Applied Chemical Engineering (Transferred)

Abstract Waste tire pyrolysis is a thermal decomposition process that converts waste tires into liquid fuel which also produce by product material such as producer gas, pyrolysis carbon black (CBp), and steel wire. Nowadays, carbon black produced by pyrolysis is being employed as a low-grade carbon base fuel. The technical feasibility of using CBp as a substitute for commercial carbon black N330 in styrene-butadiene rubber (SBR) was investigated in the study. The researcher also looked at how the composition ratio of CBp and N330 affected the mechanical characteristics of rubber in comparison to the outcomes of pure carbon black N330. It was discovered that the low composition ratio of 20% CBp and 80% N330 (R-2) had comparable Mooney viscosity to that of N330 carbon black, as well as the highest torque (MH) and torque increment (ΔM) values, but increased CBp content led to increased rubber viscosity and decreased cure time due to sulfur residues CBp was inferior to N330 in its effect on reinforcement. With an increase in CBp content, the tensile strength, shear strength, and elongation at break of SBR vulcanizates decreased considerably, while the hardness increased. Consequently, the CBp value evaluated for hardness applications provides significant manufacturing cost savings.

Abstract

Herein zinc oxide (ZnO) nanoparticles have been synthesized via a facile, environment friendly, and low-cost green synthesis method. The prepared metal oxide was characterized using powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), SEM/EDX (scanning electron microscopy/energy dispersive X-ray), volumetric analysis, and zeta potential measurements. The photocatalyst was then employed for the degradation of crystal violet (CV) dye under UV illumination (high-pressure Hg lamp 125 W). It was observed that phyto-fabricated ZnO nanoparticles exhibited high degradation efficiency towards CV dye as 95% of dye was degraded in 60 min of irradiation. The study also implies that phyto-fabrication of ZnO nanoparticles resulted in enhanced degradation efficiency of the photocatalyst.

Abstract

Regarding thermal strength, chemical stability and surface reactivity of silicon carbide (SiC), it is possible to allocate it as a suitable gas detector for commercial application. Therefore, this research was focused on the investigation of the chemo-resistivity properties of SiC nanosheet through doping with the transition metal. Thermochemical, electric and magnetic properties of titanium (Ti)-doped graphene-like monolayer silicon carbide (SiC) sheet have been studied by the first-principles methods based on the density functional theory (DFT) for scavenging of gas molecules of CO, CO₂, NO, NO₂. The results recommend that the adsorption of these gas molecules on Ti-embedded monolayer SiC sheet is more energetically desired than that on the pristine ones. Gas molecules of CO, CO₂, NO, NO₂ have been adsorbed on the Ti site of doped monolayer SiC through the formation of covalent bonds. The assumption of chemical adsorptions has been approved by the projected density of states (PDOS) and charge density difference plots. Charge density difference calculations also indicate that the electronic densities were mainly accumulated on the adsorbate of CO, CO₂, NO, NO₂ gas molecules. The results in this investigation can indicate the competence of transition metal doped silicon carbide nanosheet in sensor devices.

Abstract

In our search for a possible achilles’ heel of SARS-CoV-2, we explored the variability of 1,382,462 complete sequences of the viral spike glycoprotein, all the ones that we could retrieve from the NCBI SARS-CoV-2 databank as of 6 March 2023. Then, by using the Shannon entropy algorithm, we quantified the sequence variability of SARS-CoV-2 spike glycoprotein. With PDBePISA, we have performed a detailed analysis of protomer-protomer interfaces of the spike glycoprotein for two representative structures of different viral variants. The largest protomer-protomer contact patch that is present in the stem region of both structures is highly conserved. It is remarkable that the Asp796Tyr mutation, centered in this patch, is always present in all the Omicron variants. The structure of the SARS-CoV-2 Omicron spike glycoprotein trimer indicates that Tyr796 and Phe898 of the same protomer form a network of aromatic sidechains with Tyr707 of another protomer, yielding a strong constraint that stabilizes the spike glycoprotein quaternary assembly. We believe that the resulting structural stability of the viral trimer is among the key features for the successful proliferation of Omicron variants. This finding also supports the fact that disrupting this network of aromatic moieties with suitable small molecules would represent a powerful antiviral strategy.

Abstract

The marine ecosystem is a rich source of novel secondary metabolites with significant biomedical applications. Seaweeds are considered as the treasury of secondary metabolites with various biological activities. This study aims to analyze antioxidant and antimicrobial potential in green seaweed Ulva fasciata and brown seaweed Dictyota dichotoma. Extracts from four different solvents such as petroleum ether, chloroform, ethyl acetate and methanol using Soxhlet apparatus were tested for the qualitative analysis of phytochemicals. Secondary metabolites were analyzed quantitatively to correlate with the antioxidant (DPPH assay) and antimicrobial potential of seaweeds. Results showed a better antioxidant activity of U. fasciata in its methanolic extract (89.29%) and D. dichotoma manifested a maximum antioxidant activity (70.1%) for its ethyl acetate extract. Structural characteristics of seaweed derived bioactive material were investigated by Fourier transform infrared spectroscopy (FTIR) and manifested the presence of alcohol and phenolic compounds. The inhibition zone formed around the crude extract reveals the antimicrobial nature of bioactive substances of seaweed extract against the pathogens. High inhibition and antioxidant activity indicate an effective drug’s evolution from seaweeds against human pathogens.

Abstract

This study was conducted to determine the nutrient removal efficiency via the application of mixed cultures from the synthetic hatchery wastewater based on the first-order, second-order and Stover Kincannon models. The synthetic wastewater was prepared according to the characterization of the collected hatchery wastewater sample, and the collected mixed cultures from the pond sediment were acclimatized accordingly. The samples were tested for chemical oxygen demand (COD) and nitrate-N concentration using a Hach spectrophotometer to determine the removal value of the nutrients. The findings show that the highest removal percentage for COD was up to 31.35% on day 3. Meanwhile, the highest removal percentage for nitrate-N was obtained on day 4 at 43.48%. The obtained correlation coefficient,  for COD through first-order, second-order, and Stover Kincannon models is 1, 0.6774, and 0.965, respectively, suggesting that the kinetics of COD removal can be described most properly by the first-order model. A similar model was also reported for nitrate-N with  value of 1, 0.7563, and 0.8693 for the first-order, second-order, and Stover Kincannon models, respectively. Based on the findings, the acclimatized mixed culture used in this study could be a potent natural COD and nitrate-N removal in the hatchery wastewater.

Abstract

Sodium dimethyl dithiocarbamate (SDDC) is a universal heavy metal precipitant/chelating agent, which is widely used in the treatment of heavy metals in industrial wastewater and fly ash from waste incineration. It can be utilized as a heavy metal precipitant, fungicide, agricultural insecticide, rubber vulcanization accelerator, styrene-butadiene rubber polymerization terminator, polymerization inhibitor, mineral processing reagent, etc. This review article focuses on the research of the production and application of SDDC in heavy metal chelation. The following three benefits of using SDDC as a heavy metal chelating agent are: (1) It can chelate with various heavy metal ions at room temperature to generate insoluble chelate salts and precipitates, which can be easily removed; (2) SDDC can perform chelation reaction with varies heavy metal ions at the same time; (3) As a heavy metal chelating agent, SDDC is simple to use and low costs, which is significantly better than other heavy metal chelating agents and precipitants. This review paper presents novel ideas for the performance enhancement based on SDDC in removing heavy metals and is a prospect for the research, development, production, and applications of SDDC.

Abstract

The heavy metals found in contaminated waters are dangerous for the environment and human health, so it is necessary to seek and apply techniques to remove these pollutants, using adsorption techniques with natural biopolymers as cost effective biosorbent. Since large amounts of Jackfruit (Artocarpus heterophyllus fruit) waste part are abandoned after the pulp used around Tepi areas, the possibility of developing value-added products from them is interesting innovation. In this work, cellulose fiber was extracted from Artocarpus heterophyllus fruit waste part and modified with Isopropyl alcohol groups to produce which were then used as Lead metal ion adsorbents. The modified cellulose was characterized by several techniques including Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). This modified cellulose was used as adsorbents for adsorption studies of heavy metal ions (Pb²⁺) within batch adsorption systems. A solution of lead ion (Pb²⁺) was used as artificial wastewater for the purpose of studying biosorption efficiencies. The biosorption efficiencies of modified cellulose were studied by using four adsorption parameters. The optimum biosorption of modified cellulose at 25 °C, were found to be 94.2%, 76.12%, 82.54%, and 90.13%, of Pb²⁺ for the adsorption parameter; biosorbent dosage, contact time, Pb (II) concentration, and pH respectively.  The biosorption kinetics behaviour of modified cellulose for Pb²⁺ fitted well with a pseudo-second-order model with correlation coefficient of 0.9975. The biosorption isotherm behaviour was well described using the Langmuir biosorption isotherm model with higher correlation coefficient of 0.9935. The reusability and desorption study of modified cellulose shows that it can be reused 2 to 4 times and after 5th cycles the desorption was significantly decreased. This study showed that the modified cellulosic adsorbents made from (Artocarpus heterophyllus fruit) were able to efficiently adsorb metal ions from aqueous solution.

Abstract

Aldehyde, 1,2-diketones, and acid were prepared by copper-catalyzed oxidation of phenyl propyne, using t-BuOOH as the oxidant, heterogeneously. Aldehyde is formed as a major product under neutral conditions. Under mild conditions, catalysis was carried out using catalytic amounts of [Cu(L)Br] with N-methyl benzimidazolyl Schiff base ligand and stoichiometric amounts of oxidant in CH₃CN. The several properties of the catalyst were characterized by using UV-Vis, FT-IR, PXRD, CV, and Electron paramagnetic resonance techniques. Comparative SEM measurement of catalyst before and after the catalysis shows that the morphology and size of rods affect the catalytic efficiency. The percentage yields of products were determined by GC-MS.

Abstract

The accumulation of plastics in landfills and oceans has encouraged the development of biodegradable plastic products from renewable sources. Natural polymers are excellent candidates that need further modification of their functional and structural properties comparable to conventional plastics. This study aims to fabricate and optimize the formulation of bioplastic films from chitosan and mango kernel starch with glycerol as a plasticizer using response surface methodology (RSM). The chitosan-to-starch mass ratio (1:0.17 to 1:5.83) and glycerol concentration per gram of dry polymer (15.86% to 44.14%) were assigned as the independent variables to design an empirical model that describes the films’ elastic modulus as the sole response. The results yielded an optimal formulation of 1:0.17 chitosan-to-starch mass ratio (2% weight by volume chitosan solution blend) with 15.86% glycerol (per gram of dry chitosan and starch). Reproduction of the optimized film was carried out to validate the empirical model. Characterization of the films’ mechanical and barrier properties, surface morphology, and biodegradability were also investigated in this work. The results suggest that the functional properties of the bioplastic film surpass other chitosan-based bioplastic film blends and can be developed further to become a more sustainable alternative to conventional plastic packaging products.

Abstract

To address the adverse impacts due to rapid growth of electric vehicles (EVs), a robust planning framework is developed in this paper for optimal deployment of EV charging stations and solar energy resources in the distribution network. Uncertainty modeling of EV is done using probability density function considering stochastic parameters extracted from real National Household Travel Survey (NHTS)datasheet. Considering solar irradiance as the uncertainty parameter, a practical Photovoltaic (PV) model is developed using beta probability function. To solve the problem of optimal allocation of EV charging stations and PV in the distribution network, proposed Teaching Learning Based Optimization algorithm is used. The problem is formulated to minimize the power loss reduction index and the voltage deviation index while considering system constraints. Here this proposed approach is tested to Indian 28 bus rural distribution network and standard IEEE 69 bus system in MATLAB. Also to assess the efficiency of the proposed technique, it is compared with three different algorithms, i.e., Genetic Algorithm (GA), Particle Swarm Optimization (PSO) and Differential Evolution (DE) in terms of convergence characteristics and computational time. The system indices, i.e., voltage profile, line loss, voltage stability and the penetration level of EV charging station are improved after simultaneously optimally deploying EV charging station and PV units both in rural and standard 69 bus distribution networks. Different case studies were conducted and it was observed that deployment of EV charging station in the network leads to deterioration of voltage profile, voltage stability and line loss. The simulation outcome further reveals that the addition of PV panels concurrently with EV charging stations enhances the system performances and the penetration level of EV charging station in the network.

Abstract

Phosphorus (P) is an essential element for crop production but its non-renewable natural sources are on the verge of depletion. The few remaining P sources may be depleted in the next 30–50 years. This calls for P recycling strategies with biochar application being an appealing approach. However, very limited information is available on the use of biochar as a P source and how it affects the various P fractions in tropical paddy soils. Therefore, the aim of this study was to establish whether biochar could potentially be used as a P source. A sample tropical paddy soil was treated with 1% biochar (derived from maize straw) and/or potassium dihydrogen phosphate, waterlogged and then incubated in airtight amber glass containers at 25 ℃, to mimic tropical paddy soil conditions. Soil aliquots were sampled periodically, followed by extraction and analysis of P fractions. The generated data was subjected to correlation analysis to explore the relationships among the P fractions. The study established that under anaerobic conditions, biochar amendment and P fertilization had no effect on aluminium bound P, calcium bound P, occluded P, moderately labile P and non-labile P. Additional P increased loosely sorbed P but biochar reduced it, even when combined with supplementary P fertilization. It was established that biochar increased iron bound P and to a greater extent with P fertilization. Additional P increased labile P while it was not affected by biochar. Apart from the effect on loosely sorbed P, biochar performed as well as the P fertilizer—or better in case of Fe-bound P. There is therefore promising potential for utilization of biochar as an alternative renewable P source.

Abstract

The increasing presence of heavy metal ions in aquatic environments has become a subject of escalating concern in contemporary times. Numerous human-induced activities have contributed to an elevated presence of heavy metal ions in aquatic environments, surpassing the threshold levels established by the World Health Organisation (WHO). Recently, there has been a significant increase in the utilisation of polyethylene glycol (PEG) due to its exceptional characteristics in addressing the pressing issue of aquatic pollution resulting from the presence of heavy metal ions. This mini review evaluates the detection activities in which PEG plays a significant role. The detection strategy utilising PEG composites is thoroughly described, beginning with an examination of the inherent properties of PEG. Furthermore, it concludes with suggestions for future research in this area.

Abstract

Alzheimer’s disease (AD) is a prevalent cause of dementia in the elderly, characterized by progressive cognitive decline and neurodegeneration. This review focuses on the etiology of AD, the role of various receptors [TNF (Tumor necrosis factor) receptor, nAChR (Neuronal nicotinic acetylcholine receptors), NMDARs (N-Methyl-D-aspartate receptors), APOE (Apolipoprotein E) receptor, and amyloid-beta receptor], and risk factors contributing to its development. AD progresses through mild, moderate, and severe stages, each exhibiting distinct symptoms. The hallmark pathologies are neurofibrillary tangles and amyloid plaques, comprised of hyperphosphorylated tau protein and amyloid-beta peptides, respectively. Current pharmacotherapeutic options alleviate symptoms but lack a complete cure. To address the challenges in developing effective AD treatments, researchers have turned to artificial intelligence (AI) and computational approaches in drug design. AI techniques, including machine learning and molecular docking, enable the analysis of large datasets and prediction of molecular interactions between potential drug candidates and target receptors. Virtual screening and molecular modeling aid in identifying novel therapeutic compounds. Predictive modeling and optimization algorithms optimize drug properties and predict efficacy. AI also facilitates the repurposing of existing drugs by analyzing their interactions with AD-related receptors and pathways. Clinical trial optimization using AI algorithms enhances patient selection, treatment monitoring, and outcome prediction. Integrating AI into AD drug design holds tremendous promise for accelerating the discovery of effective interventions. By leveraging AI’s capabilities, researchers can efficiently analyze extensive data, predict drug-target interactions, and optimize drug properties, leading to the identification of novel AD treatments. However, further research and validation are needed to translate AI-driven drug design approaches into clinically viable solutions for AD patients. Through continued advancements in AI and collaborative efforts, the development of targeted and advanced therapies for AD is within reach.

Abstract

Increasing attention is being paid to bacterial nanocellulose (BNC) because of its environment-friendly properties. Researchers investigated the role of microbial hosts in BNC production due to the benefits of cellulose produced by microbes. Several research groups have developed techniques to make BNC on a large scale with the goal of developing new methods. A 3D network of micro and nanofibrils in BNC synthesized from several bacterial strains makes these BNC useful for reinforcing nanostructured composites that have increased Young’s modulus, tensile strength, purity, crystallinity, and water holding capacity. To overcome the barriers associated with the industrial scale production of BNC, different production techniques will be used, including static culture, cell-free production, agitated/shaking culture, using a variety of receptors for fermentation, and low-cost substrates as carbon sources. By in-situ and ex-situ fermentation processes, metal/metal oxide nanoparticle composites are among the most widely used materials in diagnostic and regenerative medicine. The purpose of the review is to update the researchers regarding the lucid production process and versatile applications of bacterial nanocellulose in biomedical field. We shall mainly discuss about the different methods for bacterial cellulose production and some of its applications in this mini-review.