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Dyeing industries release their hazardous dyeing effluents into the environment which affects the human health and ecosystem. Hence, the removal of dye from waste‐water is mandatory one. In this present study, focus on the fabrication of bio‐clay‐ceramic hybrid composites by dispersing bentonite (BT) clay and ceramic hydroxyapatite (HA) into alginate (Alg) and gelatin (Gel) polymeric matrixes by in‐situ method which gives BTHAAlg and BTHAGel hybrid composites for methylene blue (MB) removal. The various adsorption influencing parameters such as shaking time, adsorbent dosage, pH and initial MB concentration were optimized under batch method. The highest MB adsorption capacities of BTHAAlg and BTHAGel composites were found to be 43.70 and 47.50 mg/g respectively with optimized conditions of 100 mg/L of initial MB concentration, 40 min shaking time and 0.1 g dosages. In pH studies, the high MB adsorption capacity of bio‐clay‐ceramic composites were noticed at pH 11. The characterization techniques like FTIR, SEM and EDAX analysis were performed to find the physico‐chemical properties of bio‐clay‐ceramic composites. The equilibrium data of hybrid composites towards MB adsorption was well fitted with Langmuir isotherm model than D‐R and Fruendlich models because of higher r and low sd values. The negative values of ▵Go at three different temperatures (303, 313 and 323 K) indicate that the spontaneous nature of MB adsorption, while positive values of ΔHo and ΔSo revealed that the MB adsorption onto hybrid composites was endothermic in nature and more randomness occurred at solid/liquid interfaces. In kinetic studies, the MB adsorption onto hybrid composites was well fitted with pseudo‐second‐order and intra‐particle diffusion models. The electrostatic attraction and hydrogen bonding plays a dominant role in MB adsorption onto BTHAAlg and BTHAGel bio‐clay‐ceramic composites. The regeneration studies proposed that the hybrid composites can be reusable upto five cycles. Hence, the developed bio‐clay‐ceramic hybrid composites were act as best adsorbents for MB removal. [ABSTRACT FROM AUTHOR]

The porous, definite and nitrogen rich triaminotriazine (TAT) grafted graphene oxide (GO) known as TATGO composite was developed for nutrients (NO 3 − and PO 4 3−) retention. Additionally, the structural property of TATGO composite was improved with the use of chitosan (CS) to produce easily separable TATGO@CS hybrid beads which possess the significant NO 3 − and PO 4 3− adsorption capacities of 58.46 and 61.38 mg/g respectively than their individual materials. The instrumentations such as SEM, TGA, FTIR, EDAX, XRD and BET studies were executed for adsorbents. The optimization of the parameters accountable for adsorption process was performed in batch scale. The effect of isotherms (Langmuir, Freundlich and Dubinin-Radushkevich (D-R)), kinetics (pseudo-first/second order and particle/intraparticle diffusion) and thermodynamic parameters (ΔG°, ΔH° and ΔS°) of the adsorption was explored. The removal mechanism of TATGO@CS hybrid beads was to be electrostatic attraction on NO 3 − and PO 4 3−. The field applicability and reuse of TATGO@CS hybrid beads was also inspected. • Novel TATGO@CS composite beads were approached for NO 3 − and PO 4 3− retention. • Amidation reaction between TAT and GO was performed to convert COOH group of GO. • The adsorbent was characterized by FTIR, XRD, TGA, SEM, EDAX and BET studies. • Protonation of the porous beads leads to electrostatic interaction on NO 3 −/PO 4 3−. • The synthesized beads possess cost-effective and can be reused up to 6 cycles. [ABSTRACT FROM AUTHOR]

In the present study, we have fabricated magnetic nanocomposite based on the starch and salicylaldehyde resin embedded with magnetic Fe 3 O 4 nanoparticles (SS@Fe 3 O 4). The fabricated nanocomposite was characterized using various analytical methods including XRD, SEM, FTIR, TGA, TEM, BET and XPS. As-fabricated nanocomposite was used for the adsorption of Pb(II) and Cd(II) from aqueous solution. The adsorption results revealed that the maximum adsorption capacity was found to be 265.4 and 247.2 mg/g for Pb(II) and Cd(II) respectively at pH 6 and room temperature. The adsorption kinetic results support that the adsorption of both the toxic metals was carried out via second order reaction and the rate constants were found to be 6.31 × 10−5 and 7.18 × 10−5 g·mg−1·min−1 for Pb(II) and Cd(II) respectively. The adsorption isotherm displays the Langmuir adsorption isotherm and supports the monolayer and mainly chemisorption with poor physisorption. Additionally, the thermodynamic parameters were evaluated and the adsorption came true in exothermically and spontaneously with both Pb(II) and Cd(II). As-fabricated starch based magnetic nanocomposite displays excellent adsorption as well as outstanding reusability. Therefore, these outcomes support that the SS@Fe 3 O 4 nanocomposite can be used as a promising adsorbent for industrial application. Unlabelled Image • Starch based magnetic nanocomposite was fabricated with salicylaldehyde. • As-fabricated nanocomposite was used for the adsorption of Pb(II) and Cd(II) from aqueous solution. • The effects of pH value, contact time and concentration on the adsorption process were investigated. • Pb(II) and Cd(II) adsorption followed the pseudo-second order kinetics and Langmuir isotherm model. [ABSTRACT FROM AUTHOR]

In the present study, the magnetic nanocomposite is fabricated using chitosan, thiobarbituric acid, malondialdehyde and Fe 3 O 4 nanoparticles (CTM@Fe 3 O 4). The fabricated nanocomposite (CTM@Fe 3 O 4) is characterized using FTIR, TGA, BET, XRD, Raman, XPS, FESEM, and HRTEM techniques. The results of BET analysis confirmed that the nanocomposite has a mesoporous structure with high surface area of 376 m2 g−1 and high pore volume 0.3828 cm3 g−1. The adsorption of tetracycline (TC) onto CTM@Fe 3 O 4 adsorbent is carried out using batch technique by changing several factors such as pH, concentration, contact time, and temperature. Langmuir and pseudo-second-order nonlinear models were found to be the best-fit models to predict isotherms and kinetics of adsorption, respectively. The highest adsorption capacity of 215.31 mg/g was achieved at the optimum conditions of 0.05 g adsorbent dosage, 60 mg/ L TC concentration. Overall, results demonstrated that CTM@Fe 3 O 4 nanocomposite was an excellent adsorbent material with superparamagnetic properties, which allowed the separation as well as recovery of the adsorbent from aqueous solution using external magnet for effective industrial applications. Unlabelled Image • Mesoporous nanocomposite of chitosan/thiobarbituric acid/malondialdehyde-Fe 3 O 4 has been prepared. • CTM@Fe 3 O 4 nanocomposites show super-paramagnetic features. • The fabricated nanocomposites show high surface area of 376 m2 g−1 and high pore volume 0.3828 cm3 g−1. • The adsorption kinetics and isotherms can be well-defined by pseudo-second-order model and Langmuir isotherm model. [ABSTRACT FROM AUTHOR]

Adsorption is a commonly used technique for the removal of pollutants from wastewaters. In this study, a magnetic adsorbent (Fe 3 O 4 @BFR) was prepared using biuret-formaldehyde pre polymeric resin (BFR) and Fe 3 O 4 nanoparticles. The adsorption ability of Fe 3 O 4 @BFR was investigated using Cd(II) metal ion as a typical pollutant. Adsorption of Cd(II) was studied as a function of temperature (25–45 °C), pH (2–7), time (5–300 min) and initial Cd(II) concentration (25–75 mg L−1). The morphology, structure and magnetic character of Fe 3 O 4 @BFR nanocomposite were explored using X-ray powder diffraction, Fourier transform infrared spectroscopy, N 2 adsorption-desorption isotherm, scanning electron microscopy and VSM analyses. Adsorption kinetics, isotherms and thermodynamics studies were also carried out. The experimental adsorption data followed the pseudo-first-order kinetic model and Langmuir isotherm with a maximum adsorption capacity of 92.6 mg g−1. The reusability of Fe 3 O 4 @BFR was tested and still over 70% Cd(II) was removed after three cycles. In conclusion, Fe 3 O 4 @BFR nanocomposite showed enormous potential for remediating industrial wastewater polluted by toxic Cd(II) metal ion. • Fe 3 O 4 @BFR was prepared using biuret-formaldehyde pre polymeric resin and Fe 3 O 4 nanoparticles. • Fe 3 O 4 @BFR was used for the adsorptive removal of Cd(II) from aqueous medium. • The process obeys Langmuir isotherm and pseudo first order kinetic model. • The adsorption was increased with increasing the temperature. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biochars (BcB-1.0 and BcB-1.5) with high surface areas (1267–1520 m2g−1) were produced. • Fast kinetic processes were obtained with 95% saturation being attained in less than 23 min. • Both biochars successfully removed pharmaceuticals from the synthetic pharmaceutical industry with an efficiency of 98–99%. • DFT calculation elucidated the enalapril adsorption mechanism on biochars. Porous biochar was fabricated from Butia capitata (Bc) seed, which was used to uptake enalapril maleate from synthetic wastewater. Activated biochars were fabricated by blending Bc and ZnCl 2 at 1:1 (BcB-1.0) or 1:1.5 (BcB-1.5) proportions and furtherly pyrolyzed at 600 °C. The elemental analysis, Boehm titration, hydrophobic balance ratio, FTIR, TGA, and N 2 isotherm characterized the carbon-based materials. They presented a hydrophilic behavior with diverse polar groups on their surface. BcB-1 and BcB-1.5 biochars have a total pore volume of 0.392 and 0.492 cm3 g−1 and a surface area of 1267 and 1520 m2/g, respectively. The kinetics and isothermal data were adequately adjusted to the fractal-like pseudo-second-order and Liu models. The employment of BcB-1.0 and BcB-1.5 for treating synthetic wastewater containing high levels of pollutants had elevated efficiency in their removals (up to 99.06%). We also conducted a DFT computational study, density functional theory (DFT), to examine the interactions between enalapril and a graphitic domain of biochar by using these calculations, the most stable configuration presented interaction energy of −88.7 kJ mol−1 implies a face-to-face π–π stacking interaction involving the enalapril phenyl segment and an aromatic ring of the graphitic domain, as well as London dispersion arising from the proximity of ethoxy/pyrrolidine to biochar carbon atoms, with interatomic distances of 3.31 Å for the former and 3.60 Å /3.48 Å for the latter. Also, the DFT calculations agreed with the thermodynamic data calculated from the isotherms (283–318 K). [ABSTRACT FROM AUTHOR]

In this study, highly porous N/S doped magnetic carbon aerogel (N/S-MCA) was successfully fabricated using sugarcane bagasse based cellulose and used for the removal of bisphenol‑A (BPA) from aqueous solution. The fabricated N/S-MCA nanocomposite derived from cellulose was characterized by various analytical techniques and supports the formation of the N/S-MCA in good yield and high purity. The batch adsorption studies were used for the adsorption of BPA onto N/S-MCA. The maximum removal of the BPA (98–99%) by the N/S-MCA was noted at pH 7, temperature 343 K, and initial BPA concentration of 100 ppm. The adsorption process followed pseudo-second-order reaction kinetics, as well as Langmuir isotherms. The thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy) supported the spontaneity of the adsorption process. The results revealed that the mechanism on the synergistic adsorption between N/S doped magnetic carbon aerogel and BPA will therefore be an important guideline to design a carbon based adsorbent for high-efficient adsorption of environmental pollutants. Unlabelled Image • N/S doped magnetic carbon aerogel (N/S-MCA) was fabricated using sugarcane bagasse. • The (N/S-MCA) nanocomposite showed the high rates of adsorption for BPA. • The adsorption was support the second order adsorption for BPA. • The (N/S-MCA) was regenerated by simply washing with M methanol solution. [ABSTRACT FROM AUTHOR]

This review discusses the brief of health problem associated with the arsenic exposure found in drinking water. This review also discusses the shortcomings associated with the traditional methods, advantages with adsorption process and the new approaches towards the advance and effective techniques. The novelty of present study is a collection of latest literature and reports which comprises the latest advances made in the nanoparticles and nano-composites for the efficient removal of arsenic from aqueous medium. The mechanism of interaction of arsenic and nanomaterials surface is discussed in this novel review. The latest and novel approaches towards avoiding the preoxidation step for arsenite removal using oxidants is also highlighted, and the large numbers of nanomaterials having the photo catalytic properties and functionalities for simultaneous oxidation of arsenite to arsenate and adsorption of both forms, is also deliberated. No previous literatures have discussed the detail of oxidation of arsenite to arsenate using the nanomaterials having photocatalytic activities. Overall, this review highlights and provides an overview, advantages and features of the newly developed nanomaterials comprising virgin zero valent metallic nanoparticles, metal oxides, metal doped oxides, binary metal oxides, mixed metal oxides, functionalized metal oxides and organic-inorganic nanocomposites for arsenic removal. The comparative evaluation of cited nanomaterials and low-cost, and others micro/nano-sized adsorbent has also been also comprised. The disadvantages associated with the existing technology are deeply highlighted and future development and prospects have been discussed in depth. Therefore, this review article will definitely contribute a great role to the researches by developing the advanced materials to remove all shortcomings associated with the existing technologies. [ABSTRACT FROM AUTHOR]

Oil spills present the enormous harm to the environment, and its potential remediation for environmental protection is import worldwide. Herein, we report an effective strategy inspired by the lignin based bio-waste date palm pits powder (Phoenix dactylifera L.), which was modified with magnetic Fe 3 O 4 nanocrystals and used as a porous, hierarchical graphite carbon oil/solvent sorption magnetic materials. The fabricated nanocomposite (Fe 3 O 4 @MPC) was characterized using several analytical techniques. The results revealed that Fe 3 O 4 nanoparticles with a 22 nm in average size were embedded into the graphite carbon matrix. The rate of sorption, sorption capacity, oil retention, water uptake, adsorption isotherm model, and kinetic behavior were evaluate and >85% of both oils were adsorbed, onto Fe 3 O 4 @MPC surface in the first 30 min followed by equilibrium in both type of aqueous solution. The batch equilibrium data supported the Langmuir isotherm model with the adsorption capacity about to 23.01 mg/g. The kinetics data was well fitted with pseudo-second-order kinetic model. After saturation, the Fe 3 O 4 @MPC was recycled using ethanol and reused for further cycle. The fabricated nanocomposite exhibited a significant dual oleophilic and hydrophobic nature that can be applicable for oil removal from oil-contaminated wastewaters. Meanwhile, the magnetic properties allowed Fe 3 O 4 @MPC to be separated conveniently and effectively from the solution and used as oil absorbent without touching the oil. Unlabelled Image • Fabrication of highly porous, hierarchical graphite carbon (Fe 3 O 4 @MPC) from date palm pits • Fe 3 O 4 @MPC was used for removal and recovery of diesel and gasoline from aqueous medium. • Fe 3 O 4 @MPC was recycled and used for ten times without any considerable loss in adsorption capacity. • The magnetization saturation value of Fe 3 O 4 @MPC was found to be 37.81 emu g−1. [ABSTRACT FROM AUTHOR]

• Toxicity of arsenic and its treatment was discussed. • The review comprises the application of nanomaterials in arsenic water treatment. • The recent advances in arsenic water treatment using nanomaterials were explicated. • Described the improvements for adsorption of arsenic using latest nanomaterials. • Interaction mechanism between arsenic and nanomaterials was elucidated. This review discusses the brief of health problem associated with the arsenic exposure found in drinking water. This review also discusses the shortcomings associated with the traditional methods, advantages with adsorption process and the new approaches towards the advance and effective techniques. The novelty of present study is a collection of latest literature and reports which comprises the latest advances made in the nanoparticles and nano-composites for the efficient removal of arsenic from aqueous medium. The mechanism of interaction of arsenic and nanomaterials surface is discussed in this novel review. The latest and novel approaches towards avoiding the preoxidation step for arsenite removal using oxidants is also highlighted, and the large numbers of nanomaterials having the photo catalytic properties and functionalities for simultaneous oxidation of arsenite to arsenate and adsorption of both forms, is also deliberated. No previous literatures have discussed the detail of oxidation of arsenite to arsenate using the nanomaterials having photocatalytic activities. Overall, this review highlights and provides an overview, advantages and features of the newly developed nanomaterials comprising virgin zero valent metallic nanoparticles, metal oxides, metal doped oxides, binary metal oxides, mixed metal oxides, functionalized metal oxides and organic-inorganic nanocomposites for arsenic removal. The comparative evaluation of cited nanomaterials and low-cost, and others micro/nano-sized adsorbent has also been also comprised. The disadvantages associated with the existing technology are deeply highlighted and future development and prospects have been discussed in depth. Therefore, this review article will definitely contribute a great role to the researches by developing the advanced materials to remove all shortcomings associated with the existing technologies. [ABSTRACT FROM AUTHOR]

Abstract Amino functionalized multi-walled carbon nanotubes (NH 2 -MWCNTs) were prepared via chemical modification of the surface of multiwall carbon nanotubes. The magnetic nanoparticles (Fe 3 O 4) were embedded with NH 2 -MWCNTs and the developed magnetic carbon nanotube (NH 2 -MWCNTs@Fe 3 O 4) were characterized via several analytical techniques including FT-IR, Raman, XRD, TEM, SAED, SEM, BET and VSM. The fabricated NH 2 -MWCNTs@Fe 3 O 4 was used for the removal of toxic methylene blue dye (MB) from aqueous medium. The results of VSM indicated that the fabricated NH 2 -MWCNTs@Fe 3 O 4 had magnetic nature and the saturated magnetization was 37.91 emu/g. The effect of initial solution pH, temperature and contact time on MB adsorption was also investigated. The results of adsorption kinetics exhibited that the adsorption followed the linear pseudo-second-kinetic model well. Langmuir and Freundlich isotherm models were applied to understand the adsorption behaviors. The maximum adsorption capacity from the Langmuir isotherm equation reached 178.5 mg g−1 indicated that it was a good adsorbent for MB removal. The thermodynamics parameters such as Gibbs free energy (Δ G 0), enthalpy (Δ H 0) and entropy (Δ S 0), supported the spontaneous and exothermic nature of adsorption. It was noted that after six repetitive cycles, the adsorption capacity of NH 2 -MWCNTs@Fe 3 O 4 was 80% of the original value. Hence, it can be concluded that NH 2 -MWCNTs@Fe 3 O 4 had substantial reusability which made it an economical adsorbent for MB removal from aqueous medium. Highlights • Amino-functionalized magnetic multi-walled carbon nanotubes were prepared. • NH 2 -MWCNTs@Fe 3 O 4 was used as adsorbent for MB dye removal. • Adsorption kinetics and equilibrium isotherm models for MB dye were reviewed. • NH 2 -MWCNTs@Fe 3 O 4 was used for six cycles without significant loss in adsorptive performance. [ABSTRACT FROM AUTHOR]

Abstract Magnetic bio-composite was fabricated using curcumin and Fe 3 O 4 nanoparticles. The structure and morphology of the resin (CG) and the curcumin based magnetic nanocomposite (CMNC) was analyzed by several techniques. The CMNC was applied as an adsorbent which revealed outstanding abilities for the adsorption of Hg(II) ions. The equilibrium data coincided with the Langmuir adsorption isotherm indicating the maximum adsorption capacity of CMNC 144.9 mg/g for Hg(II). The adsorption kinetic was well-defined by the pseudo-first-order. The thermodynamic results showed that the adsorption process was spontaneous and exothermic at the studied temperatures. The cycling adsorption/desorption tests were made by using 0.1 mol/L hydrochloric acid solution which revealed that CMNC had good reusable ability up to four cycles. It can be suggested from the results that CMNC could be easily and efficiently used for the removal of Hg(II) from aqueous solution. Graphical abstract Unlabelled Image Highlights • Curcumin based biocomposite (CMNC) was successfully prepared and characterized. • The biocomposites have high adsorption capacity and selectivity for Hg(II) ions. • The adsorption kinetic data was described very well by pseudo-first-order model. • The CMNC was regenerated by simply washing with 0.01 M HCl solution. [ABSTRACT FROM AUTHOR]

In the present study, a facial synthesis of Sn/SnO 2 nanoparticles embedded in nitrogen doped carbon based nanocomposites has been disclosed which was used as a fast and high-performance NH 3 gas sensor. The prepared nanocomposite was characterized by various analytical technique including FTIR, TGA/DTA, Raman, XRD, FESEM, TEM/HRTEM and XPS. The presence of both Sn and SnO 2 nanoparticles in carbon matrix are supported by FTIR, Raman and XRD. The XRD analysis showed the tetragonal crystal phase of SnO 2 nanoparticles, and the BET results revealed 148.9 m 2  g −1 surface area of the nanocomposite. Furthermore, SEM image showed that Sn and SnO 2 nanoparticles were well dispersed in the nitrogen doped carbon matrix. The fabricated sensor was characterized against various concentration of NH 3 and the results indicated that the prepared sensor showed excellent responses at 65 °C working temperature, with 300 ppm concentration of NH 3 and the sensitivity was observed 172.70. Additionally, the fabricated sensor also showed quick response and the recovery time of 60 s and 55 s, respectively. The fabricated sensor with its quick response and recovery time, good repeatability, excellent selectivity, and slight humidity effects has the potential and could be used as NH 3 sensor on industrial scale. [ABSTRACT FROM AUTHOR]

Research on the combination of low and high-bandgap energy materials through an ion-mediated chemical transformation of the nanostructure of one material into another, especially metal chalcogenide quantum dot (QD) solar cells plays a very important role in the fast charge transformation process with high power conversion efficiencies (PCE) by reducing surface charge recombinations. Based on a coordination chemistry approach, the present study demonstrates the importance of cation-exchange process in developing bandgap engineering of tin oxide–cadmium selenide (SnO2–CdSe) with zinc selenide (ZnSe) and tin selenide (SnSe) to form SnO2–CdSe/ZnSe and SnO2–CdSe/SnSe electrodes, respectively. Experimental conditions are optimized from optical and photovoltaic performances. Our best performing cation-exchange interface-modified photoelectrochemical devices, i.e., SnO2–CdSe/ZnSe and SnO2–CdSe/SnSe have achieved improvements of 21% and 28%, respectively, in their PEC values, i.e., 3.78% and 4.41% with remarkable current densities of 19.82 and 28.40 mA cm−2 when compared with SnO2–CdSe (1.63% and 9.74 mA cm−2). This is due to (a) the fast transfer of photo-generated electrons from the CdSe QD sensitizer to SnO2 photoanode by engineering a synergistically favourable band gap and (b) mitigation of a reverse photogenerated electron flow in the presence of a high band gap buffer ZnSe/SnSe layer, which would otherwise cause excessive recombinations. A simple cation-exchange interface modification process can, in general, pave the way for improving the performance of QD-based solar cells. [ABSTRACT FROM AUTHOR]

Pectin based quaternary amino anion exchanger (Pc-QAE) was prepared using simple crosslinking polymerization method. This anion exchanger was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Pc-QAE was applied for the removal of phosphate anion from the aqueous solution. The adsorption process which was pH dependent showed maximum adsorption of phosphate anions at pH 7. Pc-QAE showed good monolayer adsorption capacity for phosphate anions which demonstrated its good capability towards Langmuir isotherm model. Moreover, the adsorption was evaluated thermodynamically and the negative value of Gibbs free energy (−1.791 KJ/mol) revealed the spontaneity of adsorption process. The value of ΔH° and ΔS° were found to be 15.28 and 49.48 KJ/mol, respectively representing the endothermic nature and enhancement in degree of freedom due to the adsorption process. [ABSTRACT FROM AUTHOR]

Nickel ferrite bearing nitrogen-doped mesoporous carbon (NiFe 2 O 4 -NC) was prepared using polymer bimetal complexes and used for the removal of Hg 2+ from aqueous medium. The nanocomposite was characterized using several analytical techniques such as SEM, TEM, FTIR, Raman, TGA/DTA, XRD, VSM, XPS and BET. The adsorption behavior of NiFe 2 O 4 -NC nanocomposites was investigated via adsorption kinetics, isotherms and thermodynamic. The adsorption isotherm could be well described with Langmuir model, with the maximum adsorption capacity of 476.2 mg g −1 at 25 °C. The desorption results showed the best recovery of Hg 2+ metal ion using 0.01 M HCl. The remarkable adsorption properties are mainly attributed to the synergetic chemical coupling effects between NiFe 2 O 4 nanoparticles and nitrogen doped graphitized carbon. The presented cost-effective strategy is developed to prepared NiFe 2 O 4 nanocrystals embedded in nitrogen-doped graphitized carbon matrix using a single source precursor offers prospects in developing highly effective magnetic adsorbent for removal of toxic pollutant form contaminated water. [ABSTRACT FROM AUTHOR]

In this research work we report Gum-ghatti supported ZnSe-WO 3 nano-hetero-assembly for solar powered degradation of endocrine disruptor Bisphenol S (BPA). The photocatalyst was characterized by Scanning electron microscopy (SEM), High resolution transmission electron microscopy (HRTEM), Small area electron diffraction (SAED), X-Ray diffraction (XRD), Fourier transform infra red spectroscopy (FTIR), Photoluminescence (PL), Energy dispersive X-ray (EDX), UV–vis spectrophotometry and Brauner Emmet Teller surface area analyzer (BET). We achieve a Z-scheme photocatalyst (ZnSe-WO 3 ) with a higher charge flow and visible absorption. Gum ghatti acts as a superadsorbent and a sink for charge carriers. The removal of BPA has been studied under three experimental protocols where 99.5% removal was achieved by symbiose of photocatalysis-adsorption-ozonation in just 45 min hetero-assembly has a high surface area, stability and reduced carrier recombination. The results have been analyzed by scavenger effect, mass spectrometry, kinetics and total organic carbon (TOC) analysis. 49.4% of TOC was removed and COD was reduced to 16.7% after 2 h in symbiotic condition. From the band edges and scavenger effect it was inferred that superoxide radical anions are major attacking species. The work paves way for designing of novel photocatalysts with increasing biogenic quotient and higher efficiency. [ABSTRACT FROM AUTHOR]

The present work reports the first demonstration of zirconium oxide (ZrO) as a photoanode and rose bengal (RB) as a sensitizer. ZrO photoanode films were deposited on indium-doped tin oxide (ITO)-coated glass substrate by doctor blade technique. ZrO photoanodes were sensitized by rose bengal dye. Scanning electron microscopy (SEM) was applied to reveal the surface morphological changes for the RB-sensitized and unsensitized ZrO photoanodes. Using UV-vis spectrophotometer, optical absorption analyses were carried out for the RB-sensitized photoanodes. Platinum-coated ITO electrode was used as a counter electrode for electrons collection. The electron transfer at the interfaces was studied by electrochemical impedance spectroscopy. The device fabricated using the photoanode with dye loading time of 24 h performed better, it showed the photocurrent density ( J ), open-circuit voltage ( V ), and fill factor ( FF) of about 0.01 mA/cm, 258 mV, and 34%, respectively. [ABSTRACT FROM AUTHOR]

Zirconium oxide (ZrO) is acquiring considerable attention of most of the research groups and leading to a large number of publications due to its unique properties, especially in the context of emerging trends in the third generation of solar cell research. ZrO films offer magnificent aspects related to physicochemical properties, and the properties are found to be dependent on synthesis methods. In the present review, various deposition techniques used to grow zirconium oxide thin films and their application to enhance the quantum efficiency of titanium oxide (TiO) based dye-sensitized solar cells (DSSCs) are discussed. Also, the modulated performances of DSSCs fabricated by growing the conformal ZrO insulating films to retard interfacial recombination dynamics on preformed TiO films are discussed. [ABSTRACT FROM AUTHOR]

In this study, the determination of noxious heavy metals, cadmium (Cd), bismuth (Bi), mercury (Hg), titanium (Ti), lead (Pb) and metalloid arsenic (As) in skin‐whitening cosmetics were examined using microwave digestion and inductively coupled plasma atomic emission spectrometry method. A complete digestion of cosmetics samples was achieved using a mixture of hydrofluoric acid/hydrogen peroxide/nitric acid. The quantification of the target compounds was done by standard addition method. The excellent quality parameters for instance, detection limits, As (4.6 ppb), Bi (7.9 ppb), Cd (0.45 ppb), Hg (3.3 ppb), Pb (3.8 ppb), Ti (4.3 ppb), linearity (r2 > 0.999) and run‐to‐run and day‐to‐day precisions with relative standard deviations <3% were obtained. The recovery rates for standard reference materials were found between 90 and 105%. The average concentration of heavy metals in cosmetics samples were in the range of 1.0–12.3 (μg g−1, As), 33–7097 (μg g−1, Bi), 0.20–0.6 (μg g−1, Cd), 0.70–2700 (μg g−1, Hg), 1.20–143 (μg g−1, Pb) and 2.0–1650 (μg g−1, Ti). [ABSTRACT FROM AUTHOR]

In this study, an effective and novel nanocomposite (Fe 3 O 4 @TAS) was prepared and applied for the removal of Cd(II), Cr(III) and Co(II) from liquid medium. The mechanism for the adsorption was elucidated by investigating the adsorption kinetics, isotherms and thermodynamics, thoroughly. The maximum adsorption capacities as found by the Langmuir model were 286, 370 and 270 mg g −1 for Cd(II), Cr(III) and Co(II), respectively. The structure, size, porosity and magnetic property, of the prepared magnetic nanocomposite were investigated by FT-IR, XPS, SEM-EDX, BET, XRD, HRTEM and VSM analyses. The saturation magnetization and BET surface area for Fe 3 O 4 @TAS were 41.4 emu g −1 and 210.34 m 2 g −1 , respectively. Fe 3 O 4 @TAS was easily separated from aqueous solution using external magnet and it was regenerated by simple washing with 0.01 M HCl solution. The thermodynamic parameters showed that the involved process was spontaneous and exothermic. The findings inferred that Fe 3 O 4 @TAS had the efficiency in treating wastewater with coexisting metals such as Cd(II), Cr(III) and Co(II) metal ions. [ABSTRACT FROM AUTHOR]

In this study, we have synthesized a starch/poly(alginic acid-cl-acrylamide) nanohydrogel (ST/PL(AA-c!-AAm) NHG) by co-polymerization method which was used as an effective adsorbent for the removal of coomassie brilliant (CB) blue R-250 dye from the aqueous solution. The synthesized nanohydrogel was characterized by FTIR, SEM and TEM techniques. The effect of initial dye concentration, temperature, and agitation time on the adsorption ability of the nanohydrogel was studied comprehensively. The experimental outcomes exhibited that the prepared nanohydrogel had high adsorption tendency to remove the CB from the aqueous solution. The regression coefficient values for Langmuir (0.99), Frendluich (0.93) and Tempkin (0.98) recommended that adsorption process fit to langmuir isotherm. The pseudo-second-order equation showed the better adsorption kinetics of the adsorption process. The feasibility of CB adsorption onto ST/PL(AA-cI-AAm) NHG was also studied thermodynamically and the results indicated that the adsorption was spontaneous and chemical in nature. [ABSTRACT FROM AUTHOR]

In the present study, the effect of various natural food condiments (garlic, ginger, pepper, tomato and onion) on the formation of heterocyclic amines (HAs) in cooked camel meat was studied. In control sample, the amount of HAs MeIQx, 4,8-DiMeIQx and PhIP were obtained between 2.10 and 5.22 ng/g, while, MeIQ and IQ were found less than quantification limit. The camel meat cooked with different food condiments, the HAs were found in lesser amounts. MeIQx, 4,8-DiMeIQx and PhIP were detected from 0.42 to 2.83 ng/g, however, MeIQ and IQ were not indentified in any analyzed samples. Consequently, camel meat cooked by various food condiments illustrates the capability to reduce the HAs formation. Such information may be elucidated because of the presence of antioxidants in such condiments which might have pro-oxidative effects with the subsequent formation of peroxyl radicals or by the scavenging of oxygen or free radicals. Practical Applications This is the first study relating to the inhibition of HAs by means of some common food condiments in cooked camel meat. In this work, five HAs such as MeIQx, 4,8-DiMeIQx, PhIP, MeIQ and IQ have been studied in camel meat samples thermally processed with or without food condiments. Our results evidently demonstrate that the formation of HAs in cooked camel meat is highly affected by using food condiments. The current study also illustrates that the concentrations of HAs can be kept at low levels by cooking the meat that include food condiments. The obtained results could be used to estimate the human intake of HAs either in Saudi Arabia or global and supplied to the search of good food condiments that reduce the threat of exposure to HAs, and thus to advance the food security and quality. [ABSTRACT FROM AUTHOR]

In this study, chitosan- crosslinked -poly (alginic acid) nanohydrogel ( CN-cl-PL(AA) NHG) was synthesized by co-polymerization method. It was used an effective adsorbent for the exclusion of Cr(VI) metal ion from aqueous medium. The synthesized nanohydrogel was characterized by FTIR, SEM and TEM. The TEM images clearly indicated the appearance of smooth surface with average size of particles ranging from 30 to 80 nm. The effect of different adsorption parameters like agitation time, temperature, initial metal ion concentration and adsorbent dosage was studied and optimized. The results demonstrated that the prepared chitosan- crosslinked -poly (alginic acid) nanohydrogel had high adsorption tendency for the removal of Cr(VI) from the aqueous solution. The pseudo-second-order equation represented the better adsorption kinetics for the adsorption process. The thermodynamic studies showed the adsorption of Cr(VI) onto CN-cl-PL(AA) NHG was spontaneous and chemical in nature. [ABSTRACT FROM AUTHOR]

Herein, trisodium citrate based magnetite nanocomposite (Fe3O4-TSC) was used for malachite green (MG) dye expulsion from aqueous medium. The adsorption tests were executed at different parameters. The maximum adsorption were took place at pH 4 in 40 min. The equilibrium studies were demonstrated using Langmuir and Freundlich isotherms and better agreement was attained with the Langmuir model. The maximum adsorption capacity (qe) was calculated 435 mg g-1 using Langmuir equation. The kinetic parameters displayed that MG adsorption onto Fe3O4-TSC followed pseudo-second-order kinetic model. Furthermore, the thermodynamic analysis suggested the adsorption of MG onto Fe3O4-TSC was impulsive and exothermic. The desorption studies showed the best recovery of MG dye in 0.1 M HCl. Finally, it was found that Fe3O4-TSC can be effortlessly separated from mixed solutions using external magnetic field. [ABSTRACT FROM AUTHOR]

In this study, starch based nanocomposite (starch/SnO 2 ) was synthesized and used as an effective adsorbent for the removal of Hg 2+ from aqueous medium. The as-prepared starch/SnO 2 nanocomposite was characterized by means of the XPS, XRD, BET, FTIR, SEM and TEM analyses. The effects of contact time, pH, initial Hg 2+ concentration and temperature on the adsorption performance of starch/SnO 2 nanocomposite were investigated thoroughly. The experimental results showed that starch/SnO 2 nanocomposite had high ability to remove Hg 2+ ion from aqueous medium. The adsorption of Hg 2+ was maximum at the pH 6 and equilibrium was achieved within 60 min. The pseudo-second-order equation represented the adsorption kinetics with high correlation coefficient (>0.998) and the Freundlich isotherm model fitted the adsorption data better than the Langmuir. The maximum adsorption capacity was found to be 192 mg g −1 at 25 °C which was increased with the temperature, indicated the endothermic adsorption. The feasibility of Hg 2+ adsorption onto starch/SnO 2 nanocomposite was also studied thermodynamically and the results showed that the adsorption was spontaneous and chemical in nature. The adsorption capacity of the regenerated adsorbents could still be maintained at 94% by the fourth adsorption–desorption cycle. [ABSTRACT FROM AUTHOR]

Examination of highly proficient photoactive materials for the degradation of antibiotics from the aqueous solution is the need of the hour. In the present study, a 2D/2D binary junction GCM, formed between graphitic-carbon nitride (g-C 3 N 4) and molybdenum disulphide (MoS 2), was synthesized using facile hydrothermal method and its photo-efficacy was tested for the degradation of sulfasalazine (SUL) from aqueous solution under visible-light irradiation. Morphological analysis indicated the nanosheets arrangement of MoS 2 and g-C 3 N 4. The visible-light driven experiments indicated that 97% antibiotic was degraded by GCM-30% within 90 min which was found to be quite high than pristine g-C 3 N 4 and MoS 2 at solution pH of 6, GCM-30% dose of 20 mg, and SUL concentration of 20 mgL−1. The degradation performance of GCM-30% was selectively improved due to enhanced visible-light absorption, high charge carrier separation, and high redox ability of the photogenerated charges which was induced by the effective Z-scheme 2D/2D heterojunction formed between g-C 3 N 4 and MoS 2. The reactive radicals as determined by the scavenging study were •O 2 −, and h+. A detailed degradation mechanism of SUL by GCM-30% was also predicted based on the detailed examination of the band gaps of g-C 3 N 4 and MoS 2. [Display omitted] • 2D/2D layered heterojunction of g-C 3 N 4 /MoS 2 showed high degradation performance. • Sulfasalazine degradation was high for consecutive adsorption-photodegradation. • Proper alignment of MoS 2 and g-C 3 N 4 in heterojunction enhanced degradation rate. • Effective & sufficient production of reactive radicals enhanced the removal rate. [ABSTRACT FROM AUTHOR]

In the present study, an ionic liquid (IL) based on 1-butyl-3- (trimethoxysilylpropyl) -imidazolium tetrafluoroborate (IL) was prepared using metathesis and anion exchange reactions and used to stabilize silver (AgNPs) nanoparticles. The IL-stabilized silver nanoparticles AgNPs@[BMSI]BF 4 were produced in an aqueous solution with NaBH 4 as a reducing agent. TGA, FTIR, XRD, BET, FSEM, TEM/HRTEM, XPS, and UV–Vis spectra were used to analyze AgNPs@[BMSI]BF 4 and were used for the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH 4. AgNPs@[BMSI]BF 4 showed excellent catalytic properties for the reduction of 4-NP to 4-AP and showed 100% conversion of 4-NP to 4-AP within 6 min and the rate constant (k) was found to be 8.33 × 10−3 s−1. The reusability results indicated that 97.8% of 4-NP was converted to 4-AP with highly stable rate constants over six consecutive cycles. The activity factor (AF) and the turn-over frequency (TOF) at room temperature were 3.33 s−1 gm−1 and 0.166 s−1, respectively. This study extends a new approach to the production of stable catalysts for the growing needs in wastewater treatment. [Display omitted] • Ionic liquid-stabilized silver nanoparticles AgNPs@[BMSI]BF 4 were produced. • AgNPs@[BMSI]BF 4 was used for the catalytic reduction of 4-nitrophenol. • AgNPs@[BMSI]BF 4 showed 100% conversion from 4-PNP to 4-AP within 6 min. • Reusability showed that 97.8% 4-NP converted to 4-AP over 4 successive cycles. [ABSTRACT FROM AUTHOR]

A new surfactant-based nanocomposite cation exchanger, sodium dodecyl sulfate-Th(IV) tungstate (SDS-TT) was prepared by the sol-gel method. The SDS-TT was characterized by FTIR, XRD, TGA, SEM, EDS and TEM. The distribution studies for various metal ions on SDS-TT were performed in different acidic mediums. On the basis of distribution coefficient values, SDS-TT was found to be selective for Cu metal ion. SDS-TT was successfully used for the quantitative separation of Cu from the synthetic mixture, pharmaceutical formulation and brass sample. The regeneration studies were performed which showed a decrease in the recovery of Cu from 88 to 70 % after seven consecutive cycles. [ABSTRACT FROM AUTHOR]

Wastewater is contaminated water that must be treated before it may be transferred into other rivers and lakes in order to prevent further groundwater pollution. Over the last decade, research has been conducted on a wide variety of contaminants, but the emerging contaminants are those caused primarily by micropollutants, endocrine disruptors (EDs), pesticides, pharmaceuticals, hormones, and toxins, as well as industrially-related synthetic dyes and dye-containing hazardous pollutants. Most emerging pollutants did not have established guidelines, but even at low concentrations they could have harmful effects on humans and aquatic organisms. In order to combat the above ecological threats, huge efforts have been done with a view to boosting the effectiveness of remediation procedures or developing new techniques for the detection, quantification and efficiency of the samples. The increase of interest in biotechnology and environmental engineering gives an opportunity for the development of more innovative ways to water treatment remediation. The purpose of this article is to provide an overview of emerging sources of contaminants, detection technologies, and treatment strategies. The goal of this review is to evaluate adsorption as a method for treating emerging pollutants, as well as sophisticated and cost-effective approaches for treating emerging contaminants. • This review focuses on high-risk emerging contaminants (ECs) in the environment. • ECs are explored in terms of their occurrence, sources and important mechanisms. • The negative environmental and health effects of ECs are addressed. • Numerous emerging pollutants and improvements in their remediation are reviewed. • Recent progress and possible advances in emerging pollutant adsorption are reviewed. [ABSTRACT FROM AUTHOR]

A novel bio-based polymeric adsorbent curcumin formaldehyde resin (CFR) was synthesized via polycondensation of curcumin (a natural bis-phenol) and formaldehyde. The synthesized resin (CFR) was characterized using various analytical techniques such as CHN, FTIR, TGA-DTA-DSC, NMR, BET, SEM and EDX. The CFR was effectively used for the removal of phenol which is one of the most common organic pollutants in the environment. Batch experiments were performed as a function of various experimental parameters such as effect of contact time (5-120 min), pH (2-8), initial phenol concentration (100-500 mg L-1) and temperature (30-65 °C). The removal rate of phenol using CFR was very fast and equilibrium established within 60 min. Kinetic studies showed better applicability for pseudo-second-order model. The applicability of Langmuir, Freundlich and Temkin isotherm models was investigated and the Freundlich isotherm exhibited the best fit with the experimental data. The antimicrobial activities of CFR were also conducted against several bacteria and fungi. These results clearly indicated the efficiency of CFR as an ecofriendly bio-adsorbent for the wastewaters treatment. [ABSTRACT FROM AUTHOR]

Abstract: A Hg2+ ion selective membrane electrode based on poly-o-toluidine Zr(IV) tungstate composite cation exchange material was fabricated using solution casting method. The effect of membrane composition and plasticizer on the potential response of the membrane electrodes were investigated by using varying amounts of electroactive material and plasticizer. The electrode with 100mg of electroactive material and 12 drops of plasticizer exhibited better performance. The optimized membrane composition was used for the fabrication of ion selective membrane electrode which exhibited typical Nernstian response towards Hg2+ ions in the concentration range 1×10−1–1×10−7 M with a Nernstian slope of 28.107mV per decade change in Hg2+ ion concentration. The response time of the electrode under study for various concentrations of Hg2+ ions was found to be 15s and the electrode can be used for 90days without any considerable divergence in response potential. It can also be successfully used at various concentrations of Hg2+ ions in the pH range from 1.5 to 3.5. It was found selective for Hg2+ ions in the presence of various monovalent, divalent and trivalent interfering ions. It was also employed as an indicator electrode in the potentiometric titration of Hg2+ ions using ethylenediaminetetraacetic acid, disodium salt (EDTA) as titrant. The sharp end point corresponds to the stoichiometry of Hg(II)-EDTA complex. [Copyright &y& Elsevier]

In the present study, De-Acidite FF-IP resin was used to remove a highly toxic and persistent organophosphorus pesticide (malathion) from the aqueous solution. Batch experiments were performed as a function of various experimental parameters such as effect of pH (2–10), contact time (10–120min), resin dose (0.05–0.5g), initial malathion concentration (0.5–2.5µgmL−1) and temperature (25–65°C). The concentration of malathion was determined using a sensitive, selective and rapid ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method. The uptake rate of malathion on De-Acidite FF-IP resin was rapid and equilibrium established within 40min. Kinetics studies showed better applicability for pseudo-second-order model. The equilibrium data was fitted to Langmuir and Freundlich isotherm models and the isotherm constants were calculated for malathion. The values of thermodynamic parameters (ΔG 0, ΔH 0 and ΔS 0) were computed from the Van't Hoff plot of ln K C vs. 1/T which showed that the adsorption of malathion was feasible, endothermic and spontaneous. The regeneration studies were carried out which demonstrated a decrease in the recovery of malathion from 95% to 68% after five consecutive cycles. Breakthrough and exhaustive capacities of malathion were found to be 1.25mgg−1 and 3.5mgg−1, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Ionic liquids have shown their potential as a solvent media for many enzymatic reactions as well as protein preservation, because of their unusual characteristics. It is also observed that change in cation or anion alters the physiochemical properties of the ionic liquids, which in turn influence the enzymatic reactions by altering the structure, activity, enatioselectivity, and stability of the enzymes. Thus, it is utmost need of the researchers to have full understanding of these influences created by ionic liquids before choosing or developing an ionic liquid to serve as solvent media for enzymatic reaction or protein preservation. So, in the present review, we try to shed light on effects of ionic liquids chemistry on structure, stability, and activity of enzymes, which will be helpful for the researchers in various biocatalytic applications. [Copyright &y& Elsevier]

To study the ion exchange kinetics of heavy metal ions on the organic-inorganic composite cation exchanger poly- o-toluidine Zr(IV) tungstate, Nernst-Planck was computer simulated. Simulated numerical results for counter ions (Cu, Zn, Cd and Pb) of equal valence and four different ionic mobilities are presented to understand the ionic diffusion process. These results are based on the fractional attainment of equilibrium U(τ), of the counter ions under study. The forward (M-H) and reverse (H-M) ion exchange processes are justified as the particle diffusion phenomenon. The self-diffusion coefficient ( D), energy of activation ( E), and entropy of activation (∆ S*) have also been estimated to understand the ion exchange process occurring over the surface of this cation exchanger and indicated that the ion exchange process is feasible and spontaneous. It is concluded that the difference in activation energies and entropy of activation may facilitate the separation of metal ions. The regeneration capability of this cation exchanger was also explained. [ABSTRACT FROM AUTHOR]

Two cation-exchange materials, aluminium tungstate (AT) and sodium dodecyl sulphate-aluminium tungstate (SDS-AT), were synthesized. Both samples were characterized by Fourier transform infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy. The distribution coefficients for various metal ions on SDS-AT cation-exchange material were performed in different solvent systems. On the basis of distribution coefficient values, the SDS-AT cation-exchange material was found to be selective for the very toxic metal ion, Cr. The hybrid cation-exchange material offered a variety of technological opportunities for quantitative determination and separation of Cr from synthetic mixtures of metal ions. Some binary and ternary separations of metal ions; viz., Cd-Cr, Zn-Cr, Cu-Cr, Pb-Cr, Mg-Pb-Cr and Mg-Cd-Cr, were performed using a packed column of this material. [ABSTRACT FROM AUTHOR]

There is an ever-increasing demand for rapid, sensitive, cost effective and selective detection methods for the analysis of many essential compounds. When chemiluminescence has been introduced to analytical chemistry as a detection technique, it has been shown to meet many of these requirements. This method has become a powerful tool for the determination of many compounds. Using this method, low detection limits can be obtained with simple and inexpensive instrumentation. Coupled with flow injection technique the method has become more popular for wider applications. Since many excellent reviews on the chemiluminogenic techniques have appeared in the literature in recent years, the present paper does not intend to cover the exhaustive studies in this area, but will selectively describe the analytical applications of nanoparticle sensitized lucigenin and luminol chemiluminescent reactions and evaluate their recent progress together with our present work. [ABSTRACT FROM AUTHOR]

A new crystalline organic-inorganic composite cation exchanger polyaniline Sn(IV) molybdate was developed by mixing polyaniline into the inorganic precipitate of Sn(IV) molybdate. This material was characterized using Fourier transform infrared spectroscopy (FTIR), simultaneous thermogravimetry-differential thermogravimetry (TGA-DTA), X-ray, scanning electron microscopy (SEM) and elemental analysis studies. Ion-exchange capacity, effect of calcinations (100-500 °C) on ion exchange capacity, pH-titrations, chemical stability, elution and distribution behavior were also carried on this material. On the basis of distribution studies, the material was found to be highly selective for Pb ion and its selectivity was tested by achieving some important binary and ternary separations. In order to demonstrate the practical utility of the material, quantitative separations of Pb from a standard reference material (Rompin Hematite) of lead have been achieved. Thermodynamic parameters viz- entropy change (ΔS), enthalpy change (ΔH) and Gibb's free energy change (ΔG) were also calculated. [ABSTRACT FROM AUTHOR]

Abstract: Organic–inorganic type composite cation-exchanger poly-o-toluidine Zr(IV) tungstate was chemically prepared. The physico-chemical properties of the material were studied using FTIR, TGA, X-ray, SEM and EDX studies. The material was also characterized for its ion exchange properties to study its cation exchange behavior. It was observed that the material is thermally stable and possessed fast elution of exchangeable H+ ions. On the basis of K d values, it was found highly selective for Hg(II) heavy toxic metal. The selectivity of this material for various metal ions varied depending upon the composition of eluting solvent. On the basis of selectivity studies, some important binary separations were also achieved to explore the potential application of this composite cation exchanger in environmental analysis of toxic heavy metals. [Copyright &y& Elsevier]

Abstract: A new inorganic cation exchange material Ti(IV) iodovanadate has been synthesized under a variety of conditions. The experimental parameters such as mixing volume ratio, order of mixing and pH established for the synthesis of the material. The most stable sample has been prepared by adding aqueous mixture of 0.1M potassium iodate and 0.1M sodium vanadate into 0.1M solution (CCl4 medium) of titanium chloride at pH 1. The material is characterized using various analytical techniques like XRD, FTIR, TGA–DTA and SEM. A tentative structural formula has been proposed on the basis of chemical composition, pH titration, FTIR and thermogravimetric analysis. The ion exchange capacity and distribution coefficients of various metal ions have been determined to understand the cation exchange behavior of the material. On the basis of distribution studies, the material was found to be selective for Pb2+ ion. Its selectivity has been examined by achieving some important and analytically difficult binary separations, viz. Cr3+–Pb2+, Fe3+–Pb2+, Zn2+–Pb2+, Cd2+–Pb2+, etc. The material has bee also used as an electron exchange material. The oxidation of Fe(II) to Fe(III) has been achieved by batch-equilibrium technique successfully. The decomposition of hydrogen peroxide by the material has also been studied. The practical utility of Ti(IV) iodovanadate has been demonstrated by separating metal ions quantitatively from a synthetic mixture using the packed column of Ti(IV) iodovanadate. [Copyright &y& Elsevier]

Abstract: A new polymeric–inorganic cation exchanger acrylonitrile stannic(IV) tungstate composite was synthesized by sol–gel technique by incorporating stannic(IV) tungstate precipitate with acrylonitrile. Composite materials formed by the combination of inorganic ion exchangers of multivalent metal acid salts and organic polymers (acrylonitrile, cellulose acetate, polyaniline, polypyrrole, polythiophene, etc.), providing a new class of ‘organic–inorganic’ composite exchangers with better mechanical and granulometric properties, good ion exchange capacity, higher stability, reproducibility and selectivity for heavy metals. The physico-chemical characterization was carried out by elemental analysis, TGA, SEM, XRD, FTIR and TEM studies. Ion exchange capacity, pH titrations, elution and distribution behavior were also carried out to understand the ion exchange behavior of the material. The adsorption behavior of heavy metal ions has been reported in nitric acid and two surfactants media by batch processes. The analytical applications of the material have been explored by achieving some analytically important binary separations from aqueous solution on its columns. The practical applicability of acrylonitrile stannic(IV) tungstate was demonstrated in the quantitative separation of Fe3+and Zn2+ contents of a commercially available pharmaceutical sample namely Fefol-Z. [Copyright &y& Elsevier]

EDTA-zirconium phosphate has been synthesized as a new amorphous hybrid cation-exchanger by the combination of the inorganic ion-exchanger zirconium phosphate and EDTA, thereby providing a new class of organic-inorganic hybrid ion-exchanger with better mechanical and granular properties, a good ion-exchange capacity (2.40 mequiv/g dry exchanger for Na+), good reproducibility, and a higher stability and selectivity towards heavy metal ions. It has been characterized using FT-IR, TGA/DTA, X-ray and SEM methods, in addition to ion-exchange studies such as the determination of its ion-exchange capacity, elution and distribution behaviour, to provide a better understanding of the ion-exchange behaviour of the material. On the basis of distribution studies, the material was found to be highly selective towards Th(IV) and its selectivity was examined by achieving some important binary separations such as Cd(II)-Th(IV), Ni(II)-Th(IV), Hg(II)-Th(IV), Zn(II)-Th(IV), Pb(II)-Th(IV) and Al(III)-Th(IV) by column means, indicating its utility in environmental pollution control in one way or other. [ABSTRACT FROM AUTHOR]

An inorganic cation exchanger, aluminum tungstate (AT), has been synthesized by adding 0·1 M sodium tungstate gradually into 0·1 M aluminium nitrate at pH 1·2 with continuous stirring. The ion exchange capacity for Na+ ion and distribution coefficients of various metal ions was determined on the column of aluminium tungstate. The distribution studies of various metal ions showed the selectivity of Fe(III) ions by this cation exchange material. So, a Fe(III) ion-selective membrane electrode was prepared by using this cation exchange material as an electroactive material. The effect of plasticizers viz. dibutyl phthalate (DBP), dioctylphthalate (DOP), di-(butyl) butyl phosphate (DBBP) and tris-(2-ethylhexylphosphate) (TEHP), has also been studied on the performance of membrane sensor. It was observed that the membrane containing the composition AT: PVC: DBP in the ratio 2 : 20 : 15 displayed a useful analytical response with excellent reproducibility, low detection limit, wide working pH range (1-3·5), quick response time (15 s) and applicability over a wide concentration range of Fe(III) ions from 1 × 10-7 M to 1 × 10-1 M with a slope of 20 ± 1 mV per decade. The selectivity coefficients were determined by the mixed solution method and revealed that the electrode was selective for Fe(III) ions in the presence of interfering ions. The electrode was used for atleast 5 months without any considerable divergence in response characteristics. The constructed sensor was used as indicator electrode in the potentiometric titration of Fe(III) ions against EDTA and Fe(III) determination in rock sample, pharmaceutical sample and water sample. The results are found to be in good agreement with those obtained by using conventional methods. [ABSTRACT FROM AUTHOR]

The aim of this article is to review and present the state of the arte about the status of toxic elements (TEs) in soils and assess the potential risk using single and total complex pollution indices in a global scale. We compiled, integrated, and analyzed soil TE pollution data over almost a decade through key maps, which have not been reviewed up to date. All the in-situ and ex-situ remediation treatments have been also reviewed, illustrated, and compared, for the first time. The future perspectives have been discussed and summarized. This review demonstrates that the cornerstone maps and integrated information provide reliable geographical coordinates and inclusive information on TEs pollution, particularly in China. In-situ treatment approaches for TEs polluted soils are more cost-effective and applicable than ex-situ treatment trials. Selecting a feasible remediation strategy should to take the extent of contamination, treatment objectives, site characteristics, cost-efficiency, and public suitability into account. The summarized findings in this review may help to develop innovative and applicable methods for assessing the global soil pollution by TEs. Also, these findings may help to develop innovative, applicable, and feasibly economic methods for sustainable management of TEs contaminated soils to mitigate the environmental and human health risk. [Display omitted] • Assessment of complex soil indices is crucial for soil quality investigation. • Maps are favorable for geographical coordinate and toxic element (TE) concentration. • Various decontamination strategies have been established for TE contaminated soils. • In situ treatments of TE contaminated soils is more cost-effective than ex-situ ones. • Contaminated soil data is essential for the selection of the best treatment strategy. [ABSTRACT FROM AUTHOR]

[Display omitted] • FeWO 4 /NC based nanocomposites were fabricated by hydrothermal process. • The FeWO 4 /NC nanocomposite showed the high porosity and excellent photocatalytic activity. • The degradation of ciprofloxacin (CIF) under visible light. • The scavenger trapping as well as EPR experiments show the role of active species. In this study, we fabricate a highly optical active photocatalytic FeWO 4 /NC by hydrothermal process and characterized. The fabricated photocatalyst was used for the degradation of ciprofloxacin (CIF) under visual light. The initial concentration, contact time and the pH of the solution variate the degradation of CIP in aqueous solution. The scavenger effect was carried out to determine the hole, radicals and the photogenerated species used for the degradation. The FeWO 4 /NC-800showed excellent photodegradation of CIP because of its larger surface area and porous structure. Around 92.23% of the degradation of these pharmaceuticals was achieved within 100 min. The kinetic results support the degradation was carried out via first order kinetics and the rate constant was found to be 0.0240 min−1. The FeWO 4 /NC-800 nanocomposite would be a good candidate for CIP degradation by photocatalysis in contaminated water. [ABSTRACT FROM AUTHOR]

Abstract: A new composite cation exchanger cellulose acetate-Zr(IV) molybdophosphate was synthesized because composite materials formed by the combination of inorganic ion exchangers of multivalent metal acid salts and organic polymers (cellulose acetate, polyaniline, polythiophene, polypyrrole, Nylon 6,6, etc.), providing a new class of ‘organic–inorganic’ composite ion exchangers with better mechanical and granulometric properties, good ion exchange capacity, reproducibility, higher stability and selectivity for heavy metals. The physico-chemical properties of this material were determined using some instrumental analyses viz. FTIR, X-ray, TGA–DTA and SEM. Ion exchange capacity, pH titrations, elution and distribution behavior were also carried out to understand the ion exchange behavior of the material. Its selectivity was examined by achieving some important binary separations like Mg(II)–Ca(II), Zn(II)–Ca(III), Fe(III)–Cr(III), Zn(II)–Cr(III), Cd(II)–Hg(II), Cd(II)–Cr(III) on its column. This new exchanger was offered a variety of technological opportunity for quantitative determination and separation of Cr3+ from a synthetic mixture of metal ions and Ca2+ from commercially available vitamin and minerals formulation namely Recovit. [Copyright &y& Elsevier]

An amorphous sample of inorganic cation-exchanger Zr(IV) tungstomolybdate was prepared by mixing varying ratios of 0. 1M aqueous solution of sodium tungstate and 0. 1M aqueous solution of sodium molybdate into 0. 1M aqueous solution of zirconium oxychloride at pH 1. This cation-exchanger was found to have a good ion-exchange capacity (2. 40mequiv. G−1 for Na+), high thermal and chemical stability. A tentative structural formula was proposed on the basis of chemical composition, FTIR and thermogravimetric analysis. Distribution coefficients (K d) values of metal ions in various solvent systems were determined. Some important and analytically difficult quantitative binary separations viz. Ni(II)–Pb(II), Ni(II)–Zn(II), Ni(II)–Cd(II), Mg(II)–Al(III), etc. were achieved. The practical applicability of the cation-exchanger was demonstrated in the separation of Cu(II)–Zn(II) from a synthetic mixture as well as from real samples of pharmaceutical formulation and brass alloy. [Copyright &y& Elsevier]

Abstract: A new crystalline cation-exchanger aluminium tungstate was synthesized by mixing solutions of 0.1M aluminium nitrate and 0.1M sodium tungstate at pH 1.2. The ion-exchange capacity of the material was found 1.17meqg−1 (for Na+). The K d values for some alkaline and transition metal ions were performed in 0.1M HNO3 and TritonX-100 (non ionic surfactant) solvent systems by batch process. Some important and analytically difficult quantitative and selective separations were achieved by using the packed column of this cation-exchange material column. Ion-exchange equilibria of alkaline and transition metal ions and thermodynamic parameters viz. equilibrium constant (K a), values of standard Gibbs free energy change (ΔG°), standard enthalpy change (ΔH°), and standard entropy change (ΔS°) were determined on this ion-exchange material. The effect of temperature on ion-exchange isotherm of alkaline earth metal ions (Mg2+, Ca2+, Sr2+, Ba2+)/H+ systems and transition metal ions (Fe2+, Co2+, Ni2+, Cu2+)/H+ systems were studied at different temperatures 30, 40, 50, and 60°C. The selectivity coefficients at constant ionic strength (0.03mol/kg) for alkaline and transition metal ions were also evaluated. [Copyright &y& Elsevier]

Abstract: Anion exchange resin Amberlite IR-400 has been modified with napthol blue–black. Effect of concentration, time, pH and temperature on the sorption of dye has been studied. The uptake sequence of various metal ions in a number of solvents has been determined. On the basis of distribution coefficients (K d) in a number of solvent systems, some important binary separations of metal ions of analytical interest have been exploited. The practical applicability of the modified material has been demonstrated in the analysis of synthetic and commercially available antacid and antioxidant formulations namely digene and I-Vit. [Copyright &y& Elsevier]