Journal of Water and Environmental Nanotechnology
Volume:7 Issue: 3, Summer 2022

In the current study, for the first time, an innovative hydrothermal method was proposed for the synthesis of TiO2/WO3 heterojunction nanocomposite from the combination of TiO2 nanorod, and WO3 nanoflakes. Because of environmental issues arising from the vast use of insecticides, this nanocomposite photocatalyst was applied for the first time for photocatalytic degradation of Nitenpyram insecticide under visible light irradiation. The prepared nanocomposite was fully characterized by XRD, FESEM, DRS, PL, and Mott-Schottky analysis. The results revealed that the heterojunction sample had the best photocatalytic performance. The enhanced photocatalytic activity of this heterojunction is attributed to the decrease of the charge carrier’s recombination rate and enhanced visible light harvesting. Moreover, based on the radical trapping experiments and Mott-Schottky calculations, hydroxide radical was determined as the main active species for decomposition of Nitenpyram insecticide, and type II charge transfer mechanism was revealed to be responsible for the enhanced photocatalytic performance, which charge transfer between the two semiconductors results in the decreasing of the charge carrier’s recombination rate.

The widespread use of antibiotics and their subsequent release into the environment has caused concern around the world. Incomplete metabolism releases these chemicals into the environment, and traditional purification systems are unable to remove them. As a result, it lingers in the environment and is one of the most serious environmental issues confronting public health. The goal of this study was to investigate the possibility of using ultrasonic and titanium dioxide nanoparticles as catalysts for the removal of amoxicillin from aqueous solutions, as well as to figure out the optimal conditions to maximize the efficiency of removal efficiency. Decomposition of amoxicillin in water in the presence of titanium magnetic catalyst with concentrations of 0.1, 0.25, 0.5, 1, and 2.5 g/L and amoxicillin concentrations of 1, 10, 25, 50, and 100 mg/L at different times of 10 to 180 minutes, pHs of 3, 4, 5, 7, 9 and 11, temperatures of 10 to 60 ºC and frequencies of 35, 300, and 700 kHz were examined. At a concentration of 1 g/L catalyst, a concentration of 10 mg/L amoxicillin, a standstill duration of 60 minutes, an acidic pH, a temperature of 40 °C, and a frequency of 35 kHz, the maximum removal of amoxicillin (91.7%) occurred. The use of an ultrasonic method in conjunction with titanium magnetic nanoparticles as an oxidizing agent proved to be a successful tool for lowering amoxicillin concentrations in aqueous media. As a result, advanced oxidation processes, particularly ultrasonic, can reduce pharmaceutical and organic contaminants in the environment.

Titanium-di-oxide nanoparticles are synthesized via a microwave-assisted solvothermal route for different pH values. The effect of the acidic and basic nature of the solvent due to the pH value is reflected in the crystalline size of the compound. The purpose of this work is to synthesize Titanium dioxide nanoparticles and to observe their application in degrading industrially contaminated water using normal tap water. The crystalline sizes are calculated using XRD analysis and confirmed with HRTEM. The chemical composition and oxidation state are confirmed with XPS studies. Optical properties are carried out with UV-Vis, FTIR, and PL spectra. Photocatalytic studies are carried out to degrade the dye in industrial water. The efficiency of degradation is calculated with the UV-Vis data and formula. The reduction in band gap and high permanence has greatly supported in making it acceptable for photocatalytic activity under visible light. Dependence of time, initial dye concentration, and pH of the dye solution on TiO2 as a catalyst is investigated under the illumination of a visible lamp, and degradation efficiency to the highest of 96.79% has been obtained.

In this work, the tetragonal Zirconium oxide (ZrO2) nanoparticles (NPs) were successfully synthesized by solution combustion method using Zirconium (IV) oxynitrate hydrate as the metal precursor and an oxidizer, Basella alba raw extract at 6000C. In this study, natural fuel is used to avoid harmful chemical fuels that may pollute the environment during combustion. The impact of the fuel-to-oxidant molar ratio on the surface morphological features of nanocrystalline zirconia particles has been documented. We investigated the Physico-chemical properties of the ZrO2 NPs via thorough characterizations like XRD, EDS, SEM, TEM, FTIR, UV-Vis, and BET. ZrO2 NPs exhibit perfect photocatalytic degradation activity towards Evans blue, a toxic dye. The influence of contact time, initial dye concentration, and pH were among the independent variables used in the study. The Response Surface Model (RSM) was used to optimize and describe the interdependencies of the different variables. The method was evaluated using the Box-Behnken design (BBD). A second-order polynomial model was used to properly understand the experimental results, and the effectiveness of the chosen model was verified by the strong agreement in determination coefficient values. ZrO2 NPs also exhibit good antibacterial activity on Gram-negative Klebsiella pneumoniae and Gram-positive bacteria, Bacillus subtilis.

Scientists and researchers from all over the world are paying close attention to the recycling of industrial waste into new materials. Aluminum and zinc sludge powders were gathered from aluminum sheets and big iron manufacturers to be used as starting materials in the synthesis of zinc aluminate nanoparticles. The XRF, XRD, and DTA examinations were used to characterize the collected sludge powders. The main components of aluminum and zinc sludges, according to the findings, are gibbsite (Al(OH)3) and hydrozincite (Zn5(CO3)2(OH)6), respectively. Without any primary advanced chemical treatments, the collected sludges were used to perform solid-state reaction (SSR) and molten salt synthesis (MSS) at 1100°C. XRD, FTIR, XPS, SEM, and TEM examinations were used to characterize the synthesized samples. Both SSR and MSS deduced pure phase zinc aluminate nanoparticles, with crystallite sizes of 17.4 and 12.7 nm for SSR and MSS samples, respectively. The microstructure of the MSS sample was characterized by a high structure homogeneity, whereas, the high degree of particle aggregation was shown by the SSR sample’s microstructure. The optical properties of the synthesized SSR and MSS samples were studied by using UV-visible and PL spectroscopy. The bandgap energies for SSR and MSS samples were calculated to be 2.78 and 2.48 eV, respectively. These samples are utilized in the photocatalytic degradation of the brilliant cresyl blue dye (BCBD), owing to their tiny bandgap energies and high absorption efficiency. The photocatalytic degradation percent of BCBD reached 94.5% and 86.7% by using MSS and SSR samples, respectively, at the optimum conditions of pH (10), dye concentration (40 mg/l), and sample dose (1 g/l).

The development of biologically enthused green synthesis of silver nanoparticles (SNPs) has concerned significant global awareness about medical science and disease treatment. This paper discusses the green synthesis of SNPs using organic green sources; here we report a facile bottom-up ‘green’ route for the synthesis of SNPs using aqueous leaves extract of Pogostemon speciosus (Benth.) and evaluate its in-vitro anti-inflammatory, antibacterial and photocatalytic activities. The nanoparticles were investigated for the preparation of denaturation particles with PSLASNPs and the evaluation of anti-inflammatory activity with Protein denaturation and HRBC stabilization assays. Later, these PSLASNPs were studied for their potential role in antibacterial activity by well diffusion method, and Photocatalytic activity on degradation of dyes was demonstrated by using dyes Crystal violet, Coomassie blue, and Congo red. At 1000 µg/ml, the PSLASNPs have the greatest prevention of protein denaturation (71.92±1.37%), whilst the stabilization of the HRBC membrane exhibited significant anti-inflammatory action (64.39±1.61 %). The PSLASNPs showed the best antibacterial activity at the concentration of 10 µg/ml against Bacillus subtilis (8.2 mm), followed by Pseudomonas stuberia (6.2 mm) and Escherichia coli (6.4 mm), Staphylococcus aureus (5.3 mm), Staphylococcus gallinarium (4.5 mm) respectively at the same concentrations. Crystal violet, Coomassie blue, and Congo red were used for Photocatalytic activity on the breakdown of dyes. After 35 minutes, the degradation process was determined to be complete by the transformation of the reaction mixture's color to colorless. As a result, the PSLASNPs have anti-inflammatory, antibacterial, and photocatalytic activities.

The environmental concern occurs due to the extreme use of synthetic materials that have been fortified to develop innovative, multifunctional, and sustainable materials using copious lignocellulosic biomass. In this present study, work was done on the extraction of nanocellulose from wheat straw, and found that wheat straw is an admirable source of cellulose. Chemical processes were used to isolate the cellulose and remove unwanted lignin and hemicellulose from wheat straw followed by sonication, cryo-crushing, and magnetic stirring to achieve nanocellulose. The observed amount of cellulose (36.1%), hemicellulose (30.3%), lignin (17%), and ash content (9.2%) of raw wheat straw. Structural, morphological, and thermal characterization were estimated from FTIR, XRD, FESEM, TEM, DSC, TGA, and AFM for the identification and characterization of extracted cellulose from wheat straw. FTIR showed that the peaks at wavelength 1430.50 cm-1 and 1638.41 cm-1 both show that cellulose is present in the extracted nanocellulose.  Extracted nanocellulose was crystalline and had a 68.96% Crystallinity Index. Morphological analysis, FESEM showed that the untreated wheat straw has an irregular porous structure but the extracted nanocellulose has a regular shape having straight fibers connected. TEM analysis showed that the extracted nanocellulose has a spherical shape structure connected, showing the regular shape, the obtained spherical shape regulates the nanocellulose for further applications. Thermal degradation was observed using TGA which shows that the nanocellulose decomposition was observed around 3600C. AFM determination shows a bell-shaped structure on a smooth surface with a particle height of 3.2 nm and the mean roughness of 110.4 nm was obtained from the extracted nanocellulose. Extracted nanocellulose has a particle size of 58.77 nm.

This paper discusses the experimental and theoretical performance of a parabolic trough receiver using a nanofluid. The main aim of this work is to analyze the performance enhancement of the parabolic trough collector system. The thermal model is developed using Engineering Equation Solver (EES). Experimental analysis was done with a water volume flow rate of 10 L/min and water inlet temperature range from 0 to 45 OC, also the volume fraction of Al2O3 nanoparticle varied from 1% to 5%. Experimental analysis conducted using Al2O3 nanoparticle mixed with water and used as heat transfer fluid in solar parabolic trough collector. Results compared and observed that the model has very good acceptance with the experimental results. It is observed that the thermal efficiency of the collector increased by 2 to 4% and receiver heat loss decreased from 0.82% to 2.72%. The receiver water temperature increased by 15% for the range of Al2O3 nanoparticle volume fraction. This work was carried out to investigate the use of renewable energy for water heating applications on rural farms in India. Small-sized PTC is simple in construction, economical, and does not require special skills to operate. However, considering the space requirement it would be better to investigate the method to improve the performance of PTC without changing the dimensions. One way to improve the performance is with the use of nanofluids. This work’s main finding is that the Nanoparticle with a volume fraction of 4 will improve the performance. It was observed that the temperature of the water was improved by 15% and the thermal efficiency was increased by 4%.