Electrospun TiO2-GO/PAN-CA nanofiber mats: A novel material for remediation of organic contaminants and nitrophenol reduction.

The outstanding properties of nanofiber composites have made them a popular choice for various structural applications. Recently, there has been a growing interest in using electrospun nanofibers as reinforcement agents, which possess exceptional properties that can enhance the performance of these composites. Herein, TiO2-graphene oxide (GO) nanocomposite incorporated into polyacrylonitrile (PAN)/cellulose acetate (CA) nanofibers were fabricated by an effortless electrospinning technique. The chemical and structural characteristics of the resulting electrospun TiO2-GO nanofibers were examined employing diverse techniques such as XRD, FTIR, XPS, TGA, mechanical properties, and FESEM. Remediation of organic contaminants and organic transformation reactions with electrospun TiO2-GO nanofibers were performed. The results indicated that the incorporation of TiO2-GO with various TiO2/GO ratios did not affect the molecular structure of PAN-CA. Still, they did significantly increase the mean fiber diameter (234-467 nm) and the mechanical properties of the nanofibers comprising UTS, elongation, Young's modulus, and toughness compared to PAN-CA. From various ratios of TiO2/GO (0.01TiO2/0.005GO and 0.005TiO2/0.01GO) in the electrospun NFs, the nanofiber containing a high content of TiO2 showed over 97% of the initial MB dyes were degraded after 120 min of visible light exposure and the same nanofibers also, achieved 96% nitrophenol conversion to aminophenol in just 10 min with activity factor kAF value of 47.7 g-1min-1. These findings illustrate the promise of TiO2-GO/PAN-CA nanofibers for use in various structural applications, particularly in the remediation of organic contaminants from water and organic transformation reactions.

Valuation of rice straw residues: Production of silylated methylcellulose containing propylamine and propylethylenediamine for use as anticorrosion and antibacterial.

Green technology is a scientific movement seeking to eliminate industrial chemicals and replace them with natural products by valorizing natural resources or biological waste. In this work, we present the extraction of cellulose from rice straw and chemically modified water-dispersible cellulose (methylcellulose) by performing a methylation process. The methylcellulose is chemically bonded to N-[3-(trimethoxysilyl)propyl]ethylenediamine, and (3-aminopropyl)triethoxysilane compounds to produce a cellulose-organosilane hybrid. The prepared compounds were studied with appropriate techniques such as 1H NMR, XRD, FTIR, TGA, Raman spectroscopy, FE-SEM, and AFM. The prepared materials were used as corrosion inhibitors of steel in 1 N H2SO4 for studies of potentiodynamic polarization measurements and electrochemical impedance spectroscopy. The materials were also studied as antibacterial agents. The results indicate the successful use of a modified extracted cellulose hybrid in the corrosion field and as an antibacterial agent. Quantum chemical assessments based on density functional theory (DFT) of the trimethoxysilyl propylamine and dimethoxymethylsilyl propylethylenediamine grafted methylcellulose were calculated. The results obtained showed the agreement of the theoretical data with the experimental data.

Assessment of Trace Elements in Urban Road Dust of a City in a Border Province Concerning Their Levels, Sources, and Related Health Risks.

Most research studies regarding the contamination of urban road dust (RD) focused on mega cities, but little consideration is given for small cities in border areas. The present work investigated the trace elements content in 16 RD samples of particle size < 63 µm at six areas with different anthropogenic activities in Sakaka city, KSA. The trace elements were analyzed using XRF and ICP-MS. Significantly high trace elements concentrations were recorded at small-scale industrial area. Concentrations of trace elements are ranked as Fe > Mn > Pb > Zn > Cr > Cu > Co > As > Se. The contamination evaluation through enrichment factor calculation refers to the existence of an anthropogenic source for certain trace elements, such as Fe, Zn, Mn, Cu, and Pb. The values of contamination factor indicate the contamination of RD samples collected from small-scale industrial area with these trace elements. The highest pollution load index value recorded at this industrial area suggests that it is a highly polluted area. This was confirmed by applying the one-way ANOVA test for the difference analysis between the investigated areas. The correlation between most of the detected trace elements at the small scale-industrial area was lost due to the variation in their industrial sources. The health risk of some detected trace elements was estimated for two groups of populations, namely workers at the small scale-industrial area and residents (adults and children) at residential areas at this city under study. Workers and resident children were more likely affected by arsenic through the ingestion pathway to cancer because of its higher cancer risk values that were more than the acceptable value 1 × 10-6. Workers and residents (adults and children) are susceptible to noncarcinogenic risks through the ingestion pathway of Fe because of its higher hazard quotient values that are more than one.

Characterization of BTEX group of VOCs and inhalation risks in indoor microenvironments at small enterprises.

Concentrations of BTEX group (benzene, toluene, ethylbenzene and xylene) were measured in indoor and outdoor environments at four printing shops and two photocopy centers in Sakaka city, KSA. Fifty four BTEX samples were collected using passive diffusion monitors (SKC VOC 575) and analyzed by GC-MS. The results showed that toluene was the most prevailing compound within the BTEX group and its indoor levels were much higher than outdoor. The average indoor concentrations (µg/m3) ranged from 2.45 to 14.66, 81.59 to 955.65, 11.19 to 97.35, 35.66 to 291.88 and 3.90 to 28.39 for benzene, toluene, ethylbenzene, m/p-xylene and o-xylene, respectively. The indoor/outdoor ratios of concentrations of BTEX species were more than one in most cases, indicating the effect of indoor emission sources. Based on (Toluene/Benzene) ratios, all sites were affected by the traffic emissions. Ventilation efficiency, ink type and outdoor pollutant concentration are responsible for results disparity. Cancer and non-cancer risks were assessed in the indoor environments by calculating the lifetime cancer risk (LCR) and hazard ratio (HR), respectively. For benzene and ethylbenzene measured concentrations, LCR values were more than the acceptable USEPA risk level of 1 × 10-6. HR values for BTEX species were in general lower than the threshold limit of one.

Analytical investigation of the influence of ornidazole on the native protein fluorescence.

A novel spectrofluorimetric method for the determination of ornidazole (ORN) in pure form and dosage forms was developed based on the influence of ORN on the native fluorescence of bovine serum albumin (BSA) in a stimulated physiological environment. The obtained data reveal that the presence of ORN has a strong quenching effect on the fluorescence of BSA through both a dynamic and a static process. The parameters of the binding of ORN to BSA were calculated at different temperatures. Thermodynamic parameters values suggest a role of electrostatic and hydrophobic forces in the binding of ORN to BSA. The investigated method for the determination of ORN is accurate, precise and sensitive with a detection limit of 0.106 µg/mL and a quantification limit of 0.353 µg/mL. The quenching method was applied successfully in the determination of ORN in pure form and dosage forms.

Production of sugarcane bagasse-based activated carbon for formaldehyde gas removal from potted plants exposure chamber.

UNLABELLED: Agricultural wastes such as rice straw, sugar beet, and sugarcane bagasse have become a critical environmental issue due to growing agriculture demand. This study aimed to investigate the valorization possibility of sugarcane bagasse waste for activated carbon preparation. It also aimed to fully characterize the prepared activated carbon (BET surface area) via scanning electron microscope (SEM) and in terms of surface functional groups to give a basic understanding of its structure and to study the adsorption capacity of the sugarcane bagasse-based activated carbon using aqueous methylene blue (MB). The second main objective was to evaluate the performance of sugarcane bagasse-based activated carbon for indoor volatile organic compounds removal using the formaldehyde gas (HCHO) as reference model in two potted plants chambers. The first chamber was labeled the polluted chamber (containing formaldehyde gas without activated carbon) and the second was taken as the treated chamber (containing formaldehyde gas with activated carbon). The results indicated that the sugarcane bagasse-based activated carbon has a moderate BET surface area (557 m2/g) with total mesoporous volume and microporous volume of 0.310 and 0.273 cm3/g, respectively. The prepared activated carbon had remarkable adsorption capacity for MB. Formaldehyde removal rate was then found to be more than 67% in the treated chamber with the sugarcane bagasse-based activated carbon. The plants' responses for this application as dry weight, chlorophyll contents, and protein concentration were also investigated. IMPLICATIONS: Preparation of activated carbon from sugarcane bagasse (SCBAC) is a promising approach to produce cheap and efficient adsorbent for gas pollutants removal. It may be also a solution for the agricultural wastes problems in big cities, particularly in Egypt. MB adsorption tests suggest that the SCBAC have high adsorption capacity. Formaldehyde gas removal in the plant chambers indicates that the SCBAC have potential to recover volatile gases. The results confirmed that the activated carbon produced from sugarcane bagasse waste raw materials can be used as an applicable adsorbent for treating a variety of gas pollutants from the indoor environment.