Capacity For Metal Ions Research Articles

PENYERAPAN ION LOGAM Cr(III) DAN Cr(VI) DALAM LARUTAN MENGGUNAKAN KULIT BUAH JENGKOL (Pithecellobium jiringa (JACK) PRAIN.)

Jengkol shells (Pithecellobium jiringa) an agricultural waste from typical Indonesian plant has been investigated for its ability to absorb heavy metal ions Cr VI and Cr III . Effect of pH, concentration, contact time, mass and the speed of stirring biosorben studied by extraction method. Concentration of metal ions Cr VI and Cr III was measured using Atomic Absorption Spectrophotometer (AAS). The optimum conditions for metal ion uptake of Cr VI occurs at pH 4, the concentration of 7000 mg/L, contact time of 60 minutes, 0.1 g biosorben mass and stirring speed 100 rpm. For the metal ions Cr III wa obtained conditions optimum at pH 5, the concentration of 1500 mg/L, contact time of 60 minutes, 0.1 g biosorben mass and stirring speed 100 rpm. Functional groups contained in the jengkol shells analyzed by Fourier Transform Infra Red (FTIR). Data equilibrium uptake of metal ions Cr VI and Cr III by the jengkol shells analyzed using two isotherm models , namely Langmuir and Freundlich isotherm models . The absorption of both the metal ions tend to follow the Langmuir isotherm models in which the absorption capacity of metal ions obtained for Cr VI ) and Cr III is 24.9376 mg / g and 39. 0625 mg /g . The optimum condition was applied to study the river Batang Arau at Padang city obtained a capacity of 15.065 mg/ g with 45 efficiency, 94 % for the uptake of metal ions Cr (total).

Removal of Cd(II) and Cu(II) from aqueous solution using Bengal gram husk as a biosorbent

In the present work, Cicer arietinum husk (Bengal gram husk BGH) has efficiently been utilized for the removal of Cd(II) and Cu(II) from aqueous solutions. Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction and proximate analysis were used to analyse the biosorbent. Batch experiments were conducted to analyse as well as to evaluate the sorption capacity of metal ions. Factors affecting metal ions adsorption, such as contact time, pH, concentration ranges and adsorbent doses were studied. Maximum sorption of Cu(II) was found at pH 5, while for Cd(II), it was achieved at pH 7. From FTIR and NMR results, it has been found that in BGH, –OH group was present in abundance, and participated in metal complex formation in the sorption experiments. The biosorption process was fast enough because equilibrium reached at 120 min, following pseudo-second-order kinetics. The biosorption data fitted well in the Langmuir isotherm model, indicating the monolayer sorption. The maximum biosorption capacity of BGH, using Langmuir adsorption plots has been determined as 8.58 and 9.70 mg g−1 for Cd(II) and Cu(II), respectively.

Room temperature synthesis of hydrated nickel(III) oxide and study of its effect on Cr(VI) ions removal and bacterial culture

Cr(VI) ion is a toxic inorganic affluent that causes carcinogenic effects on the human body. Another problem that requires immediate attention is the fouling of water borne metal surface by micro-organisms. The present study aims to suggest the synthesis of Ni2O3·H2O nanoparticles and to investigate its heavy metal adsorption capacity and bacteriotoxicity in order to address the current global problems. Stable Ni2O3·H2O nanoparticles having various particle sizes were synthesized using active halogenation of nickel(II) precursor at different temperatures. Phase purity was investigated by X-ray diffraction technique. Due to high surface area, surface heterogeneity and surface polarity, they show excellent adsorption affinity (up to 73.9 % removal capacity) of heavy metal ions like Cr(VI). Adsorption isotherms (Freundlich and Langmuir) are plotted for them. Kinetics of the adsorption process reveals it to be pseudo-first-order kinetic in nature. They are also found to be fairly toxic to bacterial subcultures. Maximum value of the minimum inhibitory concentration and minimum bactericidal concentration were found to be ~0.54 and 0.58 mg/l for particles synthesized at 70 °C. It was observed that Cr(VI) adsorption highly depends on the surface heterogeneity, while the bactericidal effect depends on the size of the nanoparticles so-prepared. Hence, the prepared particles could be used as a potential material for Cr(VI) ion removal and as an antifouling agent.

Preparation of phosphorylated polyacrylonitrile-based nanofiber mat and its application for heavy metal ion removal

A phosphorylated PAN-based nanofiber (P-PAN) mat is prepared by electrospinning technique followed by chemical grafting modification, which is suitable for metal adsorption due to their high adsorption capacity for metal ions. The content of phosphorous in phosphorylated PAN fibers is 5.45mg/g. Adsorption isotherms and adsorption kinetics are used to examine the fundamental adsorption properties. It is found that the adsorption isotherms of P-PAN nanofibers toward Pb2+, Cu2+, and Ag+ are fitted better with Freundlich isotherm model and the adsorption of Cd2+ is fitted better with Langmuir isotherm model. Kinetics of the Pb2+, Cu2+, Ag+, and Cd2+ ions adsorption are found to follow pseudo-second-order rate equation. Through the analysis of the XPS data, phosphorous and nitrogen containing functional groups play the major role in the complexation with heavy metal ions. In addition, the obtained phosphorylated PAN fibers also show high recyclable removal efficiency through the adsorption/desorption experiments. This study provides a promising adsorbent in heavy metal ions wastewater treatment.

Synthesis and metal ion sorption properties of peroxide-modified sodium titanate materials using a coprecipitation method

Peroxide-modified sodium titanate is synthesized by a coprecipitation method that uses titanium isopropoxide and sodium hydroxide precursors, with hydrogen peroxide as a mineralizer to modify the titanate to enhance actinide sorption. The mechanism and microstructure of the peroxide-modified titanate, synthesized using hydrogen peroxide at various pH values, and the effect on the sorption capacity of metal ions were studied. In the pH range of 8–9, the product experiences a highest weight loss of 34%, as well as the smallest sodium content and ion exchange capacity. In contrast, in the pH range of 6–7, the highest metal ion exchange ability is noted, up to 170mg/g. The pH value is crucial for the synthesis of peroxide-modified titanate materials.

Adsorption of Divalent Heavy Metal Ions from Aqueous Solution by Citric Acid Modified Pine Sawdust

Removal of certain divalent heavy metal ions (Cu2+, Pb2+, and Cd2+) from aqueous solutions by citric acid modified pine sawdust (CA-PS) was investigated in this study. The contribution of the citric acid modification to the increase of adsorption capacity of metal ions is significant. In the mono-component system of Cu2+, the maximum adsorption capacity of CA-PS (0.253 mmol/g or 16.19 mg/g) is more than three times higher than that of B-PS (0.079 mmol/g or 5.06 mg/g). The adsorption kinetics and isotherm of the pretreated pine sawdust (B-PS) and CA-PS can be well elucidated with the pseudo-second order model and the Langmuir model, respectively. The competitive adsorption behavior of Cu2+, Cd2+, and Pb2+ in the binary systems (Cu2++Pb2+, Cu2++Cd2+, and Pb2++Cd2+) were studied, and the preference of adsorption onto CA-PS can be ordered as Pb2+ > Cu2+ > Cd2+. The results showed the possibility of utilizing natural bio-sorbent as cost-effective adsorbent alternative for heavy metal ions removal.

Carboxyl-rich carbon microspheres prepared from pentosan with high adsorption capacity for heavy metal ions

Carboxyl-rich carbon microspheres (CSp) were synthesized through hydrothermal carbonization of hemicellulose-derived by-products of pulp refining with no other additives. Characterization of the products revealed that CSp rich in oxygen-containing groups with good dispersion and thermal stability can be obtained. Because of the abundant surface oxygen-containing functional groups, the prepared CSp exhibited excellent adsorption capacities for Pb(II) and Cd(II) from aqueous solution, with highest adsorption capacities of 380.1 and 100.8mg/g for Pb(II) and Cd(II), respectively. Following metal ion adsorption, the content of carboxyl groups decreased from 39.1% to 6.8% for CSp–Pb and to 9.8% for CSp–Cd. Freundlich and Langmuir model isotherms were used to determine the equilibrium uptakes of the two heavy metal ions, revealing that both Pb(II) and Cd(II) were chemically adsorbed as multilayers on CSp.

Magnetic and noble metallic nanoparticles deposited on silica spheres via silanization.

A sol-gel technique has been developed to deposit various nanoparticles (NPs) on silica spheres. The silanization of the silica spheres using 3-mercaptopropyltrimethoxysilane (MPS) with mercapto groups (-SH) plays an important role for the deposition. After being functionalized by MPS, the deposition of magnetic and noble metallic NPs was performed by the reduction of Au3+ and Ag+ ions in-situ using sodium borohydride (NaBH4) or the co-precipitation reaction of Fe2+/Fe3+ ions and ammonia (NH3 H2O) at low reactant concentrations at room temperature. The transmission electron microscope (TEM) observation of samples exhibited the homogeneous deposition of Ag, Au, and Fe3O4 NPs on the silica spheres, in which the average size of Au and Ag NPs is 5 nm in diameter while the ones of Fe3O4 NPs is about 10 nm. In the case of without the silanization of silica spheres, the nucleation and growth of the NPs in solutions occur instead of the homogenous deposition. The results demonstrates that MPS containing the -SH metal-chelating functionality, can grow a layer in an ethanol solution on the silica spheres, thus improving the performance of the silica surface by grafting -SH groups. These hybrids offer a high absorption capacity for metal ions, all kinds of NPs can be deposited on the surface by co-precipitation channel on the basis of such property. The results presented hear may open up a novel and simple approach for the preparation of composite NPs.

Lignosulfanate-assistant hydrothermal method for synthesis of titanate nanotubes with improved adsorption capacity for metal ions

Lignosulfonate modified titanate tubes (L-TNTs) were synthesized by a hydrothermal method. The influences of lignosulfonate on the structure and adsorption capacity of the product were investigated. The characterization results indicate that L-TNTs are layered titanates (NaxH2−xTi3O7·nH2O) with mesoporous structure, and the doped lignosulfonate increases the axial ratio and layer spacing of TNTs. The maximal adsorption capacities of L-TNTs are 740, 148 and 223mgg−1 for Pb2+, Cu2+ and Cd2+, respectively, which are higher than those of TNTs. The results demonstrate that the lignosulfanate-assistant hydrothermal method is promising for improving the adsorption capacity of nanomaterial toward heavy metal ions.

Fructose and Urea as Precursors for N‐/O‐Modified Mesoporous Carbon with Enhanced Sorption Capacity for Heavy Metal Ions

AbstractOrdered mesoporous carbon with a high heteroatom (N, O) content was prepared by nanocasting from a melt of a eutectic mixture of fructose and urea (60/40 wt.‐%; melting temperature ca. 65 °C). These precursor compounds are cheap and environmentally friendly. The material possesses enhanced pore‐wall surface polarity as compared to that of mesoporous carbon prepared by the same technique without urea. This was verified by water sorption analysis. As a result, the heteroatom‐modified material shows higher sorption capacity for the uptake of heavy metal ions (Cu2+) from aqueous solution, which may be interesting for potential application in wastewater cleaning.

Synthesis of polyamidoxime chelating ligand from polymer‐grafted corn‐cob cellulose for metal extraction

ABSTRACTA conventional free‐radical initiating process was used to prepare graft copolymers from acrylonitrile (AN) with corn‐cob cellulose with ceric ammonium nitrate (CAN) as an initiator. The optimum grafting was achieved with corn‐cob cellulose (anhydroglucose unit, AGU), mineral acid (H2SO4), CAN, and AN at concentrations of 0.133, 0.081, 0.0145, and 1.056 mol/L, respectively. Furthermore, the nitrile functional groups of the grafted copolymers were converted to amidoxime ligands with hydroxylamine under basic conditions of pH 11 with 4 h of stirring at 70°C. The purified acrylic polymer‐grafted cellulose and polyamidoxime ligand were characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy analysis. The ligand showed an excellent copper binding capacity (4.14 mmol/g) with a faster rate of adsorption (average exchange rate = 7 min), and it showed a good adsorption capacity for other metal ions as well. The metal‐ion adsorption capacities of the ligand were pH‐dependent in the following order: Cu2+ > Co2+ > Mn2+ > Cr3+ > Fe3+ > Zn2+ > Ni2+. The metal‐ion removal efficiency was very high; up to 99% was removed from the aqueous media at a low concentration. These new polymeric chelating ligands could be used to remove aforementioned toxic metal ions from industrial wastewater. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40833.

Russian

The possibility of using linen fires - lnopererabotki waste as a sorption material for the extraction of heavy metal ions from wastewater modeling. It is shown that treatment with acid solutions linen fires a low concentration increases the surface area of linen fires and thus sorption capacity for heavy metal ions. The values of the maximum sorption capacity ions Fe (III), Co (II), Ni (II) and Zn (II) under static and dynamic conditions. IR spectroscopy shows that along with the physical sorption process proceeds chemisorption.

Phenols, flavonoids and antioxidant activity of aqueous and methanolic extracts of propolis (Apis mellifera L.) from Algarve, South Portugal

Propolis is a resinous substance collected by honeybees to seal honeycomb, which has been used in folk medicine due to its antimicrobial and antioxidant properties. In the present study, water and methanol were used to extract phenols and flavonoids from propolis collected in thirteen different areas in the Algarve region during the winter and spring. The ABTS•+, DPPH•, and O2•- scavenging capacity, and metal chelating activity were also evaluated in the propolis samples. Methanol was more effective than water in extracting total phenols (2.93-8.76 mg/mL) (0.93-2.81 mg/mL). Flavones and flavonols were also better extracted with methanol (1.28-2.76 mg/mL) than with water (0.031-0.019 mg/mL). The free radical scavenging activity, ABTS (IC50=0.006-0.036 mg/mL), DPPH (IC50=0.007-0.069 mg/mL) and superoxide (IC50=0.001-0.053 mg/mL), of the samples was also higher in methanolic extracts. The capacity for chelating metal ions was higher in aqueous extracts (41.11-82.35%) than in the methanolic ones (4.33-29.68%). Propolis from three locations of Algarve region were richer in phenols and had better capacity for scavenging free ABTS and DPPH radicals than the remaining samples. These places are part of a specific zone of Algarve known as Barrocal.

Hydrogen storage capacity of alkali and alkaline earth metal ions doped carbon based materials: A DFT study

The hydrogen storage (H-storage) capacity of alkali (Li+, Na+ and K+) and alkaline earth metal ion (Mg2+ and Ca2+) doped cubane, cyclohexane and adamantane has been investigated using Density Functional Theory (DFT) based M05-2X functional employing 6-31+G∗∗ basis set. The adsorption of number of H2 molecules on the metal ion doped complexes depends on ionic radii and charge of the metal ions. Among the 15 complexes investigated in this study, Mg2+ ion doped cubane, cyclohexane and adamantane complexes have higher H-storage capacity when compared to other complexes. The calculated binding energy (BE) of 5H2@Cub-Mg2+ complex is 46.85 kcal/mol with binding energy per H2 molecule (BE/nH2) of 9.37 kcal/mol. The corresponding gravimetric density of the complexes is 7.3 wt%. In the case of 4H2@Cyc-Mg2+ complex, the BE is 32.19 kcal/mol (BE/nH2 is 8.05 kcal/mol with 6.9 wt% in gravimetric density). The Adm-Mg2+ complexes adsorb 4H2 molecules with BE of 33.33 kcal/mol, the BE of per H2 molecule is 8.33 kcal/mol. The corresponding gravimetric density of the complex is around 4.8 wt%, respectively. A new linker modified MOP-9 has been constructed based on the results and their H-storage capacity has also estimated.

Intercalation of Azamacrocyclic Crown Ether into Layered Rare-Earth Hydroxide (LRH): Secondary Host–Guest Reaction and Efficient Heavy Metal Removal

A carboxyethyl substituted azacrown ether (CSAE) derivative was intercalated as a second host into a parent host of layered gadolinium hydroxides (LGdH) by an anion-exchange reaction. The influence of intercalation temperature and starting material ratios of CSAE/LRH on the structures and compositions of CSAE-LRH nanocomposites were investigated. Higher temperature and larger initial CSAE-LGdH weight ratios favor of higher degree of ion exchange at a certain range, while lower temperature gives good morphology for the composites. The adsorptive properties for transition and heavy metal ions were studied using the 20 °C-reacted composite, which showed higher adsorptivity toward transition and heavy metal ions, accompanied by the introduction of nitrate anions. The adsorptive capacity for transition metal ions was in the sequence of Cu(2+) > Zn(2+)∼Ni(2+)∼Co(2+) with a high selectivity to Cu(2+). For the heavy metal ions Ag(+), Hg(2+), Pb(2+), and Cd(2+), the composite showed markedly high selectivity for Ag(+) and Hg(2+). When putting Cu(2+), Ag(+), Hg(2+), Pb(2+), and Cd(2+) together, Ag(+) and Hg(2+) still have higher adsorptive selectivity over Pb(2+) and Cd(2+), and Cu(2+) has also relatively high selectivity but not as high as Ag(+) and Hg(2+). The nanocomposites with a second host in the interlayer are one promising kind of material because of the synergy of the steric effect of the parent host (LRH layer) and the particular characteristics of the secondary host (interlayer crown ether anions).

Cr(vi), Pb(ii), Cd(ii) adsorption properties of nanostructured BiOBr microspheres and their application in a continuous filtering removal device for heavy metal ions

Uniform well-defined nanostructured BiOBr microspheres have been fabricated via a simple hydrothermal method in the presence of cetyltrimethylammonium bromide (CTAB) and ethylene glycol (EG). The heavy metal ion adsorption on the as-synthesized nanostructured BiOBr microspheres was systematically assessed by measuring the residual concentration during the adsorption process using a colorimetric method for Cr(VI) concentration, and an extraction-colorimetric method for Cd(II) and Pb(II) concentrations. The nanostructured BiOBr microspheres showed good removal capacity for heavy metal ions (Cr, Cd, Pb), and excellent adsorption properties for low concentration heavy metal ions, indicating potential applications in water purification. Based on the quick and efficient heavy metal ion removal ability of nanostructured BiOBr microspheres, a continuous filtering-type water purification device was designed and constructed. In using this continuous filtering type water purification device, 1 g of adsorbent can purify about 4900 g of Pb(II) contaminated water, 5900 g of Cd(II) contaminated water, or 21 500 g of Cr(VI) contaminated water having initial concentrations of 200 μg L−1 to successfully attain the World Health Organization standard for drinking water. The good removal capacity can be attributed to the hierarchical nanostructure, which displays a large specific surface area and strong adsorption of heavy metal ions.

Hydroxyapatite nanosheet-assembled microspheres: Hemoglobin-templated synthesis and adsorption for heavy metal ions

Hydroxyapatite (HAP) nanostructures have wide potential applications in many fields such as drug delivery, tissue engineering, bone repair, gas sensing, catalysis and water treatment. Inspired with the fact that HAP has a high affinity with proteins, we have designed and developed a new synthetic strategy for three-dimensional (3-D) HAP nanosheet-assembled microspheres (HAP-NMSs) by employing hemoglobin as a soft template. The as-prepared products are characterized by X-ray powder diffraction (XRD) and field-emission scanning electron microscopy (SEM). The experimental results show that 3-D HAP microspheres are constructed by the self-assembly of HAP nanosheets as the building blocks. The influences of hemoglobin concentration, hydrothermal temperature and time on the morphology and crystal phase of the product are investigated. Based on the systematic investigation, a possible formation mechanism of HAP-NMSs is proposed. The as-prepared HAP-NMSs are explored for the potential application in water treatment. The experimental results indicate that the HAP-NMSs have a high adsorption capacity for heavy metal ions and selective adsorption activity for Pb2+ ions in acidic solution, thus are promising for the application in wastewater treatment.

Fe(III)–resorcylate as a spectrophotometric probe for phospholipid–cation interactions

A simple spectrophotometric microplate assay that allows quantification of the interaction between phospholipids and metal ions or other small cationic compounds has been developed. The assay is based on the competition of the phospholipids for the Fe3+ ion in the purple-colored Fe(III)–γ-resorcylate complex and for other cations. To compare the binding affinities of several cation–phospholipid interactions, K0.5 values were derived from binding curves constructed by determination of the absorbance of the Fe(III)–γ-resorcylate at 490nm as a function of the cation concentration. The assay was used to analyze the binding of lanthanide ions, calcium ions, and amines (hydrochlorides of ethanolamine, spermidine, and hexyltrimethylammonium chloride) to small unilamellar vesicles (SUVs) and mixed micelles containing anionic lipids such as phosphatidic acid and phosphatidyl-p-nitrophenol. The method was evaluated by fluorescence measurements with Eu3+ ions as tracer. Lanthanide ions such as La3+ and Ce3+ ions showed K0.5 values smaller by one to two orders of magnitude compared with Ca2+ ions. In the presence of increasing amounts of detergents such as Triton X-100, the method also reflected transitions from SUVs to micelles. The binding capacity for metal ions was higher for phospholipid-containing micelles than for the corresponding SUVs.

Utilization on the Removal Cd(II) and Pb(II) Ions from Aqueous Solution Using Nonliving Rivularia bulata Algae

In present study, biosorption and elimination of cadmium(II) and lead(II) ions from aqueous solution was evaluated using the algae nonliving biomass (Rivularia bulata) as easy availability, natural origin and biological sorbents. The effect of contact time and metal concentration on the adsorption capacity of metal ions was investigated. The maximum adsorption capacities for Cd(II) and Pb(II) were found to be 26.36 and 34.30 mg/g at the optimum conditions, respectively. The experimental data exhibit a good compliance with the pseudo second-order equation for Cd(II) and Pb(II) ions. Langmuir and Freundlich models were also applied to experimental equilibrium data to find the best adsorption isotherm and the values of R L for Cd(II) and Pb(II) were found to be 0.735 and 0.926, respectively. Weber-Morris and Urano-Tachikawa diffusion models were also applied to experimental equilibrium data. The results are showed that the algae biomass was effectively used as a sorbent for the removal of toxic metal ions from aqueous solutions.

Facile synthesis of Mn–Co oxide with a hierarchical porous structure for heavy metal removal

Mn–Co oxide hierarchical structure assembled from nanosheets was prepared by a simple method. The structure, surface property and adsorption capacity of the product were investigated. The characterization results confirm that the Co ions are incorporated into the structure of MnO2. In comparison with MnO2, the obtained composite oxide has a more highly negatively charged surface in aqueous solution, thus enhancing its adsorption capacity for heavy metal ions. The maximal adsorption capacities of Mn–Co oxide are 656 and 762mgg−1 for Pb2+ and Cu2+, respectively. The results demonstrate that the Mn–Co oxide is a promising adsorbent for the removal of heavy metals from aqueous solution.