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1

Development of a Nanoscale (Mg/Al)-LDH Coated Waterworks Sludge Sorbent for Efficient Congo Red Dye Removal – Batch Kinetics and Isotherm Studies

Salih Sudad Adil, Naife Tariq M.

Journal of Ecological Engineering

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2023

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Vol. 24, nr 7

145--155

EN

The study’s aim was to develop a novel sorbent for removing the color Congo red (CR) from water by precipitating (Mg/Al)-layered double hydroxide (LDH) at the nanoscale onto the waterworks sludge surface as a byproduct. To achieve an effective sorbent with the removal of over 91.19%, The utilization of nanoparticles, the addition of 1 g of sludge to 50 mL of water, and a molar ratio of 2 (Mg/Al) were the optimal production conditions for sorbent. In batch experiments, the optimal operating parameters were found to be 0.5 g of adsorbent in 50 mL of CR, pH of CR solution equal to 3, and a contact time of 3 hours at 200 rpm with 25 mg/L dyes. According to the study, the adsorption capacity was 23.576 mg/g. Additionally, the pseudo-second-order and Langmuir models provided accurate descriptions of the sorption data.

2

Synthesis and applications of calcium-aluminum layered double hydroxides – an overview

Md Ghazali Ira Wahadah, Bohari Farah Liyana, Dzulkifli Nur Nadia, Abdullah Asiah, Fatimah Is, Sheikh Mohd Ghazali Sheikh Ahmad Izaddin

Polimery

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2021

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T. 66, nr 10

518--526

EN

The synthesis and application of layered calcium-aluminum double hydroxides (Ca-Al LDHs) for the encapsulation of organic anions is discussed. The mechanism of the encapsulation process was explained. These types of compounds have great potential and can be used in targeted therapies, including in drug dosing systems.

PL

Omówiono syntezę i zastosowanie warstwowych podwójnych wodorotlenków wapniowoglinowych (Ca-Al LDHs) do kapsułkowania anionów organicznych. Wyjaśniono mechanizm procesu kapsułkowania. Tego typu związki mają bardzo duży potencjał i mogą znaleźć zastosowanie w terapiach celowych m.in. w systemach kontrolowanego dozowania leków.

3

Naphthalene Removal with Layered Double Hydroxides

Butenko Eleonora, Dan Olena, Kapustin Alexey, Neverova‑Dziopak Elena

Geomatics and Environmental Engineering

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2020

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Vol. 14, no. 2

19--30

EN

Naphthalene is a hazardous pollutant. It has a negative impact on human health and environment. Its manufacturing process is accompanied by gaseous naphthalene emissions into the air of the premises and then into the atmosphere, thus polluting the environment. There is currently no existing method to remove naphthalene from the gas phase which is capable of meeting the required environmental standards. The goal of this research was to investigate the mechanism of naphthalene removal from the gas phase by the sorption method using Mg/(Al+Mg) layered double hydroxides (LDHs) and to develop naphthalene removal technology to meet the required environmental standards. The methods for obtaining selective sorbents of naphthalene and its derivatives have been investigated. The technology of naphthalene removal from gas phase using Mg/(Al+Mg) LDHs has been developed. The technological parameters of reactors have been calculated. The final concentration of naphthalene of 12 mg/m3 was obtained which appeared to be lower than the maximum allowed concentration. The efficiency of naphthalene sorption with LDHs was found to be over 95%.

PL

Naftalen należy do niebezpiecznych substancji, które mają negatywny wpływ na ludzkie zdrowie i środowisko. Procesowi jego produkcji towarzyszy emisja naftalenu gazowego do atmosfery, co przyczynia się do zanieczyszczenia innych elementów środowiska przyrodniczego. Obecnie nie istnieje efektywny sposób usuwania naftalenu z fazy gazowej, który zapewniłby spełnienie wymaganych standardów ekologicznych. Celem niniejszych badań było zbadanie mechanizmu usuwania naftalenu z fazy gazowej metodą sorpcji z zastosowaniem warstwowych materiałów nieorganicznych i na tej podstawie opracowanie efektywnej technologii usuwania naftalenu. Ob liczono parametry technologiczne reaktorów oraz opracowano technologię usuwania naftalenu i jego pochodnych z zastosowaniem selektywnych sorbentów: warstwowych podwójnych wodorotlenków na bazie Mg/(Al+Mg). W wyniku eksperymentu realizowanego w warunkach laboratoryjnych z zastosowaniem opracowanej metody udało się osiągnąć stężenia naftalenu w fazie gazowej na poziomie 12 mg/m3 , co nie przekracza ustalonych maksymalnych dopuszczalnych wartości. Efektywność redukcji naftalenu za po mocą warstwowych podwójnych wodorotlenków wynosi w tym przypadku ponad 95%.

4

Propylene oxide polymerization in the presence of layered double hydroxides

Dan O., Butenko E., Kapustin A.

Chemistry-Didactics-Ecology-Metrology

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2018

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R. 23, NR 1-2

137--142

EN

Propylene oxide polymerization in the presence of layered double hydroxides with different concentration of basic sites on their surface has been studied. It is shown that the polymerization can be catalyzed by both basic and acidic sites. On the basis of kinetic experiments the mechanisms of reaction undergoing were proposed.

PL

W artykule badano polimeryzację tlenku propylenu w obecności warstwowych wodorotlenków podwójnych o różnej ilości centrów zasadowych na powierzchni. Wykazano, że kataliza polimeryzacji zachodzi zarówno w centrach zasadowych, jak i kwasowych. Na podstawie doświadczeń kinetycznych zaproponowano mechanizmy reakcji.

5

Adsorption kinetics of fluoride on bone char and its regeneration

Hu J., Wu D., Rao R., Liu R., Lai W.

Environment Protection Engineering

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2017

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Vol. 43, nr 3

93--112

EN

The adsorbent of bone char (BC), produced from the pyrolysis of crushed animal bones, was dominated by the mesopores of the Brunauer Emmett Teller (BET) surface area. The optimal condition for defluoridation with BC was a pH level near 5.0. Chloride and nitrate ions could increase fluoride adsorption capacity in contrast with the effect of sulfate and carbonate ions. The interchangeability between fluoride and hydroxyl groups on BC sorbent was proved by the Fourier transform infrared spectroscopy. Langmuir equation had a better correlation coefficient than the Freundlich equation at various temperatures. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees, Ea and S*, have been calculated to describe the nature of fluoride adsorption onto BC. Negative Delta G degrees and Delta H degrees values at various temperatures indicate a spontaneous process, and its exothermic effect, respectively. However, a positive Delta S degrees value represents an increasing process for entropy. The E-a and S* values ranging from 5 to 40 kj.mol-1 and 0 to 1, respectively, demonstrated that the adsorption is dominated by physical process, although the adsorption kinetic process was involved external diffusion, intraparticle diffusion and chemical reaction equilibrium stage. A high concentration of NaOH solution increases efficiency of removing adsorbed F- ions from the BC surface.

6

Layered double hydroxides as transesterificationcatalysts and nanofillers for polyester resin

Kędzierski M., Bończa-Tomaszewski Z., Jaworska G., Niska A.

Polimery

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2015

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T. 60, nr 3

160--166

EN

Saturated polyester resins were prepared by reaction of dimethylterephthalate with alkylene glycols in the presence of layered doublehydroxides (hydrotalcites, HT). The effect of HT composition (cation and aniontypes) on the rate and progress of transesterification was investigated. It was found that zinc-aluminum HT intercalated with anionic form of aminolauric acid[HT(ZnAl)ALA] efficiently catalyzes transesterification process, increasing therate of reaction or lowering its temperature when compared to the reaction with use of conventional organic tin catalyst. The polyester resin obtained in this way is transparent, which along with X-ray diffraction data indicates the delamination of clay layers and formation of nanocomposite. The limitation of using ALA-intercalated HT as an additive for polyesters used in coatings is coloration of the resin with an increase of the reaction temperature above 180°C. Colorless polyester was obtained using more thermally stable hydrotalciteintercalated with ethylenediaminetetraacetic acid, however, at the expense of significantly longer reaction time. Using HT(ZnAl)ALA catalyst a two-step synthesis of carboxyl polyester resin was performed and the obtained product was used as a component of powder coating formulation.

PL

Przeprowadzono syntezę nasyconych żywic poliestrowych w reakcji tereftalanu dimetylowego z glikolami alkilenowymi, w obecności warstwowego podwójnego wodorotlenku typu hydrotalkitu (HT). Analizowano wpływ składu HT na szybkość i wydajność transestryfikacji. Najlepsze wyniki (zwiększenie szybkości reakcji lub obniżenie średniej temperatury procesu w porównaniu z szybkością i temperaturą reakcji prowadzonej w obecności tradycyjnego katalizatora organocynowego) uzyskano z zastosowaniem hydrotalkitu interkalowanego kwasem aminolaurynowym (ALA). Otrzymane w taki sposób żywice były transparentne, co w połączeniu z zanikiem refleksów hydrotalkitu w widmie XRD produktu transestryfikacji może świadczyć o utworzeniu się delaminowanego nanokompozytu. Wykorzystanie HT interkalowanego ALA w żywicach poliestrowych stosowanych do powłok jest ograniczone ze względu na zabarwienie pojawiające się w temperaturze powyżej 180 °C. W reakcji prowadzonej z udziałem bardziej stabilnego termicznie hydrotalkitu modyfikowanego kwasem etylenodiaminotetraoctowym otrzymano bezbarwny poliester, jednak kosztem znacznego wydłużenia czasu reakcji. Katalizator HT(ZnAl)ALA zastosowano w dwustopniowej syntezie poliestru o łańcuchu zakończonym grupami karboksylowymi, który następnie użyto w charakterze składnika proszkowej kompozycji powłokowej.

7

Thermal Analysis On The Kinetics Of Magnesium-Aluminum Layered Double Hydroxides In Different Heating Rates

Hongbo Y., Meiling C., Xu W., Hong G.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1357--1359

EN

The thermal decomposition of magnesium-aluminum layered double hydroxides (LDHs) was investigated by thermogravimetry analysis and differential scanning calorimetry (DSC) methods in argon environment. The influence of heating rates (including 2.5, 5, 10, 15 and 20K/min) on the thermal behavior of LDHs was revealed. By the methods of Kissinger and Flynn-Wall-Ozawa, the thermal kinetic parameters of activation energy and pre-exponential factor for the exothermic processes under non-isothermal conditions were calculated using the analysis of corresponding DSC curves.

8

Synthesis Of Magnesium-Aluminum Layered Double Hydroxides By Mechanochemical Method And Its Solid State Reaction Kinetics

Hongbo Y., Meiling C., Xiuhui W., Hong G.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2B

1455--1457

EN

A mechanochemical method is developed in preparing magnesium-aluminum-layered double hydroxides (MgAl-LDHs). This approach includes activation process and diffusion process. In order to verify the LDHs structure and study the reaction kinetics, X-ray diffraction (XRD) patterns, inductively coupled plasma(ICP) and physical adsorption instrument were characterized. The results show that activation time can change the surface of particles and affect the reaction grade. During the diffusion process, reaction time is the most important factor. The reaction energy (ΔQ) was calculated that is 6kJ/mol.

9

Synthesis and adsorption properties of nanosized Mg-Al layered double hydroxides with Cl-, NO3- or SO42- as interlayer anion

Hongo T., Wakasa H., Yamazaki A.

Materials Science Poland

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2011

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Vol. 29, No. 2

86--91

EN

Nanosized Mg-Al layered double hydroxides (LDHs) with Cl-, NO3- or SO42- as the interlayer anion have been synthesized by a modified coprecipitation method. The obtained LDHs were confirmed to be composed of a single phase and to be highly substituted by Al (Mg/Al ratio -1.9). The abilities of the LDHs to adsorb several harmful anions (F-, CrO42-, HAsO42- and HSeO3-) in aqueous solution were studied. The LDHs exhibit high adsorption abilities. The amount of adsorption onto the LDHs differed between the starting interlayer anions, and decreased in the following order of the interlayer anions: NO3- > Cl- > SO42-. The NO3-formed Mg-Al LDH reached a CrO42- adsorption equilibrium state within only 30 min, much faster than those in previous reports. Thus, the nanocrystallized, highly Al substituted phase of the NO3-formed Mg-Al LDH is found to markedly enhance the anion adsorption ability.

10

Determination of selenium(IV) after co-precipitation with Fe-Ti layered double hydroxides

Prasad K., Rao K. S., Gladis J. M., Naidu G. R. K., Rao T.P.

Chemia Analityczna

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2006

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Vol. 51, No. 4

613-622

EN

The narrow margin between beneficial and toxic properties of selenium requires precise analytical methods for its fast and reliable determination. We have developed a precise co-precipitative preconcentration and separation procedure for SeO2-3 in the pH range 4.0-6.0 using Fe-Ti layered double hydroxides prepared from synthetic solutions of Fe(III) and Ti(IV), and industrial effluent. The obtained layered double hydroxide co-precipitant with SeO2-3 was dissolved in 2 mol L-1 H2SO4 and concentration of selenium was determined spectrophotornetrically. Calibration plot was linear over the concentration range of selenium (IV) 1-100 &mi;g L-1. Detection limit (S/N = 3) for selenium(IV) was 1.0 &mi;g L-1. Relative standard deviation for 5 μg L-1 of the analyte was 3.0% (n= 5). The accuracy of the developed method was tested by analyzing certified reference materials of marine sediment (MESS-3) and soil (IAEA-Soil 7). Furthermore, the developed procedure has been success fully applied to the analysis of selenium(lV) in soil and river and marine sediment samples.

PL

Stosunkowo niewielka różnica między pożytecznymi i szkodliwymi dla zdrowia człowieka stężeniami selenu stwarza potrzebę szybkich i wiarygodnych metod oznaczania tego pierwiastka. Opracowano szybką i precyzyjną metodę zatężania i oddzielania SeO2-3 z roztworów o pH 4-6. W metodzie zastosowano warstwowo ułożone wodorotlenki Fe-Ti otrzymane z syntetycznych roztworów Fe(III) i Ti(IV) oraz z przemysłowych odcieków.Współstrącony na podwójnej warstwie wodorotlenków SeO2-3 rozpuszczano w 2 mol L-1 roztworze H2SO4 a zawartość selenu oznaczano spectrofotometrycznie. Krzywa kalibrowania była prostoliniowa w zakresie stężenia Se(IV) 1-100&mi;g L-1. Granicę wykrywalności (sygnał: szum=3) oszacowano na 1.0-100. Względne odchylenie standardowe pomiarów (5 &mi;g L-1, n = 5) wynosiło 3%. Dokładność metody testowano analizując materiały wzorcowe osadów morskich (MESS-3) i gleby (IAEA-Soil 7). Wykonano analizy zawartości selenu(IV)w próbkach osadów rzecznych i morskich oraz w glebie.

11

Preparation, characterization and testing of hydrotalcite-derived polyoxovandate-intercalated catalysts for selective catalytic reduction of NO with NH3

Dziembaj R., Chmielarz L., Węgrzyn A., Kuśtrowski P.

Bulletin of the Polish Academy of Sciences. Chemistry

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2002

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Vol. 50, No. 2

237-248

EN

Mg-Al hydrotalcites were intercalated with deca- and bivanadate that was proved by FT-IR and XRD measurements. Thermal decomposition of these precursors resulted in formation of effective catalysts for selective catalytic reduction (SCR) of NO with NHs. The catalytic performance of vanadium catalysts was compared with Cu-containing mixed metal oxides obtained from hydrotalcite precursors. The calcined Cu-Mg-Al hydrotalcites have been found to be active in low-temperature region while the V-catalysts prevailed in high temperature SCR.