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In the present study, we have synthesized a nano-adsorbent of carboxymethyl cellulose; carboxymethyl cellulose/graphitic-carbon nitride/zinc oxide (CMC/g-C3N4/ZnO) by sol–gel technique. It has been utilized for the adsorptional elimination of methyl violet (MV) from aqueous solution. Maximum surface area as determined from the BET analyses is 9.214 m2/g. XRD analysis confirmed the semi-crystalline nature of the nano-adsorbent. Presence of desired functionalities on the surface of nano-adsorbent, CMC/g-C3N4/ZnO offered maximum interactions with the MV molecules. Isotherm studies generalized the monolayer adsorption of MV molecules with maximum adsorption capacity of 96.43 mg/g. Solution pH affected the adsorption rate to large extent and maximum occurred at pH 8. Pseudo-second order model better explained the adsorption process that determines the chemical interactions between methyl violet and CMC/g-C3N4/ZnO. [ABSTRACT FROM AUTHOR]

Reaction term in the transport equation which described the migration of metal ions in the porous medium is frequently represented by conventional kinetic models such as pseudo-first order, pseudo-second order, and others. Unfortunately, these models are applicable for the constant value of solution pH, and they cannot simulate the real situation in the field scale where this pH may be changed with time. Accordingly, the present study is a good attempt to derive the kinetic model that can simulate the change in the pH of the solution through solute transport. This was achieved by modifying the adsorption capacity and reaction constant to be functions in terms of solution pH by using semianalytical analysis and numerical approximation. The results proved that the kinetic model based on the numerical approximation (using exponential functions for adsorption capacity and reaction constant) symbolled as model 2 was more representative from other models applied for the description of interaction of nickel ions (with initial concentration of 400 mg/L) and cement kiln dust with sum of squared error ≤1.54913 and determination coefficient ≥0.889. Also, the developed models had high ability for recognizing between pure precipitation and pure adsorption. [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]

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]

Oxidized activated carbon (OAC) was prepared from a waste mixture containing palm stem, paper, and plastic and used for the removal of Co(II) from aqueous medium. Adsorption was studied as a function of OAC dose (0.03-0.1 g), time (10-180 min), pH (2-6) and initial Co(II) concentration (50 mg L-1). The maximum adsorption capacity was found 83.6 mg g-1 at pH 4. The adsorption process followed the Freundlich isotherm model and pseudo-second-order kinetics. The OAC showed better efficiency comparable with other reported adsorbents. The results suggested that the prepared OAC could be used as a cost-effective adsorbent for the Co(II) removal from aqueous solutions. [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 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]

In this study, the effectiveness of amberlite IRA-938 resin for Rose Bengal (RB) dye removal from aqueous phase was evaluated. For the RB dye removal, equilibrium was achieved within 45 min because rate of adsorption was fast. The adsorption equilibrium for RB dye onto amberlite IRA-938 resin was in good agreement with Langmuir adsorption isotherm. It was observed that amberlite IRA-938 resin had excellent RB dye adsorption capacity (qm = 142.86 mg g−1at 23°C). The environmental applicability of amberlite IRA-938 resin was performed in the separation of RB dye from the tap water sample spiked with 50 mg L−1RB dye solution. The breakthrough and exhaustive capacity were 100 and 325 mg g−1, respectively. [ABSTRACT FROM AUTHOR]

The present study investigates the biosorption potentiality ofLycopersicum esculentumleaves powder as a low-cost agricultural waste biomass for the removal of Ni(II) ion from aqueous solution in batch method. The experimental kinetic data were modeled using pseudo-first-order, pseudo-second-order, and intraparticle diffusion model. It was found that the biosorption was better described by pseudo-second-order kinetic model. Langmuir and Freundlich isotherm models were applied to analyze the experimental data and to predict the relevant isotherm parameters. The best interpretation for the experimental data was given by the Langmuir isotherm, and the maximum biosorption capacity for Ni(II) is 58.82 mg/g at 323 K. Thermodynamic parameters such as ΔG°, ∆H°, and ∆S° were calculated, and it was observed that the adsorption process was feasible, spontaneous, and endothermic. [ABSTRACT FROM PUBLISHER]

A strongly acidic cation-exchange resin Amberlite IR-120 was successfully used for the separation of toxic metal ions. The distribution coefficient values for various metal ions were performed in different acidic mediums using Amberlite IR-120 resin columns. On the basis of distribution coefficient values, Amberlite IR-120 was found to be selective for Pb2+ ion. A number of important quantitative binary separations of metal ions viz. Cd2+– Pb2+, Hg2+– Pb2+, Cu2+– Pb2+, Zn2+– Pb2+, Cd2+– Al3+, and Mg2+– Al3+ were achieved on the columns of this resin. In order to demonstrate the practical utility of these separations, Mg2+ and Al3+ were determined in commercially available pharmaceutical preparation namely digene using Amberlite IR-120 resin columns. The regeneration studies were carried out which demonstrated a decrease in the recovery of Pb2+ from 88 to 74% after five consecutive cycles. [ABSTRACT FROM AUTHOR]

The polypyrrole/basic oxygen furnace slag nanocomposite (PPy–BOFS) was synthesized and characterized by FTIR, SEM, ICP-AES, and X-ray diffraction studies and was employed as an adsorbent for the removal of phosphate ions from aqueous solution by the batch sorption method. The maximal amount of adsorption was found to be 9.13 mg/g (45°C). The Langmuir and Freundlich isotherms were used to describe the adsorption equilibrium. The kinetics of the adsorption process was investigated using the Lagergren rate equation and the Weber Morris intraparticle diffusion model. The FTIR and XRD pattern of the adsorbent before and after the adsorption was recorded to get better insight into the mechanism of the adsorption process. The results of equilibrium and spectral investigations revealed that the removal of phosphate by the nanocomposite involves various mechanisms followed by the nanocomposite and the constituents present in it. [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]

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]

The thermodynamics of nicotinic acid adsorption from aqueous solution on carboxymethyl cellulose Ce(IV) molybdophosphate composite cation exchanger were studied. The composite cation exchanger was synthesized by sol-gel method and thereby characterized using scanning electron microscopy, thermogravimetric analysis, X-ray powder diffraction and fourier transform infra red spectroscopy. The analytical applicability and thermodynamic parameters, such as Freundlich constant, thermodynamic equilibrium constant ( K), standard free energy changes (Δ G°), standard enthalpy changes (Δ H°) and standard entropy changes (Δ S°) of this composite cation exchanger have been evaluated. The thermodynamic parameters showed that the adsorption of nicotinic acid onto composite cation exchanger is feasible, spontaneous and exothermic, suggesting their suitability for the potential application of nicotinic acid removal from waste water. [ABSTRACT FROM AUTHOR]

In the present study, a polymeric nanocomposite, CoFe2O4@DHBF, was fabricated using 2,4 dihydroxybenzaldehyde and formaldehyde in basic medium with CoFe2O4 nanoparticles. The fabricated nanocomposite was characterized using FTIR, TGA, XRD, SEM, TEM, and XPS analyses. The analytical results revealed that the magnetic nanocomposite was fabricated successfully with high surface area 370.24 m2/g. The fabricated CoFe2O4@DHBF was used as an efficient adsorbent for the adsorption of U(VI) and Eu(III) ions from contaminated water. pH, initial concentration, adsorption time, and the temperature of the contaminated water solution affecting the adsorption ability of the nanocomposites were studied. The batch adsorption results exposed that the adsorption capacity for the removal of U(VI) and Eu(III) was found to be 237.5 and 225.5 mg/g. The adsorption kinetics support that both the metal ions follow second order adsorption kinetics. The adsorption isotherm well fits with the Langmuir adsorption isotherm and the correlation coefficient (R2) values were found to be 0.9920 and 0.9913 for the adsorption of U(VI) and Eu(III), respectively. It was noticed that the fabricated nanocomposites show excellent regeneration ability and about 220.1 and 211.3 mg/g adsorption capacity remains with U(VI) and Eu(III) under optimum conditions. [ABSTRACT FROM AUTHOR]

• MoS 2 /ZnS embedded into N/S-doped was fabricated using polymer complex. • The MoS 2 /ZnS@NSC nanocomposite showed the high porosity. • The MoS 2 /ZnS@NSC nanocomposite showed the photocatalytic degradation of dicofol pesticide. • The scavenger traping as well as EPR experiments show the role of active species used in degradation. A highly efficient, recyclable mesoporous catalyst has been prepared via hydrothermal and post-calcination methods. The prepared nanocomposite (MoS 2 /ZnS@NSC) was characterized via several analytical techniques and used as a photocatalyst for the degradation of dicofol pesticide under visible irradiation. The results reveal that the fabricated nanocomposite show excellent catalytic activity due to the formation of active photogenerated species such as ●OH, O 2 − and e− which was supported by scavenger traping as well as EPR experiments and show excellent reusability for the treatment of pesticide in aqueous solution. [ABSTRACT FROM AUTHOR]

In this study, magnetic/graphene/chitosan nanocomposite (MGCH) is prepared through facile solvothermal process and employed as an adsorbent for the removal of 2-naphthol from aqueous solution. The physico-chemical characteristic results of FESEM, Raman, FTIR, XRD and VSM confirms that the MGCH nanocomposite is effectively prepared. The FESEM and EDS analysis reveals that the high density of spherical-like Fe 3 O 4 nanoparticles and chitosan are successfully assembled on the surfaces of the graphene sheets. VSM result of MGCH composite exhibited higher saturation magnetization of 46.5 emu g−1 and lower coercivity (H c) of 50 O e. This result discloses that MGCH possesses enough response required for the separation from aqueous solution. The batch mode adsorption studies demonstrates that MGCH based adsorbent showed almost 99.8% adsorption of 2-naphthol with a maximum adsorption capacity of 169.49 mg g−1 at pH 2. Moreover, the kinetic studies of the samples are performed by fitting adsorption models to ensure the nature of the adsorption system. This work proves that MGCH nanocomposite can be used as high-performance adsorbent for removing of phenolic pollutants from contaminated wastewater. Unlabelled Image • A novel magnetic/graphene/chitosan nanocomposite (MGCH) was prepared by solvothermal process. • MGCH exhibits higher magnetization of 46.5 emu g−1 and lower coercivity of 50 Oe. • MGCH shows a maximum adsorption capacity (169.49 mg g−1) of 2-naphthol at pH 2 • This method is cost-effective, simple and easy to separate. [ABSTRACT FROM AUTHOR]

Porous nano-crystalline cobalt ferrite (PNCoFe) composite was synthesized by an ecofriendly and economically appealing sol–gel route using egg albumen as a binder gel, and its applicability to remove anionic brilliant blue-R (BB-R) dye from aqueous phase was studied. The arousal of two characteristic peaks at 400 and 600 cm −1 in FT-IR spectra confirmed the formation of ferrite; in addition, TEM-EDX and XRD analysis also confirmed the formation of nano-crystalline ferrite composite. BET surface area analysis revealed the formation of porous adsorbent with surface area 335 m 2 /g. The adsorptive binding of BB-R on PNCoFe-80 surface was confirmed by an increase in adsorbent particle radius from 3.6 to 5.5 nm after adsorption. Acid-base titration results showed dominance of acidic sites over PNCoFe-80 surface. The pH study revealed that adsorptive forces along with electrostatic attraction between anionic dye and PNCoFe-80 surface were responsible for binding of BB-R ions over PNCoFe-80 surface. Extremely fast BB-R adsorption kinetics was observed, scavenging 65–93% of dye at various concentrations (25–100 mg/l) and temperatures (298–328 K) in 1 min. The breakthrough and exhaustive capacities were 8.75 and 37.5 mg/g, respectively. 69.75% of BB-R was recovered with EtOH @ pH 11. For five consecutive regeneration cycles, BB-R adsorption varied between 81 and 100%, while desorption efficiency was almost 100%. Preconcentration study showed 1.255 mg (66.23%) BB-R was eluted in 15 ml eluent (i.e. in three fractions of 5 ml each). [ABSTRACT FROM AUTHOR]

Ligand anchored functional nanomaterials are increasingly gaining interest as efficient materials for various types of toxic pollutants. In this study, the organic ligand of N,N′di(3-carboxysalicylidene)-3,4diamino-5-hydroxypyrazole was densely anchored onto the mesoporous silica by the building-block approach as facial adsorbent, characterized and then examined for the cobalt (Co(II)) ion detection and removal from aqueous solutions. The fixed-time approach was employed for analytical signal measurement in the detection operation. At optimum conditions, the calibration curve was linear in the range of 0.002–0.10 mg/L Co(II) and the limit of detection was also achieved at 0.24 μg/L. Moreover, the diverse ions did not show any significant absorbance intensity. Therefore, the established facial adsorbent provided a simple, rapid, cheap and sensitive method for Co(II) detection and could be used to detect Co(II) ions in the environment. This study also examined the possibility of using facial adsorbent to remove low concentrations of Co(II) ions from water solution. The sorption capacity was significantly affected by solution acidity, contact time and initial Co(II) ion concentration. The higher sorption capacity of the Co(II) ions was observed at higher pH regions. The sorption isotherms fit the Langmuir sorption model well and the maximum Co(II) ion sorption capacity was 157.73 mg/g. The effective eluent of 0.20 M HCl was used to elute the Co(II) from the facial adsorbent, and the adsorbent was simultaneously regenerated into the initial form after rinsing with water. The elution and regeneration showed that the adsorbent could be reused without significant losses of its initial properties even after 8 sorption–elution–reuse cycles. Therefore, the facial adsorbent could be used as a promising adsorbent for fast Co(II) ion detection and removal and might provide a simple and effective method for the treatment of water containing Co(II). [ABSTRACT FROM AUTHOR]

Abstract: Activated carbon was prepared from peanut shell by chemical activation with KOH. Unoxidized activated carbon was prepared in nitrogen atmosphere which was then heated in air at a desired temperature to get oxidized activated carbon. The prepared carbons were characterized for surface area and pore volume and utilized for the removal of Cr(VI) from aqueous solution. The effects of pH, contact time, initial concentration of adsorbate and temperature on adsorption of Cr(VI) were investigated. Adsorption kinetics of Cr(VI) was analyzed by pseudo first order, pseudo second order and intraparticle diffusion kinetic models. Results showed that Cr(VI) adsorption on both oxidized and unoxidized samples followed the first and second order kinetics models most appropriately. Isotherm data were treated according to Langmuir and Freundlich models. The results showed that both Langmuir and Freundlich models fitted the data reasonably but the Langmuir adsorption isotherm model fitted better in the temperature range studied. The adsorption capacity was found to increase with temperature, showed endothermic nature of Cr(VI) adsorption. The thermodynamic parameters, such as Gibb''s free energy change (ΔG°), standard enthalpy change (ΔH°), standard entropy change (ΔS°) were evaluated. The value of ΔG° was found negative for the adsorption of Cr(VI) which confirmed the feasibility and spontaneity of the adsorption process. [Copyright &y& Elsevier]

• AgO/MgO/FeO/Si 3 N 4 synthesized by microwave irradiation method. • Adsorption of tetracycline. • Maximum adsorption capacity of 172.41 mg/g. • Energy sites found to be energetically heterogeneous. Present study has been designed to govern the usage of nanocomposite of Si 3 N 4 with trimetallic oxide nanoparticles of Ag, Mg and Fe (AgO/MgO/FeO@Si 3 N 4) for the tetracycline (TC) removal from aqueous solution. Characterization techniques such as SEM, TEM, XRD, FTIR, XPS and BET were employed for analysing the successful fabrication of AgO/MgO/FeO@Si 3 N 4 nanocomposite. Adsorption process has been found to be dependent upon the surface properties of AgO/MgO/FeO@Si 3 N 4 nanocomposite (such as charge, functionality, etc), concentration of TC, solution pH and contact time. As determined from the isotherm studies, surface of AgO/MgO/FeO@Si 3 N 4 nanocomposite has been found to be energetically heterogeneous in nature as the data fitted well to Freundlich isotherm. Maximum adsorption capacity of AgO/MgO/FeO@Si 3 N 4 nanocomposite has been found to be 172.41 mg/g. Pseudo-second order kinetic model successfully explained the rate studies of TC adsorption. Also, reusability study of AgO/MgO/FeO@Si 3 N 4 nanocomposite has also been carried out. In short, the present study could determine an effective way for the removal of toxic pollutants from the wastewater system. [ABSTRACT FROM AUTHOR]

In this study, a magnetic composite was synthesized using chitosan, diphenylurea and formaldehyde with magnetic nanoparticles, (MnFe 2 O 4) via condensation polymerization. The newly synthesized magnetic nanocomposite (CDF@MF) was characterized using several analytical techniques including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) and etc. To investigate the applicability of CDF@MF, it was employed as an adsorbent for rapidly removal of an antibiotic, namely, tetracycline (TC), from aqueous solution using several factors such as pH, the adsorbent dose, the initial concentration and the contact time. The adsorption kinetics results exhibited that the adsorption process followed a pseudo-first-order model. The maximum adsorption capacity for TC was calculated to be 168.24 mg/g based on the Langmuir adsorption isotherm model, with fitting correlation coefficient (R 2), 0.9955.The regeneration study advice that no major change in the adsorption capacity was noticed and show 157.97% adsorption performance after seven cycles. These results are standing to indicate that the prepared porous CDF@MF could be used as a low-cost, effective, reusable adsorbent for pharmaceutical wastewater treatment. Unlabelled Image • Magnetic polymer nanocomposite was fabricated using chitosan, diphenyl urea and formaldehyde. • The CDF@MF nanocomposite showed the high rates of adsorption for TC. • The adsorption was support the firs order adsorption for TC. • The adsorbent was regenerated by simply washing with 0.1 M methanol solution. [ABSTRACT FROM AUTHOR]

Novel magnetic quaternary BiOCl/g-C 3 N 4 /Cu 2 O/Fe 3 O 4 (BGC-F) nano-heterojunction with excellent photocatalytic activity was prepared by facile co-precipitation method. The visible photodegradation activity of the junction was analyzed for sulfamethoxazole (SME) as target pollutant. BGC-F with a dosage of 0.2 g L −1 exhibits high photocatalytic activity with 99.5% of SME (100 µM) degraded in 60 min under visible (Xe) lamp and 92.1% in 120 min under natural sunlight. The activity of quaternary junction was found to be 7.2, 6.8 and 4.2-fold higher as compared to C 3 N 4 /BiOCl/Fe 3 O 4 , Cu 2 O/BiOCl/Fe 3 O 4 and Cu 2 O/BiOCl/C 3 N 4 junctions respectively. Formation of an effective p-n-p junction (BiOCl-C 3 N 4 -Cu 2 O) leads to shifting of energy bands and rising of an in-built electric field and charge separation. The effect of parameters as pH, catalysts loading amount, NO 3 − and HCO 3 − have been studied. The O 2 − and OH was found to be major reactive species identified by scavenging experiments and the band gap structure analysis The results for mineralization were analyzed in terms of Liquid chromatography-mass spectroscopy (LC-MS), total organic carbon (TOC) removal and chemical oxygen demand (COD). 41.6% of TOC was removed in 3 h experiment under Xe lamp exposure. The drug degradation was also confirmed by testing activity on E. coli and cyto-toxicity on human peripheral blood lymphocytes (PBL). Only 2.1 mm zone of inhibition was observed for E. coli in case of exposure to SME degraded products while for pure SME it was 18.1 mm hinting complete mineralization. In addition 99% cell viability was observed for PBL cells treated with degraded products of SME. Furthermore, BGC-F exhibited good reusability after magnetic separation and regeneration, rendering it a promising multi-functional catalyst with active use of advanced oxidation processes for treating pharmaceutical waste water. [ABSTRACT FROM AUTHOR]

Among the heavy metals, lead is one of the toxic metals which is being released into the environment through various anthropogenic sources and they are of serious threat to the ecosystem. Hence in this study, we have made efforts to utilize bacteria for the removal of lead. The lead resistant bacterial strain namely, Ralstonia solanacearum KTSMBNL 13 was isolated from heavy metal polluted electroplating industrial soil. Factors affecting the removal of lead namely, initial lead ion concentration, solution pH, temperature and contact time were investigated. Results showed that maximum removal of lead was attained (90%) at an initial pH value of 6.0, temperature of 35 °C and contact time of 26 h with an initial metal concentration of 100 mg L −1 . In order to identify the functional groups involved in the uptake of lead ions, FTIR, SEM–EDX, TEM and XRD analysis were carried out. Also the antibiotic sensitivity test for Ralstonia solanacearum KTSMBNL 13 was carried out and it was found that the isolate was sensitive to gentamicin, streptomycin and tobaramycin among the tested 12 antibiotics. From the outcome of the results, it has been demonstrated that Ralstonia solanacearum KTSMBNL 13 is a novel bacteria which can be used as an alternative and promising candidate and can be applied to remove lead from various metal contaminated sites. [ABSTRACT FROM AUTHOR]

The conjugate nanomaterial (CNM) was prepared by sulfur donor containing organic ligand onto the silica substrate for simultaneous mercury (Hg(II)) ions detection and removal from water samples through a batch technique. The potential and feasibility of the CNM as Hg(II) ions selective materials were evaluated in terms sensitivity, selectivity both in the detection and removal operations. In detection, the absorbance spectra increment was linear with the Hg(II) ions concentration in low concentration area, and the detection limit of the CNM was 0.26 μg/L. In addition, the colorimetric changes were extremely specific for Hg(II) ions, and no significant color change was evident in case of other competing metal ions in the sample matrix. In removal, the optimization of experimental conditions, including effect of pH, equilibrium time, initial Hg(II) ion concentration was examined. Due to the strong interaction between Hg(II) ions and sulfur atoms of the active surface, the CNM exhibited high adsorption capacity and excellent selectivity during Hg(II) adsorption. The experimental results showed that the solution pH had a major impact for Hg(II) adsorption by the CNM. The experimental data were well fitted with the linear form of Langmuir model the maximum adsorption capacity of Hg(II) ions was 164.22 mg/g. The Hg(II) loaded CNM could be successfully desorbed with 0.20 M HCl solution, and the adsorption capacities were not decreased sharply even after six cycles showing the practical significance in remediation of Hg(II) contaminated wastewater. In addition, the present approach has the advantages of sensitivity, selectivity, rapidity, simplicity, and low cost for Hg(II) detection and removal, and the newly developed assay might open a new assay avenue for Hg(II) ions contaminated water treatment. [ABSTRACT FROM AUTHOR]

The detection and removal of lead (Pb(II)) ions in water is essential for both human health and the natural environment. This study reported the feasibility of the large-pore diameter nano-adsorbent for capturing low level Pb(II) ions from aqueous solutions in a batch system, in order to comply with the toxicity limit for discharging wastewaters. The nano-adsorbent was prepared by incorporating organic ligand onto the mesoporous silica. The proposed Pb(II) detection system has good characteristics with high sensitivity and selectivity, robustness, easy operation, portability and use of a small sample volume. The sensitive detection was determined under specific optimum conditions and the limit of detection was 0.29 μg/L. The competing ions effect was assessed with spiked samples and the nano-adsorbent exhibited high selectivity to Pb(II) ions with optimum color formation and the detection procedure can be easily applied to rapid on-site Pb(II) ions monitoring. The sorption results clarified that the Pb(II) sorption increased as the initial Pb(II) ion concentration increased. Also the solution pH played an important role for selective uptake of Pb(II) ions. Isotherm data fitted well to the Langmuir isotherm model, indicated as monolayer and spontaneous processes and the maximum sorption capacity was 169.34 mg/g. The sorption results of the nano-adsorbent were compared with the other forms of different adsorbents. In addition, the adsorbent displayed an excellent selectivity to Pb(II) ions over diverse ions in the multi-mixtures metal species system. The adsorbent exhibited reusability and can work for many cycles of Pb(II) detection and removal without significant deterioration of the nano-adsorbent functionality. The results showed that the nano-adsorbent developed in this work has excellent performance to be applied for selective Pb(II) detection and removal from water samples. [ABSTRACT FROM AUTHOR]

In this study, the organic ligand of 4-dodecyl-6-((4-(hexyloxy)phenyl)diazenyl) benzene-1,3-diol (DPDB) and mesoporous silica have been used to prepare the nano-composite adsorbent. The nano-composite adsorbent was fabricated by indirect immobilization of DPDB onto the mesoporous silica. The adsorbent was applied as an efficient material for the detection and recovery of Ce(III) ions in aqueous solutions. The adsorbent was exhibited fast and specific capturing of Ce(III) ions observable to the naked eye and based on the stable complex formation between DPDB and Ce(III) ions. Several experimental parameters such as solution pH, color optimization with initial concentrations, contact time, foreign ions effect and regeneration studies were systematically performed. The experimental data clarified that the Ce(III) was detected and adsorbed by the adsorbent at pH 2.50. The limit of detection for Ce(III) ions by the adsorbent was 0.12 μg/L and the sorption capacity was 150.37 mg/g at optimum conditions. The co-existing ions did not affect the Ce(III) detection and sorption and sorption uptake on the adsorbent reached equilibrium with rapid kinetic performances. The adsorbed Ce(III) was completely eluted with 0.30 M HNO 3 and the adsorbent was regenerated into the initial form at the same time. In addition, the adsorbent was reused for several cycles without significant deterioration in its original functionality. Therefore, the proposed adsorbent allowed the sensitive, selective, easy to use, cost-effective, high efficiency, fast kinetics and stable capturing of Ce(III) ions even in the presence of diverse competing ions. In addition, there was no more secondary sludge produced in this operation and considered the adsorbent as the potential candidate in better replacement technology for capturing Ce(III) ions in a wide range of practical operations. [ABSTRACT FROM AUTHOR]

The water resources contamination in an alarming concern for sustainable environment. This has led to development of new technologies and materials for waste water detoxification. In the present study, we have fabricated novel trimetallic based mixed oxides decorated reduced graphene oxide (rGO) composite using facile microwave method and utilized it as an adsorbent for the removal of congo red dye from aqueous solution. The final composite showed highly agglomerated metal oxides present on the rGO surface. The high surface area and activity of the synthesized adsorbent resulted in its high adsorption capacity of 333.32 mg/g for congo red. The Langmuir model better explained the isotherm data indicating the monolayer adsorption of congo red molecules onto Ag 2 O–Al 2 O 3 –ZrO 2 /rGO surface. The grander adsorption ability of Ag 2 O–Al 2 O 3 –ZrO 2 /rGO towards organic dye indicate its probable utilization in the removal of other dyes also from wastewater. • Trimetallic oxides decorated into rGO matrix were synthesized. • Adsorption of congo red from aqueous solution was investigated. • Maximum adsorption capacity of 333.32 mg/g was obtained using Langmuir isotherm. • Langmuir model better explained the adsorption isotherm data and mechanism. [ABSTRACT FROM AUTHOR]

• Nanocomposite based photocatalyst is designed. • Nanocomposite demonstrated high degradation activity under visible light. • Photodegradation of dyes with degradation rate of 90–96%. • High reusability. Highly visible light efficient photocatalyst; ferric oxide/zinc oxide/silicon nitride (Fe 3 O 4 /ZnO/Si 3 N 4) nanocomposite has been designed. Its photocatalytic activity has been studied for the degradation of two dyes; sunset yellow and methyl orange from aqueous solution. Results showed high degradation rate of 90 and 96% for sunset yellow and methyl orange, respectively. Scavenging studies indicated the major involvement of OH radicals in the degradation process. Reusability study has been conducted for 6 consecutive cycles indicating its appreciable activity even after repetitive cycles. Antimicrobial activity studied against E. Coli and Pseudomonas strains showed an appreciable inhibition zone. [ABSTRACT FROM AUTHOR]