Papers by Keyword: Water Purification

Abstract: This research presents the green synthesis of gold nanoparticles (AuNPs) utilizing natural Gum Arabic (GA) resin as an environmentally reducing and stabilizing agent. The study addresses pressing water pollution concerns in Oman by developing a sustainable nanotechnology-based approach for the remediation of trace heavy metal ions (Cu²⁺, Pb²⁺, and Zn²⁺) from aqueous environments. GA was employed at concentrations of 5% and 10% (w/v) in reactions with chloroauric acid (HAuCl₄) under systematically varied conditions, including temperature (23.0–80.0 °C), pH (6.00–9.00), and reaction time (0.33–48.00 h). The synthesised AuNPs were characterised using ultraviolet–visible (UV–Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) to assess their optical properties, morphology, and surface chemistry. Optimal synthesis conditions—10% GA, 5 mM HAuCl₄, 55.0 °C, pH 9.00, and 0.67 h—resulted in a stable ruby-red colloidal dispersion exhibiting a distinct surface plasmon resonance (SPR) peak at 518 nm, indicative of monodisperse spherical AuNPs. FTIR analysis confirmed the involvement of hydroxyl, carbonyl, and amine functional groups in nanoparticle formation and stabilization. The biosynthesis AuNPs demonstrated efficient removal of heavy metal ions from aqueous solutions in the order of Pb²⁺ > Cu²⁺ > Zn²⁺.These findings highlight the potential of Gum Arabic as a green, cost-effective, and biocompatible material for fabricating functional AuNPs suitable for environmental sensing and water purification applications.

Abstract: Tailoring diverse characteristics of nanostructured cellulose acetate (CA) membranes by incorporating nanocomposite-tubes ZFS composed of zinc ferrites decorated over single walled carbon nanotubes (SCNTs) for desalination application, is presented in the current research. In situ coprecipitated route is adopted to synthesize ZFS composite filler that imparts morphological, structural, and thermal modifications in CA membranes. Phase inversion via immersion precipitation route has been adopted to synthesis mixed matrix membranes. Microstructural analysis divulges pore size tuning from 1µm to 5nm by increasing loading content of infused filler (ZFS) from 0 to 4wt.%. XRD and FTIR examinations verified the existence and linkages of impregnated composite nanotubes in the modified membranes. Increasing ZFS contents 1-4wt.% enhanced the thermal stability of host membranes up to 17°C in comparison to pristine CA membranes as proclaimed by thermal degrative investigations. Membranes’ performance is evaluated by deionized water flux and sulphate salts (aluminum and copper) rejection capabilities. The prepared membranes are highly effective in salts removal application as evident from 98% of aluminum sulphate rejection that emanates from micro to nano porosity transformation after increasing filler composite into the membrane matrices.

Abstract: This article presents the typification of zeolite raw materials from the Khonguruu deposit (Sakha Republic (Yakutia), Russia), in order to determine the area of its practical application in preparing the field for industrial development. The types of raw materials are distinguished by the difference in cation composition: clinoptilolite-geylandite composition (Na-and Ca-differences of zeolite) and geylandite composition (Ca-difference of zeolite). A brief description of the material composition and physicochemical properties of zeolite rocks is given. The physical and mechanical properties of the zeolite of the deposit and the possibility of its use for the purpose of drinking water purification are investigated. The performed studies have shown that the natural zeolite of Na-and Ca-differences has good sorption properties and can be used as filter materials in water purification systems intended for household and drinking purposes.

Abstract: Membrane technology advancement has gained momentous consideration around the globe because of their appealing highlights, such as effectiveness, low expenses, and effective solutions for longstanding issues in alchemical industries. This study expected to incorporate graphene nanoparticles into Polyvinylidene difluoride (PVDF) to form nanofiltration (NF) layers using DMF (Dimethyl formamide) as solvent via DIPS (diffusion induced phase separation) technique. PVDF polymer membrane performances with varied percent (1 – 6% wt.) of graphene concentrations are studied Infrared spectral, water uptake, water contact angle, and ion rejection measurements. Scanning electron microscope (SEM) analysis showed that the pore size is often regulated by incorporating graphene nanoparticles (80-90 nm) as compared to PVDF membranes. The PVDF membranes exhibited a relative increase in the contact angle from PVDF to PVDF-G6% i.e. 50.3° to 63.46 ± .3, thus, showing a relative increase in hydrophobicity. The higher percent of graphene (> 6% by wt.) results in nanoparticle accumulation that showed the performances of PVDF/graphene rejection possessing relatively the same results. The results confirmed that the prepared membranes possess an excellent ability to treat wastewater.

Abstract: Membrane distillation (MD) being an emerging technology, it suffers from many limitations. One of which is the need for membranes with specific characteristics to ensure successful operation and sustainable performance. Membrane wetting phenomenon is one of the significant disadvantages of MD which take place primarily due to membrane pore wetting with the operating liquids. The present work studies the effect of addition of graphene nanoplatelets (GNPs) on enhancing the antiwetting properties of enhanced polystyrene (PS₁₂-SDS) nanofibrous membranes. Results showed that adding 0.5wt% of GNPs to the PS₁₂-SDS polymer matrix enhanced the hydrophobicity of the produced membranes and decreased the mean fiber diameter of the produced membranes by about 5.5% and 36.6%, respectively. The composite (PS₁₂-SDS-GNPs) membrane also showed better salt rejection compared with PS₁₂-SDS at all studied feed flow rates.

Abstract: The problem of mathematical modeling the processes of water treatment from charged particles by electric field is considered. The problem is relevant due to the mass use of cleaning technologies in industry, medicine or the national economy. At the present stage, a significant improvement of purification system quality and the introduction of the technologies for the regeneration of their filtration components are required. Mathematical simulation using computer and supercomputer calculations helps to accelerate the development of new devices and cleaning technologies. On the basis of the chosen purification technology, it is important to create a numerical simulation apparatus with a controlled high accuracy of the calculations. For this purpose, we use a quasi-hydrodynamic (QHD) model of a viscous incompressible fluid flow, a system of convection-diffusion equations taking into account the action of the Lorentz force to describe the propagation of harmful impurities in aqueous medium, and an equation for the electric field potential [1, 2]. The numerical algorithm is based on the finite volume method. It is applied in the case of irregular unstructured meshes. This is important for problems of real two-dimensional (2D) and three-dimensional (3D) geometry. Time integration is performed according to an explicit scheme, which simplifies the procedure for parallelizing the algorithm. The proposed approach was tested on the examples of 2D and 3D geometry with various locations of the electrodes and various values of the potentials. The obtained results of the concentration of the ionic impurities show the possibility of this method to purify water from 10 to 40 percent. A design of a water purifier based on electrophysical purification technology can be developed on the base of this study.

Abstract: In the present study the surface morphology of electrospun fibers at different polystyrene (PS) solution concentration was studied by SEM imaging to determine the best PS solution concentration yielding continuous uniform beadles fibers. Contact angle measurements of the optimum fabricatedPS-18 membrane confirmed the super hydrophobic property of the membrane that exhibited a static water contact angle of 145o. Numerical investigation of the performance of PS-18 membrane at different membrane thicknesses and porosities on direct contact membrane distillation showed that increasing the membrane porosity increases the permeate flux considerably.

Abstract: Dyes disposal from the industrial sector into the environment greatly affects the quality of the water. Among various technologies of removing dye pollutants from wastewater, adsorption is one of the most effective and favorable methods. Graphene oxides (GO) has been applied to remove dye pollutants in solution since it has a lot of oxygen-containing groups that can attract and bind pollutants. We study the effect of stirring time on MB adsorption onto GO surfaces. We mixed MB solution with GO dispersion and stirred at varied stirring times. The mixture was kept at room temperature to allow precipitation of the GO-MB mixture and then filtered to separate the precipitate from the residual MB solution. A reduction of MB concentration in the solution was measured using spectroscopy. The experimental results show that MB was adsorbed very fast onto GO surfaces in the first minutes and then the rate of the reduction of MB concentration becomes slower. After the stirring for 60 minutes, almost there is no significant change of the MB concentration that indicated a limit of adsorption capacity of GO.

Abstract: In this work, a low-cost method to produce ZnO nanostructured materials for the treatment of water polluted with model organic pollutants (e.g. dyes) is presented. Zinc and silver-coated Zn (Ag/Zn) films, fabricated via sputtering method were naturally oxidized via a simple, low-temperature, scalable thermal process. During oxidation, Ag/ZnO nanorods were grown on Zn foils after treating their surface with various agents (e.g. acids) and annealing in an oven at temperatures 385-400 °C. The ZnO and Ag/ZnO films on Zn were characterized by X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. The cationic dye Methylene Blue (MB) was selected as model pollutant dissolved in water, and a batch photo-reactor was fabricated and used to to study the adsorption capacity and photocatalytic performance of films. The transient varation of MB concentration in aqueous solutions was measured with UV-Vis spectroscopy. Ag/ZnO demonstrated a strong MB adsorbion capacity in dark conditions, and a satisfactory MB photocatalytic degradation under UV light irradiation.The optimized doping of Ag in Ag/ZnO film enhanced its photocatalytic activity, and seems well-promising for the potential scale-up of Ag/ZnO films, and use in large-scale systems for water purification under UV light irradiation.

Abstract: Hematite mineral samples of Korshunov deposit were the subject of the study. The samples size was less than 0.1 mm; 0.5-1 mm and 1.5-2.5 mm. Some physicochemical properties of adsorbent samples were investigated: specific surface and specific pore volume were identified; zeta potential was measured; thermal and elemental analyses were carried out. Sorption properties of samples obtained under static conditions were studied. They were investigated in removing Fe³⁺ and As³⁺ ions from simulated solutions. Content analysis of the ions in filtrates was carried out by stripping voltamperometry and photocolorimetry methods. In using hematite, removal of As⁺³ ions from the solution increases if adsorption time increases. The smaller grain size, the better purification of simulated solution was. Hematite with the size of particles less than 0.1 mm is more effective in removing of Fe⁺³ ions from solution, if contact time is short. It has been found that if contact time is longer, hematite with 0.5-1 mm and 1.5-2.5 mm sizes of particles is better to use. The authors have concluded that hematite can be used for efficient water purification from iron ions and arsenic ions