共查询到20条相似文献,搜索用时 31 毫秒
1.
A new biosorbent has been prepared by coating Chrysophyllum albidum (Sapotaceae) seed shells with chitosan and/or oxidizing agents such as sulfuric acid. This study investigated the technical feasibility of activated and modified activated C. albidum seed shells carbons for the adsorption of chromium(VI) from aqueous solution. The sorption process with respect to its equilibria and kinetics as well as the effects of pH, contact time, adsorbent mass, adsorbate concentration and particle size on adsorption was also studied. The most effective pH range was found to be between 4.5 and 5 for the sorption of the metal ion. The pseudo-first-order rate equation by Lagergren and pseudo-second-order rate equation were tested on the kinetic data, the adsorption process followed pseudo-second-order rate kinetics, also, isotherm data was analyzed for possible agreement with the Langmuir and Freundlich adsorption isotherms, the Freundlich and Langmuir models for dynamics of metal ion uptake proposed in this work fitted the experimental data reasonably well. However, equilibrium sorption data were better represented by Langmuir model than Freundlich. The adsorption capacity calculated from Langmuir isotherm was 84.31, 76.23 and 59.63 mg Cr(VI)/g at initial pH of 3.0 at 30 °C for the particle size of 1.00–1.25 mm with the use of 12.5, 16.5 and 2.1 g/L of CACASC, CCASC and ACASC adsorbent mass, respectively. This readily available adsorbent is efficient in the uptake of Cr(VI) ion in aqueous solution, thus, it could be an excellent alternative for the removal of heavy metals and organic matter from water and wastewater. 相似文献
2.
Li Sun Zhigang Yuan Wenbang Gong Zili Xu Jijun Lu Qinghua Zou Yuqin Wu Gongbing Su Huafang Wang 《中国科学:化学(英文版)》2016,59(4):383-386
Chitosan-iron nanowires in porous anodic alumina (PAA) have been successfully prepared under ambient conditions as an adsorbent. The adsorbent was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy and N2-BET surface area. The results showed that PAA can disperse and protect Fe0 nanorods from oxidation. The adsorption characteristics of trace Cr(VI) onto adsorbent have been examined at different initial Cr(VI) concentrations with pH 5. Batch adsorption studies show that the removal percentage of adsorbent for the removal of trace Cr(VI) is strongly dependent on the initial Cr(VI) concentrations. Langmuir and Freundlich isotherm models were used to analyze the experiment data. The adsorption of trace Cr(VI) by adsorbent is well modeled by the Langmuir isotherm and the maximum adsorption capacity of Cr(VI) is calculated as 123.95 mg/g which is very closed to the experiment results. Intraparticle diffusion study shows that the intraparticle diffusion of adsorbent is not the sole rate-controlling step. The negative value of Gibbs free energy change, ΔGo, indicated that the process of Cr(VI) onto adsorbent was spontaneous. This work has demonstrated that chitosan-iron nanowires in porous anodic alumina as an adsorbent has promising potential for heavy metal removal at trace level. 相似文献
3.
Rezvan Nekooghadirli Farshad Mahmoudi Alami 《Journal of Dispersion Science and Technology》2016,37(6):786-798
In the present study, adsorption of Ni(II) and Pb(II) from aqueous solution was investigated using activated carbon synthesized with industrial wastewater sludge. The synthesized adsorbent was analyzed using nitrogen adsorption–desorption and Fourier transfer infrared (FTIR) techniques. Batch adsorption mode was used to evaluate the effect of solution pH, contact time, adsorbent dose, initial metal ion concentration, and temperature on the adsorption capacity of the synthesized adsorbent. The kinetic data were analyzed using different kinetic models. The pseudo-second-order equation gave the best fit to the experimental data for both metal ions. The equilibrium isotherm data were analyzed using the Langmuir, Freundlich, and Dubinin–Radushkevich (D–R) isotherm models. The results showed that the data obtained for the Ni(II) and Pb(II) adsorption are in good agreement with the Langmuir model. The Langmuir mono-layer maximum adsorption capacities for Ni(II) and Pb(II) ions were estimated to be 74.06 and 88.76 mg g?1 at 25°C, respectively. In addition, the thermodynamic studies proved that the adsorption process of both metals could be considered endothermic. 相似文献
4.
氨基功能化纳米Fe3O4磁性高分子吸附剂对废水中Cr(VI)的吸附研究 总被引:3,自引:0,他引:3
采用分散聚合法通过共聚、开环反应, 对纳米Fe3O4进行表面功能化修饰, 得到富含NH2官能团的纳米磁性高分子复合材料. 通过透射电镜(TEM)、振动样品磁强计(VSM)、热重差热分析(TGA)、X射线衍射(XRD)、红外光谱(IR)等对其进行表征, 着重研究了其作为吸附剂对Cr(VI)的吸附性能. 结果表明: 该吸附剂对Cr(VI)的吸附能在10 min内达到平衡; 废水溶液pH值能显著影响吸附剂对Cr(VI)的吸附效果, pH为2.5时效果最佳. 废水中Cr(VI)的初始浓度、吸附时间、温度等因素对吸附效果均有不同程度的影响. 结合相应pH值下Cr(VI)的形态分布, 探讨了这种新型材料对Cr(VI)的吸附机理. 结果表明: 其吸附机理及吸附容量与废水中Cr(VI)的离子形式有关; 吸附过程以离子交换与静电引力为主. 等温吸附数据符合Langmuir模型, T=308 K, pH=2.5, V=40 mL时, 吸附剂的饱和吸附容量qm=25.58 mg/g. 吸附为吸热过程, 焓变ΔH=8.64 kJ/mol. 相似文献
5.
Saad S. M. Hassan Nasser S. Awwad Awaad H. A. Aboterika 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(1):135-140
Summary Synthetic Sorel's cement [3Mg(OH)2 . MgCl2 . 8H2O], is used as a new adsorbent material for removal of chromium(VI) ion from wastewater effluents. Parameters including contact
time, adsorbent dosage and pH are examined and optimized. The equilibrium data are fitted very well to the Langmuir and Freundlich
isotherms rather than linear. The adsorption isotherm indicates that the monolayer coverage is 21.4 mg Cr(VI) ion per g of
Sorel's cement. The adsorbent is considered as a better replacement technology for removal of Cr(VI) ion from aqueous solutions
due to its low cost, good efficiency, fast kinetics, and simple preparation. It offers remarkable efficiency for Cr(VI) removal
from wastewater compared with many other natural and synthetic adsorbents. 相似文献
6.
Ca-rich water and wastewater have caused problems in water use, wastewater reuse and the operations of reactors treating Ca-rich wastewater. Nowadays, reuse of wastewaters is fast gaining importance as water sources have been polluted. Therefore, the concept of biocatalytic calcification reactors (BCR) based on urea hydrolysis, pH increase and calcite production has been studied to remove Ca from wastewaters. This biological process produces significant amounts of waste sludge. In the present study, Cr(VI) adsorption on the ureolytic mixed culture (UMC) waste by-product from BCR was investigated to evaluate its potential for metal removal. The biosorption process was investigated using equilibrium batch tests and the data were fit to the Langmuir, Freundlich and Temkin isotherm models. The Cr(VI) ion concentration dependence of sorption (1-100 mg/L) could be fit to the Langmuir isotherm model. Monolayer adsorption capacity, qm (mg/g), of the adsorbent was 8.67 and the Langmuir constant b (L/mg) was 0.881. Based on the obtained results, the waste UMC appears to be a potential biosorbent for the removal of Cr(VI) from wastewater, although its adsorptive capacity is lower than those of other biosorbents. 相似文献
7.
Fereshteh Abbasi Abdolhadi Farrokhnia Mehrdad Bamdad Roaya Mirzajani 《Journal of the Iranian Chemical Society》2017,14(8):1741-1752
The removal of Cr(VI) ions from aqueous solution by human hair waste is investigated by using UV–Vis spectrophotometer technique. The morphological analysis of the human hair was also investigated by the scanning electron microscopy, Fourier transforms infrared spectroscopy and X-ray photoelectron spectroscopy. The influence of various physicochemical effective parameters such as pH, ionic strength, adsorbent amount, contact time, initial concentration of metal ion on removal of Cr(VI) ions by human hair process was also studied. The optimum conditions for this adsorption process were obtained at pH = 2 and contact time of 150 min while the highest Cr(VI) uptake is recorded for 0.5 g of the adsorbent per 100 ml of solution. Three isotherms models including Langmuir, Freundlich and Temkin were applied to describe the equilibrium data. It was found that the experimental data were well described by Freundlich isothermal model. The maximum adsorption capacity was found to be 11.64 mg g?1.The thermodynamic study data showed that the adsorption process of Cr(VI) on human hair is an endothermic, spontaneous and physisorption reaction. The kinetics of the adsorption process was studied using three kinetics models including Lagergren-first-order, pseudo-second-order and Elovich model. The obtained data are indicated that the adsorption processes of Cr(VI) over human hair could be described by the pseudo-second-order kinetic model. 相似文献
8.
Qiang Xu Ping Yin Guifang Zhao Gui Yin Rongjun Qu 《Central European Journal of Chemistry》2010,8(1):214-222
The present study was undertaken to develop a novel adsorbent for heavy metal ions, and this paper presents the synthesis
and characterization of a composite material-silica gel microspheres encapsulated by salicyclic acid functionalized polystyrene
(SG-PS-azo-SA) with a core-shell structure. SG-PS-azo-SA was used to investigate the adsorption of Mn(II), Co(II), Ni(II),
Fe(III), Hg(II), Zn(II), Cd(II), Cr(VI), Pd(II), Cu(II), Ag(I), and Au(III) from aqueous solutions. The results revealed that
SG-PS-azo-SA has better adsorption capacity for Cu(II), Ag(I) and Au(III). Langmuir and Freundlich isotherm models were applied
to analyze the experimental data, the best interpretation for the experimental data was given by the Langmuir isotherm equation
with the maximum adsorption capacity for Cu(II), Ag(I), and Au(III) at 1.288 mmol g−1, 1.850 mmol g−1 and 1.613 mmol gt-1, respectively. Thus, silica gel encapsulated by salicyclic acid functionalized polystyrene (SG-PS-azo-SA) is favorable and
useful for the removal of Cu(II), Ag(I) and Au(III) metal ions. 相似文献
9.
Efficient Removal of Cobalt(II) and Strontium(II) Metals from Water using Ethylene Diamine Tetra‐acetic Acid Functionalized Graphene Oxide
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Hany Amer Wafaa M. Moustafa Ahmed A. Farghali Waleed M. A. El Rouby Waleed F. Khalil 《无机化学与普通化学杂志》2017,643(22):1776-1784
Graphene oxide (GO) with high specific surface area was prepared and functionalized with ethylene diamine tetra‐acetic acid (EDTA). The as‐prepared GO and the functionalized one (GO‐EDTA) were characterized using high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), and Raman spectroscopy. The as‐prepared and EDTA funcationalized GO were applied as adsorbent to remove strontium(II) and cobalt(II) from water. The results indicated that the prepared materials are efficient adsorbents for strontium(II) and cobalt(II) removal. The adsorption of CoII and SrII under effects of contact time, temperature, and pH was investigated It is concluded that the maximum adsorption capacities of GO for CoII and SrII were about 168 and 140 mg · g–1, whereas of GO‐EDTA the values were about 197 and 158 mg · g–1, respectively. It is indicated that pH 6 and temperature 40 °C are the best condition for CoII and SrII removal from water. The application of Langmuir and Freundlich isotherms indicated that Langmuir isotherm is best fit for CoII and SrII equilibrium adsorption. Adsorption kinetics were studied by applying pseudo first‐order, pseudo second‐order, and intraparticle diffusion models on the experimental data. The results proved that pseudo second‐order model is the best represented adsorption kinetics. Appling the intraparticle diffusion regressions on the experimental data indicated that intraparticle diffusion involved in adsorption process, which was not the only rate‐controlling step. 相似文献
10.
Hadi M. Marwani Hassan M. Albishri Ezzat M. Soliman Taghreed A. Jalal 《Journal of Dispersion Science and Technology》2013,34(4):549-555
This study introduces a sensitive and simple method for selective adsorption of hexavalent chromium, Cr(VI), from water samples prior to its determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The method utilized activated carbon modified with tris(hydroxymethyl)aminomethane (AC-TRIS) as an adsorbent. Surface properties of the new chemically modified AC-TRIS phase were confirmed by Fourier transform infrared (FTIR) spectroscopy. Seven metal ions, including Co(II), Cu(II), Ni(II), Pb(II), Cr(III), Cr(VI), and Fe(III) were evaluated and determined at different pH values (1.0–8.0), except for Fe(III) at pH values (1.0–4.0). Based on the results of the effect of pH on adsorption of these metal ions on AC-TRIS, Cr(VI) was selected for the study of other parameters controlling its maximum uptake on AC-TRIS under batch conditions and at the optimum pH value 1.0. The maximum static adsorption capacity of Cr(VI) onto the AC-TRIS was found to be 43.30 mg g?1 at this pH and after 1 hour contact time. The adsorption data of Cr(VI) were modeled using both Langmuir and Freundlich classical adsorption isotherms. Results demonstrated that the adsorption of Cr(VI) onto AC-TRIS followed a pseudo second-order kinetic model. In addition, the efficiency of this methodology was confirmed by applying it to real environmental water samples. 相似文献
11.
Mohamed R. El-Aassar Tamer M. Tamer Mohamed Y. El-Sayed Ahmed M. Omer Ibrahim O. Althobaiti Mohamed E. Youssef Rawan F. Alolaimi Emam F. El-Agammy Manar S. Alruwaili Omar O. Rabhy Mohamed S. Mohy-Eldin 《Molecules (Basel, Switzerland)》2022,27(23)
Methylene blue (MB) immobilized onto a sulfonated poly(glycidyl methacrylate) (SPGMA) polymer composite has been developed as a novel adsorbent for water treatment applications. The MB adsorptions onto sulfonated poly(glycidyl methacrylate) polymer characters have been studied. The adsorption isotherms, namely Langmuir and Freundlich, have been investigated. Other isotherm models. As a compromise between the Freundlich and Langmuir isotherm models, such as the D–R isotherm and the Temkin isotherm, have been compared. The results indicated that the adsorption process followed the Freundlich isotherm model, indicating heterogeneous surface site energies and multi-layer levels of sorption. This study selected three linear kinetic models, namely pseudo-first order, pseudo-second order, and Elovich, to describe the MB sorption process using SPGMA negatively charged nanoparticles (430 nm). The obtained data revealed that the adsorption process obeyed the pseudo-second-order kinetic model, suggesting that the rate-limiting step in these sorption processes may be chemisorption. Furthermore, the thermodynamic parameters have been evaluated. Moreover, the interaction of the MB molecules with SPGMA nanoparticles has been simulated using the governing equation that describes ion exchange resin derived from Nernst—Plank equations between two ion species. Finally, the developed MB-SPGMA composite adsorbent (27 mg/g) wastested for the first time for the removal of Cr6+ ions and Mn7+ metal ions from dichromate and permanganate-contaminated waters under mild adsorption conditions, opening a new field of multiuse of the same adsorbent in the removal of more than one contaminant. 相似文献
12.
A basic investigation on the removal of Cr(III) and Cr(VI) ions from aqueous solution by chitosan beads was conducted in a
batch adsorption system. The chitosan beads were prepared by casting an acidic chitosan solution into an alkaline solution.
The influence of different experimental parameters; pH, agitation period and different concentration of Cr(III) and Cr(VI)
ions was evaluated. A pH 5.0 was found to be an optimum pH for Cr(III) adsorption, and meanwhile pH 3.0 was the optimum pH
for the adsorption of Cr(VI) onto chitosan beads. The Langmuir and Freundlich adsorption isotherm models were applied to describe
the isotherms and isotherm constants for the adsorption of Cr(III) and Cr(VI) onto chitosan beads. Results indicated that
Cr(III) and Cr(VI) uptake could be described by the Langmuir adsorption model. The maximum adsorption capacities of Cr(III)
and Cr(VI) ions onto chitosan beads were 30.03 and 76.92 mg g−1, respectively. Results showed that chitosan beads are favourable adsorbents. The Cr(III) and Cr(VI) ions can be removed from
the chitosan beads by treatment with an aqueous EDTA solution. 相似文献
13.
Mustafa Tabakci 《Journal of inclusion phenomena and macrocyclic chemistry》2008,61(1-2):53-60
An aminopropyl silica gel-immobilized calix[6]arene (C[6]APS) containing both amide and acid moieties was prepared from p-tert-butylcalix[6]arene hexacarboxylate derivative and aminopropyl silica gel in the presence of N,N′-diisopropyl carbodiimide coupling reagent. C[6]APS was used to evaluate the sorption properties of Cr(VI) as a sorbent material. In sorption studies, it was observed that C[6]APS was highly effective at pH 1.5 for Cr(VI). The effect of parameters such as pH, sorbent dosage, contact time, initial Cr(VI) concentration and temperature on Cr(VI) sorption; the sorption isotherms were also studied. Maximum sorption capacity was obtained as 3.1 mg g?1 at pH 1.5 and 25 °C for 1 h and 10.4 mg L?1 initial Cr(VI) concentration. Thermodynamic parameters such as change in free energy, enthalpy, and entropy were also determined. In the isotherm studies, Langmuir and Freundlich isotherm models were applied and it was found that the experimental data confirmed to Freundlich isotherm model, and the batch sorption capacity of C[6]APS was calculated as 37.66 mg g?1. 相似文献
14.
Fatima Ouadjenia-Marouf Reda Marouf Jacques Schott Ahmed Yahiaoui 《Arabian Journal of Chemistry》2013,6(4):401-406
The removal of heavy metals, such as Cu(II), Cd(II) and Cr(III) from aqueous solution was studied using Chorfa silt material (Mascara, Algeria). The main constituents of silt sediment are quartz, calcite and mixture of clays. The experimental data were described using Freundlich, Langmuir, Dubinin–Radushkevich (D–R) and Langmuir–Freundlich models. The adsorbed amounts of chromium and copper ions were very high (95% and 94% of the total concentration of the metal ions), whereas cadmium ion was adsorbed in smaller (55%) amounts. The Langmuir–Freundlich isotherm model was the best to describe the experimental data. The maximum sorption capacity was found to be 26.30, 11.76 and 0.35 mg/g for Cr3+, Cu2+ and Cd2+, respectively. The results of mean sorption energy, E (kJ/mol) calculated from D–R equation, confirmed that the adsorption of copper, chromium and cadmium on silt is physical in nature. 相似文献
15.
Oluwasogo Adewumi Dada Folahan Amoo Adekola Ezekiel Oluyemi Odebunmi 《Journal of Dispersion Science and Technology》2016,37(1):119-133
The studies of kinetics and equilibrium sorption of Cu(II) were undertaken using nanoscale zerovalent manganese (nZVMn) synthesized by chemical reduction in a single pot system. nZVMn was characterized using scanning electron microscopy, energy dispersive x-ray, and surface area determined by Brunauer–Emmett–Teller. The effect of pH, contact time, adsorbent dose, agitation speed, initial Cu(II) concentrations, temperature, and ionic strength on the sorption of Cu(II) onto nZVMn were investigated in a batch system. The kinetic data followed pseudo-second-order. The mechanism was governed by pore diffusion. The equilibrium sorption data were tested by Freundlich, Langmuir, Temkin, Dubinin–Kaganer–Raduskevich, and Halsey isotherm models. The Langmuir monolayer adsorption capacity (Qmax = 181.818 mg/g) is much greater compared to other nano-adsorbents used in sorption of Cu(II). The thermodynamic parameters (ΔH0, ΔS0, ΔG0) revealed a feasible, spontaneous, and endothermic adsorption process. nZVMn has a great potential for effective removal of copper (II) in aqueous solution. 相似文献
16.
Juan Tan Yanfei Wang Na Liu Mouwu Liu 《Journal of Radioanalytical and Nuclear Chemistry》2018,315(2):119-126
The adsorption of uranium (VI) using tetraphenylimidodiphosphinate (Htpip) was studied. Factors of affecting sorption efficiency have been investigated and results showed the adsorption of uranium (VI) was equilibrium at pH 4.5, time 20 min, adsorbent dosage 0.005 g and initial concentration 50 mg L?1 reaching 99.86 mg g?1 of adsorption capacity and 99.86% of removal efficiency. Additionally, the interfering ions studies showed that the adsorbent possessed excellent adsorption selectivity of uranium (VI). The surface morphology of Htpip was investigated by SEM. The adsorption process of uranium (VI) onto Htpip fit the pseudo-second-order kinetic model and the Freundlich isotherm model very well. 相似文献
17.
A novel adsorbent was developed from mature leaves of the Neem tree (Azadirachta Indica) for removing metal ions from water. The adsorbent, in the form of fine powder, was found to be very effective in removing chromium (VI) from aqueous solution. The adsorption was carried out in a batch process taking different concentrations of the metal ion in aqueous solution with variation in adsorbent amount, pH, agitation time and temperature. The suitability of the adsorbent was tested with Langmuir and Freundlich isotherms and with various equilibrium kinetic data. A small amount of the Neem Leaf Powder (NLP) (1.6 g dm–3) could remove as much as 87% of Cr (VI) in 300 min from a solution of concentration 14.1 mg dm–3 at 300 K. The optimum range of pH for the adsorption process was 4.5–7.5 and since the natural pH of the Cr (VI) solution was 5.5, no addition of acid or alkali was necessary for achieving maximum adsorption. The adsorption coefficients indicated a high potentiality for the NLP to be used as an adsorbent for removing Cr (VI) from water. 相似文献
18.
De-Xin Ding Xi-Tao Liu Nan Hu Guang-Yue Li Yong-Dong Wang 《Journal of Radioanalytical and Nuclear Chemistry》2012,293(3):735-741
Experiments on the removal and recovery of U(VI) from aqueous solution by tea waste were conducted. The adsorbent was characterized by scanning electron microscope and energy dispersive spectrometer before and after the adsorption treatment. The removal of U(VI) amounts to 86.80?% at optimum pH 6. The adsorption process reaches its equilibrium in 12?h at 308?K, and the kinetic characteristic can be described by the pseudo-second-order kinetic equation. The amount of adsorption increases from 22.92 to 142.21?mg?g?1 with the decrease of tea waste dosage from 100 to 10?mg for solution with an initial uranium concentration of 50?mg?L?1. Desorption for the four strippants is higher than 80?%. The equilibrium data are more agreeable with Freundlich isotherm than Langmuir isotherm. 相似文献
19.
Lian Ai Xuegang Luo Xiaoyan Lin Sizhao Zhang 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(3):1823-1834
Uranium (VI)-containing water has been recognized as a potential longer-term radiological health hazard. In this work, the sorptive potential of sunflower straw for U (VI) from aqueous solution was investigated in detail, including the effect of initial solution pH, adsorbent dosage, temperature, contact time and initial U (VI) concentration. A dose of 2.0 g L?1 of sunflower straw in an initial U (VI) concentration of 20 mg L?1 with an initial pH of 5.0 and a contact time of 10 h resulted in the maximum U (VI) uptake (about 6.96 mg g?1) at 298 K. The isotherm adsorption data was modeled best by the nonlinear Langmuir–Freundlich equation. The equilibrium sorption capacity of sunflower straw was observed to be approximately seven times higher than that of coconut-shell activated carbon as 251.52 and 32.37 mg g?1 under optimal conditions, respectively. The positive enthalpy and negative free energy suggested the endothermic and spontaneous nature of sorption, respectively. The kinetic data conformed successfully to the pseudo-second-order equation. Furthermore, energy dispersive X-ray, fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy demonstrated that U (VI) adsorption onto sunflower straw was predominantly controlled by ion exchange as well as complexation mechanism. The study revealed that sunflower straw could be exploited for uranium remediation of aqueous streams as a promising adsorbent. 相似文献
20.
In the present study, adsorbent is prepared from neem leaves and used for Cr(VI) removal from aqueous solutions. Neem leaves
are activated by giving heat treatment and with the use of concentrated hydrochloric acid (36.5 wt%). The activated neem leaves
are further treated with 100 mmol of copper solution. Batch adsorption studies demonstrate that the adsorbent prepared from
neem leaves has a significant capacity for adsorption of Cr(VI) from aqueous solution. The parameters investigated in this
study include pH, contact time, initial Cr(VI) concentration and adsorbent dosage. The adsorption of Cr(VI) is found to be
maximum (99%) at low values of pH in the range of 1-3. A small amount of the neem leaves adsorbent (10 g/l) could remove as
much as 99% of Cr(VI) from a solution of initial concentration 50 mg/l. The adsorption process of Cr(VI) is tested with Langmuir
isotherm model. Application of the Langmuir isotherm to the system yielded maximum adsorption capacity of 62.97 mg/g. The
dimensionless equilibrium parameter, R
L, signifies a favorable adsorption of Cr(VI) on neem leaves adsorbent and is found to be between 0.0155 and 0.888 (0<R
L<1). The adsorption process follows second order kinetics and the corresponding rate constant is found to be 0.00137 g/(mg)
(min). 相似文献