Adsorbent For Water Treatment Research Articles

Single-step synthesis and modification of CTAB-hectorite for efficient adsorption of methyl orange dye

Hectorite modified with cetyltrimethylammonium bromide (CTAB) using a single-step synthesis and modification produced an efficient adsorbent for water treatment. Characterization analysis revealed that incorporating CTAB at 5–10 wt/wt increased the basal distances and the mesopore area of hectorite. The high concentration at 20–40 wt/wt deposited CTAB on the external surface of hectorite, consequently reducing the surface area. TGA-DTG analysis revealed that the surface-bound CTAB has lower thermal stability than the interlayered CTAB. CTAB-modified hectorite (40-Hec) showed the adsorption capacity of methyl orange at 164.28 mg/g, with 98.57% removal efficiency, significantly higher than hectorite. The adsorption of methyl orange followed the pseudo-second order kinetic and the Sips models. The Sips isotherm was suitable to describe the adsorption mechanism by monolayer physisorption. For thermodynamic studies, parameters such as the Gibbs free energy (ΔG°), the enthalpy (ΔH°) and the entropy (ΔS°) revealed that the adsorption of methyl orange on CTAB-modified hectorite is a spontaneous exothermic process and affected by the entropy of adsorption.

Engineering nanocomposite of graphene quantum dots/carbon foam/alginate/zinc oxide beads for efficacious removal of lead and methylene

The excessive industrial applications of methylene blue dye and lead ions with their high resistance to biodegradation in water systems have led to their detection in water effluents as pollutants of major concern and therefore they must be removed by efficient techniques. Carbonaceous based materials as carbon foam (C-Foam) and graphene quantum dots (GQDs) with sodium alginate are important reactive adsorbents in water treatment. Therefore, a novel nanocomposite was assembled via crosslinking of zinc oxide with carbon foam, GQDs and alginate to fabricate ZnO/C-Foam/GQDs/Alginate. This nanocomposite exhibited homogeneous and spherical particles with 20 nm average size. ZnO/C-Foam/GQDs/Alginate is designed to remove Pb(II) and methylene blue (MB) pollutants. The collected results referred to the optimum pH 6 and 7 for Pb(II) and MB, respectively. The computed thermodynamic parameters revealed endothermic and spontaneous reactions by the two pollutants providing ΔGo from −8.06 to −13.67 kJ/mol for lead ion and from −6.23 to −8.19 kJ/mol for MB dye. The interfering species exhibited almost insignificant impact. ZnO/C-Foam/GQDs/Alginate nanocomposite confirmed successful reusability for five successive regeneration cycles. Finally, ZnO/C-Foam/GQDs/Alginate nanocomposite provided excellent removal trends for Pb(II) and MB pollutants from real water samples with100% and 92.2 % removal, respectively.

The removal of manganese ions from industrial wastewater using local Saudi and commercial bentonite clays

Manganese compounds exist naturally in the environment as solids in soils and small particles in water. Human industrial activities and the burning of fossil fuels increase the manganese concentration in the air. Studies have shown that exposure to manganese has extremely dangerous, toxic effects on humans, resulting in ailments such as the “metal fume fever” which produces symptoms such as metallic taste in the mouth, headache, fever and chills, anxieties, chest tightness, and cough. This has led many researchers to try different techniques to eliminate this harmful metal from the environment. Among methods, adsorption is one of the most effective and efficient for the removal of contaminants, such as heavy metals, from wastewater. We focused on local (from Saudi Arabia) and commercial (from India) bentonite clay to verify the importance of natural bentonite clay as an adsorbent for water treatment. While other purification techniques are expensive, bentonite clay is cheap, natural, and accessible. Therefore, we investigated how the concentration of the solution pH, temperature, adsorbent amount, contact time and bentonite procedure (washing and heat treatment) affect the removal process. Our results demonstrated success in the local bentonite clay's adsorptive capacities, and we encourage the generalization of its use in the Saudi kingdom's industries.

Application of laterite soil in removing chloride ion from drinking water

Abstract Increasing salinity is a crucial issue for the people of coastal regions in Bangladesh. To resolve this problem, efficient and low-cost materials can be used as adsorbents to remove salinity from water. Among those, laterite soil (LS) is one of the efficient adsorbents in water treatment. This study demonstrates a low-cost salinity removal technique using laterite soil as adsorbent. The effect of burning temperature on raw laterite and synthetic laterite has been analyzed. The performance of the adsorbents has been observed in terms of efficiency in salinity removal. Both batch and column adsorption have been carried out to evaluate the adsorption capacity of raw LS and burned LS, respectively. Raw laterite shows maximum adsorption capacity of 21.24 mg/g in batch adsorption at an initial concentration of 900 mg/L. The optimum burning temperature for thermally treated LS has been found as 600 °C. However, SLS (Synthetic Laterite Soil) burned at 600 °C gives greater chloride ion removal efficiency (44.54%) than LS (38.23%) in removing salinity from water.

Commercial synthetic hydrotalcite as an adsorbent nanomaterial for removal of bacteria from contaminated water

Layered double hydroxides (LDHs) are regarded as potential adsorbents for water treatment from a wide range of pollutants. However, there are only a few studies concerning application of LDHs for elimination of microorganisms from aquatic systems. In this work, experiments were conducted to investigate the efficiency of commercial synthetic hydrotalcite Mg6Al2(CO3)(OH)16∙4H2O as an adsorbent for water purification from fecal indicator bacteria Escherichia coli BIM B-378 and Enterococcus faecalis BIM B-1530. Our findings indicate that exposure for 4 h to hydrotalcite (5 g/L) in suspension resulted in the removal of about 40% of coliforms and 25% of enterococci from water, at a high bacterial load (2×1010 CFU/L), and the removal efficiency of E. coli and E. faecalis did not significantly change when both bacteria were present in water. In addition, the percentage of removed bacteria increased with increasing of hydrotalcite concentration in the suspension (0.5 to 10 g/L), contact time (1-7 h) and decrease of pH (5.5), and decreased at low incubation temperature (16°C). Finally, hydrotalcite did not exhibit bactericidal activity and retention of bacteria was found to be reversible. Therefore, our findings suggest that commercial synthetic hydrotalcite could be potentially used in technologies of water treatment from bacterial contamination.

Synthesis and performance analysis of a mesoporous polydopamine-functionalized magnetic microcapsule adsorbent in water treatment

To scientifically and effectively solve the environmental and human hazards of polluted water bodies, this study uses the superparamagnetism of Fe3O4, the biocompatibility of mussel biomimetic polydopamine, and the large specific surface area and pore volume of mesoporous materials. Layer-by-layer self-assembled amino-functionalized modified nano-SiO2 particles were used to prepare mesoporous PDA-functionalized magnetic microcapsule adsorbents (FMNAs). After a series of microscopic characterization and performance measurement experiments, it can be concluded that the relatively large surface area (55.844m2/g) and pore volume (0.438 cm3/g) in the mesoporous structure of FMNAs provide a large number of active adsorption sites and exhibit high adsorption capacity for MB, AF and Cd (II), which are 42.35, 46.20 and 40.70 mg/g, respectively. The adsorption process of FMANs is mainly controlled by chemical adsorption, which conforms to Langmuir and Freundlich isothermal model, superparamagnetism gives FMNAs good repeatability.

Coffee Waste Biochar: a Widely Available and Low-cost Biomass for Producing Carbonaceous Water Treatment Adsorbents

Coffee Waste Biochar: a Widely Available and Low-cost Biomass for Producing Carbonaceous Water Treatment Adsorbents

Application of central composite design for optimisation of the development of metakaolin based geopolymer as adsorbent for water treatment

ABSTRACT Metakaolin-based geopolymers (MKGP) were optimised by varying the operating conditions using the central composite design (CCD) and the response surface method (RSM) to optimise the operating variables affecting MKGP formation and their adsorption efficiency. The MKGP was characterised and tested for the removal of methylene blue (MB) from an aqueous environment. Results show that the MKGP5 with the most organised structure exhibits the highest MB removal efficiency. Parameters like the adsorbent dose, the pH, the contact time, the initial dye concentration, and the temperature were optimised to improve the adsorption efficiency of MB. The results also demonstrated the accuracy and feasibility of CCD simulation to develop a well-converted geopolymer adsorbent for water treatment.

Waste to Product: Feasibility of Egyptian Peanut Shell Transformation into a Useful Product

Carbon-based materials are widely used in various fields such as wastewater treatment, gas sensing, and energy storage applications. In this study, waste peanut shell (PSH), available in Egypt, were transformed into useful materials by physical, chemical, and thermal treatments. The physical properties of materials from the different processing combinations were investigated. The activated (APSH), carbonized (CPSH), and activated/carbonized (A/CPSH) forms were successfully prepared. The prepared solids were characterized by SEM, FTIR, XRD, and nitrogen gas adsorption. Ball milling at 5 runs for 45 min resulted in 84 wt% of the ground PSH passing through the 212 μm mesh. Accordingly, the activation, carbonization, and activation/carbonization increased the surface areas of resulting solids by 6, 34, and 580 times, respectively. Among the materials prepared, the activated/carbonized PSH had a mean pore diameter of 1.9 nm, mesoporous material, and the highest electrical conductivity of 0.0042 Ω-1cm-1. This PSH is available as adsorbent in water treatment and materials for gas sensing and energy storage.

Competitive adsorption of heavy metals in a quaternary solution by sugarcane bagasse – LDPE hybrid biochar: equilibrium isotherm and kinetics modelling

Abstract Sugarcane is a notable crop grown in the tropical region of the world. It is an abundant waste material of the sugar industry which is a low cost and low combustion fuel thus the bagasse can be exploited to manufacture adsorbents for water treatment. Because the presence of contaminants in polluted water is not uniform, pollutant species compete for active sites during the adsorption process. Investigation of the competitive adsorption of Zn(II), Cu(II), Pb(II), and Fe(II) in a quaternary solution using hybrid biochar developed from sugarcane bagasse (SCB) mixed Low-Density Polyethylene (LDPE) and pure SCB biochar is the main aim of this study. The biochar was developed using the retort carbonisation process and characterised via SEM (Scanning Electron Microscopy), BET (Branueur Emmett Teller) analysis, and FTIR (Fourier Transform Infrared Spectroscopy). Both biochar species mixture possessed some orbicular properties with mesoporous heterogeneous superficial morphology. The biomass biochar and hybrid biochar specific surface area are 533.6 m2/g and 510.5 m2/g respectively. For the two used adsorbents, >99% removal efficiency was recorded over the sphere for dosage investigation. Thus, this implies they are capable of removing heavy metals from the aqueous solution simulated. The Langmuir isotherm fitted best in each domain however there was an exception for Pb(II) ions in biomass biochar with the experimental adsorption capacity of ∼ 22 mg/g for the HMs. Based on the correlation coefficient (R 2); the experimental data fitted the pseudo-first-order kinetic model well having a correlation coefficient value of greater than 0.9. The mechanism of adsorption for the HMs was chemisorption. This study has a three-pronged benefit of water treatment, resource conservation, and solid waste utilisation.

Sustainability assessment of acid-modified biochar as adsorbent for the removal of pharmaceuticals and personal care products from secondary treated wastewater

This study investigated the adsorption behavior and sustainability of biochar to remove four pharmaceutical and personal care products (PPCPs). The biochar (PEBC) was prepared via slow pyrolysis of empty palm bunch (PEB) at three temperatures (250–750 °C). To improve the adsorption capacity further, PEBC450 was acid treated with H2SO4 to develop PEBC450-A. The adsorption behavior of target pollutants (methyl paraben (MPB), carbamazepine (CZP), ibuprofen (IBP), and triclosan (TCS)) onto PEBC450-A was studied in batch experiments, and phenomenological and statistical models were applied to understand the sorption mechanism. Results demonstrated that the adsorption system was able to achieve fast equilibrium (in 4 h), with maximum adsorption capacities as 60.2 mg/g (MPB), 51.7 mg/g (CZP), 38.8 mg/g (IBP), 35.4 mg/g (TCS). The modeling results showed heterogeneous adsorption of PPCPs involving the participation of multiple functional groups in parallel and non-parallel orientations. The mass transfer kinetic models identified the internal mass transfer resistance as the rate-limiting step. The PPCPs adsorption was significantly affected by the change in solution pH and the presence of humic acid. However, no substantial change in PPCPs removal was observed in the presence of co-existing ions and different ionic strengths. In multi-pollutant systems and real water samples, PEBC450-A maintained more than 75% removal of target pollutants, indicating the developed material as a promising adsorbent for wastewater treatment. The sorption mechanism was found to be channel diffusion, hydrogen bonding, n-π and π-π interactions, and van der Waals force. The comparative life cycle assessment of PEBC450-A and commercial activated carbon showed that the total impact contribution of PEBC450-A was 20 times less than commercial activated carbon. The overall finding makes PEBC450-A a low-cost and sustainable adsorbent for water treatment.

Application of natural hydroxyapatite in the treatment of polluted water: Utilization of dromedary bone as bioadsorbent

AbstractIn this study, the dromedary bone waste was valorized by the obtainment of hydroxyapatite (HAp) and its application to remove crystal violet (CV) dye from aqueous solution. Fourier transform infrared spectroscopy, X‐ray diffraction, elemental analysis X‐ray fluorescence spectrometer (XRF), particle size laser analysis, and the point of zero charge pH value (pHpzc) were realized to characterize the natural adsorbent. The capacity of HAp to adsorb CV was measured at different contact times, pH values, and initial dye concentrations. The results showed that the model that better described the experimental data of adsorption kinetics was the pseudo‐second‐order kinetic model (PSO). Freundlich model well fitted the sorption isotherms. A maximum sorption capacity of 266.66 mg/g of CV dye on natural HAp was obtained. Hence, dromedary bone treated might be valorized as a natural adsorbent for water treatment with low environmental risks.

Chain Extensions in PhotoATRP-Induced Self-Assembly (PhotoATR-PISA): A Route to Ultrahigh Solids Concentrations and Click Nanoparticle Networks as Adsorbents for Water Treatment

Chain Extensions in PhotoATRP-Induced Self-Assembly (PhotoATR-PISA): A Route to Ultrahigh Solids Concentrations and Click Nanoparticle Networks as Adsorbents for Water Treatment

Hydrophobic magnetic bilayer micro-particles from OA@Lignin@Fe3O4 for high-efficient oil adsorption

Marine oil or heavy oil spills occur frequently, causing pollution and endangering lives in marine, sea and river, even the soil. In this paper, a magnetic, hydrophobic and bilayer composite oleic acid@Lignin@Fe3O4 was synthesized by a simple method to remove oil contaminants floating on water. SEM, TEM, FT-IR, TGA, XRD, VSM and CA analyses were used to examine its structures, chemical composition and performance. With an oleic acid (OA) monolayer on surface, OA@Lignin@Fe3O4 microspheres showed excellent oil adsorption performance with quick adsorption equilibrium of 10 s, good adsorption capacity of 3.07, 3.52, 3.04 and 2.53 times its original weight for vacuum pump oil, soybean oil, dimethicone and kerosene, respectively. Furthermore, the OA@Lignin@Fe3O4 could be guided to collect oil droplets and separated from water under a magnetic field. Meanwhile, the OA@Lignin@Fe3O4 exhibited high cycle performance, which maintained high oil adsorption capacity after 5 recycles. Therefore, the OA@Lignin@Fe3O4 is believed to a promising adsorbent for oil removal and provides a novel avenue for multifunctional adsorbents in water treatment.

Carboxyl-functionalized porous aromatic framework for rapid, selective and efficient removal of cationic pollutants from water.

The functionalization of porous aromatic frameworks (PAFs) is essential for task-specific application of these materials as advanced adsorbents in water treatment. In this study, a carboxyl-functionalized PAF was prepared by the post-synthesis modification of a HOCH2-tagged PAF, which was synthesized from a precursor-designed method. The synthesized PAFs were comprehensively characterized. The targeted PAF-COOH showed hierarchical porosity with the coexistence of micropores and mesopores. The carboxyl groups were distributed homogeneously across the whole material, and its content was as high as 4.18meqg-1. An equilibrium adsorption isotherms study demonstrated that the adsorption of cationic dyes fitted well to the Langmuir model and the maximum adsorption capacities of methylene blue (b-MB) and phenosafranine obtained at pH 10 were 775.19 and 588.24mgg-1, respectively. The adsorption kinetics of cationic dyes followed the pseudo-second order kinetic model. Quick kinetics was demonstrated with the k2 for a 100mgL-1 b-MB solution as high as 2.83gmg-1min-1 and the equilibrium time was just 0.5min. In addition, the dye-loaded PAF-COOH could be regenerated easily and showed excellent reusability. These significant characters indicated a promising prospect of the PAF-COOH for water treatment.

Valorization of cow manure via hydrothermal carbonization for phosphorus recovery and adsorbents for water treatment

The increased quantities of manure being generated by livestock and their extensive agronomic use have raised concerns around run-off impacting soil and groundwater quality. Manure contains valuable nutrients (especially phosphorus) that are critical to agriculture, but when directly land-applied the run-off of such nutrients contributes to eutrophication of waterways. This study investigates the hydrothermal carbonization of cow manure at two industrially feasible process extremes: 190 °C, 1 h and 230 °C, 3 h, to concentrate and then recover phosphorus from the solid hydrochar via acid leaching and precipitation. Up to 98 wt% of phosphorus initially present in the hydrochar (88% in the raw manure) can be recovered, with the dominant crystalline species being hydroxyapatite. Acid leached hydrochars were subsequently pyrolyzed at 600 °C for 30 min, and then evaluated as adsorbent materials for water remediation by using methylene blue as a model adsorbate. Although pyrolyzed hydrochars have surface areas an order of magnitude higher (160–236 m2/g) than the non-pyrolyzed acid leached hydrochars (11–23 m2/g), their adsorption capacity is three times lower. Furthermore, while the higher carbonization temperature leads to greater recovery of phosphorus, it likewise leads to higher heavy metal concentrations in the precipitate (ranging from 0.1 to 100 mgmetal/gppt). As such, lower temperature carbonization followed by acid-extraction – without further solid processing – is a potential pathway to recover phosphorus and adsorbent materials.

Fes Encapsulated Chitosan-G-Polyacrylamide Nanocomposite For The Removal Of Model Anionic Eosin Y From Water: Isotherm, Kinetics And Equilibrium Studies

A novel bio-nanocomposite, FeS/chitosan grafted polyacrylamide, was successfully synthesized by means of a grafting technique that employs microwave irradiation. Employing FTIR, SEM, XRD, TEM and SAED analysis, the synthesized nanocomposites were characterized. Thermodynamic and kinetic studies were performed using the batch mode via the adsorption of eosin yellow from aqueous solution using the nanocomposite. The adsorption process was tailored to the pseudo-second order kinetic model and the Freundlich isotherm model. The enthalpy change, ∆H° (-12.243 kJ/mol), was an exothermic process. The Gibbs energy, ∆G° (from -5.492 kJ/mol.K to -5.078 kJ/mol.K for temperatures from 300 K to 318 K respectively) values were indications of a thermodynamically feasible reaction process which was spontaneous within the temperature domain. The change in entropy, ∆S° (-0.023 kJ/mol), showed a reduced randomness during the adsorption process. The mean free energy of adsorption was 0.408 kJ/mol, which was an indication of physisorption. These results show the possible use of the graft copolymer as an adsorbent in water treatment.

Advances in Amine-Surface Functionalization of Inorganic Adsorbents for Water Treatment and Antimicrobial Activities: A Review.

In the last decade, adsorption has exhibited promising and effective outcomes as a treatment technique for wastewater contaminated with many types of pollutants such as heavy metals, dyes, pharmaceuticals, and bacteria. To achieve such effectiveness, a number of potential adsorbents have been synthesized and applied for water remediation and antimicrobial activities. Among these inorganic adsorbents (INAD), activated carbon, silica, metal oxide, metal nanoparticles, metal–organic fibers, and graphene oxide have been evaluated. In recent years, significant efforts have been made in the development of highly efficient adsorbent materials for gas and liquid phases. For gas capture and water decontamination, the most popular and known functionalization strategy is the chemical grafting of amine, due to its low cost, ecofriendliness, and effectiveness. In this context, various amines such as 3-aminopropyltriethoxysilane (APTES), diethanolamine (DEA), dendrimer-based polyamidoamine (PAMAM), branched polyethyleneimine (PEI), and others are employed for the surface modification of INADs to constitute a large panel of resource and low-cost materials usable as an alternative to conventional treatments aimed at removing organic and inorganic pollutants and pathogenic bacteria. Amine-grafted INAD has long been considered as a promising approach for the adsorption of both inorganic and organic pollutants. The goal of this review is to provide an overview of surface modifications through amine grafting and their adsorption behavior under diverse conditions. Amine grafting strategies are investigated in terms of the effects of the solvent, temperature, and the concentration precursor. The literature survey presented in this work provides evidence of the significant potential of amine-grafted INAD to remove not only various contaminants separately from polluted water, but also to remove pollutant mixtures and bacteria.

Manufacturing of macroporous cellulose monolith from green macroalgae and its application for wastewater treatment

Enormous interest in using marine biomass as a sustainable resource for water treatment has been manifested over the past few decades. Herein, the objective was to investigate the possible use of green macroalgae (Codium tomentosum) for cellulose-based foam production through a versatile and convenient process. Macroporous cellulose monolith was prepared from cellulose hydrogel using freeze-drying process, resulting in a mechanically rigid monolith with a high swelling ratio. The as-produced spongy-like porous cellulosic material was used as bio-sorbent for wastewater treatment, particularly for removing methylene blue (MB) dye from concentrated aqueous solution. The adsorption capacity of MB was subsequently studied, and the effect of adsorption process parameters was determined in a controlled batch system. From the kinetic studies, it was found that the adsorption equilibrium was reached within 660 min. Furthermore, the analysis of the adsorption kinetics reveals that the data could be fitted by a pseudo-second order model, while the adsorption isotherm could be described by Langmuir isotherm model. The maximum adsorption capacity was found to be 454 mg/g. The findings suggested that the produced cellulose monolith could be used as a sustainable adsorbent for water treatment.

Synthesis and Performance Analysis of a Mesoporous Polydopamine-Functionalized Magnetic Microcapsule Adsorbent in Water Treatment

Synthesis and Performance Analysis of a Mesoporous Polydopamine-Functionalized Magnetic Microcapsule Adsorbent in Water Treatment