Facile synthesis of iron nanoparticles from Camellia Sinensis leaves catalysed for biodiesel synthesis from Azolla filiculoides.

Recent years have seen an increase in research on biodiesel, an environmentally benign and renewable fuel alternative for traditional fossil fuels. Biodiesel might become more cost-effective and competitive with diesel if a solid heterogeneous catalyst is used in its production. One way to make biodiesel more affordable and competitive with diesel is to employ a solid heterogeneous catalyst in its manufacturing. Based on X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FTIR), the researchers in this study proved their hypothesis that iron oxide core-shell nanoparticles were generated during the green synthesis of iron-based nanoparticles (FeNPs) from Camellia Sinensis leaves. The fabrication of spherical iron nanoparticles was successfully confirmed using scanning electron microscopy (SEM). As a heterogeneous catalyst, the synthesised catalyst has shown potential in facilitating the conversion of algae oil into biodiesel. With the optimal parameters (0.5 weight percent catalytic load, 1:6 oil-methanol ratio, 60 °C reaction temperature, and 1 h and 30 min reaction duration), a 93.33% yield was attained. This may be due to its acid-base property, chemical stability, stronger metal support interaction. Furthermore, the catalyst was employed for transesterification reactions five times after regeneration with n-hexane washing followed by calcination at 650 °C for 3 h.

Deep insights into kinetics, optimization and thermodynamic estimates of methylene blue adsorption from aqueous solution onto coffee husk (Coffee arabica) activated carbon.

In the current study, an attempt was made to synthesize coffee husk (CH) activated carbon by chemical modification approach (sulphuric acid-activated CH (SACH) activated carbon) and was used as a valuable and economical sorbent for plausible remediation of Methylene blue (MB) dye. Batch mode trials were carried out by carefully varying the batch experimental variables: SACH activated carbon (SACH AC) dosage, pH, initial dye concentration, temperature, and contact time. The optimum equilibrium time for adsorption by SACH activated carbon was obtained as 60 min, and the maximum adsorption took place at 30 °C. Morphological and elemental composition, crystallinity behaviour, functional groups, and thermal stability were examined using SEM with EDX, XRD, FTIR, BET, TGA, and DTA and these tests showed successful production of activated carbon. The outcomes showed that chemical activation enhanced the number of pores and roughness which possibly maximized the adsorptive potential of coffee husk. The Box-Benken design (BBD) was used to optimize the MB dye adsorption studies and 99.48% MB dye removed at SACH AC dosage of 4.83 g/L at 30 °C for 60 min and pH 8.12, and the maximum adsorption was yielded for sulphuric acid-activated coffee husk carbon carbon with 88.1 mg/g maximum MB adsorption capacity. Langmuir- Freundlich model deliberately provided a better fit to the equilibrium data. The SACH AC-MB dye system kinetics showed a high goodness-of-fit with pseudo second order model, compared to other studied models. Change in Gibbs's free energy (ΔGo) of the system indicated spontaneity whereas low entropy value (ΔSo) suggested that the removal of MB dye on the SACH activated carbon was an enthalpy-driven process. The exothermic nature of the sorption cycle was affirmed by the negative enthalpy value (ΔHo). The adsorptive-desorptive studies reveal that SACH AC could be restored with the maximum adsorption efficiency being conserved after the fifth cycles. Overall, the outcomes revealed that sulphuric acid-activated coffee husk activated carbon (SACH AC) can be used as prompt alternative for low-cost sorbent for treating dye-laden synthetic wastewaters.

The bio-adsorption competence of tailor made lemon grass adsorbents on oils: An in-vitro approach.

The oil contamination in aquatic system is considered as most serious environmental issues and identifying a suitable ecofriendly solution for this oil pollution management is critical. Hence, this research was designed to evaluate the oils (petrol, diesel, engine oil, and crude oil) adsorptive features through raw lemon grass adsorbent, physically/chemically treated adsorbents. Initially, such raw and treated adsorbents were characterized by Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and Energy-Dispersive X-ray Spectroscopy (EDS) analysis. These characterization techniques revealed that the lemon grass adsorbent had considerable level of pollutant adsorption potentials owing to porous morphological structure, active functional groups and pollutants interaction with chemical elements. The physically treated adsorbent exhibited better adsorption characteristics than others. Accordingly, the petrol adsorption potential of raw adsorbent, physically treated and chemically treated ones was discovered as their weight incremented up to 2.0, 3.0, and 1.5 times their initial weight, respectively. Similarly, the weight of raw form, physically and chemically treated ones on diesel had increased significantly, up to 2.5 times, 4.0 times, and 2.0 times, respectively. It was evaluated that the weight of these tested adsorbents on engine oil incremented by 3.5, 5.0, and 3.0 times their initial weight, while on crude oil these incremented by 4.0, 6.0, and 4.0 times their initial weight respectively. When the media are compared, it's indeed evident about absorption which is preferred as follows: Crude oil, engine oil, diesel, and petrol. The physically treated lemon grass adsorbent showed maximum adsorption and retention potential than others. The kinetic study reveals that the pseudo second order kinetics is the best fit for the adsorption of oil with R2 value of 0.99.

Synthesis and characterization of barium doped CaO heterogeneous nanocatalyst for the production of biodiesel from Catharanthus roseus seeds: Kinetics, optimization and performance evaluation.

The exploitation of petroleum derivatives to meet the energy demands of the cutting edge is thought of as impractical because of asset shortage. The current necessitates that the world community improves future energy sources by developing sustainable, ecofriendly alternatives. In this work, biodiesel is produced through the transesterification of Catharanthus roseus seed oil with a barium-doped CaO heterogeneous nanocatalyst. The catalyst characterization is assessed using FTIR, GC-FID, EDAX, XRD, and SEM. The optimum conditions of time (70 min), temperature (58 °C), the molar ratio of methanol: oil is 15:1, and catalyst load (4% w/w) resulted in a conversion of the maximum biodiesel yield of 91.83%. Finally, by using Catharanthus roseus as a feedstock, the low optimal reaction conditions contribute to the development of the economic impact of biodiesel synthesis. Biodiesel blend (B20) containing barium-doped CaO nanoparticles showed better combustion engine performance and lower emissions than fossil fuels.

Emerging pharma residue contaminants: Occurrence, monitoring, risk and fate assessment - A challenge to water resource management.

Water is one of the important gifts to mankind. In recent days the accessibility of pharmaceuticals in the environment is progressively a worldwide concern. The significant wellspring of these contaminations in water assets is drugs for human use or veterinary medications. Intermediates, active metabolites and raw materials present in water from pharmaceutical industry waste because of incomplete sewage treatment systems. Various pharmaceutical components such as analgesic/antipyretics such as Ibuprofen (57.9-104 ng/L), Diclofenac (17-129 ng/L), antibiotics such as Sulfamethoxazole (28.7-124.5 ng/L), Sulfamethazine (29.2-83.9 ng/L), Azithromycin (10-68 ng/L), psychiatric drug such as Carbamazepine (9.3-92.4 ng/L), stimulants such as caffeine greater than 55 ng/L, antidepressants, antihypertensive, contraceptives etc., are present in water resources and have been detected in mg/L to µg/L range. The synergic effects and ecotoxicological hazard assessment must be developed. Studies demonstrate that these drugs might cause morphological, metabolic and sex alterations on sea-going species, and interruption of biodegradation activities. Hazard analysis and assessments are in progress. However, the conventional effluent treatment methods are not sufficient to remove API (active pharmaceutical ingredients) from this water effectively. There is necessitate for continuous monitoring of the pharmaceutical compounds in aquatic ecosystem to save the environment and living form of lives from health hazards. This work highlights the hazards, environmental assessment and the mitigation measures of pharmaceutical pollutants.

Amalgamation and application of nano chitosan cross-linked with fish scales based activated carbon as an adsorbent for the removal of reactive dye (RB9).

The extensive discomfort in the expulsion of toxic pollutants even at mild concentrations has demanded the need for prompt methods for the evacuation of dyes and heavy metals. The effective method for depuration of dye from the effluent is by sorption. Chitosan is a bio-polymer which is gaining an increasing interest as one of the sorbents. It was obtained from the crab shells by undergoing several chemical processes and used as an adsorbent for dye, metal removal and also for pharmaceutical purposes. Cross linking it with other co polymers will increase the capacity of adsorption to a maximum level. Fish scales are considered to be a major waste in the food industry and since it takes a long time for decomposing it is considered to be one of the pollutants. Hence it is utilised by converting it into activated carbon by preliminary treatment and into a muffle furnace. The obtained activated carbon is combined with chitosan by using a cross linker and utilised for adsorption mechanism. To analyse the effect of chitosan cross linked with activated carbon obtained from fish scales in adsorption of dye Reactive Blue 9 (RB9) to evaluate the adsorption studies, kinetics, mass transfer studies, thermodynamics of the bio adsorbent.