Adsorption of cadmium (II), zinc (II) and iron (III) from water by new cross-linked reusable polystyrene adsorbents (original) (raw)
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Materials, 2014
Over the past decades, organic-inorganic hybrid polymers have been applied in different fields, including the adsorption of pollutants from wastewater and solid-state separations. In this review, firstly, these compounds are classified. These compounds are prepared by sol-gel method, self-assembly process (mesopores), assembling of nanobuilding blocks (e.g., layered or core-shell compounds) and as interpenetrating networks and hierarchically structures. Lastly, the adsorption characteristics of heavy metals of these materials, including different kinds of functional groups, selectivity of them for heavy metals, effect of pH and synthesis conditions on adsorption capacity, are studied.
Adsorbents based on natural polymers for removal of some heavy metals from aqueous solution
Egyptian Journal of Petroleum, 2017
Heavy metal ions are discharged into water from several industries. They are carcinogenic and they cause severe environmental hazards. In the present work the ability of removal of copper and lead from aqueous solutions has been studied using carboxy methyl b cyclodextrin, poly(ethylene glycol) b cyclodextrin and their magnetic counterparts. Effects of pH, concentration of the metal ion, temperature and contact time have been studied. Equilibrium isotherms for the adsorption of the metals were measured experimentally. Results were analysed at different temperatures and the characteristic parameters for each adsorption isotherm were determined. The adsorption process has been found exothermic in nature and thermodynamic parameters, Gibb's free energy (DG), change in enthalpy (DH) and change in entropy (DS) have been calculated. The paper also includes results on the kinetic measurements of adsorption of the metal on modified b cyclodextrin and their magnetic nano composites at different temperatures. It was found that poly (ethylene glycol) b cyclodextrin showed better performance than carboxy methyl b cyclodextrin.
Scientia Iranica, 2020
Heavy metal ions have been recognized as the most hazardous contaminants of water sources. In this study, a novel polymeric adsorbent based on 2-hydroxyethyl methacrylate (HEMA), acrylic acid (AA), and 1,4-butanediol dimethacrylate (BDDMA) was successfully synthesized and its efficiency in removal of selected heavy metal ions (Pb 2+ and Cd 2+) were investigated. The role of significant parameters such as pH, contact time, adsorbent dose, metal ions concentration and temperature on removing harmful metal ions were logically studied. Results showed that the amount of pH, contact time and polymer adsorbent dose had direct relation in adsorption of metal ions. While increasing metal ion concentrations have no significant effect in metal ions adsorption and that was fixed up to 15 mg/L. Adsorption isothermal process of the new polymeric adsorbent was studied by several selected models and also maximum values of adsorption capacities of the introduced adsorbent for Pb 2+ and Cd 2+ ions were characterized. Adsorption /desorption cycles of synthesized polymer adsorbent were around 15 times. According to the modeling of adsorption data, the pseudosecond-order kinetic equation could best describe the adsorption kinetics. According to the intra-particle diffusion studies adsorption of heavy metal ions might be dominated by external diffusion mechanism.
2014
Water pollution is a serious environmental crisis all over the world hence unsafe water is rated among the top ten risks to health. Heavy metals are among the most threatening water contaminants because of their toxic effects on human health. This research was dedicated to the development of insoluble polyethylenimine derivatives; with the suitable functionalities for use as adsorbents to abstract specific toxic elements from mining and industrial wastewater. Branched polyethylenimine (PEI), well known for its metal chelating potential, was cross linked by epichlorohydrin in order to convert it into a water-insoluble form. The water-insoluble property gives the advantage of being used in situ and a possibility of regeneration and re-use, making it a more feasible and cost-effective method. Its surface was then modified for selective removal of uranium (U), mercury (Hg, arsenic (As), and selenium (Se). Three different functional groups were chosen according to the targeted elements namely: the phosphate group for selective removal of U and As; sulphate group for selective removal of Hg and Se, and the thiol group for selective removal of Hg. The adsorption performance of the developed materials was assessed in batch and column experiments. The selectivity of the synthesized materials as well as their ability to be regenerated for reuse was assessed. The results obtained demonstrated that the phosphonated derivative had a superior selectivity towards U with up to 99% adsorption (at pH 3 and 8) even in presence of competing ions, as well as a very good removal for As showing 88%.
Polymers for Advanced Technologies, 2008
The competitive removal of Pb 2R , Cu 2R , and Cd 2R ions from aqueous solutions by the copolymer of 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) and itaconic acid (IA), P(AMPS-co-IA), was investigated. Homopolymer of AMPS (PAMPS) was also used to remove these ions from their aqueous solution. In the preparation of AMPS-IA copolymer, the molar percentages of AMPS and IA were 80 and 20, respectively. In order to observe the changes in the structures of polymers due to metal adsorption, FTIR spectra by attenuated total reflectancetechnique and scanning electron microscopy (SEM) pictures of the polymers were taken both before and after adsorption experiments. Total metal ion removal capacities of PAMPS and P(AMPS-co-IA) were 1.685 and 1.722 mmol Me 2R /g polymer , respectively. Experimental data were evaluated to determine the kinetic characteristics of the adsorption process. Competitive adsorption of Pb 2R , Cu 2R , and Cd 2R ions onto both PAMPS and P(AMPS-co-IA) was found to fit pseudo-second-order type kinetics. In addition, the removal orders in the competitive adsorption of these metal ions onto PAMPS and P(AMPS-co-IA) were found to be Cd 2R > Pb 2R > Cu 2R and Pb 2R > Cd 2R > Cu 2R , respectively. 1210 S. Ç avuş and G. Gü rdag 3 Â W APS 1 a, b: NMBA and APS were used in the amount of 3 and 1 mol% of total amounts of the monomers in feed, respectively. W APS : the weight of APS in gram.
Synthesis and implication of grafted polymeric adsorbent for heavy metal removal
Springer Nature Applied Sciences, 2020
Nowadays, grafted polymeric composite has received much attention as an alternative adsorbent of heavy metal removal. The grafted polymeric adsorbent (GPA) in the form of composite was prepared using diallyl dimethyl ammonium chloride (DADMAC) and acrylic acid embedded nonwoven irradiated polythene sheet. The prepared GPA was characterized using Fourier transform infra-red (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis to understand molecular interaction, surface morphology and physical phenomena of them. The effect of parameters including pH, initial metal concentration, contact time, as well as temperature on the adsorption of Cu(II)/Cr(VI) was studied sequentially. The result shows that the GPA had utmost grafting yield of 192% with reaction time 4.0 h at 50 kGy. The maximum adsorption was found up to 153.89 mg Cu/g and 17.34 mg Cr/g with an initial concentration of 1000 ppm, a contact time of 24 h, pH of 4.84 [Cu(II)], and 1.5 [Cr(VI)] at room temperature (25 °C) indicating superb synergetic adsorption capacity of the GPA. Comparing the Langmuir and Freundlich adsorption isotherm models, the former fitted well with Cr and latter with Cu adsorption data implying that the models can be applied to uptake Cu(II)/Cr(VI) by GPA. In the kinetic adsorption experiment, adsorbed metal almost reached equilibrium about 10 h for the GPA and followed the pseudo-second-order kinetic model. Thus, the GPAs are propriety and competent in terms of capability and reusability to remove heavy metal ions.
2010
Crosslinked polyethylene-graft-polystyrene sulfonic acid (PE-g-PSSA) adsorbent prepared by simultaneous radiation induced grafting of styrene/divinyl benzene (DVB) mixture onto low density polyethylene (PE) film followed by sulfonation was investigated for the adsorption of Co(II), Cu(II), Ni(II), Pb(II) and Ag(I) ions from aqueous solutions on batch process basis. The effects of treatment parameters such as contact time, initial metal ion concentration, pH and temperature of the solution, on the adsorption capacity of the membrane were studied. The adsorption capacity of metal ions were found to be strongly dependent on the initial metal ion concentration and pH of adsorption medium and increased in the order of Ni(II)>Co(II)>Cu(II)>Pb(II)>Ag(I). Langmuir isotherm model was found to be more fitting to the adsorption equilibrium data of all metal ions than Freundlich isotherm model. The adsorption kinetics of all tested metal ions was found to follow the pseudo-first order kinetic model. The membrane showed an interesting stability represented by five repeated adsorption/desorption cycles of heavy metal ions without any significant loss in its adsorption capacity. It can be suggested that crosslinked PEg -PSSA membrane obtained in this work can be effectively used for the adsorption of heavy metal ions from aqueous solutions and the preference order is Ni(II)> Co(II)>Cu(II)>Pb(II)> Ag(I).
Polimery, 2017
Poly(vinyl chloride) (PVC) has been subjected to numerous chemical modifications which were undertaken in order to improve its properties, the use of PVC in new applications and understanding of PVC-related phenomena. This work describes the chemical modification of PVC by amino groups (benzylamine and diethylenetriamine) through nucleophilic substitution reactions of its chlorine atoms to obtain P 1 polymer. The modified polymer was subsequently reticulated with dichlorodiethyl ether to obtain P 2 polymer. The obtained polymers were characterized using infrared spectroscopy (FT-IR), elemental analysis (CHN), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and X-ray diffraction (XRD). The modified polymers (P 1 and P 2) were tested for metal ion extraction (cadmium, cobalt, lead, or chromium) using the solid-phase extraction (SPE) method and the inductively coupled plasma atomic emission spectrometry (ICP-AES) technique. Quantitative adsorption measurements were performed using solutions containing 2 • 10-4 M of heavy metal ions with pH = 3.5-4.5 at a flow rate of 0.6 dm 3 /min. The new extractants based on modified PVC (P 1 and P 2) were able to remove the negative effects of heavy metals contained in aqueous solutions. For Pb 2+ , the extraction percentage was 98 % using P 1 and 90.3 % using P 2 .
Green Synthesis of Reusable Adsorbents for the Removal of Heavy Metal Ions
ACS Omega, 2021
Industrial wastewater often contains heavy metals, like lead, copper, nickel, cadmium, zinc, mercury, arsenic, and chromium. Overdoses of heavy metals will impose a severe threat to human health. Adsorption is the most efficient way of wastewater treatment for eliminating heavy metals. A novel material-reusable hydrogel-based adsorbent was developed in overcoming the regeneration issue. The polyethylene glycol diacrylate-3-sulfopropyl methacrylate potassium salt (PEGDA-SMP) hydrogel performed an ion-exchange rate to remove heavy metals from wastewater in 30−120 min. The adsorption capacity of PEGDA-SMP increases the increasing pH of a solution, in which pH 5 reaches the maximum. Pseudo-second-order adsorption and the Langmuir adsorption model can fully describe the adsorption properties of PEGDA-SMP for heavy metals. PEGDA-SMP prefers to exchange Pb 2+ through K + , and its adsorption capacity can achieve 263.158 mg/g. Ag + , Zn 2+ , Ni 2+ , and Cu 2+ were 227.27, 117.647, 102.041, and 99.010 mg/g, respectively. The hydrated ionic radius of the heavy metal might play an essential role to affect the adsorption preference. The removal efficiency of heavy metals can approach over 95% for each heavy metal. PEGDA-SMP performs rapid desorption and reaches desorption equilibrium in 15 min. After 10 consecutive adsorption−desorption cycles, the adsorption capacity remained over 90%. The hydrogel developed in this study showed reversible heavy metal absorption. Therefore, excellent adsorption−desorption properties of PEGDA-SMP can be potentially extended to industrial wastewater for removing heavy metals.
Separation of heavy metals from water samples using anion exchange polymers by adsorption process
Desalination, 2011
The present study focuses the efficiency of an anion exchange polymer for the adsorption of different heavy metal ions from water samples. Solutions with different concentrations of the heavy metals were prepared and the efficiency of the ionomer in separation of the metals was evaluated by adsorption technique. Quaternized poly styrene ethylene butylene poly styrene (QAPSEBS) was used as the ionomer and it was prepared by two step method, viz. chloromethylation and amination. The membrane was prepared by solution casting method using an appropriate solvent. There are various factors affecting the metal ion adsorption on the polymer membrane such as metal ion concentration, pH, treatment time and temperature were studied. From the results obtained, it was found that the percentage adsorption increased with (a) increase in the metal ion concentration, (b) increase in the treatment time up to 2 h after which it levels off, (c) decrease in temperature from 75°C to 35°C. In addition to that, the effect of extent of amination of the polymer membrane was also examined. The polymer membrane was characterized using FT-IR, 1 H-NMR, DSC, TGA, XRD and SEM. The results revealed that the polymer membrane showed high efficiency in adsorption for Cr(VI) ion rather than removal of Cu(II) and Ni(II) ions.