16 research outputs found
Dispersion of U-series natural radionuclides in stream sediments from Edale, UK
The spatial distribution of 238U-series radionuclides, specifically 238U, 234U, 230Th and 226Ra, has been determined in stream sediments from Edale, Derbyshire, United Kingdom, to explore the behaviour of U-series radionuclides during weathering.</p
Pilot Study of Trace Elements in the Infusion of Medicinal Plants Used for Diabetes Treatment
The purpose of this study was to evaluate trace element contents in different medicinal plants used for diabetes treatments by residents in Asir region. Five medicinal plants—Tut leaves (Mulberry), olive leaves (Olea europaea), clove (Syzygium aromaticum), Luban Dhakar (Boswellia carterii), and Karela or bitter melon (Momordica charantia)—were collected from two cities, Khamis Mushait and Abha, in the Asir region, Saudi Arabia. Infusions (hot water extracts) were obtained from each plant, and elemental analysis was conducted using inductively coupled plasma mass spectrometry (ICP-MS). Fourteen elements (Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Cd, Ba, and Pb) were measured in all plants. The results revealed that the fourteen elements were present at different levels (µg/g) in all plants. Momordica charantia exhibited high levels of essential (Mn (251.4), Co (1.18), Cu (54.64), and Se (2.18)) and toxic elements (Al (39.20), As (0.57), Cd (0.33), and Pb (4.48)), followed by Syzygium aromaticum (Mn (736.36)) and Boswellia carterii (Pb (0.93)), which exceeded the PMTDI in traditional doses used for diabetes treatments. However, Mulberry and Olea europaea did not exceed the daily guideline values for all elements. Based on our findings, we cautiously recommend the latter two plants for the traditional treatment of diabetes, because they are not considered as source of harm based on their levels of elements. Their use should be restricted by comprehensive compound analysis to guarantee their safe use
Microbial Flocculants as an Alternative to Synthetic Polymers for Wastewater Treatment: A Review
Microorganisms such as bacteria, fungi, and microalgae have been used to produce bioflocculants with various structures. These polymers are active substances that are biodegradable, environmentally harmless, and have flocculation characteristics. Most of the developed microbial bioflocculants displayed significant flocculating activity (FA > 70⁻90%) depending on the strain used and on the operating parameters. These biopolymers have been investigated and successfully used for wastewater depollution in the laboratory. In various cases, selected efficient microbial flocculants could reduce significantly suspended solids (SS), turbidity, chemical oxygen demand (COD), total nitrogen (Nt), dye, and heavy metals, with removal percentages exceeding 90% depending on the bioflocculating materials and on the wastewater characteristics. Moreover, bioflocculants showed acceptable results for sludge conditioning (accepted levels of dry solids, specific resistance to filtration, moisture, etc.) compared to chemicals. This paper explores various bioflocculants produced by numerous microbial strains. Their production procedures and flocculating performance will be included. Furthermore, their efficiency in the depollution of wastewater will be discussed
Simultaneous Removal of Calconcarboxylic Acid, NH4+ and PO43− from Pharmaceutical Effluent Using Iron Oxide-Biochar Nanocomposite Loaded with Pseudomonas putida
In the current study, the Fe2O3/biochar nanocomposite was synthesized through a self-assembly method, followed by the immobilization of Pseudomonas putida (P. putida) on its surface to produce the P. putida/Fe2O3/biochar magnetic innovative nanocomposite. The synthesized nanocomposite was characterized using different techniques including X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FT-IR). Then, the efficiencies of this material to remove calconcarboxylic acid (CCA) organic dye, ammonium ions (NH4+), and phosphate ions (PO43−) from industrial wastewater were analyzed. The removal rates of up to 82%, 95%, and 85% were achieved for CCA dye, PO43−, NH4+, respectively, by the synthesized composite. Interestingly, even after 5 cycles of reuse, the prepared nanocomposite remains efficient in the removal of pollutants. Therefore, the P. putida/Fe3O4/biochar composite was found to be an actual talented nanocomposite for industrial wastewater bioremediation
A First-Principles Investigation on the Structural, Optoelectronic, and Thermoelectric Properties of Pyrochlore Oxides (La<sub>2</sub>Tm<sub>2</sub>O<sub>7</sub> (Tm = Hf, Zr)) for Energy Applications
A first-principles calculation based on DFT investigations on the structural, optoelectronic, and thermoelectric characteristics of the newly designed pyrochlore oxides La2Tm2O7 (Tm = Hf, Zr) is presented in this study. The main quest of the researchers working in the field of renewable energy is to manufacture suitable materials for commercial applications such as thermoelectric and optoelectronic devices. From the calculated structural properties, it is evident that La2Hf2O7 is more stable compared to La2Zr2O7. La2Hf2O7 and La2Zr2O7 are direct bandgap materials having energy bandgaps of 4.45 and 4.40 eV, respectively. No evidence regarding magnetic moment is obtained from the spectra of TDOS, as a similar overall profile for both spin channels can be noted. In the spectra of ε2(ω), it is evident that these materials absorb maximum photons in the UV region and are potential candidates for photovoltaic device applications. La2Tm2O7 (Tm = Hf, Zr) are also promising candidates for thermoelectric device applications, as these p-type materials possess ZT values of approximately 1, which is the primary criterion for efficient thermoelectric materials
Iron Oxide/Chitosan Magnetic Nanocomposite Immobilized Manganese Peroxidase for Decolorization of Textile Wastewater
Because of its effectiveness in organic pollutant degradation, manganese peroxidase (MnP) enzyme has attracted significant attention in recent years regarding its use for wastewater treatment. Herein, MnP was extracted from Anthracophyllum discolor fungi and immobilized on the surface of magnetic nanocomposite Fe3O4/chitosan. The prepared nanocomposite offered a high surface area for MnP immobilization. The influence of several environmental factors like temperature, pH, as well as storage duration on the activity of the extracted enzyme has been studied. Fourier transmission infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM) techniques were used for the characterization of the prepared MnP/Fe3O4/chitosan nanocomposite. The efficiencies of the prepared MnP/Fe3O4/chitosan nanocomposite for the elimination of reactive orange 16 (RO 16) and methylene blue (MB) industrial dyes were determined. According to the results, the immobilization of MnP on Fe3O4/chitosan nanocomposite increases its capacity to decolorize MB and RO 16. This nanocomposite allowed the removal of 96% ± 2% and 98% ± 2% of MB and RO 16, respectively. The reusability of the synthesized nanocomposite was studied for five successive cycles showing the ability to retain its efficiency even after five cycles. Thus, the prepared MnP/Fe3O4/chitosan nanocomposite has potential to be a promising material for textile wastewater bioremediation
Effective Heavy Metals Removal from Water Using Nanomaterials: A Review
The discharge of toxic heavy metals including zinc (Zn), nickel (Ni), lead (Pb), copper (Cu), chromium (Cr), and cadmium (Cd) in water above the permissible limits causes high threat to the surrounding environment. Because of their toxicity, heavy metals greatly affect the human health and the environment. Recently, better remediation techniques were offered using the nanotechnology and nanomaterials. The attentions were directed toward cost-effective and new fabricated nanomaterials for the application in water/wastewater remediation, such as zeolite, carbonaceous, polymer based, chitosan, ferrite, magnetic, metal oxide, bimetallic, metallic, etc. This review focused on the synthesis and capacity of various nanoadsorbent materials for the elimination of different toxic ions, with discussion of the effect of their functionalization on the adsorption capacity and separation process. Additionally, the effect of various experimental physicochemical factors on heavy metals adsorption, such as ionic strength, initial ion concentration, temperature, contact time, adsorbent dose, and pH was discussed
Synthesis of Manganese Ferrite/Graphene Oxide Magnetic Nanocomposite for Pollutants Removal from Water
These days, environmental pollution, notably water pollution, has increasingly caused severe human health problems. The major water pollutants are heavy metals. MnFe2O4/GO nanocomposite was prepared in the current work via in situ method and tested to remove lead ion Pb2+ and neutral red (NR) dye from water. The prepared nanocomposite was characterized using different techniques, including X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectra, and vibrating sample magnetometer. The prepared nanocomposite showed high adsorption capacity toward Pb2+ and NR dye removal according to Langmuir fitting indicating the monolayer homogeneous adsorption of pollutants over the adsorbent surface and can be separated easily with an external magnet. The effect of different factors, including contact time, pH, initial concentration, and adsorbent dose on the adsorption, were also studied. The increased concentration of pollutants led to increased adsorption capacity from 63 to 625 mg/g for Pb2+ ions and from 20 to 90 mg/g for NR dye. The increased adsorbent dose led to increased removal efficiency from 39% to 98.8% and from 63% to 94% for Pb2+ and NR dye, respectively. The optimum pH for the adsorption of both pollutants was found to be 6.0. The reusability of MnFe2O4/GO nanocomposite was studied for up to five cycles. The nanocomposite can keep its efficiency even after the studied cycles. So, the prepared magnetic nanocomposite is a promising material for water treatment
The Application of Nanomaterials for the Electrochemical Detection of Antibiotics: A Review
Antibiotics can accumulate through food metabolism in the human body which may have a significant effect on human safety and health. It is therefore highly beneficial to establish easy and sensitive approaches for rapid assessment of antibiotic amounts. In the development of next-generation biosensors, nanomaterials (NMs) with outstanding thermal, mechanical, optical, and electrical properties have been identified as one of the most hopeful materials for opening new gates. This study discusses the latest developments in the identification of antibiotics by nanomaterial-constructed biosensors. The construction of biosensors for electrochemical signal-transducing mechanisms has been utilized in various types of nanomaterials, including quantum dots (QDs), metal-organic frameworks (MOFs), magnetic nanoparticles (NPs), metal nanomaterials, and carbon nanomaterials. To provide an outline for future study directions, the existing problems and future opportunities in this area are also included. The current review, therefore, summarizes an in-depth assessment of the nanostructured electrochemical sensing method for residues of antibiotics in different systems
Comparative Study of Natural Radioactivity and Radiological Hazard Parameters of Various Imported Tiles Used for Decoration in Sudan
Various commercially imported ceramic materials used in the building of Sudanese dwellings were examined in order to determine their natural radioactivity and radiological hazard parameters. In this context, twenty-five different consignments were sampled and analyzed using (3″ × 3″) sodium iodide gamma spectrometry system NaI(Tl). The identified average activity concentrations of 238U, 232Th, and 40K were 183 ± 70, 51 ± 44, and 238 ± 77 Bq/kg dry-weights, respectively. A positive correlation between 238U and 232Th in the investigated samples was identified from the observed significant correlation (R2 = 0.8). Interestingly, a low Th/U ratio (~0.3) was recorded, which could be related to the systematic loss of thorium during the fabrication process. The measured activity concentrations for these radionuclides were comparable with the reported data obtained from similar materials used in other countries showing similarity in ceramic materials used in buildings. Five different radiation indices, such as the average radium equivalent (Raeq), the absorbed dose rate (D), the annual effective dose equivalent (AEDE), the external hazard index (Hex), and the radioactivity level index (lγ), which indicate hazardous radiation, were estimated from these measurements. The obtained results revealed average values of 274 ± 106 Bq/kg, 125 ± 48 nGy/h, 1.23 ± 0.48 mSv/y, 0.74 ± 0.29, and 0.94 ± 0.37, for Raeq, D, AEDE, Hex, and lγ, respectively. The mean values of Raeq and Hex were in good agreement with the international limits, while the means of D and lγ were higher than the universal values. Calculated AEDE in about 60% of the samples exceeded the universal limit of 1 mSv/y for the public exposure (maximum value of 2.16 mSv/y). The investigated parameters were in the same range for the majority of imported samples; however, they were slightly higher than the locally produced ceramic, highlighting the importance of monitoring imported materials for their radioactivity contents