Dr. Mst. Maria Rahman | Jagannath University, Dhaka (original) (raw)

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tannin gel by Dr. Mst. Maria Rahman

Catalysis Communications, 2010

Platinum particles were electrochemically deposited over glassy carbon (GC) to prepare GC-Pt elec... more Platinum particles were electrochemically deposited over glassy carbon (GC) to prepare GC-Pt electrodes. The electrocatalytic behaviors of this electrode have been compared with that of an ordinary polycrystalline(OPC) Pt and GC electrode in reducing NO 2 − at neutral medium. The as prepared GC-Pt electrode reduced NO 2 − , exhibiting double-peak reduction waves. The reduction performance of this electrode was noticed at least 7.8 times higher than that of an OPC Pt electrode. The sensitivity of the GC-Pt electrode was found to be enhanced by the temperature rise. A consecutive mechanism, NO 2 − → NO → NH 4 + , over the as prepared GC-Pt electrode has been investigated.

Papers by Dr. Mst. Maria Rahman

ABSTRACT Oxidative degradation of malachite green was performed in presence of Fe(III) + H2O2 mix... more ABSTRACT Oxidative degradation of malachite green was performed in presence of Fe(III) + H2O2 mixture in dark and in light. The UV radiation completely mineralized the dye molecules where the degradation rate was decreased in the order of UV > visible > dark. Malachite green molecules showed optimum colour in the pH range of 3.8-5.9. The effective Fenton activity was noticed at [H2O2]/[Fe(III)] ratio of 7.01. The degradation rate was positively influenced by the temperature where the activation energy degradation was estimated as 16.83 kJ mol-1. A maximum 86 % degradation was achieved at 45 ºC.

Journal of Environmental Chemical Engineering, 2014

Biosorption processes deserve imminent possibility from environmental viewpoint as they ensure el... more Biosorption processes deserve imminent possibility from environmental viewpoint as they ensure elimination of toxic and non-biodegradable compounds from industrial waste waters. Textile sector is one of the foremost economical bases for a country, but the effluents produced from dyeing, and finishing processes of textile industries are reported to afflict public health, and biodiversity as they contain various hazardous materials [1]. A significant part of textile effluents are the unused dyes which is unfeasible to recover or recycle [2]. Through some complex series of physical, chemical, and biological phenomena, these dyes consume dissolved oxygen in aquatic system, reduce the transmitted sunlight into water streams, and finally interrupt many regular processes such as photosynthesis, respiration, and many other metabolic processes of aquatic species [3,4]. As some direct consequences, these dyes also cause eye burn and injury to human, and animals [5]. Therefore, to minimize these threats, in most of the countries, the government's legislation has attributed textile industries to confirm effluent treatment before discharging into environment [6]. Regarding this issue, various water treatment methods, including physical and chemical processes, have been studied widely. Some typical processes includes: solar photo-Fenton degradation [7-11], electrochemical degradation [12], and adsorption [13]. However, the adsorption processes has attracted worldwide concern for its economical, and environmental perspectives. In this sequence, adsorption on activated carbon has become a popular technique though the high cost renders the feasibility [14]. Considering the cost effectives adsorption of cationic dye by using clay materials [15], Montmorillonite [16], fly ash [17] was reported as well. The use of non-living microbial biomaterials as biosorbents has been developed only within last few decades, and represents prospective alternative methods. Such typical replacements include palm ash [3], pomelo (Citrus grandis) peel [13], aspergillus fumigatus beads [18] and zeolite [19]. Even though, some of these techniques have been found to be effective, they are associated with some restrictions such as lack of effective color attenuation, excess amount of chemical usage, accumulation of concentrated sludge with noticeable disposal problems, operational costs, and sensitivity to a variable dye containing wastewater [20,21]. However, adsorbents with more cost effectiveness, availability and higher efficiency are still desirable. Herein, we have reported the use of Tannin gel (TG) as an effective adsorbent to remove the Brilliant Red (BR) dye from waste water.

International Journal of Chemical Reactor Engineering, 2010

Oxidative degradation of Brilliant Red X–3B has been carried out using Fenton’s reagent both in t... more Oxidative degradation of Brilliant Red X–3B has been carried out using Fenton’s reagent both in the dark and in the presence of visible light. The degradation rate was increased using Fenton’s process in the order of Dark < Visible < UV. At pH 3.3, the maximum Fenton and photo-Fenton effect were noticed. At [H2O2]/[Fe(III)] = 3.5, a steady Fenton effect was observed. Meanwhile, at [H2O2]/[Fe(III)] = 0.7, Fenton process in the dark minimized the photo effect. The degradation rate was positively influenced by the temperature where the activation energy of degradation was evaluated as 36.98 kJ mol-1.

Catalysis Communications, 2010

Hydrogen peroxide was efficiently decomposed on Pt-Pd surface deposited on Nafion membrane. Compa... more Hydrogen peroxide was efficiently decomposed on Pt-Pd surface deposited on Nafion membrane. Comparing the activities for the different materials, the activity for the decomposition of hydrogen peroxide was found to decrease in the order of Pt-Pd surface N MnO 2 N K 2 Cr 2 O 7 N Au N Polycrystalline Pt plate. Kinetics and thermodynamics of the decomposition process were investigated. It was observed that the decomposition process followed bimolecular first order kinetics, which was well fitted with Eley-Rideal (E-R) model. In this paper, the reason of efficient catalytic decomposition of hydrogen peroxide over bi-metallic Pt-Pd surface has been discussed.

Catalysis Communications, 2010

Platinum particles were electrochemically deposited over glassy carbon (GC) to prepare GC-Pt elec... more Platinum particles were electrochemically deposited over glassy carbon (GC) to prepare GC-Pt electrodes. The electrocatalytic behaviors of this electrode have been compared with that of an ordinary polycrystalline(OPC) Pt and GC electrode in reducing NO 2 − at neutral medium. The as prepared GC-Pt electrode reduced NO 2 − , exhibiting double-peak reduction waves. The reduction performance of this electrode was noticed at least 7.8 times higher than that of an OPC Pt electrode. The sensitivity of the GC-Pt electrode was found to be enhanced by the temperature rise. A consecutive mechanism, NO 2 − → NO → NH 4 + , over the as prepared GC-Pt electrode has been investigated.

ABSTRACT Oxidative degradation of malachite green was performed in presence of Fe(III) + H2O2 mix... more ABSTRACT Oxidative degradation of malachite green was performed in presence of Fe(III) + H2O2 mixture in dark and in light. The UV radiation completely mineralized the dye molecules where the degradation rate was decreased in the order of UV &gt; visible &gt; dark. Malachite green molecules showed optimum colour in the pH range of 3.8-5.9. The effective Fenton activity was noticed at [H2O2]/[Fe(III)] ratio of 7.01. The degradation rate was positively influenced by the temperature where the activation energy degradation was estimated as 16.83 kJ mol-1. A maximum 86 % degradation was achieved at 45 ºC.

Journal of Environmental Chemical Engineering, 2014

Biosorption processes deserve imminent possibility from environmental viewpoint as they ensure el... more Biosorption processes deserve imminent possibility from environmental viewpoint as they ensure elimination of toxic and non-biodegradable compounds from industrial waste waters. Textile sector is one of the foremost economical bases for a country, but the effluents produced from dyeing, and finishing processes of textile industries are reported to afflict public health, and biodiversity as they contain various hazardous materials [1]. A significant part of textile effluents are the unused dyes which is unfeasible to recover or recycle [2]. Through some complex series of physical, chemical, and biological phenomena, these dyes consume dissolved oxygen in aquatic system, reduce the transmitted sunlight into water streams, and finally interrupt many regular processes such as photosynthesis, respiration, and many other metabolic processes of aquatic species [3,4]. As some direct consequences, these dyes also cause eye burn and injury to human, and animals [5]. Therefore, to minimize these threats, in most of the countries, the government's legislation has attributed textile industries to confirm effluent treatment before discharging into environment [6]. Regarding this issue, various water treatment methods, including physical and chemical processes, have been studied widely. Some typical processes includes: solar photo-Fenton degradation [7-11], electrochemical degradation [12], and adsorption [13]. However, the adsorption processes has attracted worldwide concern for its economical, and environmental perspectives. In this sequence, adsorption on activated carbon has become a popular technique though the high cost renders the feasibility [14]. Considering the cost effectives adsorption of cationic dye by using clay materials [15], Montmorillonite [16], fly ash [17] was reported as well. The use of non-living microbial biomaterials as biosorbents has been developed only within last few decades, and represents prospective alternative methods. Such typical replacements include palm ash [3], pomelo (Citrus grandis) peel [13], aspergillus fumigatus beads [18] and zeolite [19]. Even though, some of these techniques have been found to be effective, they are associated with some restrictions such as lack of effective color attenuation, excess amount of chemical usage, accumulation of concentrated sludge with noticeable disposal problems, operational costs, and sensitivity to a variable dye containing wastewater [20,21]. However, adsorbents with more cost effectiveness, availability and higher efficiency are still desirable. Herein, we have reported the use of Tannin gel (TG) as an effective adsorbent to remove the Brilliant Red (BR) dye from waste water.

International Journal of Chemical Reactor Engineering, 2010

Oxidative degradation of Brilliant Red X–3B has been carried out using Fenton’s reagent both in t... more Oxidative degradation of Brilliant Red X–3B has been carried out using Fenton’s reagent both in the dark and in the presence of visible light. The degradation rate was increased using Fenton’s process in the order of Dark < Visible < UV. At pH 3.3, the maximum Fenton and photo-Fenton effect were noticed. At [H2O2]/[Fe(III)] = 3.5, a steady Fenton effect was observed. Meanwhile, at [H2O2]/[Fe(III)] = 0.7, Fenton process in the dark minimized the photo effect. The degradation rate was positively influenced by the temperature where the activation energy of degradation was evaluated as 36.98 kJ mol-1.

Catalysis Communications, 2010

Hydrogen peroxide was efficiently decomposed on Pt-Pd surface deposited on Nafion membrane. Compa... more Hydrogen peroxide was efficiently decomposed on Pt-Pd surface deposited on Nafion membrane. Comparing the activities for the different materials, the activity for the decomposition of hydrogen peroxide was found to decrease in the order of Pt-Pd surface N MnO 2 N K 2 Cr 2 O 7 N Au N Polycrystalline Pt plate. Kinetics and thermodynamics of the decomposition process were investigated. It was observed that the decomposition process followed bimolecular first order kinetics, which was well fitted with Eley-Rideal (E-R) model. In this paper, the reason of efficient catalytic decomposition of hydrogen peroxide over bi-metallic Pt-Pd surface has been discussed.