time can be minimized by 97.6% as opposed to that in one-stage adsorber. The sensitivity analysis of affinity on mass minimization shows a significant saving of 28.5% when the affinity is reduced to 0.01 L/mg. The response surface methodology was used to optimize the two-stage absorber for methylene blue removal, wherein the most significant parameter is the contact time.

Extraction of Value-Added Minerals from Various Agricultural, Industrial and Domestic Wastes

Environmental pollution is one of the major concerns throughout the world. The rise of industrialization has increased the generation of waste materials, causing environmental degradation and threat to the health of living beings. To overcome this problem and effectively handle waste materials, proper management skills are required. Waste as a whole is not only waste, but it also holds various valuable materials that can be used again. Such useful materials or elements need to be segregated and recovered using sustainable recovery methods. Agricultural waste, industrial waste, and household waste have the potential to generate different value-added products. More specifically, the industrial waste like fly ash, gypsum waste, and red mud can be used for the recovery of alumina, silica, and zeolites. While agricultural waste like rice husks, sugarcane bagasse, and coconut shells can be used for recovery of silica, calcium, and carbon materials. In addition, domestic waste like incense stick ash and eggshell waste that is rich in calcium can be used for the recovery of calcium-related products. In agricultural, industrial, and domestic sectors, several raw materials are used; therefore, it is of high economic interest to recover valuable minerals and to process them and convert them into merchandisable products. This will not only decrease environmental pollution, it will also provide an environmentally friendly and cost-effective approach for materials synthesis. These value-added materials can be used for medicine, cosmetics, electronics, catalysis, and environmental cleanup.

Synergistic effect in concurrent removal of toxic methylene blue and acid red-1 dyes from aqueous solution by durian rind: kinetics, isotherm, thermodynamics, and mechanism

In the present study, a synergistic effect between cationic methylene blue (MB) and anionic acid red 1 (AR1) on their concurrent adsorptive removal from aqueous binary solution onto durian rind (DR) was systematically investigated in batch mode across different parameters. The concurrent adsorption was pseudo-second-order kinetics and followed the Langmuir isotherm model, similar to their respective single component. The kinetics and intraparticle diffusion analyses demonstrated that the adsorption rate of MB was a 15-fold faster than AR1, and mass transports were governed by a combination of intraparticle and film diffusion. The synergistic effect was evidenced by an enhanced adsorption efficiency of AR1 from 27 to 42%, while that of MB was almost unchanged (97-98%). By changing the molar ratios of MB and AR1, it was found that the maximum adsorption capacity of MB and AR1 was 249 and 200 mg g^-1, respectively, in the binary system higher compared with those in their respective single system (108 and 16 mg g^-1). Overall data indicated that the synergistic effect was due to electrostatic interactions between cationic and anionic synthetic dyes, supported by negatively charged DR surface, leading to the formation of their stacking layers on the adsorbent surface. Novelty statement: A synergistic effect in concurrent adsorptive removal of synthetic dyes from multicomponent wastewater remains a critical research challenge. We believed that electrostatic interaction between ionic dyes could be explored to enhance their removal efficiency. This report is the first time that such a synergistic effect between cationic methylene blue (MB) and anionic acid red 1 (AR1) on their concurrent adsorption from aqueous binary system is systematically investigated. The kinetics, isotherm, thermodynamics, and mechanism of the concurrent adsorption of MB and AR1 attributed to the synergistic effect are elucidated in detail.

Preparation and Utilization of Jute-Derived Carbon: A Short Review

This article summarizes the preparation and applications of carbon derived from jute sticks and fibers that are low-cost, widely available, renewable, and environmentally friendly. Both the fibers and sticks are considered ideal candidates of carbon preparation because they are composed of cellulose, hemicelluloses, and lignin, and contain negligible ash content. Various carbon preparation methods including simple pyrolysis, pyrolysis with chemical and physical activations are discussed. The impacts of several parameters including types of activating agents, impregnation ratio, and temperature on their morphology, surface area, pore size, crystallinity, and surface functional groups are also emphasized. Various treatments to endow functionalization for increasing the practical applicability, such as chemical, physical, and physico-chemical methods, are discussed. In addition, applications of jute-derived carbon in various practical areas, including energy storage, water treatment, and sensors, are also highlighted in this report. Due to the porous fine structure and a large specific surface area, the jute-derived carbon could be considered as a powerful candidate material for various industrial applications. Finally, possible future prospects of jute-derived carbon for various applications are pointed out.

Valorization of mangosteen, "The Queen of Fruits," and new advances in postharvest and in food and engineering applications: A review

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This review highlights recent advances of mangosteen research in the postharvest, food and engineering fields.

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In postharvest fields, phytohormones, metabolites, and pest/disease management are described.

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Mangosteen has also been used in various food products and for animal feed supplementation.

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In engineering, mangosteen extract is useful in solar cells, carbon dots and advanced materials.

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Mangosteen-based products may benefit consumers and the engineering and biomedical industries.

One of the most prolific plants utilized in various applications is mangosteen (Garcinia mangostana L.). Rich in potent bioactive compounds, such as xanthones, mangosteen is known to possess pharmacologically important anti-inflammatory and anti-tumor properties. However, most previous reviews have only discussed the application of mangosteen in medicinal areas, yet more recent studies have diverged and valorized its usage in other scientific fields. In this review, the utilization of this exotic fruit in postharvest biology (phytohormone roles, metabolite profiling, bioactive compounds, isolation method optimization, chemical contaminant identification, and management of pests and fruit disorders), food science (food products, animal feed supplementation, and food shelf-life determination), and engineering fields (fabric and solar cell dyes, carbon dots, activated carbon, and biomedical advanced materials) is presented in detail. Research papers published from 2016 onward were selected and reviewed to show the recent research trends in these areas. In conclusion, mangosteen has been utilized for various purposes, ranging from usage in industrially important products to applications in advanced technologies and biomedical innovation.