Materials For Water Treatment Research Articles

Imprinted membranes for sustainable separation processes

The rapid industrial growth and the necessity of recovering and recycling raw materials increased the interest in the production of highly selective and efficient separation tools. In this perspective, a relevant input was given by the membrane-based technology and the production of imprinted membranes, which possess specific recognition properties at molecular and ionic level, offers the possibility of developing sustainable and green processes. Furthermore, the integration of imprinted membranes with traditional or membrane-based approaches is a promising strategy in the logic of process intensification, which means the combination of different operations in a single apparatus. This work discusses the concept and separation mechanisms of imprinted membranes. Furthermore, it presents an overview of their application in organic solvent nanofiltration, for the removal of toxic agents and recovery solvent, as well as valuable compounds. The recent advances in water treatment, such as pesticide removal and recovery of metal ions, are also discussed. Finally, potential applications of imprinted membranes in hybrid processes are highlighted, and a look into the future of membrane separations for water treatment and recovery ofcritical raw materials is offered.

Improvement of the fabricated and application of aluminosilicate-based microfiltration membrane

Aluminosilicate composite materials are characterized by their low cost, nontoxicity and facilely shaped. Membrane prepared using aluminosilicate composites have the following disadvantages: large mean pore size and low mechanical strength. To address these limitations, flat microfiltration membranes were fabricated using SiO2 powder and aluminosilicate composite as raw materials. The membrane performance was optimized by regulating the particle size of SiO2, the ratio of SiO2 to aluminosilicate composite (s/a), and the type of chemical admixture. The X-ray diffraction results indicated that the crystalline SiO2 particles were favorable for the preparation of membranes with higher bending strengths. The decreasing particle sizes of SiO2 (1.33–0.15 μm) decreased the pore size distribution. The bending strength of the membrane reduced with an increase in s/a, while was effectively enhanced by adding dissolved Na2SiO3. The optimized inorganic microfiltration membrane could also catalyze ozone to remove 100% of benzophenone-4 with an initial concentration of 10 mg L−1 within 15 min, and TOC removal by 52.67%. This paper presents a revised method for preparing an inorganic microfiltration membrane, which is an increasingly promising material for water treatment because of its low cost, low energy consumption, and high catalytic performance.

Design of hybrid Chitosan-Montmorillonite materials for water treatment: Study of the performance and stability

Using hybrid chitosan-montmorillonite materials as environmentally-friendly alternatives to metallic salts in water treatment, and especially for drinking water production, is a new challenge. However, the coagulation-flocculation process requires minimization of polymer release and reactivity optimization to guarantee low Dissolved Organic Carbon content of the treated waters. To meet these requirements, hybrid materials were designed in this study to combine structural stability and good sorption efficiency, even in hard waters. The influence of preparation parameters (polymer molecular weight, polymer to clay mass ratio, addition method and post-preparation treatment) was evaluated and the obtained composites were fully characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Jar-Test experiments were carried out to assess the performance of the hybrids toward MethylOrange, a model molecule for the hardly removable hydrophilic compounds. The best results were obtained by drying the hybrids prepared at a 0.5:1 polymer to clay mass ratio by the direct addition method. Structural analysis revealed that the polymer chains of the dried-hybrid were more strongly bound to the Montmorillonite particles while remaining accessible to the organic molecules. This structure prevented its destabilization in the presence of high ionic strength. Under these conditions, all chitosan based materials exhibited some reactivity loss. However, the dissolved chitosan release was reduced to 13% of the initial dosage for the optimized dried hybrid compared to 47% for the undried version. To conclude, the optimized hybrids still outperformed pristine chitosan, Montmorillonite and FeCl3 for the removal of MethylOrange, thus highlighting their potential for future use.

Research on Microwave-Assisted Catalytic Persulfate Technology in the Field of Environmental Energy

Catalytic persulfate technology is a new type of catalytic technology that has been extensively studied in recent years. Among them, the new copper and silver materials synthesized by microwave assist have broad application prospects and are a class of catalysts with excellent performance, environmental friendliness, and stable structure. This article introduces a new type of material loaded with metal copper and silver and activated carbon, analyzes the mechanism of catalytic oxidation, and focuses on summarizing the influencing factors, degradation mechanism, and potential pollutant degradation pathways of this new type of material in water treatment.

Study on the effect of modified zeolite on treating nitrate in water and its influencing factors

In view of the current application of modified materials in water treatment, the research status of nitrate removal from water by modified zeolite was summarized and analyzed. In this paper, several modification methods of zeolite are summarized, the adsorption mechanism is analyzed, the influencing factors of adsorption are discussed, the adsorption effect of modified zeolite is compared, and the study on the modification of zeolite is prospected.

Textile water treatment via adsorption of basic brown 1 dye on ZnO/PVC nanocomposite membrane through membrane adsorption process

Textile water treatment via adsorption of basic brown 1 dye on ZnO/PVC nanocomposite membrane through membrane adsorption process

Beta-FeOOH nanoparticles: a promising nano-based material for water treatment and remediation

The use of nanomaterials in water treatment operations has taken a prominent position in recent years due to the perceived outstanding efficiencies and outputs. The selection of appropriate nanoparticles from the plethora available for application in large-scale projects is still a daunting challenge. Beta-FeOOH (β-FeOOH) has been identified as a non-toxic, low cost and easy to synthesize nanomaterial. Furthermore, it possesses adsorptive, catalytic, ion-exchange properties, and also monitoring functionalities. This review highlights the potential of β-FeOOH as a promising nano-based option for water treatment operations. The natural occurrences and reported synthesis methods and procedures are discussed, as well as the characteristics and properties which make it a choice candidate to consider for large-scale water treatment processes. Advances on the application of β-FeOOH and its composites in water treatment and remediation processes are highlighted and profiled to emphasize its potential. The future outlook on the β-FeOOH synthesis and application procedure was also discussed.

Tamanrasset’s Clay Characterization and Use as Low Cost, Ecofriendly and Sustainable Material for Water Treatment: Progress and Challenge in Copper Cu (II)

In this study, the adsorption of copper Cu (II) from aqueous solution, on Tamanrasset’s clay which is low cost adsorbent, was studied using batch experiments. The adsorption study includes both equilibrium adsorption isotherms and kinetics. The characterization of the adsorbent necessitated several methods such as X-Ray Diffraction, Scanning Electron Microscopy coupled with Energy Dispersive X-ray, BET for specific surface area determination, Fourier transform infrared spectroscopy and thermogravimetric analysis. Indeed, various parameters were investigated such as contact time, initial metal ion concentration, mass of solid, pH of the solution and temperature. The adsorption process as batch study was investigated under the previews experimental parameters. The results revealed that the adsorption capacity of Cu2+is maximized at naturel pH of metal 5.5. Removal of copper by the clay of Tamanrasset (kaolinite) achieved equilibrium within 50 minutes; the results obtained were found to be fitted by the pseudo-second order kinetics model. The equilibrium process was well described by the Langmuir model and the maximum adsorption capacity was found to be 26.59 mg/g.

Filtration Process and Alternative Filter Media Material in Water Treatment

In drinking water treatment, filtration plays an important role in the multi-barrier approach employed for the removal of pathogens. The presence of suspended solids and other particulate matter in water increases the resistance of most microbes to disinfection. Therefore, high performance in the removal of particles achieved by granular filtration can increase the disinfection efficiency. Although sand is one of the major filter media, alternative media have been developed and used in recent years. In this review, the performance of alternative media is compared with traditional sand/anthracite for drinking water treatment. Advantages in the use of alternative media, especially glass media, have been found, including high filtration performance in removing residual particles and turbidity, minor modification requirements to the existing filtration configuration and slow head loss development. However, before the employment of them in industry, additional tests are recommended. In particular, full scale tests with variations in the operating conditions and analyses of pathogen removal should be performed. Moreover, this paper reviews the filtration processes and operating configurations which provide overall references to those who are studying and working in the field of water technology and treatment. In this paper, legislations/standards of safe drinking water are summarized as they are the driving force of developing new treatment technologies; mathematical modules for predicting the media filtration performance are briefed. Finally, future work on the application of alternative filter media is recommended.

Preparation of graphdiyne-doped TiO2/SiO2 composite for enhanced photocatalytic activity

Enhancing the efficiency of visible light degradation is important for the actual application of TiO2/SiO2 (Ti/Si) composite materials for waste water treatment. In this manuscript, graphdiyne-doped TiO2/SiO2 (Ti/Si/GDY) (the Ti/Si composite exhibits a spherical shape with a diameter between 200 and 500 nm) composite material was successfully prepared using a hydrothermal method, which was utilized as photocatalyst for the photocatalytic degradation of methylene blue (MB) in aqueous solution under visible light illumination. Studies showed that Ti/Si/GDY-0.8 wt% exhibited superior photocatalytic degradation efficiency (91.8%) under visible light illumination than other composite materials such as Ti/Si/GDY-0.6 wt% (87.9%), Ti/Si/GDY-1.0 wt% (85.9%), and bare Ti/Si composite (32.3%). Moreover, Ti/Si/GDY also showed a higher photocatalytic degradation efficiency than other carbon materials (graphene (GR) and carbon nanotube (CNT) composited Ti/Si (Ti/Si/GR, Ti/Si/CNT)). The studies of the possible mechanism for the degradation of MA indicated that h+ was the major substance for the smooth degradation of methylene blue. Such a high efficiency photocatalyst might be also useful for the degradation of other contaminates in waste water or air.

CRUSTACEAN WASTE SHELLS AS ADSORPTION MATERIALS FOR HEAVY METALS IN AN AQUEOUS SOLUTION

Laguna de Bay is one of the country’s major lakes, providing a third of the fish consumed by Metro Manila’s 16 million residents. It also provides support for agriculture, industry, and hydropower generation, as well as providing a welcome respite for many Filipinos. However, because of the lake’s importance, it is threatened by a variety of issues, including pollution. Heavy metals such as mercury and lead are present in high concentrations in the lake. And these heavy metals may persist in fish, water, air and the human body. As a result, an adsorption technique for heavy metal removal in an aqueous solution was investigated. As an adsorbent, the produced chitosan from crustacean waste shells was employed. The study’s parameters were contact time, adsorbent quantity, and pH. Results showed that 0.5 g of chitosan has a higher absorption rate of 99% in 500 mg/L solutions compared to 1.0 g of chitosan with an adsorption rate of 98%. In terms of contact time, 60 minutes showed almost 100% adsorption rate while 120 minutes was 98%. With increasing pH, the amount of metal adsorption rises. This developed chitosan from crustacean waste shells indicates high capacity as adsorbent materials for heavy metals. As a result, it appears to be a viable material for water treatment.

CRUSTACEAN WASTE SHELLS AS ADSORPTION MATERIALS FOR HEAVY METALS IN AN AQUEOUS SOLUTION

Laguna de Bay is one of the country's major lakes, providing a third of the fish consumed by Metro Manila's 16 million residents. It also provides support for agriculture, industry, and hydropower generation, as well as providing a welcome respite for many Filipinos. However, because of the lake's importance, it is threatened by a variety of issues, including pollution. Heavy metals such as mercury and lead are present in high concentrations in the lake. And these heavy metals may persist in fish, water, air and the human body. As a result, an adsorption technique for heavy metal removal in an aqueous solution was investigated. As an adsorbent, the produced chitosan from crustacean waste shells was employed. The study's parameters were contact time, adsorbent quantity, and pH. Results showed that 0.5 g of chitosan has a higher absorption rate of 99% in 500 mg/L solutions compared to 1.0 g of chitosan with an adsorption rate of 98%. In terms of contact time, 60 minutes showed almost 100% adsorption rate while 120 minutes was 98%. With increasing pH, the amount of metal adsorption rises. This developed chitosan from crustacean waste shells indicates high capacity as adsorbent materials for heavy metals. As a result, it appears to be a viable material for water treatment.

Strong Adsorption of Arsenite and Phosphate from Aqueous Solution Using La2O3–CeO2 Composite

In the present paper, the synthesis of La2O3–CeO2 composite using the sol–gel combustion method with gelatin as a template and its application for arsenite and phosphate removal are demonstrated. The obtained composite was characterized using thermal analysis (TG–DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy elemental mapping (EDX-elemental mapping). It is found that the La–Ce bimetallic oxide consists of nanoparticles of La2O3 and CeO2 with a size of around 10–20 nm. The La2O3 and CeO2 particles in the composite are highly dispersed. The adsorption of arsenite and phosphate from aqueous solutions on the La2O3–CeO2 composite was investigated at ambient temperature utilizing a batch technique. The arsenite and phosphate adsorption capacity derived from the Langmuir isotherm is 102.5 and 193.3 mg g−1, respectively, which is higher than those reported in the previous papers. The material does not lose much capacity even after eight cycles. The high capacity for phosphate adsorption at low and high concentrations enables the La2O3–CeO2 composite to become a potential material for water and wastewater treatment.

Versatile Biomass Carbon Foams for Fast Oil–Water Separation, Flexible Pressure-Strain Sensors, and Electromagnetic Interference Shielding

Carbon foam based on nature biomass resources has great prospective applications in water treatment, sensors, electronic devices, and electromagnetic shielding materials due to their low cost, stab...

Covalent Organic Frameworks for Water Treatment

AbstractCovalent organic frameworks (COFs) are an emerging type of porous crystalline material with highly ordered aperture size and tunable structures with designer properties. COFs have been proposed as promising materials for water treatment because of their notable intrinsic properties like excellent chemostability, high surface area, abundant functional sites, and uniform adjustable aperture size. This review focuses on fundamental COF design principles for water treatment (stability, aperture size, and surface functionalization) and the state‐of‐the‐art application of COFs in desalination, organic contaminant sorption, and ion capture. Additional potential promising applications of COFs for water treatment, including solar steam generation, photocatalysis for degradation of organic contaminants, and capacitive deionization are also presented along with an outlook toward future opportunities in the field.

Consecutive removal of heavy metals and dyes by a fascinating method using titanate nanotubes

Titanate nanotubes TNT are promising materials for water treatment due to properties. Sodium titanate nanotubes (Na-TNT) were hydrothermally synthesized and characterized using XRD, FESEM, HRTEM, Zeta potential, nitrogen adsorption and desorption, and FT-IR spectra techniques. The efficiency of Na-TNT for adsorption of Ni(II) from water was tested through different conditions including pH, Na-TNT dose, initial metal concentration, and contact time. The results showed efficient adsorption performance with rapid removal of 90 % of Ni(II) ions within the first 15 min and after 30 min, the equilibrium was attained with removal efficiency close to 100 % at pH = 7 and with an adsorption capacity of 181.2 mg/g. Ni-TNT was collected and recycled for the removal of methylene blue (MB) by combined adsorption and photocatalytic degradation. The adsorption efficiency reached (99.5 %) and the equilibrium adsorption capacity was 916 mg/g and 330 mg/g for Ni-TNT and Na-TNT respectively. The correlation coefficient R2, error function Chi2, SSE, and MSE were used to evaluate the best fit models to the experimental data. The adsorption mechanism was explored using density functional theory and Monte Carlo simulation. The photocatalytic activity of Ni-TNT was tested through two different types of experiments. More attention was paid to the effect of the light path length through the dye solution and the effect of the experiment container dimensions on the photocatalytic degradation process. Also, both Na-TNTs and Ni-TNTs showed potent antifungal and antimicrobial activity. This work successfully represents TNT as a multifunctional material.

Nitrogen Doping and Carbon Coating Affects Substrate Selectivity of TiO2 Photocatalytic Organic Pollutant Degradation.

A series of carbon-coated, nitrogen-doped titanium dioxide photocatalysts was produced and characterized. N-doped TiO2 powder samples were prepared using a sol-gel method and subsequently used for making doped-TiO2 thin films on glass substrates. Carbon layers were coated on the films by a thermal decomposition method using catechol. Diffuse reflectance spectra and Mott-Schottky analyses of the samples proved that nitrogen doping and carbon coating can slightly lower the band gap of TiO2 , broaden its absorption to visible light and enhance its n-type character. According to photocatalytic tests against model contaminants, carbon-coated nitrogen-doped TiO2 films have better performance than simple TiO2 on the degradation of Rhodamine B dye molecules, but are poorly effective for degrading 4-chlorophenol molecules. Several possible explanations are proposed for this result, supported by scavenging experiments. This reveals the importance of a broad substrate scope when assessing new photocatalytic materials for water treatment, something which is often overlooked in many literature studies.

Sodium Lignosulfonate Modified Polystyrene for the Removal of Phenol from Wastewater.

An eco-friendly and novel water treatment material was synthesized using sodium lignosulfonate modified polystyrene (SLPS), which can be used to eliminate phenols in aqueous solution. SLPS was characterized by BET, FTIR, SEM, and EDS. The effect of the initial pH value, phenol content, adsorption time, and temperature on the absorbability of phenol in SLPS was investigated through adsorption experiments. It was found that SLPS could efficiently adsorb phenol in aqueous solution at a pH value of about 7. The test results revealed that the kinetic adsorption and isotherm adsorption could be successfully described using the pseudo second-order and Langmuir models, respectively. It was illustrated that the phenol adsorption on SLPS was dominated by chemisorption and belonged to monolayer adsorption. The max. phenol adsorption value of SLPS was 31.08 mg/g at 30 °C. Therefore, SLPS displayed a great potential for eliminating phenol from polluted water as a kind of novel and effective adsorbent.

Fungal chitin-glucan nanopapers with heavy metal adsorption properties for ultrafiltration of organic solvents and water

Membranes and filters are essential devices, both in the laboratory for separation of media, solvent recovery, organic solvent and water filtration purposes, and in industrial scale applications, such as the removal of industrial pollutants, e.g. heavy metal ions, from water. Due to their solvent stability, biologically sourced and renewable membrane or filter materials, such as cellulose or chitin, provide a low-cost, sustainable alternative to synthetic materials for organic solvent filtration and water treatment. Here, we investigated the potential of fungal chitin nanopapers derived from A. bisporus (common white-button mushrooms) as ultrafiltration membranes for organic solvents and aqueous solutions and hybrid chitin-cellulose microfibril papers as high permeance adsorptive filters. Fungal chitin constitutes a renewable, easily isolated, and abundant alternative to crustacean chitin. It can be fashioned into solvent stable nanopapers with pore sizes of 10−12 nm, as determined by molecular weight cut-off and rejection of gold nanoparticles, that exhibit high organic solvent permeance, making them a valuable material for organic solvent filtration applications. Addition of cellulose fibres to produce chitin-cellulose hybrid papers extended membrane functionality to water treatment applications, with considerable static and dynamic copper ion adsorption capacities and high permeances that outperformed other biologically derived membranes, while being simpler to produce, naturally porous, and not requiring crosslinking. The simple nanopaper production process coupled with the remarkable filtration properties of the papers for both organic solvent filtration and water treatment applications designates them an environmentally benign alternative to traditional membrane and filter materials.

Nigella sativa seeds based antibacterial composites: A sustainable technology for water cleansing - A review

The presence of pollutants such as organic dyes and heavy metals in water has become a serious problem for aquatic environment. These pollutants that reach the human body through drinking water pose a serious threat to human life. These pollutants can be responsible for diabetes, cancer, high blood pressure, cardiovascular, neurological arteriosclerosis, and many other serious diseases in the human body. The elimination of such water pollutants is an urgent need of the society. But the present adsorption techniques available are costly and out of reach of the masses. The biofilm formation by bacterial cells onto the solid surface is also a subject of concern. In this regard, many efforts have been made to achieve an effective adsorption technology. Adsorption technology using Nigella Sativa and its composites has gained attention because of the biofilm resistance activities of the Nigella Sativa. Owning to its unique physicochemical characteristics, antibacterial properties of Nigella Sativa based composites provide a preferred material for water treatment. This review puts in a nutshell the application of Nigella Sativa based composites for water treatment. The methods of synthesis and physio-chemical properties Nigella Sativa based materials by making use of various techniques have been discussed in depth. Pollutants removals from water have been discussed in light of various parameters that affect it. The implementing and reusing of the adsorbent are also detailed out. The comparative cost, antibacterial activity, adsorption capacities and partition coefficients have also been discussed. This review will definitely be useful for the scientific community to develop the more sustainable material for water purification with high quality.