The study investigates the effect of aluminium oxide nanoparticles as an additive to Madhuca Indica (mahua) methyl ester blends on performance, emission analysis of a single-cylinder direct injection diesel engine operated at a constant speed at different operating conditions. The test fuels are indicated as B10A0.2, B10A0.4, B20A0.2, B20A0.4 and diesel respectively. The results indicate that the brake thermal efficiency for aluminium oxide nanoparticles blended biodiesel increases slightly when compared to the mineral diesel. The carbon monoxide (CO), unburnt hydrocarbon (HC) and smoke emission marginally decrease as compared to mineral diesel. Oxides of nitrogen (NOx) emissions are minimum for the aluminium oxide nanoparticles blended mahua methyl esters. Higher cylinder gas pressure and heat release rate were observed for aluminium oxide nanoparticles blended mahua methyl ester. From the study, the blending of aluminium oxide nanoparticles in biodiesel blends produces a most promising results in engine performance and also reduces the harmful emission from the engines.

The present study prepares alkali lignin (AL) via acidification of black liquor, obtained from a pulp and paper factory. The average molecular weight of AL (equal to 2,530 g/mol) has been determined with gel permeation chromatography. AL has been modified by ethylene glycol, while lignin nanoparticles (LN) has been prepared through acid precipitation technology, their size being assessed by means of DLS to show that the average diameter of the nanoparticles at pH = 4 has been 52.7 nm. Afterwards, it has used AL and LN to remove Basic Red 2 (BR2) from aqueous solutions. The absorbent structures and morphologies of AL and LN have been investigated using SEM, and FT-IR spectroscopy. The optimal conditions for the absorption of AL and LN, using 0.1 gr of the absorbent, include 100 min of duration, at pH of 7, and an initial dye concentration amounting to 100 mg/L. Furthermore, the absorption amount has been mathematically described as a function of experimental parameters, modeled by means of Response Surface Methodology (RSM). A central composite design (CCD) has been applied to evaluate the impacts of four independent variables. Optimum absorption values, obtained via empirical methods, completely match with the values, calculated by the program called Design-Expert. Both absorbent AL and LN show agree with Langmuir Isotherm with maximum absorption capacities of AL and LN being 55.2 mg/gr and 81.9 mg/gr, respectively. The experimental results show that both absorbent LN and AL follow both pseudo-second kinetic and the intraparticle diffusion models.

Conventional remediation techniques have become outdated and insufficient to treat the influx of pollution from different fronts (air, water, and soil). Green synthesis of nanoparticles is an eco-friendly approach to remediate these contaminants and Membrane technology is increasingly becoming popular for the treatment of wastewater due to their efficiency and versatility against a wide array of contaminants. Cellulose acetate (CA) is a polymer obtained from cellulose and hence considered biodegradable, making it a more environmentally friendly option over other conventional polymers. In this present study, silver nanoparticles were synthesized using Staphylococcus aureus and characterized by UV-vis Spectrometer, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDAX). The synthesized green silver nanoparticles were assimilated onto synthesized CA membrane films to fabricate nanocomposite membranes (CA-X, CA-X1 and CA-X2). EDAX results showed higher counts of silver at 3keV on the CA-X, confirming that silver nanoparticles were properly embedded on the membrane. Physio-chemical tests performed on the collected sewage, showed that the total dissolved solids (TDS) were found to decrease significantly during the first hour of treatment, CA-X1 showed 16.2% decrease and 21.95% decrease was observed by CA-X2. A decrease in total nitrogen content by 38.88% and 41.36% for CA-X1 and CA-X2 respectively was recorded after a week’s treatment. Therefore, the work displayed the capability of cellulose acetate nanocomposite membrane for leachate treatment, since it displayed its potential in remediating leachate in a short span of time and scalability could be achieved for a larger volume of leachate with larger nanocomposite membranes.

This work explores the synthesis and characterization of two novel nanocomposites that can be used in various applications, such as aqueous solution adsorption of pollutants. The first nanocomposite consists of tin (Sn)-doped titanium dioxide (TiO2) on activated carbon, while the other one consists of polypyrole (PPy), chitosan (CS), and Sn-doped TiO2. A contrast was made of their effective adsorbent materials for the removal of Cibacron Brilliant Yellow dye from aqueous solutions. Different analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDX), and Fourier transform - infrared (FT-IR) were used to analysis the nanocomposite samples. SEM images show that the average particle diameter of PPy-CS/Sn-doped TiO2 NC is 75 ± 3 nm, while Sn-doped TiO2/AC particles have an average diameter of 40 ± 2 nm. The greater PPy-CS/Sn-doped TiO2 nanocoposite particle diameter indicates that the polymers cover the Sn-doped TiO2 nanoparticles, which leads to higher in the diameter of the particles. The adsorption efficiency of Sn-doped TiO2/AC was higher than that of PPy-CS/Sn-doped TiO2 sample due to its smaller particle size which resulted in a higher surface area which provides more adsorption sites. However, both samples showed remarkable adsorption capacity, where the adsorption capacity of Sn-doped TiO2/AC and PPy-CS/Sn-doped TiO2 were 104 and 103 mg/g, respectively.

Increasing the pollution rate of water sources is one of the most severe issues that the world faces. This issue has stimulated researchers to investigate different treatment methods such as adsorption, chemical precipitation, membrane filtration, flocculation, ion exchange, flotation, and electrochemical methods. Among them, adsorption has gained broad interest due to its ease of operation, low cost, and high efficiency. The critical factor of the successful adsorption treatment process is finding attractive adsorbents with attractive criteria such as low cost and high adsorption capacity. In the last few decades, nanotechnology has attracted much attention, and numerous nanomaterials have been synthesized for water and wastewater treatment. This work provides a quick overview of nanomaterials, which have been investigated for water remediation as adsorbent and photocatalyst. This work reviewed more than 100 articles to provide a critical review that would determine the limitation of using nanomaterials in water treatment at the commercial scale.