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Modified Graphite with Tin Oxide as a Promising Electrode for Reduction of Organic Pollutants from Wastewater by Sonoelectrochemical Oxidation

Nsaif Hind Jabbar, Majeed Najwa Saber

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

307--320

EN

Most of the studies on tin oxide coatings as electrode materials were conducted on titanium; in this study, the aim was to create pure tin oxide (SnO2) films on graphite substrate, which is more prevalent than titanium. There is a lack in investigation the effect of SnCl2 and HNO3 concentrations on the prepared SnO2 electrode; therefore, the aim of this work was to study these effects precisely. Also, no previous study investigated the removal of phenol sonoelectrochemically by a SnO2 electrode, which would be accomplished in the present work. The tin dioxide electrode was produced by cathodic electrodeposition using a SnCl2·2H2O solution in the presence of HNO3 and NaNO3 on a graphite plate substrate. The impact of various operating parameters (current density – CD, HNO3 concentration, and SnCl2·2H2O concentration) on the morphology and structure of the SnO2 deposit layer was thoroughly investigated. The physical structures of the SnO2 film were determined by X‐ray diffraction (XRD), surface morphology was characterized using field-emission scanning electron microscopy (SEM), and chemical composition was analyzed using energy-dispersive X-ray spectroscopy (EDX). In a batch reactor, the sonoelectrochemical oxidation of phenol was tested to determine the performance of the best SnO2 electrodes for phenol degradation and any organic byproducts. It was discovered that 10 mA/cm2 , 50 mM of SnCL2·2H2O, and 250 mM of HNO3 were the optimum conditions to prepare SnO2 electrodes, which produced the smallest crystal size, with no appeared cracks, and gave the best phenol removal. The best prepared electrode was tested in the sonoelectrochemical oxidation of phenol with two different electrolytes and different CD, and the results showed that the phenol removal was 76.87% and 64.68% when using NaCl and Na2SO4, respectively, as well as was 63.39, 76.87, and 100% for CD at 10, 25, and 40 mA/cm2, respectively.

2

Evaluation of the use of regenerated activated carbons for the adsorption of phenol from a river

Marszałek Anna, Puszczało Ewa

Journal of Water and Land Development

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2023

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no. 59

93--99

EN

The aim of the study was to use regenerated activated carbon to adsorb phenol from a river. Coconut shell activated carbon was derived from used tap water filter cartridges. The activated carbon was carbonised and then activated with KOH at 200°C, under a nitrogen atmosphere. The resulting adsorbent was characterised on the basis of nitrogen adsorption by Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) analysis and point of zero charge (pH PZC). The study of periodic adsorption included kinetic and equilibrium modelling, determined the effect of solution pH on efficiency and the possibility of regeneration and reuse of the adsorbent. The efficiency of phenol removal from model water was evaluated, followed by the possibility of their adsorption from a polluted river in Silesia Province. Phenol adsorption followed pseudo-second-order kinetics. The adsorbents showed high adsorption abilities, as determined by the Langmuir isotherm model. The model fits the experimental data well. The concentration of phenol in the river was in the range of 0.45-0.77 mg∙dm-3, which means that its value was at least five times higher than the standard values. The use of regenerated activated carbon from waste filter cartridges removed phenol from the river by 78% using optimal test parameters.

3

Synthesis of Mn-Co-Ni Composite Electrode by Anodic and Cathodic Electrodeposition for Indirect Electro-oxidation of Phenol: Optimization of the Removal by Response Surface Methodology

Ahmed Yamama A., Salman Rasha H.

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 8

107--119

EN

In the present work, Response Surface Methodology (RSM) was utilized to optimize process variables and find the best circumstances for indirect electrochemical oxidation of mimicked wastewater to remove phenol contaminants using prepared ternary composite electrode. The electrodeposition process is used for the synthesis of a ternary composite electrode of Mn, Co, and Ni oxides. The selected concentrations of metal salts of these elements were 0.05, 0.1, and 1.5 M, with constant molar ratio, current density, and electrolysis time of 1:1:1, 25 mA/cm2, and 2 h. Interestedly, the gathered Mn-Co-Ni oxides were deposited at both the anode and cathode. X-ray diffraction (XRD) and scanning electron microscopy (SEM) facilitated the qualitative characterization of surface structure and morphology of the accumulated oxides. The energy dispersive X-ray (EDX) provided a semi-quantitative analysis of deposit composition. The atomic force microscopy (AFM) apparatus quantified the roughness. We examined the efficiency of composite electrodes in coinciding with the removal of Chemical Oxygen Demand (COD) under current densities of 40, 60, and 80 mA/cm2, pH values of 3, 4, and 5, and NaCl concentrations of 1, 1.5, 2 g/l. RSM covered the optimization of process parameters in conjunction with Central Composite Design (CCD). The COD represented the response function in the optimization procedure. The optimal current density, NaCl concentration, and pH magnitude were 80 mA/cm2, 1.717 g/l, and 3, respectively. The efficiency of COD elimination of 99.925% attained after 1 hour of indirect electrochemical oxidation with an energy consumption of 152.380 kWh per kilogram of COD. The COD elimination model is significant based on the correlation coefficient (R2) and F-values, and the experimental data fitted well to a second-order polynomial model with R2 of 98.93%.

4

Membranes obtained on the basis of cellulose acetate and their use in removal of phenol from liquid phase

Przybył Joanna, Bazan-Wozniak Aleksandra, Nosal-Wiercinska Agnieszka, Pietrzak Robert

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 144174

EN

The membranes based on cellulose acetate (CA) were obtained by the method of phase inversion and used for removal of phenol (in concentrations of 15 and 25 mg/L) from liquid phase. To differentiate the hydrophilic properties of the membrane surfaces, different amounts of cellulose acetate (14 and 18 wt. %) and polyvinylpyrrolidone as a pore-generating agent (PVP, 1, 2, 3 or 4 wt. %) were used. The membranes were characterised by determination of their porosity, equilibrium water content, wetting angle and content of surface oxygen functional groups. After the application of membranes to phenol removal, the following parameters characterising the process were determined: permeability, membrane resistance, coke resistances, pore resistances, total filtration resistance and flux recovery ratio. The membranes were found to show higher effectiveness in phenol removal from a solution of the initial concentration 15 mg/L, and more effective were the membranes with higher contents of cellulose acetate. On the surface of the membranes the oxygen functional groups of acidic nature are dominant, both before and after filtration. The membranes of higher contents of cellulose acetate show higher resistances.

5

Usuwanie fenolu w procesie adsorpcji

Puszkarewicz A., Kaleta J., Papciak D.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2015

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z. 62, nr 3/II

351--362

PL

Do usuwania związków fenolu z roztworów wodnych zastosowany został naturalny adsorbent mineralny (surowy attapulgit - Abso’Net Superior Special (ASS)). Właściwości adsorpcyjne attapulgitu zostały określone metodą statyczną i dynamiczną. Badania przeprowadzono na modelowym roztworze fenolu o stężeniu początkowym C0 = 20 mg⋅dm-3, w temperaturze 20°C. Dla testowanego minerału proces adsorpcji dobrze opisywały izotermy adsorpcji Froundlicha. W badaniach stwierdzono, że adsorpcja fenolu nieco lepiej zachodziła przy odczynie obojętnym i kwaśnym. Na podstawie badań zaobserwowano, że czas adsorpcji miał istotny wpływ na skuteczność usuwania fenolu, a równowaga adsorpcyjna nastąpiła po 180 minut. W warunkach przepływowych najefektywniej pracowało złoże z najdłuższym czasem retencji tr = 10 minut. Związki fenolu w początkowej fazie pracy kolumny usuwane były do wartości poniżej 0,5 mg⋅dm-3. W punkcie wyczerpania złoża uzyskano pojemność adsorpcyjną P = 2,45 mg⋅g-1. Usuwanie fenolu w procesie filtracji na złożu z attapulgitu okazało się skuteczne. Badania wykazały, że adsorbent, o granulacji 0,6 - 1,3 mm zastosowany jako złoże adsorpcyjne mógłby stanowić alternatywę dla skutecznego podczyszczania roztworów zawierających fenol o stężeniach nie przekraczających 20 g⋅m-3.

EN

The natural mineral adsorbent (raw attapulgite - Abso’Net Superior Special (ASS)) was used for removing phenol compounds from water solutions. The adsorptive properties of attapulgite have been determined using static and dynamic methods. The tests were performed on/with a model solution of phenol at initial concentration of C0=20 g⋅dm-3, at the temperature of 20°C. For tested attapulgite grades the adsorption processes was described adequately by Froundlich adsorption isotherms. The tests showed that phenol adsorption proceeded slightly better in neutral and acid reaction. Based on the research, it was found that the adsorption time had a considerable impact on the efficiency of removing phenol. Time adsorption equilibrium occurred after 180 minutes. In the flow conditions, the most effectively worked the bed with the longest retention times tr = 10 min. The compounds of the phenol in the initial phase of operation of the column were removed to less than 0.5 mg⋅dm-3. At the point of exhaustion deposits obtained adsorption capacity P = 2.45 mg⋅g-1. Removal of phenol by filtration on a bed of attapulgite - Abso’Net Superior Special (ASS) proved effective. Studies have shown that the adsorbent with particle size 0.6 -1.3 mm used as an adsorbent bed could be an alternative to the effective pretreatment solutions containing phenol of concentration not exceeding 20 mg⋅dm-3.

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Characterization of manganese exchanged zeolite type X as catalyst for decomposition of hydrogen peroxide and removal of phenol

Sarbak Z., Durski R.

Chemia i Inżynieria Ekologiczna

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2004

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Vol. 11, nr 1

27--34

EN

The effect of Na+ into Mn[formula] ion exchange on the crystaline structure of X type zeolites has been studied. The material investigated were samples containing manganese ions in five different concentrations.The crystal structure of the samples was determined on the basis X-ray diffraction study (XRD) and infraredstudy (IR) in the range 1500-400 [formula]. Thermal stability of the X type zeolites studies was established. The reaction of phenol removal with hydrogen peroxide as the oxidising agent was examined. The catalytic decomposition of hydrogen peroxide was also analysed. Phenol was found to undergo total decomposition.

PL

Badano możliwość zastosowania zeolitów typu NaX, w którym jony Na+ wymieniono na [formula], w katalitycznym usuwaniu fenolu z roztworu wodnego na drodze utleniania nadtlenkiem wodoru. Wykazano, że fenol uległ całkowitemu rozkładowi. Zeolity po wymianie jonowej poddano badaniom dyfraktometrycznym, spektralnym w podczerwieni oraz określono stabilność termiczną - parametr wskazujący na możliwość regeneracji termicznej katalizatora. Ponadto badano rozkład katalityczny nadtlenku wodoru.

7

Fotokatalityczny labiryntowy reaktor przepływowy do usuwania fenolu z wody

Morawski A. W., Radyno-Książkiewicz K., Grzechulska J.

Gaz, Woda i Technika Sanitarna

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2002

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Nr 6

216-218

EN

Characteristics of used photocatalyst. Phenol disintegration level for different initial concentrations of reacting mixture. Installation scheme for photocatalytic phenol oxidation in water.