Efficiency Of Water Purification Research Articles

Formation and Antibacterial Activity of AlOOH/Ag Composite Coating on Macroporous α-Al2O3 Ceramics

In this study, the modification of macroporous α-Al2O3 ceramics with AlOOH nanostructures impregnated with silver particles is carried out using bicomponent Al/Ag nanoparticles obtained by the simultaneous electrical explosion of Al and Ag wires. Nanoparticle suspension impregnation of porous ceramics followed by oxidation with water is shown to lead to the formation of a continuous AlOOH nanosheet coating on the ceramic surface, with silver releasing on the surface of nanosheets in the form of individual particles sized 5–30 nm. Modified with AlOOH/Ag nanostructures, macroporous α-Al2O3 pellets with a diameter of 11 mm and a thickness of 5 mm show 100% efficiency for water purification from bacteria with a concentration of 105 CFU/mL for 7.5 min at a flow rate of 6.7 mL/min.

Dynamics of Topology-dependent Water Purification by Siliceous Zeolite Membranes

• Simulated the effect of topology and pore size of zeolites on water purification. • Compared porous LTA, FAU, and MFI zeolites in purification of Cl - , Pb 2+ , and Co 2+ . • Tersoff and Lennard-Jones hybrid force fields, and TIP3P water models were used. • Applying PMF in MD simulation, the efficiency of zeolite membranes was conceptualized. • Applying a long time of 15 ns, heavy metal ions behaved differently in rejection. The efficiency of pollutant rejection (PR, %) and water purification of the zeolite membranes is highly dependent on their topology, i.e., porosity and chemical composition. Nevertheless, mechanisms controlling such a physicochemical phenomenon have been limitedly discussed. Herein, we provide insights into the physics and dynamics of water purification by zeolite nanosheets in terms of topological variables. The molecular dynamics (MD) simulation pictured the molecular-lever water purification having heavy metal ions (Co 2+ and Pb 2+ ) as typical water contaminants. Three siliceous zeolites having different topologies, i.e., LTA, FAU, and MFI zeolites, were positioned in the simulation space. MD simulation was served under pressure and temperature of 24 MPa and 300 K, respectively, applying the Canonical ensemble (NVT) condition. The intermolecular interactions between contaminant ions, zeolite, and graphene were tracked by hybridizing Tersoff and Lenard-Jones potentials, while the TIP3P model of the CHARMM force field was used to simulate water dynamics. The LAMMPS software and Visual Molecular Dynamics (VMD) were used to collect data and graphics over 15 ns, with early 5 ns devoted to reaching equilibrium. Interestingly, we demonstrated by the aid of potential of the mean force (PMF) pollutant ions which encounter the zeolite pores smaller than their kinetic diameter consume more energy for permeation across the membrane, -reason why LTA appeared selective against Pb 2+ , Co 2+ , and Cl - ions, with PR of 40, 60, and 100%, respectively. The absolute water flux values were monitored, and LTA and FAU fluxes were ∼ 50% higher than MFI zeolite, but 5 ns after equilibrium, LTA flux was overtaken sharply by the simulation because of the larger pore size. Overall, the electrostatic forces showed absolute control over the purification but were governed by the zeolite topology.

Effect of the Electroconductivity of an Electrofilter Load on the Mechanism, Efficiency, and Energy Consumption of Water Purification from Dispersed Impurities

Effect of the Electroconductivity of an Electrofilter Load on the Mechanism, Efficiency, and Energy Consumption of Water Purification from Dispersed Impurities

CuO@carbon nanofiber as an efficient peroxymonosulfate catalyst for mitigation of organic matter fouling in the ultrafiltration process

Persulfate oxidation has been increasingly integrated with membrane separation for water purification, whereas the oxidizing ability of persulfate is relatively limited, and appropriate activation methods are urgently required. In this work, a novel catalyst of carbon nanofiber (CNF) supported CuO (CuO@CNF) was synthesized for peroxymonosulfate (PMS) activation. The micro-morphology showed that CuO nanoparticles were well dispersed on the CNF support, which solved the agglomeration problem of nanoparticles and improved the catalytic ability. Furtherly, PMS oxidation activated by CuO@CNF was proposed as a pre-processing means for improving ultrafiltration (UF) water purification efficiency and mitigating membrane fouling. The prepared CuO@CNF was more efficient than individual CNF and CuO in activating PMS for the reduction of various typical natural organic matter, improving permeation flux, and mitigating membrane fouling. The fouling control efficiencies were also verified by characterizing the membrane surface functional groups. The CuO@CNF catalyst could signally promote the oxidative capacity by generating a series of reactive oxygen species, thus enhancing the removal of organics with varying species and molecular weight ranges in surface water. With respect to the fouling condition, the specific permeation flux after filtration was improved from 0.25 to 0.61, with the removal rate of reversible fouling resistance reached 89.6%. The fouling mechanism was apparently altered, with both standard and complete blocking dominated throughout the filtration process. The findings are beneficial for the development of new strategies to improve membrane-based water purification efficiency.

Intensification of the wastewater treatment process using magnesium-containing materials

An analysis was made of the use of magnesium-containing materials of natural and technogenic origin in complex systems for the purification of wastewater from mining enterprises from heavy metals. The transfer mechanisms of dissolved heavy metals into the precipitate and onto the surface of the sorbent have been theoretically studied. Magnesium-containing minerals in water partially undergo hydration, forming an association of complex molecules. The main purification mechanism is the formation of sparingly soluble metal hydroxides. The mechanisms of adsorption, co-precipitation, co-crystallization of impurities with products of hydration and hydrolysis of magnesium-containing minerals also work. Exploratory studies of the intensification of the wastewater treatment process using magnesium-containing materials have been carried out, which have shown that the residual concentration of almost all metals, with the exception of nickel and chromium, when using brucite at the same pH level is lower. The highest water purification efficiency is observed for zinc and lead ions. The addition of dolomite to brucite in an amount of less than 10% makes it possible to reduce the residual concentration of cadmium in water at 20-60 minutes of contact and other equal experimental conditions.

Succession characteristics of phytoplankton functional groups and water quality responsiveness evaluation in an artificial constructed wetland-reservoir ecosystem

ABSTRACT The artificial constructed wetland-reservoir ecosystem has become a research hotspot in the field of the pretreatment of micro-polluted water. In this study, the water purification efficiency and phytoplankton dynamics, the succession characteristics of phytoplankton functional groups and water quality responsiveness evaluation were investigated. The results showed that the Yanlong project can effectively purify water, and there were significant spatial differences in DO, pH, turbidity and transparency (P<0.001), while the temporal differences in water temperature, DO, electrical conductivity, TP and NH4 +-N were the most significant (P<0.001). B, D, P, MP, X1, J and Lo were consistently dominant FGs, Group I, Group IV, Group V and Group VI were dominant MBFGs throughout the year. The results indicated that MBFG was better than that of the FG while water temperature, pH and BOD5 were the key environmental factors. Overall, our findings could provide important implications to improve sustainable safety of drinking water sources.

Technology of primary water purification

The polluted wastewater treatment is one of the main issues in agro-industrial complex. This article is devoted to the primary water purification research for its further treatment with ferrate technology. The technology implies the wastewater treatment from household and industrial waste resulting from agricultural enterprises. The ferrate technology provides a high efficiency of pretreated water purification, in comparison with other existing methods. The article substantiates such an advantage accordingly. The waste generated as a result of wastewater treatment is non-toxic and disposal. The article proposes a new method of preliminary water purification based on its treatment between a galvanic couple in the presence of the calcium hydroxide. This method can be used at water treatment plants and at enterprises carrying out industrial activities in agriculture. The method is applicable only after mechanical filtration at the stage of primary water treatment. The proposed method provides water treatment from a wide range of various origins contaminants. The article also describes an experimental equipment specially designed for the proposed method’s implementation and further research. The equipment provides continuous water treatment consuming electricity, quicklime and compressed air. To maintain the lime particles in suspension condition the airflow is supplied through an aerator. The article applies the turbidimetric analysis method to conduct an in-depth analysis of the water treatment processes and determine the relative reagent concentration in the working area. The article also proves the absence of interface formation between water and milk of lime when subjected to air flow.

Constructing bifunctional Co3O4@Ni3S2 as pair of electrooxidations catalysts with superior photoelectrocatalytic efficiency for water purification

Finding a bifunctional heterostructure catalyst that can act as a pair of electrooxidations to decompose refractory organic dyes in wastewater is an important issue. Herein, we succeeded in preparing a Co3O4@Ni3S2 heterostructure by the two-step hydrothermal method as promising bifunctional catalysts that function simultaneously as the anode and cathode. Remarkably, the optimized bifunctional Co3O4@Ni3S2-3.0 electrodes exhibit a degradation rate of ~ 95% and acceptable stability for practical usage, which can be attributed to its low Tafel slope, large electrochemically active surface area, and low charge transfer resistance. Free radical capture experiments using auxiliary probe molecular fluorescence experiments suggest that the Z-scheme heterostructure of Co3O4@Ni3S2-3.0 is proposed to promote charge separation and produce the main active species. The rational design of this work--a new strategy for establishing a highly efficient bifunctional pair of electrooxidation heterostructure catalysts of Co3O4@Ni3S2-3.0 with a Z-scheme band structure—will lead to other catalysts designs.

Sorption filtration of organic microdrops in a hydrocyclone

It is developed a construction of a hydrocyclone with sorption filter elements, providing effective purification of irrigation water from mechanical impurities and microdrops of organic pollutants. Increasing the efficiency of water purification from various types impurities is achieved due to a larger working area of the sorption filter, varying the structure of the sorption filter by changing the number of filter layers and the distance between the layers depending on the organic pollutants nature, increasing the resource of the sorption filter and reducing the downtime of the hydrocyclone for regeneration with replacement of the sorption filter with a replaceable one. The geometric parameters of the designed hydrocyclone have been determined by the calculation method for capacity 3.5 m3/h: D = 100 mm, din = 32 mm and ddrain = 40 mm. As a sorbing material, it was adopted a carbon fiber sorbent made of viscose technical thread with carbonation, the total sorption capacity of which was 20.9 g/g.

Fluorine-free fabrication of a magnetic-responsive sponge as absorbent for highly efficient and ultrafast oil-water separation

In this article, polydimethylsiloxane (PDMS) was grafted onto the Fe3O4 particle by thermal treatment to obtain superhydrophobic powder (Fe3O4-PDMS) with magnetic response. In order to improve the adhesion between the particle and the sponge, double -layer binder include epoxy and PDMS was used. The epoxy owed good adhesion with the substrate, while the PDMS provided good hydrophobicity. The two-layer binder fastened the superhydrophobic Fe3O4-PDMS particles firmly on the sponge, endowing it with durable superhydrophobicity and high recyclability. The coated sponge showed very low adhesion and superior liquid-repellent properties. It could absorb various oils and solvents at a very fast speed, which showed high water-purification efficiency. Moreover, it presented superior magnetic-responsive property, which fast absorbed oils manipulated by the magnet. The coated sponge also absorbed various oils from oil-in-water emulsions and separated various water-in-oil emulsions with high efficiency. It also continuously and repeatedly separated oils from oil-water mixtures with a high recyclability. After it was repeated used for 100 times, its separation efficiency was still greater than 98%. This as-prepared sponge was believed to find various real applications in many fields.

Entangled ZnO on Ultrathin Hollow Fibers for UV-Aided Pollutant Decomposition.

Zinc oxide (ZnO), a widely used ultraviolet (UV) degrading substance, offers high selectivity for wastewater treatment, but the leaching of ZnO into water could cause secondary contamination. Using porous substrates to fix and load ZnO is a promising technical method to improve the water purification efficiency and recycling durability of ZnO. However, limited by the slow kinetics and shielding effects, it is challenging to use traditional techniques to introduce ZnO into the interior of a hollow structure. Here, inspired by an ancient dyeing procedure, we formed a unique single-molecule bio-interfacial entanglement as an absorption layer to capture the catalyst for ZnO electroless deposition (ELD) on the surface of natural ultrathin hollow-structured Kapok fibers. With curcumin serving as a linking bridge, ELD allowed the spontaneous formation of intensive ZnO nanocrystals on both the outer and inner walls. ZnO-kapok as the catalyst for ultraviolet photodecomposition of organic pollutants (methylene blue (MB) and phenol as model pollutants) delivered a decomposition efficiency of 80% and outstanding durability. Further modification of the ZnO-kapok catalyst by doping with reduced graphene oxide (rGO) showed an improvement in photodegradation performance of 90% degradation under 2-h irradiation with 21.85 W/dm2 light power. Moreover, to the best of our knowledge, this is the first report featuring ZnO loading on both the outer and inner walls of a fiber-structured hollow kapok material, which provides inspiration for immobilization of metallic oxides on hollow-structured materials for further applications in renewable catalysis, chemical engineering, and energy storage fields.

Constructing S-scheme Co3O4-C3N4 catalyst with superior photoelectrocatalytic efficiency for water purification

Choosing satisfactory semiconductor materials as photoanode to promote the production of intermediate active species (hydroxyl radical and superoxide radicals) is a challenging problem for the decomposition of refractory organic from wastewater. Herein, Co3O4-C3N4 heterogeneous photoanode (a two-dimensional ɣ-C3N4 is coated on one-dimensional Co3O4 nanowire) was fabricated using a simple impregnation-heating treatment process. By optimizing the amount of ɣ-C3N4, the Co3O4-C3N4-10 catalyst has been systematically investigated by experimental and theoretical aspects. The Co3O4-C3N4-10 catalyst exhibits excellent PEC activity for degrading reactive brilliant blue KN-R with a degradation rate of ∼91.3% owing to its low Tafel slope, numerous active sites, low charge transfer resistance, and PEC synergistic effects. The carrier transfer mechanism of S-scheme for Co3O4-C3N4 heterostructure was proposed because hydroxyl radical (•OH) and superoxide anion radical (•O2−) are the dominant active species, endowing Co3O4-C3N4-10 as promising catalysts for practical application. This work enlightens the rational design of advanced photoanode for water purification and environmental remediation.

An Assessment of the Use of Static Magnetic Field for Sodium Fluoride Defluoridation and Removal of Escherichia Coli and Rotavirus Pathogens from Water

The use of chemicals such as chlorine in water purification leaves harmful biproducts in the water while filtration techniques such as reverse osmosis, ultrafiltration, nanofiltration, and forward filtration are costly and require external energy for their operation. Ceramic water filters that would have addressed these issues are brittle and incapable of filtering viruses. In this work, we report on the efficiency of water purification using a 0.8 T static magnetic field from permanent magnets in defluoridation of sodium fluoride and purification of Escherichia coli, and Rotavirus. The contaminated water was circulated at varying velocities of 0.1 ml/s to 2.0 ml/s at an ambient temperature of 16.0 °C to 40.0 °C for 0.5 hours to 9.0 hours. It was found that when ionized water was circulated under the static magnetic field for nine hours, its pH was lowered by 9.7% and the velocity of water in circulation did not affect the purification efficiency. The static magnetic field equally lowered the replication of Escherichia coli and Rotavirus by 9.8% and 7.1% respectively. Furthermore, 14.1% of defluoridation of water was also achieved. Thus, a 0.8 T static magnetic field was not able to purify water to recommended levels.

Efficiency of using the Kazakhstan zeolites for the purification of water from iron ions

The problem of provision of the population with high-quality drinking water is currently one of the most topical in connection with the unsatisfactory technical condition of the existing water supply systems and pollution of the water sources. Natural zeolites, which have a sufficiently high sorption capacity, cation-exchange properties, relatively low cost and availability, are increasingly being used in recent times for water purification. The mineralogical properties of natural zeolites of the Tayzhuzgen and Shankanai deposits have been investigated. A comparative study of the sorption properties of the natural and modified zeolites of the Kazakhstan deposits has been carried out on model solutions, containing iron ions (Fe2+). The exchange mechanism and the degree of extraction of ions from the solutions have been established. The efficiency of the municipal water purification in the Auezovskiy district of Almaty with zeolites of the Shankanai field has been equal to 85.94%. This suggests a possibility of using these zeolites to purify water from iron ions with the purpose of water treatment in the dairy industry.

О возможностях подготовки питьевой воды из поверхностных источников Сирии

The purpose of the study is to assess the possibilities of combining the processes of mixing coagulant and agitating (formation of flocculant), developing, designing and testing the installation that ensures the compatibility of processes and the use of compressed air in the mixing process to achieve standard indicators of drinking water quality at the lowest possible economic costs. The article contains the results of research to assess the possibilities of achieving the quality indicators of drinking water from surface sources of the Syrian Arab Republic in conditions of regulated runoff. The experiments used water from reservoir 16 Tishrin, as a coagulant aqueous aluminum sulfate [Al2 (SO4)3. 18H2O], water samples for experiments were stored until a temperature close to ambient temperature was reached. A combination of a flocculation chamber and a mixer for a water purification plant is proposed, as well as a method for using compressed air as a mixing factor instead of mechanical mixers. Before the start of the experiment, measurements of the temperature and pH of the water were carried out, as well as the calculation of the amount of air required to perform the processes of mixing and the formation of a flocculant. Due to the combination of the mixer and the flocculation chamber, the possibility of increasing the efficiency of water purification and reducing operating costs when using compressed air for mixing has been established; it has also been possible to determine the optimal values of the parameters of mixing and mixing processes used in water treatment; to improve mixing efficiency and water purifi cation quality; to reduce operating costs for water treatment; to optimize the layout of individual elements of the water treatment system.

Improvement of the Mine Water Purification Efficiency via Modified Settling Tank

Improvement of the Mine Water Purification Efficiency via Modified Settling Tank

ДОСЛІДЖЕННЯ ПРОЦЕСІВ ОЧИЩЕННЯ ВОДИ ВІД ІОНІВ МАНГАНУ ПРИ ВИКОРИСТАННІ РОЗЧИНІВ НАТРІЙ ГІПОХЛОРИТУ

The creation of effective demanganization technologies by the development of new and intensification of known processes of manganese removal from natural waters are currently of increasing importance.The search for promising ways to demanganize water to regulatory values is a topical issue for the modern water treatment domain.Recent publications of methods for extraction of manganese ions from water by sorption, membrane, ion exchange methods were reviewed. The prospects of application of oxidative methods for water demanganation are shown.The purpose of the article is to investigate the manganese ions removal methods from water during their oxidation by sodium hypochlorite and to establish the dependence of the efficiency of demanganization on the consumption of oxidizing agent and the concentration of manganese ions in water.The study presents the application of sodium hypochlorite as an oxidant in the purification of artesian water from manganese ions. It was determined in static conditions that the degree of manganese removal is affected by both its initial concentration in water and the dose of sodium hypochlorite. Water purification process is more efficient with initial manganese concentrations above 5 mg/dm3. At a manganese ion concentration 30 mg/dm3, its complete removal was achieved in 4 hours of settling at a stoichiometric ratio of manganese and sodium hypochlorite in water and at any excess of oxidant. The process of manganese ions oxidation in artesian water by sodium hypochlorite depending on its dose and contact time was studied. The dose of oxidant for the removal of manganese ions from artesian water was also determined. Thus, the research allowed to improve the methods of water purification from manganese ions during their oxidation by sodium hypochlorite and found that the water purification efficiency increased both with increasing consumption of oxidizing agent and increasing the concentration of manganese ions in water.

Design of Solar Still Using Phase Change Material as Storage Medium with an Enhancement of Efficiency of Water Purification

Fresh water is becoming scarce with time, leading to severe water crisis in many parts of the world. Among the various methods of purification of water solar distillation is more prominent. Solar distillation has the inherent advantage of low energy consumption. Moreover it is simpler and more economical than other methods.

Prospects for creating regenerated photocatalytic materials for solar water treatment units

This article considers the possibility of obtaining regenerated photocatalytic materials of cylindrical shape for flow-through water purification systems. The method of cementation in a ceramic base matrix was compared to the method of laser fusion with a ceramic base of standard powder photocatalysts (ZnO, TiO2) according to the criteria of photocatalytic activity. The obtained materials were tested in a flow-through water purification unit (WPU) during the photo-oxidation of cationic - methylene blue (MB) and anionic - methyl orange (MO) model organic pollutants. The efficiency of water purification from MB at three cycles of regeneration of the obtained materials’ photocatalytic surface by layer-by-layer grinding was shown.

Analysis of the efficiency of industrial water purification from heavy metals with a carbon-containing sorbent

The article presents the results of determining the efficiency of removing heavy metals from industrial wastewater by the sorption method using the “charge”, which is a waste of a coal mining enterprise, as well as activated carbon. Also, in addition to experimental data, the research material contains photographic materials of the sorbent surface and the result of its X-ray spectroscopy.