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Functionalizing nanosilica (n-SiO2) particles with suitable active organic moiety leads to the formation of surfaces with precisely controlled physical and chemical characteristics. In this work, a novel nanosorbent (31 ± 2.4 nm), namely succinic acid functionalized nanosilica (n-SiO2@SA), was synthesized via a simple protocol using microwave irradiation to remove Cu(II) ions from aqueous media. The successful functionalization of n-SiO2 was confirmed by FTIR, and the thermal stability of n-SiO2@SA was investigated by TGA study. Other techniques, including HRTEM, DLS and zeta-potential, were utilized to investigate the chemical, surface, and morphological properties of the fabricated n-SiO2@SA. The response surface methodology (RSM) combined with three-level, three-factorial Box–Behnken design (BBD) was applied to optimize the multivariable sorption system using data obtained from 17 batch runs to reach 98.9% of Cu(II) ion removal. The predicted optimal conditions were as follows: contact time = 30 min, pH = 7.1, initial Cu(II) concentration = 317.5 mg L−1, and sorbent dose = 15 mg at which the maximum sorption capacities for n-SiO2 and n-SiO2@SA were 209.3 and 386.4 mg g−1, respectively, at 25 °C, thus supporting the validity of functionalization process. Non-linear regression and linear least-squares methods confirm the suitability of Langmuir model to describe the experimental endothermic, feasible, and chemisorption data, whereas the normalized standard deviation Δq% recommends the pseudo second-order kinetic model to represent the kinetic data. Real Cu-contaminated wastewaters were used to examine n-SiO2@SA nanosorbent for removing Cu(II) ions.

The use of carboxylated graphene oxide (CGO) in the removal of organic pollutants from aquatic life is a recent and significant issue. In this study, EDTA-functionalized magnetite-carboxylated grap...

Folic acid (VB9) was used as an eco-friendly sequestering chemical compound to modify and develop a novel nanocomposite via surface immobilization and chemical bonding with nanosilica (Nano-SiO2) in the chloride form to generate Nano-SiO2@VB9. The synthesized materials were investigated and characterized by several means of SEM, HR-TEM, TGA, FT-IR, XRD and surface area determination. The tendency of Nano-SiO2@VB9 nanocomposite to extract and remove bivalent lead, cadmium and copper ions was studied and optimized under various variables including pH of contact medium, nanocomposite dose, contact time, effect of metal ion concentration and interfering cations-anions. The highest determined capacity values were 562.1, 973.8 and 152.1 mg g−1 for Cd(II), Pb(ІІ) and Cu(II), respectively. The optimum contact time for sorption of metal ions was identified as 25 min, while 10.0 mg of Nano-SiO2@VB9 nanocomposite was the optimum dosage to establish the maximum capacity values. The adsorbed ions were arranged in a multilayer surface and the equilibrium up-take of metal ions by Nano-SiO2@VB9 nanocomposite was favorably characterized by the Freundlich adsorption isotherm model. The potential applications of Nano-SiO2@VB9 for removal and preconcentration of Cu(II), Pb(II) and Cd(II) from real water samples using multistage microcolumn were also studied to confirm excellent percentage extraction values 94–100%, 100% and 57–81%, respectively.

The present study is aimed to examine the adsorption characteristics of Cu(II) by using the novel cellulose acetate composite and to apply it for the removal of Cu(II) from real wastewater samples. In order to achieve this objective, ethylenediamine, diethylenetriamine, triethylenetetramine and te-traethylenepentanene were used for immobilization of grafted cellulose acetate-nanoscale manganese dioxide. Cellulose was extracted from mangrove species Avicennia marina and converted to cellulose acetate then it was formed composite with nano-manganese dioxide via precipitation of nano-manganese dioxide on it. The composite was grafted with acrylamide monomer before immobilization. The synthesized compounds were used for adsorption of Cu(II) and characterized by FT-IR, TGA and SEM. The adsorption characteristics of synthesized sorbents were optimized. Langmuir and Freundlich models were used to establish sorption equilibria. The analytical applications of these modified materials were applied successfully for the removal of Cu(II).

A novel magnetic nanocomposite based on magnetite nanoparticles-functionalized-graphene oxide and hexadecyltrimethyl ammonium bromide has been synthesized (MAGO-CTAB) by a facile route for efficient, fast and sensitive binding with Sunset Yellow (SY). The MAGO-CTAB (27 ± 3 nm) has been successfully characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and vibrating sample magnetization techniques. The influences of different experimental parameters on the % SY removal efficiency were fully investigated. The adsorption rates of SY by MAGO-CTAB were conducted by fitting the experimental data to four kinetic models. Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D–R) adsorption isotherms were applied to study SY removal. The adsorption-desorption stability performance of the novel magnetic nanosorbent was evaluated and confirmed after 5 cycles. The designed MAGO-CTAB was successfully utilized for removal of SY from different food and soft drink samples with excellent recoveries values (98–103%).

Lauryl sulfate is utilized to functionalize magnetic graphene oxide (MGOLS) for fast removal of methylene blue (MB) using batch sorption experiments. The effects of different analytical parameters including medium pH, equilibration time, MGOLS dosage, initial MB concentration and temperature on the % MB removal are investigated. Among different isotherm and kinetic models, the experimental data were best fitted to the Langmuir and pseudo-second-order rate equations. The maximum Langmuir loading capacity reaches 624.42 mg g−1 for MGOLS under optimal conditions. Sorption kinetic of MGOLS is very fast: Approximately 96% of dye extraction was recorded within the first 2 minutes of this sorption process. The sorption mechanism is proposed and the feasibility, thermic and entropic characteristics were evaluated. Sorption and desorption performances of MGOLS are maintained almost constant over five cycles of sorption/desorption. The results concluded MGOLS as an efficient extractor for fast and feasible recovery of MB from aqueous matrices.

A chemical modification method is presented to establish a surface functionalization procedure of amino modified nanosilica (NS-amine) with 1-(3-cyanopropyl)-3-methylimidazolium-bis(trifluoromethylsulfonyl) type of ionic liquid, [CN-C3-MIm]+[NTf2]− for the formation of a novel NS-amine-IL nanocomposite. Based on the TEM analysis and DLS technique, the diameter of the proposed nanocomposite was found 25.4 ± 0.8 nm. The designed NS-amine-IL nanocomposite was additionally characterized using FT-IR, XRD, EDX, TGA, SEM and zeta potential. The sequestration performance of NS-amine-IL was investigated for remediation of bivalent lead and cadmium ions from aqueous solutions. The effects of medium acidity, contact time, NS-amine-IL dosage, interfering ions, temperature and initial adsorbates concentrations on the removal processes of investigated cations were excessively studied. The maximum extraction values of Pb(II) and Cd(II) were recorded at pH 4–5 and pH 7, respectively. The thermodynamic profiles of the adsorption process were searched at optimal conditions. The adsorption processes were feasibly endothermic and fitted well with the Langmuir isotherm and pseudo-second-order kinetics equation. The experimental data indicated that the novel nanocomposite was a promising material for the extraction of both metal ions from wastewater and soil samples with determined recoveries 98.0–99.0% ± 4.9.

Pollution by tetracyclines antibiotics has a great potential risk on human and animal health even at trace levels. Copper nanoparticles immobilized-β-cyclodextrin functionalized reduced graphene oxide (Cu/β-CD/rGO) were successfully prepared as an efficient extractor of tetracycline (TC), oxytetracycline (OTC) and doxycycline (DC) antibiotics from different environmental water samples. Tetracyclines (TCs) are strongly deposited in the matrix of Cu/β-CD/rGO nanocomposite via surface complexation with the Cu-nanoparticles besides the formation of inclusion complexes with β-cyclodextrin and π-π interaction of reduced graphene oxide. The novel nanocomposite was characterized by HRSEM, TEM, TGA, FT-IR, XPS, and XRD. The optimization of variables such as the pH, contact time, ionic strength and TC concentration were successfully analyzed. The maximum adsorption capacity (qm) of Cu/β-CD/rGO calculated from the Langmuir isotherm was 403.2 mg.g−1 for TC, 476.2 mg.g−1 for OTC and 434.8 mg.g−1 for DC at 298 K. The removal efficiency was decreased by 3.7% after five adsorption-desorption cycles. The Cu/β-CD/rGO nanocomposite was applied for removing TCs from tap water and the Nile River water samples. The novel nanocomposite demonstrated fast and highly efficient removing performance for different TCs with low levels and large sample volume.

Zirconium (Zr) decorated with manganese dioxide (MnO2) nanoparticles-functionalized reduced graphene oxide (RGO); (Zr-MnO2@RGO) tertiary nanocomposite was fabricated by a facile chemical route. The bi-functionality of the novel nanocomposite by Zr and MnO2 nanoparticles has greatly enhanced the efficiency and kinetics of its adsorptivity towards arsenic As(V). The physicochemical properties of the fabricated nanocomposite were characterized extensively by using XRD, Raman spectroscopy, TGA, HR-TEM, FT-IR, SEM, and EDX techniques. The effects of medium pH, mass dosage, kinetics, initial arsenate concentration were investigated via batch-adsorption experiments. Contact time study revealed that pseudo-second-order equation fitted well the kinetic data indicated a fast and feasible sorption process. The reusability and stability performance of the nanocomposite was evaluated and confirmed after five adsorption-desorption cycles. The efficacy of the potential novel nanocomposite towards the simultaneous removal of As(V) from industrial and groundwater samples has been examined.

In this manuscript, we have studied the removal of Cd(II) and Pb(II) ions from aqueous solution by using triethylenetetramine functionalized cellulose acetate grafted with the copolymer-manganese dioxide composite. The novel sorbent cellulose was extracted from the mangrove trees ( Avicennia marina ) and it was then acetylated and grafted with acrylamide. The sorbent composite was designed to interact simultaneously with higher metal loading by complexation-adsorption process. FT-IR, SEM, EDAX and TGA techniques were employed to characterize the cellulose modified composite. Sorption equilibria were established after 30 min and their data were described by Langmuir and Freundlich models. The functionalized hybrid cellulose composite showed maximum adsorption capacity 82.06 and 196.84 mg g −1 for Cd(II) and Pb(II), respectively. The studied metal ions were successfully recovered from real wastewater samples of different matrices.

In this study, the ease of magnetic separation was hybridized with the excellent hydrophilicity of both graphene oxide (GO) and dodecyl sulphate (DS) to synthesize a novel nanosorbent (Fe3O4@GO–DS; 10–25 nm) for simple, fast and efficient remediation of malachite green (MG) from aqueous media. The structure and morphology of Fe3O4@GO–DS were elucidated by FTIR, HRTEM, XRD and TGA techniques. Different analytical parameters including medium acidity, equilibration time, Fe3O4@GO–DS dose, initial MG concentration and temperature were optimized for maximum percentage MG removal efficiency. The experimental results indicated that Fe3O4@GO–DS had excellent sorption capacity (714.3 mg g−1 at pH 7.0 and 25 °C) which decreased from 98.75% to 95.60% after five sorption–desorption cycles. The adsorption isotherm data best-fitted to Langmuir model and the sorption reactions follow second order rate equations. Thermodynamic study is inspected and different mechanistic pathways are proposed for the sorption process.

Nanosilica (NSi) was functionalized by oxalic acid (NSi-Ox) and tartaric acid (NSi-Tar) using solvent-free microwave-assisted approach. The two surface-modified NSi sorbents were characterized by Fourier transform infrared, scanning electron microscopy, transmission electron microscopy, and thermal gravimetric analysis. NSi-Ox and NSi-Tar sorbents were examined for the removal of Co(II) from aqueous solutions by the batch adsorption technique. Removal of Co(II) was carried out at different controlling parameters such as pH, contact time, sorbent mass, and interfering ions. The maximum Co(II) uptake values were identified as 733.3 and 1026.7 μmol g−1 for NSi-Ox and NSi-Tar, respectively, and these were higher than the identified value by NSi sorbent (440 μmol g−1). This trend is mainly due to the surface functionalization with several active groups. The adsorption isotherms were evaluated using Langmuir and Freundlich models and the results were better fitted to the Langmuir model (R2 = 0.983 and 0.989 for NSi-Ox and NSi-Tar, respectively). Kinetic studies were performed and the experimental data were found in good agreement with the pseudo-second-order model. The thermodynamic parameters were also determined. The potential applications of NSi sorbents for removal of Co(II) from drinking tap water and sea water samples were successfully achieved using microcolumn studies.

Chitosan, CS was chemically engineered by maleic anhydride via simple protocol to produce N-maleated chitosan, MCS which immobilized on anatase TiO2 to synthesize novel eco-friendly nanosorbent (51±3.8 nm), MCS@TiO2 for cost-effective and efficient removal of Pb(II) ions from aqueous media. The chemical structure, surface properties and morphology of MCS@TiO2 were recognized by FTIR, (1)H NMR, XRD, TEM, DLS and zeta-potential techniques. The relations between %removal of Pb(II) and different analytical parameters such as solution acidity (pH), MCS@TiO2 dosage, time of contact and initial Pb(II) concentration were optimized using response surface methodology (RSM) and Box-Behnken design (BBD) statistical procedures. The fitting of the experimental data to four different isotherm models at optimized conditions was carried out by various statistical treatments including the correlation coefficient (r), coefficient of determination (r(2)) and non-linear Chi-square (χ(2)) test analyses which all confirm the suitability of Langmuir model to explain the adsorption isotherm data. Also, statistics predicted that the pseudo-second-order model is the optimum kinetic model among four applied kinetic models to closely describe the rate equation of the adsorption process. Thermodynamics viewed the adsorption as endothermic and feasible physical process. EDTA could release the sorbed Pb(II) ions from MCS@TiO2 with a recovery above 92% after three sorption-desorption cycles. The novel synthesized nanosorbent is evidenced to be an excellent solid phase extractor for Pb(II) ions from wastewaters.

Biopolymers are derived from natural sources and are abundant in nature. Biopolymers have received a great deal of attention in drug delivery compared with conventional polymers because they are nontoxic, biocompatible, biodegradable, and relatively cheap. The drug-delivery systems can be synthesized with controlled composition, morphology (shape, size), and functionality. The surface properties can be modified to enhance the solubility, immunocompatibility, and cellular uptake. The application of biomaterials in living systems would reduce immunological reactions and toxicity. Biomaterials with nano-scale organizations have been projected to tune release kinetics, regulate biodistribution, and reduce toxic side effects and thereby increase the therapeutic index of a given drug. In this chapter mainly nanostructured biopolymers based on proteins and polysaccharide are discussed.

An increasing demand of nanomedicines over the last two decades has led scientists to develop 1–100 nm sized drug delivery systems, to improve the delivery of various hydrophobic compounds to achieve an efficient therapeutic outcome and overcome various obstacles such as low-molecular weight, low solubility, and high hydrophobicity of anticancer agents. Polymeric micelles are promising vehicles for the hydrophobic compounds in drug delivery systems. The is because they enhance the circulation time and improve the administration and target site accumulation. Polymeric micelles are based on amphiphilic block–copolymers consisting of hydrophobic core and a hydrophilic shell. On the other hand polymeric micelles can self-assemble into well-defined core–shell structures at concentrations above their critical micelle concentration. These well-defined characteristics of polymeric micelles have made them highly suited for enabling the enhanced permeability and retention (EPR)-mediated passive drug delivery of hydrophobic compounds. This chapter includes an introduction to polymeric micelles, as well as the preparation, characterization, and biomedical applications of polymeric micelles.

Food safety problems caused by tetracycline antibiotics residues are a significant concern due to their great risk to human health even at trace levels. In the current work, a highly sensitive and selective determination of similar chemical composition tetracycline (TC) and doxycycline (DC) antibiotics in milk samples was developed by offline solid phase extraction using β-cyclodextrin functionalized magnetic graphene oxide nanoparticles (β-CD-MGONPs) followed by differential pulse voltammetric determination with a β-cyclodextrin modified carbon paste (β-CD-MCP) sensor. β-CD-MGONPs was prepared, characterized by XRD, FTIR, TEM, and TGA and applied for the removal of TC/DC using batch adsorption experiments. The effects of medium acidity, equilibration time, adsorbent dose, initial antibiotic concentration, and ionic strength were extensively investigated using UV-Vis spectrophotometry at optimal adsorption conditions. The experimental data are well described by the Langmuir isotherm and pseudo-second-order kinetic model. The maximum adsorption capacity was found to be 666.7 mg g−1 for TC and 769.2 mg g−1 for DC. Furthermore, loss in the removal efficiency was 3.5–5.6% after three adsorption–desorption cycles. Then, the electrochemical response of the β-CD-MCP sensor following β-CD-MGONPs extraction was investigated by differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Under optimal electrochemical parameters, anodic differential pulse voltammetry (ADPV) at +320.0 mV and cathodic differential pulse voltammetry (CDPV) at −800.0 mV were selectively used to detect TC and DC, respectively. The response currents of the β-CD-MCP sensor exhibited a linear relationship towards TC/DC concentrations ranging from 0.5–90.0 ng L−1. The limit of detection (LOD) of TC or DC was calculated as 0.18 ng L−1. Other validation parameters confirmed the adequate applicability of the proposed system to detect TC/DC in milk samples. The proposed platform showed advantages of simplicity, rapidity, reliability, and low cost compared to other previously published reports.

A low cost and very sensitive method for the assessment of tyrosine in blood serum, urine and hair samples was developed. The method was based upon measuring the luminescence intensity of the nano optical sensor Eu–ciprofloxacin doped in a sol–gel matrix at 617 nm and in the presence of different concentrations of tyrosine in acetonitrile at pH = 9.1, λex = 380 nm. The significant quenching of the luminescence intensity of the Eu–ciprofloxacin complex by different concentrations of tyrosine was successfully used as an optical sensor in acetonitrile at 617 nm. The effects of different analytical parameters, e.g. pH, solvent, tyrosine concentration and foreign ion concentrations, were fully analysed. A calibration plot was achieved over the tyrosine concentration range 1.2 × 10−6 to 1.0 × 10−9 mol L−1, with a correlation coefficient of 0.997 and a detection limit of 1.0 × 10−10 mol L−1. The developed method is simple and proceeds without practical artifacts compared to other published methods.

Hexavalent chromium, Cr(VI), is a highly toxic species, while trivalent chromium, Cr(III), is an essential trace element for humans and other organisms. In the present work, a simple, rapid, and efficient procedure for water treatment of Cr(VI) is described. Active carbon (AC) was chemically treated with HCl and NaOH for the formation of surface modified Acidic-AC and Basic-AC sorbents, respectively. In addition, AC sorbent was treated with HNO$_{3}$ as an oxidizing agent and sodium sulfite as a reducing agent for the formation of Ox-AC and Rd-AC sorbents, respectively. The modified AC sorbents were tested to identify their potential applications in removal of Cr(VI) under various controlling factors using the batch technique. The results indicated that these sorbents can be used in water treatment due to their excellent and efficient reduction of Cr(VI) into Cr(III) with percentage transformation values in the range of 90%-100%. Acidic-AC was found to be the superior sorbent in the reduction process of Cr(VI). The produced Cr(III) was removed from aqueous solutions via adsorption on the surface of these sorbents. The reduction and adsorption processes of Cr(VI)-Cr(III) were evaluated and optimized under different experimental parameters. The potential applications of these sorbents in real water treatment were also explored.

The aluminon functionalized MNPs (Fe 3 O 4 @aluminon) as a novel magnetic nano-sorbent have been synthesized by a simple hydro-thermal method for the removal of Cr(VI) and Cr(III) from aqueous solution. Fe 3 O 4 @aluminon MNPs were characterized using SEM, HRTEM, FTIR, VSM and TGA techniques. The Fe 3 O 4 @aluminon nano-sorbent has good dispersibility and valuable magnetic property. The effects of pH, equilibration time, mass of nano-sorbent and initial concentration of adsorbate on the percentage recovery of Cr(VI) and Cr(III) by Fe 3 O 4 @aluminon were investigated. The adsorption equilibrium was attained in 20 min at 25 °C and the adsorption kinetics obeyed the pseudo-second order model. The experimental data for the adsorption of Cr(VI) and Cr(III) better fitted the Langmuir isotherm and the maximum adsorption capacities were 263.2 mg/g for Cr(VI) at pH 1.0 and 400.0 mg/g for Cr(III) at pH 7.0. The adsorption–desorption cycles revealed that Fe 3 O 4 @aluminon nanoparticles had high stability and appropriate reusability. The removal efficiencies of chromium ions from different water samples were successfully accomplished (∼ 95.0–96.7 ± 1.4–2.1%).

Potassium permanganate is commonly used in multidiscipline processes as a strong oxidizing agent for oxidative treatment of a great number of organic and inorganic compounds. In this work, a method...

In this work, dioctyl phthalate (Dop) was used as a highly plasticizing material to coat and link the surface of basic cellulose (Cel) with baker's yeast for the formation of a novel modified cellulose biosorbent (Cel-Dop-Yst). Characterization was accomplished by Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and Scanning Electron Microscope (SEM) measurements. The feasibility of using Cel-Dop-Yst biosorbent as an efficient material for removal of Co(II), Cu(II), Cd(II), Hg(II) and Pb(II) ions was explored using the batch equilibrium technique along with various experimental controlling parameters. The optimum pH values for removal of these metal ions were characterized in the range of 5.0-7.0. Cel-Dop-Yst was identified as a highly selective biosorbent for removal of the selected divalent metal ions. The Cel-Dop-Yst biosorbent was successfully implemented in treatment and removal of these divalent metal ions from industrial wastewater, sea water and drinking water samples using a multistage microcolumn technique.

A magnetic nano-sorbent was synthesized via direct surface impregnation of dioctyl phthalate (Dop) on magnetic nano-iron oxide (nano-Fe 3 O 4 ) for the formation of (nano-Fe 3 O 4 -Dop). The produced material was further functionalized with nitrogen and oxygen donor atoms by surface immobilization of hydroxylamine for the formation of a novel magnetic nano-sorbent (nano-Fe 3 O 4 -Dop-HA). This was identified using SEM, HR-TEM, TGA, FT-IR and surface area determination. The average particle size was found in the range of 5–16 nm based on the HR-TEM analysis. The incorporated selectivity was examined for removal of Cd(II), Hg(II) and Pb(II) from aqueous solutions by the static and dynamic techniques. Nano-Fe 3 O 4 -Dop-HA was identified by high Hg(II) uptake capacity values (1433.3–1633.3 μmol g −1 in pH 1.0–7.0) compared to Cd(II) and Pb(II). The contributions of pH, contact time and nano-sorbent dosage, initial metal ion concentration and interfering ions on the magnetic solid phase extraction by nano-Fe 3 O 4 -Dop-HA were also studied and optimized. The potential applications of nano-Fe 3 O 4 -Dop-HA for removal of Cd(II), Hg(II) and Pb(II) from industrial wastewater, sea water and drinking tap water samples were successfully accomplished using a multistage micro-column technique.

A simple and solvent-free method is proposed for synthesis of novel magnetic nano-sorbents. Dioctyl phthalate (DOP) was used to encapsulate nano-Fe 3 O 4 and produce a nano-Fe 3 O 4 -DOP sorbent. This was treated with triethylenetetramine (TETA) in another solvent-free procedure for the formation of a novel nano-Fe 3 O 4 -DOP-TETA. The synthesized nano-sorbents were characterized by FT-IR, TGA, SEM and HR-TEM (3.0–12.0 nm). The magnetic solid phase sorption characteristics were studied and optimized. The potential applications of these magnetic solid phase extractors for removal of Ni(II), Cd(II) and Pb(II) from drinking tap water, industrial wastewater and sea water samples were accomplished using a multi-stage micro-column technique.

Baker’s yeast (Saccharomyces cerevisiae) was immobilized on mango (Mangifera indica L.) leaves to prepare a novel, low cost, and eco-friendly biosorbent Mi-yeast. The fabricated biosorbent was characterized by FTIR and SEM and applied to remove Co(II) and Ni(II) ions from aqueous solutions via batch mode technique. The biosorption equilibria were established in 30 min and the experimental data were applied to Freundlich, Langmuir, and Dubinin–Radushkevich isotherm models. The maximum biosorption capacities were found to be 526 mg g−1 for Co(II) at pH 6 and 250 mg g−1 Ni(II) at pH 7. Among four kinetic models, the experimental data were best described by the second-order expression. Different foreign ions were found to have a negligible interfering effect on the biosorption capacities. Mi-yeast could be regenerated using 0.2 M HCl during repeated biosorption–desorption cycles with 4–7% loss in metal efficiency after five cycles. The potential applications of Mi-yeast for selective removal of Co(II)...

We have studied the extraction of Cu(II) and Pb(II) ions from different types of aqueous solution by novel cross-linked graphene oxide sheets by modified extracted cellulose. The novel sorbent cellulose was extracted from the mangrove trees (Avicennia marina) and it was then grafted with acrylamide and immobilized by ethylenediamine for cross-linking process. The cross-linked graphene oxide sheets were identified by means of FT-IR, SEM and XRD. The adsorption studies of synthesized sorbent was optimized. Langmuir and Freundlich models were used for establish sorption equilibria. The cross-linked graphene oxide sheets showed maximum adsorption capacity 46.39 and 186.48 mg g−1 for Cu(II) and Pb(II), respectively. The potential applications of this sorbent was applied to remove Cu(II) and Pb(II) metal ions from hard water samples by using a multi-stage micro-column technique.

Biosorption and water treatment of Mg(II) and Ca(II) hardness was designed via surface loading of heat inactivated Fusarium verticillioides fungus (Fus) on nano-silica (NSi) for developing the (NSi–Fus) as a novel biosorbent. Surface characterization was confirmed by FT-IR and SEM analysis. The (NSi), (Fus) and (NSi–Fus) sorbents were investigated for removal of Mg(II) and Ca(II) by using the batch equilibrium technique under the influence of solution pH, contact time, sorbent dosage, initial metal concentration and interfering ion. The maximum magnesium capacity values were identified as 600.0, 933.3 and 1000.0 μmole g −1 while, the maximum calcium values were 1066.7, 1800.0 and 1333.3 μmole g −1 for (NSi), (Fus) and (NSi–Fus), respectively. Sorption equilibria were established in ∼20 min and the data were well described by both Langmuir and Freundlich models. The potential applications of these biosorbents for water-softening and extraction of magnesium and calcium from sea water samples were successfully accomplished.

Novel biosorbent systems were designed, investigated and implemented for bioaccumulation of Pb(II) from aqueous solutions. These are based on the combination of SiO 2 -nanoparticles (N-Si) with Penicillium funiculosum fungus (Pen) for the formation of (N-Si-Pen) as well as heat inactivated Penicillium funiculosum (Pen). The SiO 2 -nanoparticles were also investigated as a solid sorbent phase. Surface characterization and immobilization were examined and confirmed by using FT-IR and SEM analysis. A batch equilibrium technique was used to follow-up the adsorption processes of lead under the effect of pH, contact time, sorbent dosage and initial metal concentration. The maximum capacity values were 1200.0 and 1266.7 μmol g −1 for (Pen) and (N-Si-Pen), respectively at pH 5. Sorption equilibria were established in ∼20 min and their data were well described by Langmuir, Freundlich and Dubinin–Radushkevich models. The potential applications of these biosorbents for extraction of Pb(II) from real samples contaminated with lead, were successfully accomplished.

Heat inactivated Aspergillus ustus (Asp), silicon dioxide-nano-powder (N―Si), and silicon dioxide nano-powder-combined-heat inactivated Aspergillus ustus (N―Si―Asp) were used to study the biosorption of Cd(II) from aqueous solutions via batch equilibrium technique. Surface characterization and immobilization of the fungal cells on silicon dioxide-nano-powder were examined and confirmed by using FT-IR and ESM analysis. Cadmium biosorption processes were investigated under the effect of pH, contact time, sorbent dosage and initial metal concentration. The three examined sorbents were found to exhibit maximum μmol g-1 capacity values in pH 7.0. The maximum determined cadmium capacity by silicon dioxide-nano-powder (N―Si) (600 μmol g− 1) was found higher than that exhibited by the heat inactivated fungal cells (Asp) (400 μmol g− 1). However, (N―Si―Asp) exhibited the highest sorption cadmium capacity (1000 μmol g− 1) as a combined behavior of both silicon dioxide nano-powder and Aspergillus ustus units. Sorption equilibria were established in 20 min and their data were well described by both Langmuir and Freundlich models. The potential applications of these sorbents for biosorptive removal of Cd(II) from real samples contaminated with cadmium, were successfully accomplished via a micro-column under constant flow rate.

Dowex anion exchanger-immobilized-baker’s yeast [Dae-yeast] were synthesized and potentially applied as environmental friendly biosorbents to evaluate the up-take process of anionic and cationic mercury(II) species as well as other metal ions. Optimization of mass ratio of Dowex anion exchanger versus yeast (1:1–1:10) in presence of various interacting buffer solutions (pH 4.0–9.0) was performed and evaluated. Surface modification of [Dae-yeast] was characterized by scanning electron microscopy (SEM) and infrared spectroscopy. The maximum metal biosorption capacity values of [Dae-yeast] towards mercury(II) were found in the range of 0.800–0.960, 0.840–0.950 and 0.730–0.900 mmol g−1 in presence of buffer solutions pH 2.0, 4.0 and 7.0, respectively. Three possible and different mechanisms are proposed to account for the biosorption of mercury and mercuric species under these three buffering conditions based on ion exchange, ion pair and chelation interaction processes. Factors affecting biosorption of mercury from aqueous medium including the pH effect of aqueous solutions (1.0–7.0), shaking time (1–30 min) and interfering ions were searched. The potential applications of modified biosorbents for selective biosorption and extraction of mercury from different real matrices including dental filling waste materials, industrial waste water samples and mercury lamp waste materials were also explored. The results denote to excellent percentage extraction values, from nitric acid as the dissolution solvent with a pH 2.0, as determined in the range of 90.77–97.91 ± 3.00–5.00%, 90.00–93.40 ± 4.00–5.00% and 92.31–100.00 ± 3.00–4.00% for the three tested samples, respectively.

A method is proposed and explored for speciation of Cr(III) and Cr(VI), selective extraction and preconcentration in various water samples based on dynamic and static techniques. Three newly designed alumina phases-physically adsorbed-2-pyridenecarboxyladehyde-thiosemicarbazone [Al-2PC-TSC (I–III)] were synthesised and characterised. Stability tests and application of [Al-2PC-TSC (I–III)] as inorganic ion exchangers and chelating solid sorbents for various metal ions were studied and evaluated. The distribution coefficient and separation factors of chromium species versus other interfering metal ions were determined to examine the incorporated selectivity into these alumina phases. Quantitative recovery of Cr(VI) was accomplished by [Al-2PC-TSC (I–III)] at pH = 1.0 while Cr(III) was found to be quantitatively recovered on these sorbents at pH = 7.0 with minimal or no interference between these two species under the studied buffering conditions. Selective solid phase speciation and preconcentration of Cr(I...

A method is presented and described for speciation, extraction and preconcentration of Cr(III) and Cr(VI) based on dynamic and static solid phase extraction techniques. Three newly designed alumina phases-physically adsorbed-isatin-thiosemicarbazone (I-III) were synthesized, characterized, tested for stability and applied as inorganic ion exchangers and chelating solid sorbents for various metal ions. The selectivity characteristics incorporated into these alumina phases were studied and evaluated via determination of the distribution coefficients and separation factors of chromium species versus other interacting metal ions. Quantitative recovery of Cr(VI) was accomplished by alumina phases (I-III) in pH 1.0 giving percentage extraction values of approximately 99.9-100.0%, while Cr(III) was found to be quantitatively recovered by these sorbents in pH 7.0 leading to percentage extraction values approximately 100.0% with minimal or no interference between these two species under the studied buffering conditions. Selective solid phase speciation and preconcentration of Cr(III) and Cr(VI) in various real water samples were successfully performed and accomplished by newly designed alumina phases (I-III) via a preconcentration micro-column.

A speciation method is developed for Cr(III) and Cr(VI) at selected medium pH range via solid phase extraction on three designed and synthesized chelating inorganic solid sorbents based on adsorption of thiosemicarbazide, as the nitrogen and sulfur containing chelating compound, on alumina surface [Al-TSC (I–III)]. The influence of various parameters including medium pH, time of contact, and interference of matrix and coexistent elements on the speciation and selective extraction processes of chromium species are studied and evaluated on the basis of determination of the metal adsorption capacity, distribution coefficient, and separation factor. Quantitative recovery of Cr(VI) was accomplished by [Al-TSC (I–III)] at pH = 1.0, while Cr(III) was found to be recovered on these sorbents at pH = 7.0 with minimal or no interference between these two species under the studied buffering conditions. The proposed method has been successfully applied for speciation, selective extraction, and preconcentratio...

Chitosan, CS was chemically engineered by maleic anhydride via simple protocol to produce N-maleated chitosan, MCS which immobilized on anatase TiO2 to synthesize novel eco-friendly nanosorbent (51±3.8 nm), MCS@TiO2 for cost-effective and efficient removal of Pb(II) ions from aqueous media. The chemical structure, surface properties and morphology of MCS@TiO2 were recognized by FTIR, (1)H NMR, XRD, TEM, DLS and zeta-potential techniques. The relations between %removal of Pb(II) and different analytical parameters such as solution acidity (pH), MCS@TiO2 dosage, time of contact and initial Pb(II) concentration were optimized using response surface methodology (RSM) and Box-Behnken design (BBD) statistical procedures. The fitting of the experimental data to four different isotherm models at optimized conditions was carried out by various statistical treatments including the correlation coefficient (r), coefficient of determination (r(2)) and non-linear Chi-square (χ(2)) test analyses which all confirm the suitability of Langmuir model to explain the adsorption isotherm data. Also, statistics predicted that the pseudo-second-order model is the optimum kinetic model among four applied kinetic models to closely describe the rate equation of the adsorption process. Thermodynamics viewed the adsorption as endothermic and feasible physical process. EDTA could release the sorbed Pb(II) ions from MCS@TiO2 with a recovery above 92% after three sorption-desorption cycles. The novel synthesized nanosorbent is evidenced to be an excellent solid phase extractor for Pb(II) ions from wastewaters.

Chromium is one of the most toxic and carcinogenic heavy metals. Conventional techniques which are commonly applied for removal of chromium ions from aqueous matrices have several drawbacks whereas biosorption has a high performance for metal extraction. Three fungal strains, i.e., (1) Aspergillus ustus (Asp), (2) Fusarium verticillioides (Fus), and (3) Pencillium funiculosum (Pen), have been immobilized on nanosilica (NSi) surface to develop highly effective three biosorbents, i.e., (1) NSi-Asp, (2) NSi-Fus, and (3) NSi-Pen. They are used for solid phase extraction and selective removal of Cr(III) and Cr(VI) ions. Surface characterization and immobilization of fungal cells on nanosilica were examined and confirmed by using scanning electron imaging and Fourier-transform infrared analysis. Biosorption and removal of chromium ions were followed up via batch experiment under the influence of pH, contact time, biosorbent dosage, and initial metal ion concentration. The maximum biosorption capacity va...

Metal pollution is well recognized as one of the major environmental problems that must be imperatively addressed and solved. In this study, three types of alumina adsorbents (I-III) were physically immobilized with purporogallin as a chelating ion exchangers. These were found to exhibit strong capability and selectivity characters for a series of heavy metal ions. Surface modification of hybrid alumina was characterized and identified from the determination of surface coverage and infrared analysis. Hybrid alumina adsorbents were identified for their strong resistivity to acid leaching in pH>2-7 as well as their high thermal stability up to 350 degrees C. The ability of newly synthesized hybrid inorganic/organic alumina adsorbents (I-III) to bind and extract various metal ions was examined and evaluated in various buffer solutions (pH 1.0-7.0) via determination of the metal adsorption capacity values. These were identified as high as 420-560, 500-580 and 500-590 micromol g(-1) for alumina adsorbents (I), (II) and (III), respectively in the case of high concentration levels of Cr(III), Fe(III) and Cu(II). The influence of alumina matrices were highly characterized when low concentration levels (microg ml(-1) and ng ml(-1)) of metal ions were used. Hybrid alumina adsorbents were successfully applied for selective extraction, removal and preconcentration of various heavy metals from underground water samples with percentage recovery values of 92-100+/-1-3%.