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66 result(s) for "Irshad, Muhammad Atif"
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Green synthesis of magnetite iron oxide nanoparticles using Azadirachta indica leaf extract loaded on reduced graphene oxide and degradation of methylene blue
In the current arena, new-generation functional nanomaterials are the key players for smart solutions and applications including environmental decontamination of pollutants. Among the plethora of new-generation nanomaterials, graphene-based nanomaterials and nanocomposites are in the driving seat surpassing their counterparts due to their unique physicochemical characteristics and superior surface chemistry. The purpose of the present research was to synthesize and characterize magnetite iron oxide/reduced graphene oxide nanocomposites (FeNPs/rGO) via a green approach and test its application in the degradation of methylene blue. The modified Hummer's protocol was adopted to synthesize graphene oxide (GO) through a chemical exfoliation approach using a graphitic route. Leaf extract of Azadirachta indica was used as a green reducing agent to reduce GO into reduced graphene oxide (rGO). Then, using the green deposition approach and Azadirachta indica leaf extract, a nanocomposite comprising magnetite iron oxides and reduced graphene oxide i.e., FeNPs/rGO was synthesized. During the synthesis of functionalized FeNPs/rGO, Azadirachta indica leaf extract acted as a reducing, capping, and stabilizing agent. The final synthesized materials were characterized and analyzed using an array of techniques such as scanning electron microscopy (SEM)-energy dispersive X-ray microanalysis (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis, and UV–visible spectrophotometry. The UV–visible spectrum was used to evaluate the optical characteristics and band gap. Using the FT-IR spectrum, functional groupings were identified in the synthesized graphene-based nanomaterials and nanocomposites. The morphology and elemental analysis of nanomaterials and nanocomposites synthesized via the green deposition process were investigated using SEM–EDX. The GO, rGO, FeNPs, and FeNPs/rGO showed maximum absorption at 232, 265, 395, and 405 nm, respectively. FTIR spectrum showed different functional groups (OH, COOH, C=O), C–O–C) modifying material surfaces. Based on Debye Sherrer's equation, the mean calculated particle size of all synthesized materials was < 100 nm (GO = 60–80, rGO = 90–95, FeNPs = 70–90, Fe/GO = 40–60, and Fe/rGO = 80–85 nm). Graphene-based nanomaterials displayed rough surfaces with clustered and spherical shapes and EDX analysis confirmed the presence of both iron and oxygen in all the nanocomposites. The final nanocomposites produced via the synthetic process degraded approximately 74% of methylene blue. Based on the results, it is plausible to conclude that synthesized FeNPs/rGO nanocomposites can also be used as a potential photocatalyst degrader for other different dye pollutants due to their lower band gap.
Assessment of drinking water quality using Water Quality Index and synthetic pollution index in urban areas of mega city Lahore: a GIS-based approach
The aim of the present study was to assess the drinking water quality in the selected urban areas of Lahore and to comprehend the public health status by addressing the basic drinking water quality parameters. Total 50 tap water samples were collected from groundwater in the two selected areas of district Lahore i.e., Gulshan-e-Ravi (site 1) and Samanabad (site 2). Water samples were analyzed in the laboratory to elucidate physico-chemical parameters including pH, turbidity, temperature, total dissolved solids (TDS), electrical conductivity (EC), dissolved oxygen (DO), total hardness, magnesium hardness, and calcium hardness. These physico-chemical parameters were used to examine the Water Quality Index (WQI) and Synthetic Pollution Index (SPI) in order to characterize the water quality. Results of th selected physico-chemical parameters were compared with World Health Organization (WHO) guidelines to determine the quality of drinking water. A GIS-based approach was used for mapping water quality, WQI, and SPI. Results of the present study revealed that the average value of temperature, pH, and DO of both study sites were within the WHO guidelines of 23.5 °C, 7.7, and 6.9 mg/L, respectively. The TDS level of site 1 was 192.56 mg/L (within WHO guidelines) and whereas, in site 2 it was found 612.84 mg/L (higher than WHO guidelines), respectively. Calcium hardness of site 1 and site 2 was observed within the range from 25.04 to 65.732 mg/L but, magnesium hardness values were higher than WHO guidelines. The major reason for poor water quality is old, worn-out water supply pipelines and improper waste disposal in the selected areas. The average WQI was found as 59.66 for site 1 and 77.30 for site 2. Results showed that the quality of the water was classified as “poor” for site 1 and “very poor “ for site 2. There is a need to address the problem of poor water quality and also raise the public awareness about the quality of drinking water and its associated health impacts.
Removal of oxytetracycline from pharmaceutical wastewater using kappa carrageenan hydrogel
This study investigated the adsorption of Oxytetracycline (OTC) from pharmaceutical wastewater using a kappa carrageenan based hydrogel (KPB). The aim of the present study was to explore the potential of KPB for long-term pharmaceutical wastewater treatment. A sustainable adsorbent was developed to address oxytetracycline (OTC) contamination. The hydrogel’s structural and adsorption characteristics were examined using various techniques like Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), X-ray powder diffraction (XRD), and kinetic models. The results revealed considerable changes in the vibrational modes and adsorption bands of the hydrogel, suggesting the effective functionalization of Bentonite nano-clay. Kappa carrageenan based hydrogel achieved the maximum removal (98.5%) of OTC at concerntration of 40 mg/L, pH 8, cotact time of 140 min and adsorbent dose of 0.1 g (KPB-3). Adsorption of OTC increased up to 99% with increasing initial concentrations. The study achieved 95% adsorption capacity for OTC using a KPB film at a concentration of 20 mg/L and a 0.1 g adsorbent dose within 60 min. It also revealed that chemisorptions processes outperform physical adsorption. The Pseudo-Second-Order model, which emphasized the importance of chemical adsorption in the removal process, is better suited to represent the adsorption behavior. Excellent matches were found that R 2  = 0.99 for KPB-3, R 2  = 0.984 for KPB-2 and R 2  = 0.989 for KPB-1 indicated strong chemical bonding interactions. Statisctical analysis (ANOVA) was performed using SPSS (version 25) and it was found that pH and concentration had significant influence on OTC adsorption by the hydrogel, with p-values less than 0.05. The study identified that a Kappa carrageenan-based hydrogel with bentonite nano-clay and polyvinyl alcohol (PVA) can efficiently remove OTC from pharmaceutical effluent, with a p-value of 0.054, but weak positive linear associations with pH, temperature, and contact time. This research contributed to sustainable wastewater treatment and environmental engineering.
Aloe-inspired eco-friendly synthesis of Ag/ZnO heterostructures: boosting photocatalytic potential
The current research focuses on the development of Ag–ZnO heterostructures through a “bottom-up” approach involving the assembly and extraction of Aloe barbadensis Miller gel. These heterostructures composed of metals/semiconductor oxide display distinct and notable optical, electrical, magnetic, and chemical properties that are not found in single constituents and also exhibit photocatalytic applications. These synthesized heterostructures were characterized by XRD, FTIR, SEM, and UV–visible spectroscopy. The high peak intensity of the Ag/ZnO composite shows the high crystallinity. The presence of Ag–O, Zn–O, and O–H bonding is verified using FTIR analysis. SEM analysis indicated the formation of spherical shapes of Ag/ZnO heterostructures. The Zn, O, and Ag elements are further confirmed by EDX analysis. Ag–ZnO heterostructures exhibited excellent photocatalytic activity and stability against the degradation of tubantin red 8BL dye under visible light irradiation.
Green synthesis of graphene oxide and magnetite nanoparticles and their arsenic removal efficiency from arsenic contaminated soil
Graphene-based nanomaterials have been proved to be robust sorbents for efficient removal of environmental contaminants including arsenic (As). Biobased graphene oxide (bGO-P) derived from sugarcane bagasse via pyrolysis, GO-C via chemical exfoliation, and magnetite nanoparticles (FeNPs) via green approach using Azadirachta indica leaf extract were synthesized and characterized by Ultraviolet-Visible Spectrophotometer (UV-vis.), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), mean particle size and Scanning electron microscopy (SEM) along with Energy dispersive spectroscopy (EDX) analysis. Compared to cellulose and hemicellulose, the lignin fraction was less in the precursor material. The GOC, bGO-P and FeNPs displayed maximum absorption at 230, 236, and 374 nm, respectively. FTIR spectrum showed different functional groups (C-OH, C-O-C, COOH and O-H) modifying the surfaces of synthesized materials. Graphene based nanomaterials showed clustered dense flakes of GO-C and thin transparent flakes of bGO-P. Elemental composition by EDX analysis of GO-C (71.26% C and 27.36% O), bGO-P (74.54% C and 24.61% O) and FeNPs (55.61% Fe, 4.1% C and 35.72% O) confirmed the presence of carbon, oxygen, and iron in synthesized nanomaterials. Sorption study was conducted with soil amended with different doses of synthesized nanomaterials (10, 50 and 250 mg) and exposed to 100, 300 and 500 ppm of As. Arsenic concentrations were estimated by colorimetry and atomic absorption spectroscopy (AAS). GO-C, bGO-P, and FeNPs showed substantial As removal efficiency i.e., 81 to 99.3%, 65 to 98.8% and 73.1–89.9%, respectively. Green synthesis of bGO-P and magnetite nanoparticles removed substantial amounts of As compared to GO-C and can be effectively deployed for As removal or immobilization. Higher and medium sorbent doses (250 and 50 mg) exhibited greater As removal and data was best fitted for Freundlich isotherm evidencing favorable sorption. Nevertheless, at low sorbent doses, data was best fitted for both models. Newly synthesized nanomaterials emerged as promising materials for As removal strategy for soil nano-remediation and can be effectively deployed in As contaminated soils.
Chromium (III) removal by perennial emerging macrophytes in floating treatment wetlands
Floating treatment wetlands (FTWs) are a sustainable solution to treat polluted water, but their role in chromium (Cr(III)) removal under neutral pH conditions remains poorly understood. This study evaluated the potential of FTWs planted with two perennial emergent macrophytes, Phragmites australis and Iris pseudacorus, to remove Cr(III) and nutrients (N and PO 4 -P) from water containing 7.5 mg/L TN, 1.8 mg/L PO 4 -P, and Cr(III) (500, 1000, and 2000 µg/L). Within 1 h of exposure, up to 96–99% of Cr was removed from the solution, indicating rapid precipitation. After 50 days, Phragmites bound 9–19% of added Cr, while Iris bound 5–22%. Both species accumulated Cr primarily in the roots (BCF > 1). Biomass production and growth development were inhibited in Cr treatments, but microscopic examination of plant roots revealed no histological changes at 500 and 1000 µg/L Cr, suggesting high resistance of the tested species. At 2000 µg/L Cr, both species exhibited disruptions in the arrangement of vessel elements in the stele and increased aerenchyma spaces in Phragmites . At the end of the experiment, 70–86% of TN and 54–90% of PO 4 -P were removed.
Effect of daily thinning on biweekly increment of growth and yield of maize (Zea mays L.) in mountainous agroecosystem
Maize ( Zea mays L.) growth and yield are severely affected due to intraspecific competition and agroclimatic conditions when cultivated with high plant densities. Field trials comprising four daily thinning patterns (0, 0.5, 1.0, &1.5% till silking) carried out in three consecutive years (2019–2021) using RCBD experimental design consisting of three replicates. Growth variables, dry matter allocation and growth rates in maize were examined during five biweekly periods starting from the emergence (15, 30, 45, 60 and 75 days after emergence, DAE) till silking whereas yield parameters i.e., biological yield, economic yield, and sustainability yield index (SYI) were recorded. Biweekly increase in growth variables, dry matter partitioning and growth rates of maize differed significantly due to the influence of daily thinning computed for the periods from 31 to 45, 46 to 60 and 61 to 75 DAE but the same parameters didn’t differ significantly during the first two biweekly periods (1–15 & 16–30 DAE). Increase in growth variables, dry matter distribution, absolute growth rate (AGR), yield and SYI was the greatest where maize was established with 1% daily thinning. This increase in growth and dry matter partition observed highly associated to economic yield and biological yield. Current research highlighted that 3, 4 th, and 5 th biweekly periods are the most critical stages and daily thinning of 1% is suggested for higher and sustainable economic and biological returns from high density broadcasted maize.
Physico- and phytochemical properties of Brassica juncea as affected by agroclimatic conditions
Physicochemical and phytochemical assessment of leaf mustard ( Brassica juncea L.) grown in different agroclimatic conditions is essential to highlight their compositional variability and evaluate the most suitable bunch of agroclimatic and agronomic practices. B. juncea is one of the important leafy vegetables that serve as source of vitamin A and C and iron, and plenty of antioxidants. This in situ research was executed to assess the quality variability of B. juncea grown in different agroecosystems. Leaves’ samples of B. juncea were procured from 15 farmers’ fields exhibiting different agroclimatic conditions i.e., elevation, nutrient management, temperature, irrigation, and tillage practices. Leaves’ samples were subjected to physicochemical and phytochemical analysis, i.e., moisture, pH, TSS, ascorbic acid, carotenoids, phenolics, flavonoids, and antioxidant potential. In the leaves’ samples of B. juncea , the target properties were found to vary significantly ( P  ≤ 0.05) in different agroclimatic conditions. The moisture content, ascorbic acid, phenolic content, carotenoids, and antioxidants were found in the range of 62.7–79.3%, 74–91 mg/100 g, 49.2–49.2 mg GAE/100 g, 436.3–480 mg β carotene/100 g, 32.7–46.67%, respectively. This study elaborates the significant variation of physicochemical and phytochemical attributes of B. juncea due to the prevailing agroclimatic conditions. This necessitates the appropriate choice of B. juncea concerning its composition and ecological conditions of its cultivation in the prospective health benefits.
Water Quality Index and Human Health Risk Assessment of Drinking Water in Selected Urban Areas of a Mega City
The present study was conducted to evaluate the quality of drinking water and assess the potential health hazards due to water contaminants in selected urban areas of Lahore, Pakistan. Water samples were collected from ten sites and analyzed for different physico-chemical parameters including turbidity, color, pH, total dissolved solids (TDS), nitrates, fluoride, residual chlorine, and total hardness. Additionally, heavy metal (arsenic) and microbial parameters (E. coli) were also determined in the water samples. Drinking water quality evaluation indices, including the water quality index (WQI) for physico-chemical and biological parameters and human health risk assessment (HHRA) for heavy metal were estimated using the analytical results of the target parameters. It was found in most of the areas that the levels of arsenic, fluoride, TDS, and residual chlorine were higher than those recommended by the National Environmental Quality Standard (NEQS) and World Health Organization (WHO) guidelines. In addition to the physico-chemical parameters, microbial content (E. coli) was also found in the drinking water samples of the selected areas. Statistical analysis of the results indicated that levels of target parameters in drinking water samples are significantly different between sampling sites. The WQI for all physico-chemical and microbial parameters indicated that drinking water in most of the areas was unfit and unsuitable (WQI > 100) for drinking purposes except for the water of Bhatti Gate and Chota Gaon Shahdara with a WQI of 87 and 91, respectively. Drinking water in these areas had a very poor WQI rating. According to HHRA, drinking water from the selected sites was found to be of high risk to children and adults. The carcinogenic risk of arsenic indicated that all samples were of high risk to both adults and children (4.60 and 4.37 × 10−3, respectively). Regular monitoring of drinking water quality is essential, and proactive measures must be implemented to ensure the treatment and availability of safe drinking water in urban areas.
Recent Strategies to Improve the Photocatalytic Efficiency of TiO2 for Enhanced Water Splitting to Produce Hydrogen
Hydrogen production is one of the best solutions to the growing energy concerns, owing to its clean and sustainable assets. The current review gives an overview of various hydrogen production technologies, highlighting solar water splitting as a promising approach for its sustainable production. Moreover, it gives a detailed mechanism of the water-splitting reaction and describes the significance of titania-based catalysts for solar water splitting. It further highlights diversified strategies to improve the catalytic efficiency of TiO2 for the enhanced hydrogen production. These strategies include the doping of TiO2, dye sensitization, and the addition of co-catalysts. Doping reduces the bandgap by generating new energy levels in TiO2 and encourages visible-light absorption. Sensitization with dyes tunes the electronic states, which in turn broadens the light-absorption capacity of titania. Constructing heterojunctions reduces the charge recombination of TiO2, while co-catalysts increase the number of active sites for an enhanced reaction rate. Thus, every modification strategy has a positive impact on the stability and photocatalytic efficiency of TiO2 for improved water splitting. Lastly, this review provides a comprehensive description and future outlook for developing efficient catalysts to enhance the hydrogen production rate, thereby fulfilling the energy needs of the industrial sector.