scholarly journals Enhanced Removal of Lead by Chemically and Biologically Treated Carbonaceous Materials

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Mohamed E. Mahmoud ◽  
Maher M. Osman ◽  
Somia B. Ahmed ◽  
Tarek M. Abdel-Fattah
Keyword(s):  
Active Carbon ◽  
Isotherm Models ◽  
Infrared Analysis ◽  
Carbonaceous Materials ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Potential Applications ◽  
Microscope Imaging ◽  
Carbonaceous Sorbents ◽  
Sorption Mechanisms

Hybrid sorbents and biosorbents were synthesized via chemical and biological treatment of active carbon by simple and direct redox reaction followed by surface loading of baker’s yeast. Surface functionality and morphology of chemically and biologically modified sorbents and biosorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Hybrid carbonaceous sorbents and biosorbents were characterized by excellent efficiency and superiority toward lead(II) sorption compared to blank active carbon providing a maximum sorption capacity of lead(II) ion as 500 μmol g−1. Sorption processes of lead(II) by these hybrid materials were investigated under the influence of several controlling parameters such as pH, contact time, mass of sorbent and biosorbent, lead(II) concentration, and foreign ions. Lead(II) sorption mechanisms were found to obey the Langmuir and BET isotherm models. The potential applications of chemically and biologically modified-active carbonaceous materials for removal and extraction of lead from real water matrices were also studied via a double-stage microcolumn technique. The results of this study were found to denote to superior recovery values of lead (95.0–99.0±3.0–5.0%) by various carbonaceous-modified-bakers yeast biosorbents.

scholarly journals Equilibrium and kinetics study on removal of arsenate ions from aqueous solution by CTAB/TiO2 and starch/CTAB/TiO2 nanoparticles: a comparative study

2016 ◽  
Vol 15 (1) ◽  
pp. 58-71
Author(s):  
Pankaj Gogoi ◽  
Debasish Dutta ◽  
Tarun Kr. Maji
Keyword(s):  
Comparative Study ◽  
Tio2 Nanoparticles ◽  
Removal Rate ◽  
Ammonium Bromide ◽  
X Ray ◽  
Maximum Sorption Capacity ◽  
Ion Removal ◽  
Maximum Sorption ◽  
Equilibrium And Kinetics ◽  
Sorption Mechanisms

We present a comparative study on the efficacy of TiO2 nanoparticles for arsenate ion removal after modification with CTAB (N-cetyl-N,N,N-trimethyl ammonium bromide) followed by coating with starch biopolymer. The prepared nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), thermogravimetry, scanning electron microscopy (SEM) and electron dispersive X-ray analysis (EDX). The removal efficiency was studied as a function of contact time, material dose and initial As(V) concentration. CTAB-modified TiO2 showed the highest arsenate ion removal rate (∼99% from 400 μg/L). Starch-coated CTAB-modified TiO2 was found to be best for regeneration. For a targeted solution of 400 μg/L, a material dose of 2 g/L was found to be sufficient to reduce the As(V) concentration below 10 μg/L. Equilibrium was established within 90 minutes of treatment. The sorption pattern followed a Langmuir monolayer pattern, and the maximum sorption capacity was found to be 1.024 mg/g and 1.423 mg/g after starch coating and after CTAB modification, respectively. The sorption mechanisms were governed by pseudo second order kinetics.

scholarly journals Waste Foundry Sand as Permeable and Low Permeable Barrier for Restriction of the Propagation of Lead and Nickel Ions in Groundwater

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ayad A. H. Faisal ◽  
Zaid Abed Al-Ridah ◽  
Laith A. Naji ◽  
Mu. Naushad ◽  
Hamed A. El-Serehy
Keyword(s):  
Permeable Reactive Barrier ◽  
Coefficient Of Determination ◽  
Infrared Analysis ◽  
Permeability Barrier ◽  
Foundry Sand ◽  
Nickel Ions ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Waste Foundry Sand ◽  
The Fourier Transform

This work aims to investigate the ability of using waste foundry sand (WFS) resulting as inexpensive by-product from steel industry in the low permeability barrier (LPB) and permeable reactive barrier (PRB) technologies for restriction of the movement of lead and nickel ions in the groundwater. Outputs of flask and tank tests certified that this material could capture these ions with sorption efficiency greater than 95% at time, pH, sorbent dosage, and speed equal to 60 min, 4 for lead and 6 for nickel, 2.5 g/100 mL, and 250 rpm, respectively. Sorption isotherm measurements were represented in a good manner by Langmuir model in comparison with Freundlich model with coefficient of determination (R2) greater than 0.99. So, the chemisorption was the predominant mechanism which could be supported by O-H, H-O-H, C-O, O-Si-O, and Si-O functional groups based on the Fourier transform infrared analysis. The maximum sorption capacity of WFS was 13.966 and 4.227 mg/g for lead and nickel ions, respectively, with corresponding affinities equal to 0.647 and 0.099 L/mg. Measurements signified that the hydraulic conductivity of WFS was 3.8 × 10−7 cm/s which satisfies the requirements of LPB. To obtain the acceptable values of permeability and reactivity, PRB was prepared from mixing 18% WFS with 82% filter sand. COMSOL software was able to simulate the measurements of two-dimensional tank packed with Iraqi soil aquifer in combination with WFS-LPB and WFS-filter sand PRB. Thicker barriers have a high ability in the protection of locations in the down-gradient side because their longevity increased dramatically with increase of barrier thickness.

scholarly journals Boron Removal by Sorption on Modified Chitosan Hydrogel Beads

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5646
Author(s):  
Joanna Kluczka ◽  
Gabriela Dudek ◽  
Wojciech Pudło ◽  
Alicja Kazek-Kęsik ◽  
Roman Turczyn
Keyword(s):  
Aqueous Media ◽  
Freundlich Isotherm ◽  
Sorption Kinetics ◽  
Isotherm Models ◽  
Isotherm Equation ◽  
Hydrogel Beads ◽  
Maximum Sorption Capacity ◽  
Modified Chitosan ◽  
Maximum Sorption ◽  
Naoh Solution

An excess concentration of boron in irrigation and drinking water can negatively affect the yield of plants and the human nervous system, respectively. To meet the recommended levels, hybrid biosorbent hydrogel beads based on chitosan and manganese (II-IV) were employed for the removal of boron from aqueous media. The results showed that the biosorbent effectively removed boric acid from the aqueous medium at neutral pH over a sorption time of 2 h and the liquid/hydrogel ratio of 20 mL/g, achieving a maximum sorption capacity near 190 mg/g. The modeling of the sorption equilibrium data indicated that the Freundlich isotherm equation gave the best fit out of the isotherm models examined. A pseudo-second-order model was found to best describe the sorption kinetics. The favorable attachment of manganese to the chitosan structure enabled the sorption of boron and was confirmed by FTIR, RS, XRD, SEM and ICP-OES methods. Boron desorption from the spent biosorbent was successfully achieved in three cycles using a NaOH solution. In general, the results of this research indicate that this method is one of the possibilities for improving water quality and may contribute to reducing pollution of the aquatic environment.

scholarly journals Removal of Salicylic and Ibuprofen by Hexadecyltrimethylammonium-Modified Montmorillonite and Zeolite

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 898
Author(s):  
Jiyeon Choi ◽  
Won Sik Shin
Keyword(s):  
Sorption Isotherms ◽  
Organic Carbon Content ◽  
Sorption Data ◽  
Maximum Sorption Capacity ◽  
Ideal Adsorbed Solution Theory ◽  
Modified Montmorillonite ◽  
Maximum Sorption ◽  
Competitive Model ◽  
Sorption Mechanisms ◽  
Positively Charged

The removal of salicylic acid (SA) and ibuprofen (IB) by sorption onto HDTMA-modified montmorillonite (HM) and zeolite (HZ) was investigated at pH 7. The single sorption data were fitted well by the Freundlich, Langmuir, Dubinin−Radushkevich (DR), and Polanyi−Dubinin−Manes (PDM) models (R2 > 0.94). The sorption affinity of Freundlich and the maximum sorption capacity of Langmuir and PDM models of pharmaceuticals onto HM were consistently higher than that of HZ mainly owing to the higher organic carbon content. In addition, the KF, qmL, and qm values were in the order of IB > SA owing to higher hydrophobicity and molar volume. Since the predominant speciation of SA and IB is anionic at pH 7 (>pKa), sorption onto HM occurs mainly by the two-dimensional surface adsorption onto the pseudo-organic medium in the HM, whereas the interaction of anionic pharmaceuticals with the positively charged “head” of HDTMA is responsible for HZ. Sorption isotherms were fitted well by the PDM model, which indicated that pore-filling was one of the dominating sorption mechanisms. The extended Langmuir model, modified Langmuir competitive model, and ideal adsorbed solution theory employed with Freundlich and Langmuir sorption models were applied to predict binary sorption. The effect of competition between the solutes was clearly evident in the characteristic curves; the maximum sorbed volume (qv.m) was reduced, and the sorbed volume (qv) had a wider distribution toward the sorption potential density.

Performance of biochar derived from rice straw for removal of Ni(II) in batch experiments

2018 ◽  
Vol 2017 (3) ◽  
pp. 824-834
Author(s):  
Lijia Dong ◽  
Wensheng Linghu ◽  
Donglin Zhao ◽  
Yinyan Mou ◽  
Baowei Hu ◽  
...  
Keyword(s):  
Rice Straw ◽  
Fulvic Acids ◽  
Langmuir Model ◽  
Isotherm Models ◽  
Ionic Exchange ◽  
Batch Experiments ◽  
Maximum Sorption Capacity ◽  
Major Interest ◽  
Maximum Sorption ◽  
Endothermic Process

Abstract Biochar, as a cost-efficient adsorbent, is of major interest in the removal of heavy metals from wastewater. Herein, batch experiments were conducted to investigate the performance of biochar derived from rice straw for the removal of Ni(II) as a function of various environmental conditions. The results showed that Ni(II) sorption was strongly dependent on pH but independent of ionic strength and the effects of electrolyte ions could be negligible over the whole pH range. Ionic exchange and inner-sphere surface complexation dominated the sorption of Ni(II). Humic/fulvic acids clearly enhanced the Ni(II) sorption at pH <7.2 but inhibited the sorption at pH >7.2. The sorption reached equilibrium within 10 hours, and the kinetics followed a pseudo-second-order rate model. Any of the Langmuir, Freundlich, or Dubinin-Radushkevich isotherm models could describe the sorption well, but the Langmuir model described it best. The maximum sorption capacity calculated from the Langmuir model was 0.257 m·mol/g. The thermodynamic parameters suggested that Ni(II) sorption was a spontaneous and endothermic process and was enhanced at high temperature. The results of this work indicate that biochar derived from rice straw may be a valuable bio-sorbent for Ni(II) in aqueous solutions, but it still requires further modification.

scholarly journals Sorption of Ce(III) by Silica SBA-15 and Titanosilicate ETS-10 from Aqueous Solution

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3263
Author(s):  
Inga Zinicovscaia ◽  
Nikita Yushin ◽  
Doina Humelnicu ◽  
Dmitrii Grozdov ◽  
Maria Ignat ◽  
...  
Keyword(s):  
Nitrogen Adsorption ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Adsorption Desorption

The adsorption capacity of two sorbents, silica SBA-15 and titanosilicate ETS-10, toward Ce(III) was tested. The obtained sorbents were characterized using X-ray diffraction, nitrogen adsorption-desorption, Scanning electron microscopy, and Fourier-transform infrared spectroscopy. The effects of solution acidity, cerium concentration, time of contact, and temperature on Ce(III) sorption were investigated. The maximum Ce(III) removal by silica SBA-15 was achieved at pH 3.0 and by titanosilicate ETS-10 at a pH range of 4.0–5.0. The Freundlich, Langmuir, and Temkin isotherm models were applied for the description of equilibrium sorption of Ce(III) by the studied absorbents. Langmuir model obeys the experimentally obtained data for both sorbents with a maximum sorption capacity of 68 and 162 mg/g for silica SBA-15 and titanosilicate ETS-10, respectively. The kinetics of the sorption were described using pseudo-first- and pseudo-second-order kinetics, Elovich, and Weber–Morris intraparticle diffusion models. The adsorption data fit accurately to pseudo-first- and pseudo-second-order kinetic models. Thermodynamic data revealed that the adsorption process was spontaneous and exothermic.

Природные материалы для сорбционной очистки хром- и кадмийсодержащих инфильтратов полигонов ТБО

2019 ◽  
pp. 13-19
Author(s):  
A. Safonov ◽  
N. Andriushchenko ◽  
N. Popova ◽  
K. Boldyrev
Keyword(s):  
Sorption Capacity ◽  
Electron Acceptors ◽  
Bacterial Cells ◽  
Maximum Sorption Capacity ◽  
Sorption Material ◽  
Maximum Sorption ◽  
Properties Of Materials ◽  
Solid Waste Landfills ◽  
Sorption Characteristics

Проведен анализ сорбционных характеристик природных материалов (вермикулит, керамзит, перлит, цеолит Трейд ) при очистке кадмий- и хромсодержащих сточных вод с высокой нагрузкой по ХПК. Установлено, что цеолит обладает максимальными сорбционными характеристиками для Cd и Cr и наименьшим биологическим обрастанием. При использовании вермикулита и керамзита или смесей на их основе можно ожидать увеличения сорбционной емкости для Cd и Сr при микробном обрастании, неизбежно происходящем в условиях контакта с водами, загрязненными органическими соединениями и биогенами. При этом биообрастание может повысить иммобилизационную способность материалов для редоксзависимых металлов за счет ферментативных ресурсов бактериальных клеток, использующих их в качестве акцепторов электронов. Эффект микробного обрастания разнонаправленно изменял параметры материалов: для Cr в большинстве случаев уменьшение и для Cd значительное увеличение. При этом дополнительным эффектом иммобилизации Cr является его биологическое восстановление биопленками. Варьируя состав сорбционного материала, можно подбирать смеси, оптимально подходящие для очистки вод инфильтратов с полигонов твердых бытовых отходов с высокой нагрузкой по ХПК и биогенным элементам как при использовании in situ, так и в системах на поверхности.The analysis of the sorption characteristics of natural materials (vermiculite, expanded clay, perlite, Trade zeolite) during the purification of cadmium and chromium-containing leachate with a high COD load was carried out. It was determined that zeolite had the maximum sorption capacity for Cd and Cr and the lowest biological fouling. When using vermiculite and expanded clay or mixtures on their basis, one can expect an increase in the sorption capacity for Cd and Cr during microbial fouling that inevitably occurs during contacting with water polluted with organic compounds and nutrients. In this case biofouling can increase the immobilization properties of materials for redox-dependent metals due to the enzymatic resources of bacterial cells that use them as electron acceptors. The effect of microbial fouling changed the parameters of materials in different directions: for Cr, in most cases, downward, and for Cd, significantly upward. Moreover, chromium biological recovery by biofilms is an additional effect of immobilization. Varying the composition of the sorption material provides for selecting mixtures that are optimally suitable for the purification of leachates from solid waste landfills with high COD and nutrients load, both when used in situ and in surface systems.

scholarly journals Phosphate Removal Using Polyethylenimine Functionalized Silica-Based Materials

2021 ◽  
Vol 13 (3) ◽  
pp. 1502
Author(s):  
Maria Xanthopoulou ◽  
Dimitrios Giliopoulos ◽  
Nikolaos Tzollas ◽  
Konstantinos S. Triantafyllidis ◽  
Margaritis Kostoglou ◽  
...  
Keyword(s):  
Sorption Capacity ◽  
Removal Rate ◽  
Phosphate Concentration ◽  
Phosphate Removal ◽  
Equilibrium Studies ◽  
Maximum Sorption Capacity ◽  
Algae Blooms ◽  
Maximum Sorption ◽  
Phosphate Anions ◽  
Adsorbent Dose

In water and wastewater, phosphate anions are considered critical contaminants because they cause algae blooms and eutrophication. The present work aims at studying the removal of phosphate anions from aqueous solutions using silica particles functionalized with polyethylenimine. The parameters affecting the adsorption process such as pH, initial concentration, adsorbent dose, and the presence of competitive anions, such as carbonate, nitrate, sulfate and chromate ions, were studied. Equilibrium studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. The adsorption isotherm data fitted well with the Langmuir and Sips model. The maximum sorption capacity was 41.1 mg/g at pH 5, which decreased slightly at pH 7. The efficiency of phosphate removal adsorption increased at lower pH values and by increasing the adsorbent dose. The maximum phosphate removal was 80% for pH 5 and decreased to 75% for pH 6, to 73% for pH 7 and to 70% for pH 8, for initial phosphate concentration at about 1 mg/L and for a dose of adsorbent 100 mg/L. The removal rate was increased with the increase of the adsorbent dose. For example, for initial phosphate concentration of 4 mg/L the removal rate increased from 40% to 80% by increasing the dose from 0.1 to 2.0 g/L at pH 7. The competitive anions adversely affected phosphate removal. Though they were also found to be removed to a certain extent. Their co-removal provided an adsorbent which might be very useful for treating waters with low-level multiple contaminant occurrence in natural or engineered aquatic systems.

scholarly journals Modified Exfoliated Carbon Nanoplatelets as Sorbents for Ammonium from Natural Mineral Waters

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3541
Author(s):  
Ion Ion ◽  
Daniela Bogdan ◽  
Monica Maria Mincu ◽  
Alina Catrinel Ion
Keyword(s):  
Natural Waters ◽  
Mineral Waters ◽  
Aqueous Samples ◽  
Sorption Mechanism ◽  
Characteristic Parameters ◽  
Sorption Characteristic ◽  
Natural Mineral ◽  
Maximum Sorption Capacity ◽  
Ammonium Removal ◽  
Maximum Sorption

In this manuscript an improved sorbent based on modified exfoliated carbon nanoplatelets, applied in the removal of ammonium from aqueous samples, is presented. This sorbent showed better efficiency in comparison with the previous one obtained in our group for ammonium removal, the values of the maximum sorption capacity being improved from 10 to 12.04 mg/g. In terms of kinetics and sorption characteristic parameters, their values were also improved. Based on these results, a sorption mechanism was proposed, taking into account ion-exchange and chemisorption processes at the surface of the oxidized exfoliated carbon nanoplatelets. Future applications for simultaneous removal of other positive charged contaminants from natural waters might be possible.

Sorption Profile of Hg(II) onto Mixed Phase of Copper Sulphide and Copper Sulphate

2011 ◽  
Vol 356-360 ◽  
pp. 537-546
Author(s):  
Yow Loo Au Yoong ◽  
Pei Lay Yap ◽  
Muralithran G. Kutty ◽  
Olaf Timpe ◽  
Malte Behrens ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Copper Sulphate ◽  
Surface Complexation ◽  
Mixed Phase ◽  
Copper Sulphide ◽  
Reaction Parameters ◽  
Sorption Behaviour ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Equilibrium Data

The use of surface oxidized covellite (CuS), namely mixed phase copper sulphide (CuS and CuSO4) was studied for the removal of mercury from aqueous solution under the effect of various reaction parameters (pH, time, Hg(II) concentration). From batch sorption studies, the equilibrium data revealed that the sorption behaviour of Hg(II) onto mixed phase copper sulphide follows well with Langmuir isotherm and the maximum sorption capacity (Qmax) determined ≈ 400mg Hg(II) /g of sorbent. Meanwhile, all the unreacted and reacted mixed phase copper sulphides were also characterized by Powder XRD, SEM and XPS techniques. The results indicated that the sorption of Hg(II) onto mixed phase copper sulphide occurs initially through the dissolution of surface oxidized CuSO4layer. After that, the surface complexation product formed and sorbed onto the surface of CuS. These outcomes suggest the potential ability of CuS in removing Hg(II) even if the CuS layer is being surrounded by oxidized layer of CuSO4.

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