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1

Adsorption of Methyl Orange Dye by Modified Fly Ash-Based Geopolymer – Characterization, Performance, Kinetics and Isotherm Studies

Purbasari Aprilina, Ariyanti Dessy, Fitriani Evi

Journal of Ecological Engineering

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2023

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Vol. 24, nr 3

90--98

EN

Geopolymer has been widely used as adsorbent for heavy metals and dyes. Modification on geopolymer surface with cationic surfactant can improve the anion exchange capacity of geopolymer. In this paper, fly ash-based geopolymer had been modified with cetyltrimethylammonium bromide (CTAB) which is cationic surfactant and applied as adsorbent of methyl orange (MO) anionic dye. Modified geopolymer had shown better performance as MO dye adsorbent compared to unmodified geopolymer. The adsorption of MO dye showed the best result at low pH and reached equilibrium after 90 minutes. On the basis of kinetics and isotherm studies, MO dye adsorption by modified geopolymer followed pseudo-second-order model and Langmuir model with maximum adsorption capacity of 19.231 mg∙g-1.

2

An Innovative Interaction between Organo-Kaolinite and Methyl Orange for Industrial Wastes Removal – A Kinetic Investigation and Modeling

Al-Zubaidi Hussein A. M., Alquzweeni Saif S., Al-Khalaf Safaa K. Hashim, Naje Ahmed Samir

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 8

329--345

EN

Since organic dyes are the main component of many industrial wastes, it is necessary to be removed efficiently and instantaneously. The aim of this research focuses on the synthesizing of organoclay by modifying kaolinite with cetyl trimethyl ammonium bromide and applying it for the removal of (methyl-orange) dye from water by the mechanisms of adsorption. The effects of several parameters, mainly agitation time, water pH, adsorbent doses, and dye concentrations, on the adsorption process were optimised using the central composite design (CCD) method, which was performed using MINITAB package (version 17). Results showed that the dye was completely (100%) removed at pH of 4.0, adsorbent dose of 0.4 g, dye concentration of 50 mg/L, and agitation speed of 160 rpm. In addition, it was found that Freundlich and Sips isotherms were the best models to track lab data. Moreover, the Pseudo second order method was found to be more convenient compared to other models for studying kinetics of the sorption mechanism. For column testing, an appropriate hydraulic conductivity and reactivity were obtained by combining modificatory kaolinite and glass waste with weight proportions of 50:50. Thus, empirical simulations such as those in the kinetic model of Clark have provided satisfactory consent for using the simulated methyl orange.

3

Adsorptive performance of MCM-41 towards hg(II) in water. Adsorption and desorption studies

Zhai Q. Z., Hu W.-H., Guo X.-Y.

Environment Protection Engineering

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2016

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Vol. 42, nr 1

5--15

EN

MCM-41 mesoporous material was prepared under a standard conditions by using cetyltrime-thylammonium bromide as a structure-directing agent and tetraethyl orthosilicate as silica source from the liquid phase at 80 °C. Powder X-ray diffraction and scanning electron microscopy used to characterize the product, showed that the MCM-41material had an average particle size of 110 nm. The synthesized material was used to investigate the effects of acidity, adsorption time, the concentration of Hg2+, adsorbent dosage and temperature on the adsorption of Hg2+. The results showed that the optimal adsorptive conditions were: pH 5.0, m(MCM-41):mHg2+ 6.67, temperature 20 °C and contact adsorption time 60 min, for the initial Hg2+concentration of 1.0 mg/cm3. The maximum adsorptive amount of Hg2+ was 56.48 mg Hg2+/g MCM-41. The results of the desorptive effect of three desorption agents such as HCl, HNO3 and HAc showed that the best desorbent was HCl at the concentration of 0.10 mol/dm3. The highest desorption efficiency was 77.21% for the desorption time 2 h.

4

Liquid-liquid extraction and spectrophotometric determination of Mn(II) in geochemical samples

Tarafder P. K., Mondal R. K., Kunkal L., Murugan P., Rathore D. P. S.

Chemia Analityczna

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2004

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Vol. 49, No. 2

251-260

EN

A new, simple, precise, selective and sensitive method for the extraction and spectrophotometric determination of manganese has been described. Manganese(II) forms a bluish-violet anionic chelate, [MnL2]2- with 2,3-dihydroxynaphthalene(H2L) in alkaline medium (pH 11-12). The colour of the anionic chelate intensifies when the compound is extracted to ethyl acetate as an ion-associate, Q2[MnL2] with a cetyltrimethylammonium(Q+) counter cation. The molar absorptivity of the complex at 547 nm ( [lambda]max) is 1.2 × 104 L mol-1 cm-1 with the detection limit of 0.04 žg mL-1 for Mn. The Beer's law is obeyed in the concentration range from 0 to 5 žg mL-1. Zn, Cd, Cu, Co, Ni, Al, Be, La, Ti, Zr, Y, Ta, W, U, Mo, As, Se and Bi do not interfere, while Fe does, so should be removed by prior extraction at pH 4-5 using the same reagent. The method has been also applied to the recovery studies on Mn present in silicate rocks, ores, minerals, soils, plant ash and hydrogeochemical samples. The results differed favourable from those obtained by oxidation of Mn with KIO4 to KMnO4 and further spectrophotometrical and AAS investigations.

PL

Opisano nową, prostą, precyzyjną selektywną i czulą metodę ekstrakcji oraz spektrofotometrycznego oznaczania manganu. Mangan(II) tworzy z 2,3-dihydroksynaftalenem (H2L)w środowisku alkalicznym (pH 11-12) niebieskofioletowy anionowy chelat (MnL2). Kolor anionowego chelatu ulega wzmocnieniu po ekstrakcji z kationem cetylo-trimetyloamoniowym do octanu etylu. Współczynnik absorpcji molowej kompleksu, przy di. fali 547 nm wynosi 1,2 x l 0(4) L mol(-1) cm(-1). Granica wykrywalności manganu wynosi 0,04 ugmL(-1). Prawo Beera jest spełnione w zakresie stężeń od O do 5 ugmL(-1). Zn, Cd, Cu, Co, Ni, Al,Be, La, Ti, Zr, Y, Ta, W, U, Mo, As, Se i Bi nie przeszkadzają, natomiast żelazo przeszkadza i powinno być usunięte metodą ekstrakcyjną przy pH 4-5 z użyciem tego samego odczynnika. Metodę zastosowano do badań odzysku manganu obecnego w skałach krzemianowych,rudach, minerałach, glebach, popiele roślinnym i próbkach hydrogeochemicznych. Otrzymane wyniki różniły się korzystnie od wyników uzyskanych metodą utleniania manganu do KMnO(4) za pomocą KIO(4) i dalszym oznaczeniem metodą spektrofotometryczną i AAS.

5

New cethyltrimethylammonium methods for the determination of perchlorates

Cygański A., Kowalczyk P., Krystek J., Ptaszyński B.

Chemia Analityczna

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2000

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Vol. 45, No. 6

911-919

EN

In the presence of cetyltrimethylammonium bromide (CTA) perchlorates form a sparingly soluble compound. The analysis has proved that it is cetyltrimethylammonium per-chlorate. In the present work gravimetric, nephelometric and turbidimetric methods of determination of perchlorates have been worked out. Measurements can be made in the pH range from 1.5 to 11.5. For 5 to 20 mg of perchlorate the gravimetric method and for 0.05 to 1.00 mg of perchlorate the nephelometric and turbidimetric methods can be used. The effect of foreign ions has been examined. Only large anions (e.g. MnO-(4), CrO4", Cr2O(2-), I-) interfere with the determination.

PL

Chlorany(VII) w obecności bromku cetylotrimetyloamoniowego (CTA) tworzą trudno rozpuszczalny osad. Analiza wykazała, że jest to chloran(VII) cetylotrimetyloamo-niowy. Opracowano wagową, nefelometryczną i turbidymetryczną metodę oznaczania chloranów(VII). Oznaczenia można wykonywać w zakresie pH od 1,5 do 11,5 dla chloranów(VII) w ilości 5-20 mg (metoda wagowa) lub 0,05-1,00 mg (metoda nefelometryczną i turbidymetryczną). Zbadano wpływ jonów obcych. W oznaczeniu przeszkadzają tylko duże aniony (np. MnO4, CrO(2)(4), Cr7(2), I(-).