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In this study, alginate reinforced reduced graphene oxide@hydroxyapatite (rGO@HAP-Alg) hybrids have been fabricated via co-precipitation technique. The developed adsorbent was effectively utilized for the removal of Reactive Blue 4 (RB4), Indigo Carmine (IC) and Acid Blue 158 (AB158) azo dyes from aqueous solution, and found to have the adsorption efficiency of 45.56, 47.16 and 48.26 mg/g, respectively. The thermodynamic parameters demonstrated the endothermic and spontaneous nature of the adsorption process. The adsorption system was pH-dependent and showed maximum dye removal at pH 6–7, which was indicative of the electrostatic interactions, surface complexation and the hydrogen bonding mechanisms involved between the adsorbate and adsorbent during the adsorption process. Furthermore, the renewability studies demonstrated the reusability and stability of rGO@HAP-Alg hybrids up to five successive cycles. This study delivers a promising strategy for removing dye molecules and extends the potential application of rGO@HAP-Alg hybrids to treat practical dye contaminated water/wastewater.

With the advancement of modern industries and metropolitan areas, negative environmental impacts such as eutrophication have become serious issues obstructing the usage of water sources in many countries. In this study, two-dimensional (2D) MXene materials were employed for the adsorptive removal of phosphate and nitrate ions from waters. The adsorption parameters of the sorption system including reaction time, solution pH, background ions, and reusability, were evaluated in batch experiments. Material characterization techniques, including X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy, thermal gravimetric analysis, Brunauer–Emmett–Teller analysis, and high-resolution transmission electron microscopy were performed. The mechanism of removing phosphate and nitrate was clearly described by various kinds of interactions such as electrostatic interactions, and the complexation was significant to elucidate the adsorption mechanism. The adsorption data for phosphate and nitrate update was determined using different isotherms and kinetic models. Reusability and field studies on the MXenes were also conducted. The above findings demonstrate that 2D MXenes could act as promising adsorbents for the elimination of toxic ions from water/wastewater.

Phosphate and nitrate are the vital micro-nutrients and a substantial contributor to the growth of biomass, energy storage, and agricultural activities. However, in their increased concentrations, they also cause potential health problems to human and all other living beings. Layered double hydroxides (LDHs) are highly selective and efficient material for the remediation of the ions of phosphate and nitrate from water, but agglomerate easily due to their high surface properties and are difficult to recover from aqueous solutions. The preparation of LDHs functionalized beads of the biopolymeric background is an alternative to overcome these difficulties. Herein, the present work examined the adsorptive removal of the above-mentioned toxic ions from water using ZnFe-LDHs assembled alginate (ZnFe-LDHs@Alg) beads. The removal efficiency and percentage were examined along with various influencing factors like sorbent dosage, solution pH, contact time, and co-ions also carried out. ZnFe-LDHs@Alg beads revealed an extreme removal efficiency of 94.64 and 74.12 mg/g for the ions of phosphate and nitrate, respectively. The phosphate and nitrate removal by ZnFe-LDHs@Alg beads showed reliability with the Freundlich isotherms. The above findings suggested that ZnFe-LDHs@Alg beads can be used as an efficient and selective sorbent for the remediation of toxic ions from water/ wastewater. Highlights •A Facile ZnFe-LDHs@Alg beads were fabricated and used for the removal of phosphate and nitrate ions•Electrostatic interaction, ion exchange and complexation are main mechanisms.•ZnFe-LDHs@Alg beads obeyed for pseudo-second-order kinetic and Freundlich isotherm model.•Field studies were opted to analyze the performance of the ZnFe-LDHs@Alg beads

In order to remove noxious Congo Red (CR), Acid Red 1 (AR1) and Reactive Red 2 (RR2) dye molecules from water, an environment responsive and biodegradable spherical chitosan-gelatin biopolymeric beads were designed and embedded with Al3+ ions. The surface morphology, specific surface area, crystalline phases, elemental composition and thermal properties of the CAG spherical beads had examined. Adsorption experiments were explored to investigate the adsorption properties of dye molecules on CAG spherical beads. The adsorption parameters like solution pH, contact time, co-existing ions, adsorbent dosage and regeneration studies were optimized using batch experiment method. The maximum adsorption efficiency of CR, AR1, and RR2 dye molecules on CAG spherical beads were 34.89, 32.36 and 33.63 mg/g, respectively. The adsorption system fits well with pseudo-second-order kinetics and Freundlich isotherm model. The molecular interactions followed in the adsorption mechanisms were the electrostatic force of attraction, surface complexation and hydrogen bondings that exist between dye molecules and the CAG spherical beads. The CAG spherical beads could be regenerated up to six consecutive cycles using an aqueous 0.1 M NaOH solution. The study emphasizes that the fabricated CAG spherical beads could act as a potential adsorbent in the water/wastewater treatment process.

Herein, we discuss the application of Al3+ incorporated chitosan and gelatin (Al@CS-Ge microspheres) based biopolymeric hybrid microspheres were fabricated and utilized as an effective sorbent for the selective remediation of phosphate and nitrate ions from water/ wastewater. The surface morphology, functional groups, thermal performance, crystallographic information and elemental composition of the fabricated microspheres were performed by different techniques. The adsorption experiments contained with isotherm, thermodynamic, kinetics and several influencing aspects like shaking time, adsorbent dosage, pH, background ions and pHZPC. In addition, the alternative approach of yielding the biopolymeric microspheres was sufficiently good adsorption capacity and stability in the acidic, neutral and weakly in alkaline medium is proposed. Furthermore, five regeneration cycles were conducted with Al@CS-Ge microspheres to evaluate the removal performance after regeneration to attain equilibrium adsorption efficiency was achieved. In addition, the impact of prepared Al@CS-Ge microspheres was evaluated by calculating the significant sustainability metrics and economic impacts.

The metal incorporated bio-polymers and clay particle composites have been widely used for water/wastewater purification. Since these materials preserve the entire existing features of each component and at the same time, the metal imprinting will enhance the efficiency of adsorption of such composites. Herein, Zr(IV) encapsulated carboxymethyl cellulose-montmorillonite (Zr-CMC-MMT) composite matrix was fabricated and utilized for the removal of aqueous solution of Reactive red 2 (RR) and Acid orange 7 (AO) dyes. The Zr-CMC-MMT composite was characterized using FTIR, XRD, TGA, EDAX, SEM analytical techniques. The surface area, pore volume and the pore size distribution of the Zr-CMC-MMT composite were calculated using the BET isotherm technique. The optimal conditions for adsorption of dyes were found to be; molar ratio of Zr-CS-CMC, 1:1, pH: 3, and temparature: 303 K for 50 mL of 50 mg/L dye solutions. The entire process of dye removal was completed within 40 min. for 100 mg of the Zr-CMC-MMT adsorbent. The isotherms of the adsorption process were in good agreement with the Freundlich model fitting which indicates the heterogeneous surface interaction. Thermodynamic studies suggested that the adsorption process was spontaneous and endothermic in nature. The highly porous nature, electrostatic attraction of the composite, ability to form hydrogen bond between free –OH groups present in the composites, and surface complexation of the composite with the dye molecules enhance the adsorption process.

The eutrophication of water bodies resulting from the excessive amounts of phosphate and nitrate ions in the water systems will cause serious environmental problems. This study deals with the adsorptive removal of toxic anions from aqueous medium using zirconium entrenched chitosan-starch membrane (Zr-CS-ST). The optimization of several influencing key factors like adsorbent dosage, shaking time, solution pH, aggressive ions, zero point charge and temperature were examined by batch mode adsorption experiments. In addition, Freundlich isotherm model showed an outstanding fit with the experimental data's, yielding the maximum adsorption capacities of 86.28 and 70.88 mg/g for phosphate and nitrate, respectively. Thermodynamic parameters, including the Gibbs free energy, entropy and enthalpy change indicated that the removal of both anions by Zr-CS-ST membrane was feasible, spontaneity and endothermic in nature. The diffusion and reaction based kinetic models were exposed to study about the kinetics and adsorption process were followed by pseudo-second-order and intra-particle diffusion kinetic models. The removal mechanism involved by different types of interactions such as complexation, ion exchange and electrostatic interaction, which were adopted for the removal mechanisms. We exposed that, Zr-CS-ST was successfully developed and will be effectively employed for the remediation of phosphate and nitrate ions in field/practical applications.

The aim of this present scenario is to examine the removal performance and mechanism of phosphate and nitrate removal onto metal (Fe3+) loaded chitosan and alginate biopolymeric hybrid beads (Fe-CS-Alg) from aqueous solution. The batch adsorption experiments were accomplished via various operating parameters like pH, dosage, contact time, co-existing anions, and temperature. The equilibrium isotherm study was scrutinized by three different isotherm models like Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The thermodynamic statics specifies that the spontaneous and endothermic nature of phosphate and nitrate adsorption. The proposed mechanism indicated that the removal of phosphate and nitrate ions was mainly governed by electrostatic interaction, complexation and ion exchange mechanism. Consequently, the adsorption mechanism was examined by studying the physicochemical characteristics of the beads and sorbate adsorbed beads using the FTIR, XRD, SEM and EDAX with mapping analysis and TGA analytical techniques. The performance of the Fe-CS-Alg beads in field condition was assessed with contaminated water sample taken from nearby an industrial area. Thus, the experimental outcomes clearly indicated that the developed biopolymeric hybrid beads could be utilized as the potential adsorbents for the removal of phosphate and nitrate ions from aqueous solution.

Phosphate and nitrate are commonly used industrial and agricultural nutrients that are of great anxiety because of their ubiquitous existence in water and wastewater sources and association with harmful health effects. Herein, we aimed to fabricate a novel and environmental-friendly chitosan encapsulated magnetic kaolin beads for the first time and applied for the adsorption of phosphate and nitrate ions from water. The physico-chemical properties of MK-chitosan beads were established by XRD, FTIR, and TGA-DSC techniques. Surface area (BET) analysis shows that MK-chitosan beads have a specific surface area of 2.12 m2/g. Surface morphology and elemental studies (SEM and EDAX) revealed the porous nature of MK-chitosan beads. The synthesized bead material employed as selective and effective adsorbent material for the remediation of phosphate and nitrate from water/ wastewater. The impact of external adsorption influencing effects likes, adsorbent dose, contact time, co-anions, pH of the solution, and temperature experiments have been performed. Adsorption isotherm and kinetic experiments have been studied and the data have been well tailored by the Freundlich isotherm and pseudo-second-order kinetic models. Thermodynamic parametric studies revealed endothermic and spontaneous nature of the overall sorption system. Besides, MK-chitosan beads were found to regeneration performance up to eight consecutive cycles. Furthermore, the adsorbent-adsorbate system implying that MK-chitosan beads could be a promising candidate for the removal of phosphate and nitrate ions from aqueous solutions.

The discharge of organic dyes into the aquatic environment is a serious problem owing to the persistence of possible health risks and ecological hazards of these pollutants. This paper reports a facile method for the preparation of composite material consisting of lanthanum incorporated carboxymethylcellulose-bentonite (LCB) composite and utilized for the removal of Indigo Carmine (IC), Acid Blue 158 (AB158) and Reactive Blue 4 (RB4) dyes from water by batch adsorption techniques. The optimal conditions for the dye adsorption were found to be pH = 3, initial dye concentration: 50 mg/L and adsorbent dosage of 100 mg. The adsorption efficiency of IC, AB158 and RB4 dye molecules were 80.41%, 83.54% and 86.91% respectively. The entire adsorption process was completed within 40 min. The adsorption data fits well with the pseudo-second-order kinetic model, demonstrating the physico-chemical adsorption of the dyes on LCB matrix. The Langmuir, Freundlich, and D-R isotherm models were used to describe saturation point. The fabricated adsorbent material was characterized using PXRD, FTIR, SEM-EDAX, TGA-DSC and surface area measurements. The thermodynamic studies revealed that the adsorption was spontaneous and endothermic in nature. The LCB composite showed remarkable adsorption-desorption efficiency for dye removal in water/wastewater treatment process; hence it can be considered as a competent and potential adsorbent for dye removal.

Nitrate and phosphate are primary pollutants of water/wastewaters for eutrophication and methemoglobinemia diseases, harshly threatening the security of aquatic environments and human health as well as all living beings. The present work investigates the adsorption performance and mechanism of lanthanum encapsulated chitosan-kaolin clay (LCK) hybrid composite was prepared and utilized for the remediation of nitrate and phosphate from water. The fabricated LCK hybrid composite was characterized using XRD, SEM, BET, EDAX, TGA-DTA and FTIR analysis. The removal of nitrate and phosphate onto the LCK composite defined by pseudo-second-order kinetic model whereas the isotherms are described by Freundlich adsorption isotherm model and thermodynamic experiments showed spontaneous and exothermic nature of the adsorption process. Results also demonstrated that the LCK hybrid composite exhibited extremely high nitrate and phosphate adsorption capacity and stability which followed the mechanisms by ion exchange, complexation and electrostatic interactions. Adsorption-desorption experiments revealed that the LCK hybrid composite could be potentially reused with maintaining high adsorption efficiency. This study highlights the novel low-cost, eco-friendly and promising adsorbent for efficient denitrification and dephosphorization from water/ wastewater.

The efficient and selective removal of toxic dye molecules from water/surface water remains a problematic task, owing to their high water solubility and low biodegradability. We fabricated the hydroxyapatite-decorated reduced graphene oxide (HA@rGO) nanocomposites via a simple hydrothermal process and used them as efficient adsorbents for the diazo dyes removal. In the batch experiments, the resultant HA@rGO nanocomposites exhibited fast and excellent removal performance for Trypan blue and Congo red dye molecules in a wide pH range and the maximum adsorption efficiencies of 146.51 and 150.09 mg/g, respectively. Several characterization analysis results demonstrated that the removal performance of the HA@rGO nanocomposites for the toxic dyes was mainly driven by electrostatic, hydrophobic, π–π interactions, and H-bonding between the adsorbents and dye molecules in the aqueous solution. Ubiquitous co-anions have significant influence on the dye removal performance of the HA@rGO nanocomposites because of the higher ionic radius and electronegativity. After adsorption, the exhausted HA@rGO nanocomposites could be regenerated in alkaline solution and reused throughout five successive adsorption–desorption cycles. We believe that the adsorbent fabricated in this work can be effectively used to remove toxic diazo dye molecules from aqueous media.

In the current industrial scenario, the dye molecules are the most rigorous contributors to water pollution, and the removal of these pollutants becomes a problematic task. Carbon adsorbents have been used as superior materials for the water/wastewater treatment process. However, the adsorption system could not use the pristine carbon materials in practical applications as it causes significantly less efficiency in adsorption. Conversely, the tuning of carbon with magnetic materials have been employed. Herein, a magnetically retrievable adsorbent was successfully fabricated using carbon-biomass from the seeds of Moringa oleifera and manganese ferrite viz.; MnFe2O4@MOAC. The organic dyes such as Reactive Blue 4 (RB4), Indigo Carmine (IC) and Acid Blue 158 (AB158) were chosen as the adsorbates for this study, and MnFe2O4@MOAC shows the adsorption efficiency of 32.45, 33.53 and 35.27 mg/g, respectively and the maximum adsorption observed in the pH range of ~3. The adsorption followed the Freundlich isotherm and the pseudo-second-order kinetics. The adsorption thermodynamics revealed that the process was endothermic and spontaneous. The fabricated adsorbent was recovered and reclaimed in five successive cycles of adsorption. Electrostatic attractions, hydrogen bonding and π-π interactions were the essential mechanisms involved in the adsorption. The newly fabricated bio-mass could be visualized as a capable adsorbent for water/wastewater treatment process since the MnFe2O4@MOAC possesses high removal efficiency towards dye molecules.

The rapid industrialization and explosion of the population result in increased usage of water and its consequent discarding causes environmental pollution. The biochar based materials are effectively employed for the removal of dyes from contaminated water. However, the pristine biochar shows less efficiency towards dye adsorption in practical applications. Herein, sulfur tethered adsorbent of Tapioca peel (S@TP) biochar was successfully fabricated and utilized for the removal of organic dyes such as Malachite Green (MG) and Rhodamine B (RhB) from water. The peel of tapioca was used as a precursor for the biochar preparation. The isotherm analysis demonstrates that the S@TP biochar has the adsorption efficiency of 30.18 and 33.10 mg/g for MG and RhB dye molecules, respectively. 25 mg/L concentration of 50 mL dye solutions were used for the adsorption study. The maximum adsorption was observed at a pH range ~8, and the adsorption attained saturation within 120 min. The adsorption followed the pseudo-second-order kinetics, and the adsorption process was composed of the Freundlich isotherm model. The newly fabricated adsorbent could be utilized as a capable adsorbent for the water/wastewater treatment process. The newly fabricated bio-mass could be visualized as a capable adsorbent for water/wastewater treatment process since the S@TP matrix possesses high removal and reusable efficiency towards dye molecules.

The removal of emerging contaminants including heavy metals and perfluorinated compounds has been an increasing concern globally due to their harmful effects on human health and other creatures in the environment. Mixtures of perfluorinated chemicals with heavy metals are often found in polluted areas, which is a critical challenge in water remediation. This study proposes a multifunctional magnetic adsorbent, cerium-incorporated ferrite (CMF) decorated polyaniline (PANI) (CMFx%@PANI) hybrid composites by co-precipitation followed by calcination methods. FTIR, VSM, and zeta potential measurements confirmed the successful incorporation of CMF on PANI. The textural properties and surface morphologies of CMFx%@PANI were examined using BET, FE-SEM, HR-TEM, and EDX analysis. The conventional raw forms of CMF nanoparticles and PANI were inadequate for the removal of the mentioned contaminants. However, the synchronous role of PANI with CMF nanoparticles exhibited higher adsorption capacities toward the perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and hexavalent chromium (Cr(VI)) ions than the individual forms. The sorption kinetics and isotherms indicated that adsorption behaviors of PFOA, PFOS, and Cr(VI) onto CMFx%@PANI followed a pseudo-second-order and Langmuir isotherm model, respectively. The feasible mechanisms of PFOA, PFOS, and Cr(VI) adsorption on CMFx%@PANI were investigated using XPS analysis.

In this study, we have rationally designed and grafted a bio-assisted 2D/2D TiO2/MIL-88(Fe) (TCS@MOF) heterojunction by growing granular TiO2 on the surface of MIL-88(Fe) nanosheet, as hybrid photocatalyst. The hierarchical TCS@MOF composite was prepared via the one-pot solvothermal process and employed for monocrotophos (MCP) degradation under visible light region, since its persistent nature on soil and water causes major threat to the environment. The TCS@MOF promotes a number of packed high-speed nano-tunnels in the (p-n) heterojunctions, which significantly enhance the migration of photo-induced electrons (e−) and holes (h+), respectively and thus limits the charge recombination of e−s. The optimized photocatalyst achieves significant catalytic activity of ~98.79% for the degradation of MCP within 30 min of irradiation. The prominent oxidative radicals namely •OH, •O2− etc., were involved in the oxidation of organic pesticide. Besides, TCS@MOF exhibits outstanding stability even after five repetitive cycles for the oxidation of MCP with a negligible decrease in photo-activity. The proposed mechanism and oxidative pathways of MCP were rationally deduced in detail subject to experimental results. The mechanism renders insight into the oxidation and consequent bond rupture of pollutant as well as into the formation of products such as H2O, CO2, etc. This report unveils a novel architecture of proficiently optimized TCS@MOF material structure for the perceptive oxidation of organic contaminants.

The adsorption of dye molecules from the contaminated water onto the biopolymer is regarded as insignificant since such materials have weak physical, chemical and mechanical stability. However, their surface modification with various organic and inorganic materials lead to a drastic change in their adsorption behaviour. The work revealed the fabrication of a new Ce(III) networked chitosan/β-cyclodextrin (Ce@CCD) adsorbent beads and their utilization for the adsorption of RB4, IC and AB158 dye molecules from water/wastewater. The maximum adsorption capacity of Ce@CCD beads for the removal of RB4, IC and AB158 dye molecules were 29.56, 30.57 and 30.57 mg/g, respectively. The adsorption of RB4, IC and AB158 dye molecules on Ce@CCD beads mainly take place through the electrostatic attraction, hydrogen bonding and surface complexation interactions. The experiments recommended a promising method for the preparation of Ce@CCD adsorbent beads and their application in the advanced adsorption of dye molecules from water.

A hetero-structured adsorbent with outstanding adsorption performance has acquired an increased attention due to their excellent behaviour in environmental applications. Tailoring of graphene oxide and hydroxyapatite with suitable biopolymeric adsorbents would enhance the porosity, stability, specific surface area and shows high sorption performance. Herein, chitosan reinforced graphene oxide-hydroxyapatite (CS@GO-Hap) matrix was fabricated efficiently in the atmosphere of nitrogen by co-precipitation technique. Here, chitosan acted as a host in the preparation and provided the surface for a composite generation. The batch mode method was applied to investigate the adsorption performance of CS@GO-Hap composite, showed an adsorption efficiency of 43.06, 41.32 and 40.03 mg/g for the removal of the toxic Congo Red (CR), Acid Red 1 (AR1) and Reactive Red 2 (RR2) dyes from water, respectively. The composite showed enhanced adsorption at the pH of 2 and the removal efficiency of CS@GO-Hap composite decreased with increase in pH. The adsorption kinetic and isotherm fitted well with pseudo-second-order and the Freundlich model, respectively. The thermodynamic study of the adsorption of dyes showed that the process was spontaneous. The regeneration experiments emphasized that the desorption was ideal, and exhibited more than 65% regeneration ability with 0.1 M NaOH solution. The mechanism of dyes adsorption on CS@GO-Hap composite involved the electrostatic force interaction, surface complexation, hydrogen bondings and π−π stacking interactions. The findings of the study revealed the exceptional behaviour of CS@GO-Hap composite in removing the azo dyes from aqueous solutions and the great significance of the composite in the future application in water/wastewater treatment process.

The consumption of agricultural wastes as environmentally friendly and endorses green chemistry. The potential use of agricultural waste sources with additional treatment for the removal of anionic pollutants from water was examined. Herein, the removal performance of a stable inorganic-organic hybrid composite of porous carbon (Porous carbon derived from papaya seeds) was fabricated through one-pot synthesis and employed for the removal of phosphate and nitrate from water. The as-prepared hybrid composite properties were examined using FTIR, XRD, SEM, VSM, TGA-DSC, BET and EDAX with mapping analysis. The various parameters for the removal of phosphate and nitrate from water using cobalt ferrite coated-porous carbon composite (CoFe2O4@PC) were optimized. The maximum adsorption capacity is 92.34 for phosphate and 78.98 mg/g for nitrate at 303 K. Freundlich adsorption isotherm model is found to be superior fir and heterogeneous surface interaction of phosphate and nitrate ions onto the CoFe2O4@PC composite. The pseudo-second-order and intra-particle diffusion kinetic model describes the removal mechanism and rate-determining steps. Thermodynamic studies recommend that the adsorption process to be endothermic and spontaneous nature. The prepared CoFe2O4@PC composite displayed good removal capacity and was effectively utilized for the removal of phosphate and nitrate ions in real water sample. In addition, this study provides useful insights into the removal of phosphate and nitrate by magnetic separable CoFe2O4@PC composite in water/wastewater.

A lithe zinc-aluminium layered double hydroxides were imprinted on activated carbon and fabricated Zn/Al LDHs@C composite. The composite matrix was utilized for the removal of toxic Congo Red (CR), Acid Red 1 (AR1) and Reactive Red 2 (RR2) dyes from water. The Zn/Al LDHs@C composite was characterized by Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy Dispersive X-Ray Analysis (EDAX), Brunauer-Emmett-Teller (BET), Thermogravimetric analysis-Differential scanning calorimetry (TGA-DSC) and Powder X-ray diffraction (PXRD) analytical techniques. The adsorption process was evaluated by varying the parameters such as contact time, composite dosage, pH of the solution, initial dye concentration and interfering anions. The maximum adsorption of CR, AR1 and RR2 dyes on Zn/Al LDHs@C composite were 44.09, 48.37 and 49.52 mg/g, respectively. The enhanced adsorption efficiency of the composite might be due to the existence of binding forces such as electrostatic attraction of the layered double hydroxide, hydrogen bonding sites on the Zn/Al LDHs@C and the surface complexation phenomena of the composite with the dye molecules. The Freundlich isotherm model was fit superior at the saturation point, indicating the heterogeneous surface interaction. Thermodynamic studies recommend that the adsorption process was spontaneous and endothermic in nature. The adsorption-desorption studies of Zn/Al LDHs@C composite were achieved up to five successive cycles with high efficiency. The enhanced adsorption efficiency of the Zn/Al LDHs@C composite suggested that the fabricated composite was suitable for the removal of CR, AR1 and RR2 dye molecules from water than any other developed hybrids.

In this study is to propose that for the removal of phosphate and nitrate ions from aqueous solutions using zirconium burdened carboxymethylcellulose-surfactant assisted kaolin (Zr-CMC-SKa) membrane as an effective adsorbent. The prepared membrane was synthesized by phase inversion method via polyethylene glycol as a flexible reagent and the developed membrane was extensively characterized by the details of the terms like morphological, compositional, thermal, roughness, functional and microscopic techniques. The optimization of various operating experimental conditions like the function of time, dosage, co-anions, pH, and pHZPC was studied. The adsorption kinetic phenomenon followed by pseudo-second-order and intraparticle diffusion models with good correlations. The fitting of the Freundlich adsorption isotherm model confirms multilayer adsorption of heterogeneous surface interaction between the toxic anions. Thermodynamic parameters, including the (ΔGo), (ΔSo) and (ΔHo) indicated that the phosphate and nitrate adsorption was feasible, spontaneity and endothermic in nature. The mechanistic pathway was mainly governed by electrostatic interaction, complexation followed by the ion-exchange mechanism, which was adopted for the removal of phosphate and nitrate anions from aqueous solutions. Furthermore, the applicability of the synthesized membrane towards promising results against the eutrophicated water sample by reducing the concentration of the toxic anions below the acceptable limit.

Nowadays, efficient and selective remediation of phosphate and nitrate ions from water/ wastewater is a problematical task. In this study, magnetic particles (Fe3O4) decorated GO-CMC (Fe3O4@GO-CMC) composite beads were synthesized via the one-pot process and applied for the remediation of phosphate and nitrate from aqueous medium. XRD, BET, SEM, FTIR, EDAX with mapping images and TGA analysis were done on the synthesized beads in order to examine the structural and textural properties. Batch scale adsorption experiments in phosphate and nitrate solution demonstrated the dynamic behaviours of phosphate and nitrate remediation using Fe3O4@GO-CMC composite beads under various experimental conditions such as agitation time, the influence of beads dosage, solution pH, zero point charge and co-interfering anions. The adsorption isotherm experiments, the Freundlich adsorption isotherm model showed a superior fit than the Langmuir isotherm model, yielding the maximum removal capacity of 84.90 and 76.01 mg/g for phosphate and nitrate ions, respectively. The removal mechanisms and adsorption-desorption experiments were also examined. The aptness of Fe3O4@GO-CMC composite beads at field trail was also analysed by real sample collected from nearby eutrophic endemic area. These results suggested that the Fe3O4@GO-CMC composite beads could be a suitable material for the remediation of phosphate and nitrate ions from wastewater treatments.

Inorganic anions plays an important role in biological, industrial and environmental processes. Among the several anions, phosphate and nitrate ions are highly toxic and harmful to human health and the environment. Herein, we report the porous nature of the cerium incorporated chitosan-β-cyclodextrin (Ce-CS-β-CD) microspheres were prepared and systematically studied for their adsorption performance towards these toxic anions. The connection between the most substantial parameters such as agitating time, adsorbent dosage, co-interfering ions, pH as well as ionic strength with the adsorption percentage and capacity were optimized. The prepared microspheres were broadly characterized by XRD, EDAX with mapping images, SEM, FTIR, and TGA analysis. In the single component system, the adsorption performance showed that multilayer adsorption capacity of 88.54 and 72.12 mg/g for phosphate and nitrate ions respectively. The adsorption of the pseudo-second-order kinetic model showed a superior apt than the pseudo-first-order kinetic model can be effectively defined the uptake of kinetics. The thermodynamic parameters studies shows that the nature of the adsorption is feasible, endothermic and spontaneous nature. The feasible phosphate and nitrate adsorption mechanism of the prepared microspheres were ensued by ion-exchange, complexation and electrostatic interaction. Regeneration and reusability experiments were studied up to seven cycles by 0.1 M of NaOH as a regenerant to assess the reusability of the prepared microspheres. The aptness of Ce-CS-β-CD microspheres has been tested with field condition was investigated with industrial wastewater.