A modified cellulose adsorbent for the removal of nickel(II) from aqueous solutions

A series of adsorption studies was carried out on a glycidyl methacrylate‐ modified cellulose material functionalised with imidazole (Cellulose‐g‐GMA‐Imidazole) to assess its capacity in the removal of Ni(II) ions from aqueous solution. The study sought to establish the effect of a number of parameters on the removal of Ni(II) from solution by the Cellulose‐g‐GMA‐Imidazole. In particular, the influence of initial metal concentration, contact time, solution temperature and pH were assessed. The studies indicated a Ni(II) uptake on the Cellulose‐g‐GMA‐Imidazole sorbent of approximately 48 mg g^?1 of nickel from aqueous solution. The adsorption process fitted the Langmuir model of adsorption and the binding process was mildly endothermic. The kinetics of the adsorption process indicated that nickel uptake occurred within 400 min and that pseudo‐second order kinetics best describe the overall adsorption process. Nickel(II) adsorption, recovery and re‐adsorption studies indicated that at highly acidic pH values the adsorbent material becomes unstable, but in the range pH 3–6, the adsorbent is stable and shows limited but significant Ni(II) recovery and re‐adsorption capability. Copyright © 2006 Society of Chemical Industry     

氧化改性橡椀单宁对铜离子溶液的吸附性

以橡椀栲胶为原料,通过双氧水氧化降解改性,研究水解类橡椀单宁改性后对铜离子溶液的吸附沉淀以及pH值、金属溶液初始浓度对铜离子吸附沉淀容量的影响和规律。结果表明,氧化橡椀单宁对Cu2+的吸附平衡符合Freundlich方程。改性后吸附沉淀容量受初始浓度影响较大,初始浓度为20 mg/L时基本不发生吸附沉淀,试验最大初始浓度100 mg/L时吸附量达到39.300 mg/g。     

Melamine‐based microporous polymer for highly efficient removal of copper(II) from aqueous solution

In this study, we investigated the ability of a melamine‐based microporous polymer network as an adsorbent for removal of copper(II) species from aqueous solutions. A designed Schiff based network (SNW) with high specific surface area was synthesized using melamine and terephthalaldehyde monomers at 180 °C for 3 days followed by a freeze‐drying process. The porous structure of the material was confirmed by SEM analysis and CO₂ adsorption/desorption studies at 77.3 K. The adsorption character of the SNW polymer for various metal salts, namely Pb(II), Fe(II), Hg(II), Zn(II), Ni(II) and Cd(II), was investigated and a specific sorption behaviour against Cu(II) salts was observed. The role of pH and contact time was examined and the highest adsorption capacity for Cu(II) was found as 92% with pH 3.5 at the end of 300 min. As evidenced by XRD and Fourier transform infrared spectral analysis, the sorption mechanism is attributed to the coordination system formed between amino groups in the porous structure and Cu(II) ions. Reusability of the system was also demonstrated by applying four cycles without any significant loss of activity. © 2016 Society of Chemical Industry     

碱改性气化煤泥对水溶液中对氨基苯酚的吸附

采用NaOH溶液对气化煤泥（CS-R）进行改性,考察了改性时间、温度、NaOH溶液浓度、液固比等因素的影响,利用静态吸附法研究了碱改性煤泥（CS-OH）对水溶液中对氨基苯酚（PAP）的吸附性能.结果表明,碱改性的最佳工艺条件是：改性时间24h,温度100℃,液固比10∶1,NaoH溶液浓度2 mol/L;CS-OH吸附PAP的综合性能优于CS-R.对于低浓度PAP废水,经CS-OH处理后可以达到国家工业废水排放标准.     

Removal of copper ions from aqueous solution by adsorption using LABORATORIES-modified bentonite (organo-bentonite)

Equilibrium, kinetic and thermodynamic aspects of the adsorption of copper ions from an aqueous solution using linear alkylbenzene sulfonate (LABORATORIES) modified bentonite (organo-bentonite) are reported. Modification of bentonite was performed via microwave heating with a concentration of LABORATORIES surfactant equivalent to 1.5 times that of the cation exchange capacity (CEC) of the raw bentonite. Experimental parameters affecting the adsorption process such as pH, contact time and temperature were studied. Several adsorption equations (e.g., Langmuir, Freundlich, Sips and Toth) with temperature dependency were used to correlate the equilibrium data. These models were evaluated based on the theoretical justifications of each isotherm parameter. The Sips model had the best fit for the adsorption of copper ions onto organo-bentonite. For the kinetic data, the pseudo-second order model was superior to the pseudo-first order model. Thermodynamically, the adsorption of copper ions occurs via chemisorption and the process is endothermic (ΔH⁰>0), irreversible (ΔS⁰>0) and nonspontaneous (ΔG⁰>0).     

Preparation and use of a mesoporous silicate material for the removal of tetramethyl ammonium hydroxide (TMAH) from aqueous solution

A cubic mesoporous silicate (CMS) was prepared, characterised, and assessed as an adsorbent for tetramethyl ammonium hydroxide (TMAH) from aqueous solution. The adsorption process was studied as a function of temperature and time. Sorption closely followed the Langmuir model. The adsorption of TMAH on CMS was endothermic and kinetic studies suggest that the overall rate of adsorption was pseudo‐second‐order. Pore diffusion effects contribute to limiting the overall rate of adsorption while at lower initial TMAH concentrations, film diffusion becomes more important. Desorption studies were carried out using water and methanol. Methanol was the superior desorbing agent. © 2001 Society of Chemical Industry     

用溶剂萃取法回收电镀废水中的铜和镍(英文)

The solvent extraction technology was applied to recover Cu2+ and Ni2+ from plating wastewater. Lix984N was chosen as the extractant due to its good extraction performance. The influence parameters were examined. The results show that the separation of Cu2+ and Ni2+ from sulphate medium can be realized by adjusting pH value with the help of Lix984N. For extracting Cu2+ and Ni2+, the optimal pH values are 4 and 10.5, and the maximal extraction percentages are 92.9% and 93.0%, respectively. With recovered Cu2...     

Preparation,characterization, and adsorption properties of chitosan microspheres crosslinked by formaldehyde for copper (II) from aqueous solution

The chitosan microspheres crosslinked by formaldehyde were prepared by spray drying method and used as an adsorbent for copper (II) from aqueous solution. A batch adsorption system was applied to study the adsorption of copper (II) from aqueous solution by chitosan microspheres. The maximum adsorption capacity of the chitosan microspheres for copper (II) was 144.928 mg/g at pH 6.0. Langmuir adsorption model was found to be applicable in interpreting the adsorption process. To elucidate the adsorption mechanism, the chitosan microspheres before and after copper (II) adsorption were further characterized by Fourier transform infrared spectra, zeta potential analysis, and scanning electron microscope. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A chelating cellulose adsorbent for the removal of Cu(II) from aqueous solutions

Regenerated cellulose wood pulp was grafted with the vinyl monomer glycidyl methacrylate (GMA) using ceric ammonium nitrate as initiator and was further fuctionalised with imidazole to produce a novel adsorbent material, cellulose‐g‐GMA‐imidazole. All cellulose, grafted cellulose and functionalized cellulose grafts were physically and chemically characterized using a number of analytical techniques, including elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential thermal analysis, and scanning electron microscopy. The cellulose‐g‐GMA material was found to contain 1.75 mmol g^?1 epoxy groups. These epoxy groups permitted introduction of metal binding functionality to produce the cellulose‐g‐GMA‐imidazole final product. Following characterization, a series of adsorption studies were carried out on the cellulose‐g‐GMA‐imidazole to assess its capacity in the removal of Cu²⁺ ions from solution. Cellulose‐g‐GMA‐imidazole sorbent showed an uptake of ～70 mg g^?1 of copper from aqueous solution. The adsorption process is best described by the Langmuir model of adsorption, and the thermodynamics of the process suggest that the binding process is mildly exothermic. The kinetics of the adsorption process indicated that copper uptake occurred within 30 min and that pseudo‐second‐order kinetics best describe the overall process. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 2006     

废水中除铜研究的最新进展

随着铜在工业生产中的广泛应用,铜污染废水的排放量逐渐增加,由于溶解性铜的生物毒性,铜污染废水的处理日益引起人们的重视。针对近五年来对废水中铜去除的研究,文章介绍了沉淀法、吸附法、离子交换法、电化学法,并对已有文献中的技术特点进行了简要总结与分析。对水体中除铜的未来发展方向进行了分析。分析表明,结合原始水质特点,多种方法的工艺组合是从水体中去除铜的未来重点研究方向之一。     

Preparation of an adsorbent by graft polymerization of acrylamide onto coconut husk for mercury(II) removal from aqueous solution and chloralkali industry wastewater

Graft copolymerization of acrylamide onto coconut husk (CH), initiated by the ferrous ammonium sulfate/H₂O₂ redox initiator system, was studied. To determine the optimum conditions of grafting, the effect of the concentrations of ferrous ammonium sulfate, the monomer, and H₂O₂ and the time and temperature on percentage of the graft yield was studied. A new adsorbent media having a carboxylate functional group was synthesized by the surface modification of polymer‐grafted coconut husk (PGCH COOH). The mechanism of graft polymerization and surface functionalization is proposed. The material exhibits a very high adsorption potential for Hg(II). The sorption of Hg(II) was found to be dependent on the contact time, concentration, pH, and temperature. Maximum removal of 99.4% with 2 g/L of the sorbent was observed at 125 μmol L⁻¹ Hg(II) concentration at pH 6.0. The slow step which determines the rate of exchange of Hg(II) ions is diffusion through the adsorbent particles. The diffusion coefficients, energy of activation, and entropy of activation were calculated and used to determine the theoretical behavior of the sorption process. The applicability of the Langmuir isotherm established the endothermic character of the adsorption. Acid regeneration was tried for several cycles with a view to recover the adsorbed metal ions and also to restore the sorbent to its original state. The adsorbent efficiency toward Hg(II) removal was tested using synthetic and chloralkali industry wastewaters. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1261–1269, 2000     

Removal of Copper (II) and Nickel (II) Ions from Aqueous Solutions by a Composite Chitosan Biosorbent

Abstract

A composite chitosan biosorbent (CCB) was prepared by coating chitosan on to ceramic alumina. The adsorption characteristics of the sorbent for copper and nickel ions were studied under batch equilibrium and dynamic flow conditions at pH 4.0. The equilibrium adsorption data were correlated with Langmuir, Freundlich, and Redlich‐Peterson models. The ultimate monolayer capacities, obtained from Langmuir isotherm, were 86.2 and 78.1 mg/g of chitosan for Cu(II) and Ni(II), respectively. In addition, dynamic column adsorption studies were conducted to obtain breakthrough curves. After the column was saturated with metal ions, it was regenerated with 0.1 M sodium hydroxide. The regenerated column was used for a second adsorption cycle.     

粉煤灰微波改性及其对含铬废水的吸附性能

将取自于西安市西郊热电厂的原粉煤灰(FA)球磨5h得到超细粉煤灰(UFA),再经过微波辐照处理得到微波辐照改性超细粉煤灰(MFA),并研究其对含铬废水的吸附性能.动力学研究结果表明,改性粉煤灰对Cr(VI)的吸附符合二级吸附动力学模型,通过模型计算出的FA,UFA和MFA的二级吸附速率常数(k2)分别为2.45×10-2 ,3.88×10-2 和5.14×10-2g·mg-1·min-1; 热力学研究结果表明,吸附过程可以用Langmuir方程描述.     

Copper(II) removal from aqueous solution by organosolv lignin and its recovery

In this study the removal of Cu(II) ions from aqueous solution was performed at different concentrations, temperatures, and pHs using ethanol‐based organosolv lignin as the adsorbent. The results indicated that the amount of Cu(II) ions adsorbed onto the lignin increased with increasing concentration and pH; however, it decreased with an increase in temperature. It was possible to remove 40.74% (maximum removal) of Cu(II) ions from aqueous solution by using organosolv lignin within 10 min under certain conditions (3 × 10^?4 M and 20°C). The adsorption process was determined to be consistent with the Freundlich isotherm. Furthermore, it was found that 40% (maximum recovery) of the Cu(II) ions adsorbed on the organosolv lignin could be recovered using HCl with an initial concentration of 3 × 10^?4 M and a contact time of 10 min. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1537–1541, 2003     

Effect of pH,cation concentration and sorbent concentration on cadmium and copper removal by a granular activated carbon

The single adsorption of cadmium and copper from aqueous solutions has been investigated on Darco 12–20 mesh granular activated carbon for a wide range of experimental conditions: pH, metal concentration and carbon concentration. The results showed the efficiency of the activated carbon as sorbent for both metals. Metal removal increases on raising pH and carbon concentration, and decreases on raising the initial metal concentration. The adsorption processes have been modelled using the surface complex formation (SCF) Triple Layer Model (TLM) with a single surface bidentate species or with an overall surface species with fractional stoichiometry. Bidentate stoichiometry considering pH, metal concentration and carbon concentration dependencies successfully predicted cadmium and copper removals for all experimental conditions. The Freundlich isotherm has been also checked. © 1999 Society of Chemical Industry     

Electrochemical remediation of metal-bearing wastewaters Part II: Corrosion-based inhibition of copper removal by iron (iii)

A hitherto undocumented inhibition to electrodeposition of Cu(ii) from dilute (<200 mg L–1) wastewaters was traced to the presence of Fe(iii) at concentrations comparable to those of copper ion. This inhibition was found to differ from heterogeneous side-reduction of Fe(iii) that is well known to decrease faradaic efficiency for copper removal. Based on bench-scale electrolysis as well as cyclic voltammetry studies, an inhibition mechanism was qualitatively identified that involved copper corrosion by Fe(iii). This corrosion process was found to be strongly favoured by sluggish heterogeneous reduction of Fe(iii) at carbon electrode materials. One procedure shown to substantially improve copper removal from solutions demonstrating corrosion inhibition was alkali precipitation of iron. Real mine drainage wastewater that was pretreated in this manner was consistently depleted of copper by flow-through electrolysis to levels below 50 g L–1.     

The use of fly ash from the combustion of poultry litter for the adsorption of chromium(III) from aqueous solution

Fly ash, from the combustion of poultry litter, was assessed as an adsorbent for chromium(III) from aqueous solution. The adsorption process was studied as a function of temperature and time. Adsorption was best described by the Langmuir model. The adsorption of chromium(III) on the fly ash was endothermic and kinetic studies suggest that the overall rate of adsorption was pseudo‐second order. At low initial concentrations film diffusion effects contribute to limiting the overall rate of adsorption while at higher initial chromium(III) concentrations pore diffusion becomes more important. An adsorption capacity of 53 mg dm^?3 was reached at 20 °C. © 2002 Society of Chemical Industry     

Efficient removal of Cr(VI) and Pb(II) from aqueous solution by magnetic nitrogen-doped carbon

The magnetic nitrogen-doped carbon (MNC) was prepared from polypyrrole by a simple high temperature calcination process in this paper. The structure and properties of MNC were analyzed by scanning electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Brunner-Emmet-Teller, vibrating sample magnetometer, and X-ray photoelectron spectroscopy. The capacity of MNC to adsorb Cr(VI) and Pb(II) was evaluated. The effects of the initial pH, dosage, concentration and temperature on the adsorption capacity of MNC were measured. MNC had a large specific surface area and a special porous structure. Its nitrogen and carbon sources were rich, and the ratio of carbon to nitrogen was fixed. The maximum Cr(VI)-adsorption capacity and maximum Pb(II) adsorption capacity of MNC could reach 456.63 and 507.13 mg∙g⁻¹ at 318 K, respectively. The pseudo-second-order model was used to describe the adsorption kinetics of MNC, and the Freundlich model was employed to discuss its isotherms. The adsorption process was affected by the electrostatic force, the reducing reaction, pores and chelation. The results of this study suggest that MNC is a material with superior performance, and is very easily regenerated, reused, and separated in the adsorption process.     

Adsorption of Cu(II) ions from an aqueous solution by crosslinked amphoteric starch

The adsorption process of Cu(II) ions from aqueous solutions by crosslinked amphoteric starch with quaternary ammonium and carboxymethyl groups was investigated. The adsorption capacity was found to be dependent on the solution pH, the dose of the crosslinked amphoteric starch, and the initial concentration of Cu(II) ions. Moreover, the adsorption capacity increased with an increasing degree of substitution (DS) of the carboxymethyl groups. The adsorption followed a Freundlich adsorption isotherm. The adsorption process was endothermic, and the thermodynamic parameters were calculated at different DS values. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 728–732, 2004