The main objective of this paper is to study the removal of Cadmium(II), Lead(II), Chromium(VI), and Mercury(II) ions by sorption onto different natural and synthetic nanoparticles. Special attention has been given to...The main objective of this paper is to study the removal of Cadmium(II), Lead(II), Chromium(VI), and Mercury(II) ions by sorption onto different natural and synthetic nanoparticles. Special attention has been given to the application of fish bone in nanoform as a useful, inexpensive and eco-friendly alternative material. A comparison between natural hydroxyapatite (fish bone), synthetic hydroxyapatite nanoparticles (HAP) and alginate-hydroxyapatite composite (Alg/Hap) to assess their removal efficiencies to remediate the selected heavy metals has been done. Surface characterization by using different techniques has also been performed to understand the influence of surface characteristics of the adsorbent materials in the removal process. Different parameters (pH, contact time, mass dose and metal ion concentration) have been examined to identify the optimum conditions for remediation of different metals from polluted water. The potential applications of the biosorbents for removal and sorption of these metal ions from seawater and wastewater samples were also investigated and evaluated.展开更多
Magnetic alumina nano composite (MANC) was prepared for combination of the adsorption features of nano activated alumina with the magnetic properties of iron oxides to produce a nano magnetic adsorbent, which can be s...Magnetic alumina nano composite (MANC) was prepared for combination of the adsorption features of nano activated alumina with the magnetic properties of iron oxides to produce a nano magnetic adsorbent, which can be separated from the medium by a simple magnetic process after adsorption. MANC was characterized using XRD, SEM, TEM, EDX and surface area (BET). Quantum design SQUID magnetometer was used to study the magnetic measurement. The present study was conducted to evaluate the feasibility of MANC for the removal of cadmium ions from aqueous solutions through batch adsorption technique. The effects of pH, adsorbent dose, temperature, contact time and initial Cd2+ concentration on cadmium ions adsorption were studied. Equilibrium data were fitted to Langmuir, Freundlich and Temkin isotherms. The equilibrium data were best represented by the Langmuir isotherm. The kinetic data were fitted to pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models, and it was found to follow closely the pseudo-second-order model. Thermodynamic parameters were calculated for the Cd2+ ion-MANC system and the positive value of ΔH° showed that the adsorption was endothermic in nature. Furthermore, a single-stage batch adsorber was designed for the removal of Cd2+ ions by MANC based on the equilibrium data obtained.展开更多
The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles(PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid(3-MPA). The resulting mate...The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles(PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid(3-MPA). The resulting material(i.e. 3-MPA@PMNPs) characterized by FTIR, powder XRD, SEM, TEM, EDX, VSM, BET and TGA techniques and then further employed for the investigation of the adsorptive removal of lead(Pb^2+) and cadmium(Cd^2+) ions from aqueous solutions in single and binary systems. The material showed fastest adsorptive rate(98.23%) for Pb^2+ and(96.5%) Cd2+within the contact time of 60 min at pH 6.5 in the single system. The experimental data were fitted well to Langmuir isotherm, indicated monolayer adsorption of both metal ions onto 3-MPA@PMNPs and an estimated comparable adsorptive capacity of 68.41 mg·g^-1(Pb2+) and 79.8 mg·g^-1(Cd2+) at p H 6.5. However, kinetic data agreed well with pseudo-second-order model, and indicated that the removal mainly supported chemisorption and/or ion-exchange mechanism. Thermodynamic parameters such asΔGo,ΔHo, and ΔSo, were-3259.20, 119.35 and 20.73 for Pb^2+, and-1491.10, 45.441 and 7.87 for Cd^2+ at temperature 298.15 K, confirmed that adsorption was endothermic, spontaneous and favorable. The material demonstrated higher selectivity of Pb2+ and its removal efficiency was(98.20 ± 0.3)% in binary system experiments. The material persisted performance up-to seven(07) consecutive treatment cycles without losing their stability and offered comparable fastest magnetic separation(35 s) from aqueous solutions. Therefore, it is recommended that the prepared material can be employed to remove toxic heavy metal ions from water/wastewaters and this "green" method can easily be implemented at large scale in low economy countries.展开更多
The water crisis is an increasingly severe global problem that may be reduced by reusing wastewater after suitable treatment methods. Nowadays, biosorption is one of the main parts of environmental technology which co...The water crisis is an increasingly severe global problem that may be reduced by reusing wastewater after suitable treatment methods. Nowadays, biosorption is one of the main parts of environmental technology which could adsorb heavy metals. This paper describes the adsorption of Copper(II) ions from aqueous solution using a mixture of corn stalk and tomato waste which were oxidized with nitric acid. Kinetic and isotherm studies were carried out by studying the effects of parameters such as concentration dosage, time and pH. It was found that the maximum sorption capacity of the mixture of modified corn stalk and modified tomato waste (q<sub>m</sub> = 25 mg/g) was higher than the modified corn stalk (q<sub>m</sub> = 20.8 mg/g). Analysis indicated that pseudo-second-order kinetics controlled the adsorption rate and it has been proposed to correlate the experimental data well.展开更多
Conversion of rice straw (RS) as one of agricultural plant wastes (about 45% of the volume of rice production) to valuable industrial product was achieved, by grafting different amounts of dimethylaminoethyl methacryl...Conversion of rice straw (RS) as one of agricultural plant wastes (about 45% of the volume of rice production) to valuable industrial product was achieved, by grafting different amounts of dimethylaminoethyl methacrylate (DMAEM) on it using potassium permanganate/nitric acid redox system. This was done to obtain six levels of poly (DMAEM)—rice straw graft copolymers (PDMAEMRS) having different graft yields (expressed as N%) with increasing order and designated as (PDMAEMRS 1 to PDMAEMRS 6). The latter copolymers were dispersed in aqueous solution of heavy metal ions Cu (II) ions and filtered to form rice straw co-polymer—metal ions complex. Different factors affecting the heavy metal ions removal such as pH, extent of grafting, treatment time and rice straw dose were studied in detail. It was found from the obtained results that;the residual metal ions removal from their aqueous solutions increased with 1) increasing the extent of grafting of PDMAEMRS i.e. from PDMAEMRS 1 to PDMAEMRS 6;2) increasing the pH of the metal ions solution complex from 1 to 8;3) increasing the rice straw dosage from 0.50 to 2.0 g, then leveled off thereafter;4) increasing the time of the reaction up to 20 minute then leveled off after that. On the other hand, Pb (II), Cd (II) and Hg (II) ions were also removed from their solutions with different extent. Furthermore, the prepared co-polymer could be recovered by washing the metal ions from the complex with weak acid 1 N HNO3 (pH 2) and the metal-binding activity of the rice straw was slightly reduced by this process. Finally, the ability of PDMAEMRS to remove three types of acid dyes from their solutions was also reported.展开更多
文摘The main objective of this paper is to study the removal of Cadmium(II), Lead(II), Chromium(VI), and Mercury(II) ions by sorption onto different natural and synthetic nanoparticles. Special attention has been given to the application of fish bone in nanoform as a useful, inexpensive and eco-friendly alternative material. A comparison between natural hydroxyapatite (fish bone), synthetic hydroxyapatite nanoparticles (HAP) and alginate-hydroxyapatite composite (Alg/Hap) to assess their removal efficiencies to remediate the selected heavy metals has been done. Surface characterization by using different techniques has also been performed to understand the influence of surface characteristics of the adsorbent materials in the removal process. Different parameters (pH, contact time, mass dose and metal ion concentration) have been examined to identify the optimum conditions for remediation of different metals from polluted water. The potential applications of the biosorbents for removal and sorption of these metal ions from seawater and wastewater samples were also investigated and evaluated.
文摘Magnetic alumina nano composite (MANC) was prepared for combination of the adsorption features of nano activated alumina with the magnetic properties of iron oxides to produce a nano magnetic adsorbent, which can be separated from the medium by a simple magnetic process after adsorption. MANC was characterized using XRD, SEM, TEM, EDX and surface area (BET). Quantum design SQUID magnetometer was used to study the magnetic measurement. The present study was conducted to evaluate the feasibility of MANC for the removal of cadmium ions from aqueous solutions through batch adsorption technique. The effects of pH, adsorbent dose, temperature, contact time and initial Cd2+ concentration on cadmium ions adsorption were studied. Equilibrium data were fitted to Langmuir, Freundlich and Temkin isotherms. The equilibrium data were best represented by the Langmuir isotherm. The kinetic data were fitted to pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models, and it was found to follow closely the pseudo-second-order model. Thermodynamic parameters were calculated for the Cd2+ ion-MANC system and the positive value of ΔH° showed that the adsorption was endothermic in nature. Furthermore, a single-stage batch adsorber was designed for the removal of Cd2+ ions by MANC based on the equilibrium data obtained.
基金Supported by the State Key Laboratory of Environmental Criteria and Risk Assessment(No.SKLECRA 2013FP12)Shandong Province Key Research and Development Program(2016GSF115040)the financial support by the Chinese Scholarship Council,China(CSC No:2016GXYO20)
文摘The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles(PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid(3-MPA). The resulting material(i.e. 3-MPA@PMNPs) characterized by FTIR, powder XRD, SEM, TEM, EDX, VSM, BET and TGA techniques and then further employed for the investigation of the adsorptive removal of lead(Pb^2+) and cadmium(Cd^2+) ions from aqueous solutions in single and binary systems. The material showed fastest adsorptive rate(98.23%) for Pb^2+ and(96.5%) Cd2+within the contact time of 60 min at pH 6.5 in the single system. The experimental data were fitted well to Langmuir isotherm, indicated monolayer adsorption of both metal ions onto 3-MPA@PMNPs and an estimated comparable adsorptive capacity of 68.41 mg·g^-1(Pb2+) and 79.8 mg·g^-1(Cd2+) at p H 6.5. However, kinetic data agreed well with pseudo-second-order model, and indicated that the removal mainly supported chemisorption and/or ion-exchange mechanism. Thermodynamic parameters such asΔGo,ΔHo, and ΔSo, were-3259.20, 119.35 and 20.73 for Pb^2+, and-1491.10, 45.441 and 7.87 for Cd^2+ at temperature 298.15 K, confirmed that adsorption was endothermic, spontaneous and favorable. The material demonstrated higher selectivity of Pb2+ and its removal efficiency was(98.20 ± 0.3)% in binary system experiments. The material persisted performance up-to seven(07) consecutive treatment cycles without losing their stability and offered comparable fastest magnetic separation(35 s) from aqueous solutions. Therefore, it is recommended that the prepared material can be employed to remove toxic heavy metal ions from water/wastewaters and this "green" method can easily be implemented at large scale in low economy countries.
文摘The water crisis is an increasingly severe global problem that may be reduced by reusing wastewater after suitable treatment methods. Nowadays, biosorption is one of the main parts of environmental technology which could adsorb heavy metals. This paper describes the adsorption of Copper(II) ions from aqueous solution using a mixture of corn stalk and tomato waste which were oxidized with nitric acid. Kinetic and isotherm studies were carried out by studying the effects of parameters such as concentration dosage, time and pH. It was found that the maximum sorption capacity of the mixture of modified corn stalk and modified tomato waste (q<sub>m</sub> = 25 mg/g) was higher than the modified corn stalk (q<sub>m</sub> = 20.8 mg/g). Analysis indicated that pseudo-second-order kinetics controlled the adsorption rate and it has been proposed to correlate the experimental data well.
文摘Conversion of rice straw (RS) as one of agricultural plant wastes (about 45% of the volume of rice production) to valuable industrial product was achieved, by grafting different amounts of dimethylaminoethyl methacrylate (DMAEM) on it using potassium permanganate/nitric acid redox system. This was done to obtain six levels of poly (DMAEM)—rice straw graft copolymers (PDMAEMRS) having different graft yields (expressed as N%) with increasing order and designated as (PDMAEMRS 1 to PDMAEMRS 6). The latter copolymers were dispersed in aqueous solution of heavy metal ions Cu (II) ions and filtered to form rice straw co-polymer—metal ions complex. Different factors affecting the heavy metal ions removal such as pH, extent of grafting, treatment time and rice straw dose were studied in detail. It was found from the obtained results that;the residual metal ions removal from their aqueous solutions increased with 1) increasing the extent of grafting of PDMAEMRS i.e. from PDMAEMRS 1 to PDMAEMRS 6;2) increasing the pH of the metal ions solution complex from 1 to 8;3) increasing the rice straw dosage from 0.50 to 2.0 g, then leveled off thereafter;4) increasing the time of the reaction up to 20 minute then leveled off after that. On the other hand, Pb (II), Cd (II) and Hg (II) ions were also removed from their solutions with different extent. Furthermore, the prepared co-polymer could be recovered by washing the metal ions from the complex with weak acid 1 N HNO3 (pH 2) and the metal-binding activity of the rice straw was slightly reduced by this process. Finally, the ability of PDMAEMRS to remove three types of acid dyes from their solutions was also reported.
