Vol 5 No 2 (2023)

• Green Chemistry Advancement: Unravelling Dye Removal Potential Using Nitrogen-Doped Palm Oil Mill Effluent Sludge-Biochar as Peroxydisulfate Activator

  Aida Humaira Sallehuddin, Sabrina Karim, Abbas F. Mubarek Al Karkhi, Mohamad Ali Ahmad

  Transition metal-based homogeneous or heterogeneous catalysts have been studied for activating persulfate and shown to be a good alternative for the activation of persulfate in organic pollutant recalcitrants. Nevertheless, a significant problem with these catalysts is the secondary contamination due to metal leaching during the process. Therefore, researchers have drawn their attention to nitrogen-doped biochar as a promising alternative persulfate activator due to its lower cost and being more environmentally friendly. In this study, the researchers focused on synthesising nitrogen-doped biochar from Palm Oil Mill Effluent sludge (POS). In Malaysia, POS generated an average of 2.2 million tonnes annually and was disposed of and utilised as fertiliser, indirectly creating secondary soil pollution. Various studies have reported the feasibility of Palm Oil Mill Effluent sludge biochar (POSB) in removing inorganics; however, no research has investigated the efficacy of POSB as a peroxydisulfate (PDS). Recent studies suggest that POSB sludge can be effectively transformed into biochar using low-temperature pyrolysis, resulting in substantial yields. The POS was prepared through a simple pyrolysis process and doped with Urea at temperatures of 400°C and 700°C under nitrogen conditions and used to activate peroxydisulfate (PDS). This study was conducted based on three mass ratios of the urea-doped process, which were 25:75, 50:50, and 75:25 N-doped POSB. Based on surface morphology results, the incorporation of N-doping reagents into the raw biochar leads to the development of a more expansive porous structure and the N-doped POS biochar exhibited functional group peaks falling within the range of 1383 cm^-1 to 1460 cm^-1, signifying the existence of nitro compounds. POSB at 700 °C has greater catalytic activity than POSB at 400 °C. Dye was completely degraded within 180 minutes of reaction time using 1.0 g of 50:50 Urea-doped POSB at 700 °C, 6 mM PDS, and a pH 5 initial solution as the optimum operating parameters. The pseudo-second-order kinetic model accurately described the dye degradation kinetics. This research demonstrates the efficacy of non-metallic nitrogen-doped biochar as a green catalyst in removing dye in wastewater treatment technology and simultaneously reduces the disposal of POS onto soil that leads to soil pollution.

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• Hydrotalcites as Versatile Functional Materials for Renewable Feedstock Upgrading to Value-added Chemicals

  Zahra Asgar Pour, Khaled Omar Sebakhy

  Hydrotalcites are inorganic layered materials which have been used in a wide spectrum of applications from catalysis and adsorption to heavy metals immobilization and polymer stabilization. Apart from this, they can act as drug carriers or acid scavengers. More recently, due to the urgent need for developing functional materials required in the production of renewable fuels and chemicals, hydrotalcites have been increasingly noticed as versatile compounds. For instance, they are applicable in biofuel synthesis, biomass upgrading, plastics degradation, hydrogen storage and so forth. In addition, they are cost-efficient materials and thus beneficial for the realization of the above-mentioned applications on the industrial scale. It is noteworthy that for further development of novel hydrotalcites, validation of their performance and their stability are essential. To elucidate these aspects, the major significance of these materials and their capability for application in various catalytic fields are discussed in this survey. Particular focus is given to their most recent utilization in sustainable and green applications.

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• Design of New Process to Utilize Stubble Char for Constraction of M25 Concrete

  Sujit Kumar Guchhait, Ankush, Krishna K. Yadav, Sunaina, Asheesh Yadav, Ramesh Zutshi, Niranjan Singh, Menaka Jha

  Considering the challenges posed by agricultural waste, specifically rice straw, this study focuses on implementing cost-effective and eco-friendly processes to transform rice straw waste intovaluable, high-demand materials (sodium carbonate and M-25 concrete). The analysis of rice straw reveals its primary composition of cellulose and sodium silicate, with a layered cellulose microstructure. To produce sodium carbonate, rice straw is subjected to incineration ina furnace, with the resulting effluent gas passing through aqueous NaOH to effectively capture CO₂ at room temperature and ambient pressure. Simultaneously, the ash generated from burning rice straw is employed as a pozzolanic material in the production of M25 grade concrete.Notably, the concrete containing 20% ash demonstrates an impressive compressive strength of 29.05 MPa after a 28-day curing period. These results are highly promising for the potentialutilization of agricultural waste in the production of soda and concrete.

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• Graphitic Carbon Nitride (g-C3N4): A Proficient Electrode Material for Flexible Supercapacitors

  Dipanwita Majumdar, Rudra Sarkar, Munmun Mandal

  In the recent years, graphitic carbon nitride (g-C₃N₄), the metal-independent semiconductor, has captured immense interest in the field of supercapacitor technology owing to its numerous superior qualities together with layered morphology, unique physico-chemical features, ease of synthesis, low fabrication cost, environmental compatibility in addition to mechanical tenacity. Its’ graphitic type double-bonded nitrogen-rich layered structure promotes large number of reactive regimes and effective binding sites that considerably boost the electrochemical activity compared to other widely known graphene analogues. Besides, the architectural distinctiveness in g-C₃N₄ has introduced better designing opportunities for fabricating various types of nanocomposites with improved structural, electronic and electrochemical features. Thus, meticulously engineered g-C₃N₄ electrode materials have displayed high electrochemical and mechanical tenacity, which have opened up new dimensions in the manufacturing of flexible supercapacitors with advanced technological applications. This review addresses these recent progresses of g-C₃N₄ based systems in the electrochemical energy storage arena, embracing the current challenges faced and some of the prospects that are presumed to possibly emerge in the near future with this highly promising material.

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• Tailored Non-ionic Surfactant Vesicles of Cyclosporine for the Treatment of Psoriasis: Formulation, Ex-Vivo and In-Vivo Investigation-Application of Box-Behnken Design

  Peeyush Bhardwaj, Purnima Tripathi, Sonia Pandey, Deepti Chaurasia, Purushottam Ramchandra Patil

  Psoriasis is an autoimmune skin disease characterized by hyperproliferation of keratinocytes. Topical delivery of drugs is mostly favored for the treatment of mild psoriatic conditions. But permeation of drugs across psoriatic skin is too complex. Niosomes are the non-ionic surfactant vesicles, reported to enhance dermal drug delivery. In the present work, cyclosporine niosomes were, formulated, optimized, and evaluated in-vitro to boost the dermal penetration of cyclosporine for the better management of psoriasis. Niosomes were developed using the thin film hydration method. Formulated niosomes were characterized and optimized for their percent encapsulation efficiency, size, and polydispersity index using Box-Behnken design. Optimized formulation was developed using cholesterol and span 60 (1:2.2), 30 minutes of hydration time, and 30 mg of cyclosporine. Niosomes’ size, polydispersity index, and percent encapsulation efficiency were in the scale of 180.5 ± 11.16 nm, 0.156, and 93.2% ± 2.5%, respectively. The ex-vivo studies were carried out using excised goat skin. In the ex-vivo permeation experiments, though the percent drug permeated was low but the quantity of drug permeated across the skin from the niosomes was significantly greater than from suspension. Skin deposition studies revealed deeper and more significant accumulation of cyclosporine niosomes than the free cyclosporine in the epidermis. The in-vivo experiments were carried out using imiquimod induced psoriatic mice, where both the histopathology and psoriasis area severity index displayed significant recovery in the skin condition of mice treated with niosomes of cyclosporine, in comparison with the dispersion of the drug. The results indicate that the non-ionic surfactant vesicles of cyclosporine can be employed for the enhanced management of psoriasis and reduction of side effects linked with the systemic delivery of cyclosporine.

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• An Insight to the Various Applications of Hydroxyapatite

  Quentin Ray Tjieh Lim, Xin Yi Cheng, Chien Yi Wee

  Hydroxyapatite is a naturally occurring calcium phosphate widely used in biomedical applications because of its osteoconductivity, biocompatibility and it possesses the closest chemical similarity to natural bone. Hydroxyapatite is also a versatile material and can be used in a plethora of ways beyond biomedical applications. This review summarises the applications of hydroxyapatite in biomedical, bioimaging, separation, purification, catalysis, surface treatment and energy storage applications. Finally, this review aims to shed light on its potential for new applications of hydroxyapatite in the future.

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