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Enhanced Removal of Phosphates by the Adsorbent Consisting of Iron Oxide Loaded on Porous Chitosan/Cellulose Acetate Particle

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Engineering（科研） 2019年第7期11卷 366-394页

作者： Nancy m. Waweru Jingjing Yang Herbert C. Bolokonya Suzhou University of Science and Technology Suzhou China Department of Civil Engineering University of Nairobi Nairobi Kenya

The effective and economical removal of phosphates from aqueous solution, mostly applied in waste water treatment, is one of the significant issues globally. Removal of phosphates ions in aqueous solution was analysed by chitosan blended with cellulose acetate, and iron oxide loaded chitosan-cellulose acetate adsorbents. The adsorbents were made in the form of beads. Batch experiments were performed to investigate the performance of the beads under various conditions on phosphate adsorption. Contact time, effect of initial phosphate concentration, adsorbent dosage, pH and temperature were investigated. Zeta potential measurements were also undertaken. The results showed that the adsorption process was highly pH dependent. The adsorption kinetics data were modelled with the application of adsorption reaction models and adsorption diffusion models. The results revealed that the pseudo 2nd order model was the best fitting in all cases. The experimental data were tested with Langmuir and freundlich isotherms. The equilibrium data were well fitted to the Langmuir isotherm model with a maximum adsorption capacity of 958 μg/g. The freundlich isotherm model also had a close fit with a maximum adsorption of 233 μg/g, which was very close to the experimental maximum adsorption. The mechanism of adsorption followed two stages in which the first one was fast followed by a slower gradual stage. SEm images showed that the adsorbent was macroporous. Fourier Transform Infrared Red (FT-IR) Spectroscopy, X-ray Diffraction Spectroscopy (XRD) and X-ray photoelectron Spectroscopy (XPS) showed that the phosphate adsorption on the HFO-CS/CA beads was due to surface complexes, and mainly involved Nitrogen atoms. HFO loading also increased surface area.

关键词： Phopshates Adsorption Chitosan/Cellulose Acetate Iron Oxides

Elimination of Cationic and Anionic Dyes by Natural Phosphate

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Journal of Chemistry and Chemical Engineering 2012年第8期6卷 721-725页

作者： A. Achkoun J. Naja R. m'Hamdi Applied Chemistry and Environment Laboratory University of Science and Technology Settat 577 Morocco Water and Environment Laboratory Study and Research Center of Mineral Phosphates Casablanca 25679 Morocco

The present work aims to study the adsorption, determining the ability of phosphate to remove cationic dyes, mB （methylene blue） and CV （crystal violet） and an anionic dye, the mO （methyl orange）. To explain the important reduction of pollution parameters obtained from its use as a filter bed. Natural phosphate is contacted with an aqueous solution having a concentration of 20 mg/L for 90, 45 and 20 min respectively for the mB, CV and mO. Experimental results show that the phosphate totally eliminates the CV and the WB. While, the adsorption of mO is very low. The Langmuir isotherm applies to mB and mO while the adsorption of CV uses the freundlich isotherm.

关键词： Natural phosphate adsorption isotherm methylene blue crystal violet methyl orange adsorption kinetics.

Ammonium Ion Adsorption and Settleability Improvement Achieved in a Synthetic Zeolite-Amended Activated Sludge

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Chinese Journal of Chemical Engineering 2013年第9期21卷 1062-1068页

作者： Emilia Otal Luls F. Vilches Yolanda Luna Rodrigo Poblete Juan m. Garcia-maya Constantino Ferneindez-Pereira Department of Chemical and Environmental Engineering School of Engineering University of Seville Camino delos Descubrimientos s/n 41092 Seville Spain

municipal wastewater treatment plants typically exhibit two classic problems： high ammonium concen- tration in water after conventional biological treatment and, in some cases, poor activated sludge sediment ability. Potential solutions to these problems were investigated by adding a synthetic zeolite obtained from coal fly ash to different steps of activated sludge treatment. The experimental results for ammonium removal fit well with the theoretical adsorption isotherms of the freundlich model with a maximum adsorption capacity of 13.72 mg.g-＇. Utiliza- tion of this kind of zeolite to improve activated sludge sediment ability is studied for the first time in this work. It is found that the addition of the zeolite （1 g. L-1） to an activated sludge with settling problems significantly enhances its sediment ability and comoact ability. This is confirmed by the sludge volume index （SVI）, which was reduced from 163 ml.g-1 to 70 ml.g-r, the V60 value, which was reduced from 894 ml.L-1 to 427 ml.L-1, and the zeta poten- tial （0, which was reduced from -19.81 mV to -14.29 mV. The results indicate that the addition of this synthetic zeolite to activated sludge, as an additional waste management practice, has a positive impact on both ammonium removal and sludge settleability.

关键词： low-cost sorbent nitrogen settleability zeolite adsorption zeta potential

Copper Ions Uptake on m-Phenylene Damine-Furfural Resin： Equilibrium and Kinetic Studies

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Journal of Environmental Science and Engineering 2010年第6期4卷 24-30页

作者： T.S. Najim A.J. mejli m.S. Sultan Chemistry Department College of Science Mustansiriya University Baghdad Iraq

The batch removal of Cu（II） from aqueous solution using m-phenylene diamine-furfural （phdm-fu） resin under different experimental conditions was investigated in this study. The influences of initial Cu（II） ion concentration （10 to 120 ppm ）, pH （4 to 8） and time have been reported. Adsorption of Cu（II） is highly pH dependent and the results indicate that the optimum pH for the removal was found to be 6. The experimental equilibrium adsorption data are tested for Langmuir, freundlich, Tempkin and Dubinin- Rodushkevich （D-R） equations. Results indicate that all isotherm are applicable except D-R isotherm which is not applicable . Adsorption kinetics data were modeled using the pseudo-first and pseudo-second order and intraparticle diffusion models. Results show that the pseudo-second order kinetic model was found to correlate the experimental data well.

关键词： Adsorption Cu(II) m-Phenylene diamine-furfural resin kinetic isotherm model

Aqueous Lead Removal under Optimized Conditions Using Phosphoric Acid Activated Coconut Coir Activated Carbon

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American Journal of Analytical Chemistry 2020年第12期11卷 389-405页

作者： D. D. Tharindu Trishan Darshana Senarathna Vithushana Thangarajah K. H. Dushmantha Namal Abeysooriya W. m. Yalini Hansika Wijesundara A. H. m. Lihini Nilma Kumari m. G. Gayan Sasanka Nirodha Thilakarathna Department of Aquaculture and Fisheries Faculty of Livestock Fisheries & Nutrition Wayamba University of Sri Lanka Makadura Gonawila (NWP) Sri Lanka Environmental Science Degree Programme Faculty of Science University of Peradeniya Peradeniya Sri Lanka Department of Chemistry University of Texas at Dallas Richardson TX USA Postgraduate Institute of Science University of Peradeniya Peradeniya Sri Lanka

The global burden of heavy metal environmental pollution remains one of the most challenging issues to be addressed urgently. Lead (Pb) has been well recognized as a toxic environmental pollutant. The main objective of this study was to examine the adsorption efficiency of phosphoric activated coconut coir activated carbon for lead (II) removal from an aqueous solution. Synthesized activated carbon was characterized before and after the adsorption of Pb(II) by powder X-Ray diffraction, Fourier transforms infrared spectroscopy and scanning electron microscopy coupled with energy dispersive X-Ray. Furthermore, the removal efficiency of Pb(II) of synthesized activated carbon was tested with different concentrations of Pb(II) solutions, pH levels, adsorbent dosages, and contact time. Atomic absorption spectroscopy was used to analyze the Pb(II) concentrations in water samples. The maximum Pb(II) removal percentage of 100% was obtained with 50 mL of 5 mg/L Pd(II) ion solution and 0.20 g of the synthesized activated carbon. Adsorption data were well fitted with the freundlich adsorption isotherm model, and adsorption kinetics were fitted with the pseudo-second-order kinetic model with R2 of 0.99. These results conclude that the synthesized activated carbon can be used as a potential sorbent for the removal of lead from wastewaters.

关键词： Activated Carbon Adsorption Lead Removal Coconut Coir

Analysis of the Adsorption of Toxic Chromium (VI) by Untreated and Chitosan Treated Banana and Areca Fiber

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Journal of Textile Science and Technology 2020年第2期6卷 81-106页

作者： Hosne Ara Begum A. K. m. monjurul Haque md. Didarul Islam m. mehedi Hasan Suza Ahmed md. Razzak Ruhul Amin Khan Department of Yarn Engineering Bangladesh University of Textiles Dhaka Bangladesh Department of Applied Science & Chemical Engineering University of Dhaka Dhaka Bangladesh Department of Fabric Engineering Bangladesh University of Textiles Dhaka Bangladesh Institute of Radiation and Polymer Technology Bangladesh Atomic Energy Commission Dhaka Bangladesh

This paper work involves bunch experiments to investigate the effect of contact time, pH, and adsorbent dose on the extent of adsorption by bio-composites. Adsorption capacity of Chromium (VI) onto chitosan coated with banana and areca fiber was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH and adsorbent dose. The chitosan and fibers (banana and areca) were then cross-linked with glutaraldehyde to remove chromium [Cr (VI)] from water via static adsorption. It was found that optimum chromium absorption capacity of chitosan was assessed at pH of 2.5 to 4.5 and contact time of 30 to 180 minutes for raw banana and areca fiber and for chitosan treated banana & areca fiber. Though optimum adsorption of chromium of chitosan was measured 34.17 ppm (85.42%) from a 100 ml solution containing 40 parts per million (ppm) of Cr (VI) at 120 minutes, pH of 3.0 and 120 milligram (mg) adsorbent dose size, use of composite will be more favorable in the point of environmental concern as well as low cost because chitosan preparation is comparatively costly then banana and areca fiber. On the other hand, untreated banana and areca fiber optimum adsorption of chromium measured 3.65 ppm (9.1%) at 180 min and, pH of 4.5 and 140 mg adsorbent dose size and 3.76 ppm (9.4%) at 180 min, pH of 4.5 and 160 mg adsorbent dose size respectively. In case of chitosan treated banana fiber, it was observed that adsorption was increased from 17.664 to 30.057 (75.14%). On the other hand, for areca fiber with chitosan, it was observed that adsorption was increased from 21.664 to 30.156 (75.39%) ppm. The Langmuir and freundlich adsorption models were used for the mathematical description of the adsorption of chromium ion onto composites and it was found that the Langmuir adsorption isotherm was more fitted models which mean that a monolayer adsorption surface was created. After analyzing from IBm SPSS 25 software, we got the stand

关键词： Adsorption Heavy metal Chitosan Banana Fiber Areca Fiber Toxicity

Adsorption Isotherms and Kinetic Studies of Congo-Red Removal from Waste Water Using Activated Carbon Prepared from Jujube Seed

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American Journal of Analytical Chemistry 2020年第1期11卷 47-59页

作者： Idris Aminu Sani m. Gumel Wasila A. Ahmad Adamu A. Idris Department of Pure and Industrial Chemistry Faculty of Physical Sciences College of Natural and Pharmaceutical Sciences Bayero University Kano Nigeria

In this study, adsorption of Congo red dye onto activated carbon prepared from Jujube (Ziziphus mauritiania) seeds with phosphoric acid as the activating agent was investigated. Batch adsorption studies were carried out to study the influence of contact time, adsorbent dosage and initial dye concentration on the adsorption. The data was analysed using pseudo-first order and pseudo-second order kinetic models. The pseudo-second order kinetic model was found to describe the adsorption more effectively with a perfect correlation coefficient of unity. The rate constant, K was obtained as 0.182 (g/mg min) and the calculated qe (9.81) is very close to the experimental value (9.78). A high correlation coefficient obtained when the data was analysed with the intraparticle diffusion rate equation, revealed the presence of intraparticle diffusion in the adsorption process even though it is not the sole controlling step as shown by the value of the intercept (C ≠ 0). Isotherm studies showed that there is high correlation in each case when the data was modelled with Langmuir, freundlich, Temkin and Dubinin-Radushkevic isotherm models but the best fit was obtained with the freundlich model with R2 = 0.9991, adsorption capacity, KF = 19.73 (mg/g)(mg/L)1/n and n = 1.563 indicating the adsorption is favourable and occurs on a heterogeneous surface by multilayer. The study showed that activated carbon from jujube seeds is an effective adsorbent for the removal of Congo red dye from solution.

关键词： Adsorption Kinetics Isotherms Jujube Seeds Congo Red

Adsorptive Removal from Aqueous Solution of Cr(VI) by Green moringa Tea Leaves Biomass

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Journal of Encapsulation and Adsorption Sciences 2017年第2期7卷 108-119页

作者： Candice C. Timbo martha Kandawa-Schulz marta Amuanyena Habauka m. Kwaambwa Department of Chemistry and Biochemistry University of Namibia Windhoek Namibia Faculty of Health and Applied Sciences Namibia University of Science and Technology Windhoek Namibia

Hexavalent chromium, Cr(VI), is a toxic metal present in industrial effluents. The study was carried to test the use of green moringa leaves biomass as adsorbent for Cr(VI) from aqueous solutions. Batch adsorption method was used and the concentration of Cr(VI) measured using an ultraviolet-visible (UV-Vis) spectrophotometry. The effects of the adsorption contact time, adsorbent dosage, pH, initial adsorbate concentration and temperature were studied. Results show maximum removal of Cr(VI) of 99% ± 1%, with maximum adsorption capacity of 33.9 mg/g at a pH 2, 60 minutes contact time and 100 mg/l initial Cr(IV) concentration. The Langmuir and freundlich adsorption isotherm models were used to fit the experimental data. The data showed that adsorption on green moringa oleifera leaves tea biomass fitted well to freundlich isotherm (r2 = 0.9432) compared to the Langmuir isotherm (r2 = 0.9122). m. oleifera leaves biomass can be used in water purification systems. The sludge of m. oleifera leaves is biodegradable, cost effective and environmentally friendly and therefore attractive in hexavalent chromium removal in water.

关键词： Adsorbent Adsorption Isotherm Heavy metals Hexavalent Chromium moringa oleifera

碳纳米管纱作为填料应用于硝基芳烃污水处理（英文）

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新型炭材料 2016年第4期31卷 415-423页

作者： Sushil R.Kanel Heath misak Dhriti Nepat Shankar mall Seth W.Brittle Ioana Sizemore David m.Kempisty mark N.Goltz Department of Systems Engineering and management Air Force Institute of Technology2950 Hobson WayWright-Patterson AFBOH 45433-7765USA Department of Aeronautics and Astronautics Air Force Institute of Technology2950 Hobson WayWright-Patterson AFBOH 45433-7765USA materials and manufacturing Directorate Air Force Research LaboratoryWright-Patterson AFBOhio 45433-7702USA Department of Chemistry Wright State University3640 Colonel Glen HighwayDaytonOH 45435USA

碳纳米管纱(CNTY)因具有优异的力学强度、化学稳定性、热稳定性和高比表面积而成为去除废水中有机污染物的潜在材料。本文将CNTY用于含2,4-二硝基甲苯(DNT)的污水处理。CNTY对DNT的吸附能力与文献报道值作对比研究,同时探讨吸附动力学... 详细信息

碳纳米管纱(CNTY)因具有优异的力学强度、化学稳定性、热稳定性和高比表面积而成为去除废水中有机污染物的潜在材料。本文将CNTY用于含2,4-二硝基甲苯(DNT)的污水处理。CNTY对DNT的吸附能力与文献报道值作对比研究,同时探讨吸附动力学。采用SEm-EDX、HRTEm、Raman与XPS表征CNTY吸附DNT前后的尺寸、表面形貌及表面化学。结果表明,经CNTY对DNT污水处理后的水质达到实验室无离子水级纯度。CNTY对DNT吸附符合freundlich吸附等温线,freundlich参数由K/nF为55.0 mg/g(L/mg)1,指数1/n为0.737得到,表明其比活性炭吸附性弱,但更易再生。CNTY比活性炭的吸附性速率更快,遵循拟二级动力学模型。CNTY吸附DNT引起D、G常偏移,归因于CNTs与DNT间电子受体和供体效应。

关键词：碳纳米管纱 2,4-二硝基甲苯吸附 freundlich吸附等温线新兴技术