Papers by Haydar A. Mohammad Salim
Heavy metal pollution in wastewater has always been a serious environmental problem. Chromium is ... more Heavy metal pollution in wastewater has always been a serious environmental problem. Chromium is considered one of the most noxious heavy metals. Adsorption is now reorganized as an alternative technology of defence for chromium removal because of cost effectiveness, local availability and technical feasibility. Potato peel powder was used as a low cost biosorbent to remove hexavalent chromium from aqueous solution under various operating conditions. The effect of different parameters such as contact time, initial metal ion concentration, potato peel dose, pH and temperature was investigated through a number of batch sorption experiments. Both the Langmuir and Freundlich were found to fit the adsorption isotherm of Cr (VI) onto potato peel. The Langmuir adsorption capacity was found to be 1.97 mg/g while Freundlich constants Kf and n were 1.57 and 2.5, respectively. The adsorption process can be described by the pseudo-first equation. The results revealed that potato peel is very effective for the biosorption of Cr (VI) from aqueous solutions.
The adsorption of Acid Alizarin Black (AAB) dye (C.I. 21725) on zinc oxide was investigated in th... more The adsorption of Acid Alizarin Black (AAB) dye (C.I. 21725) on zinc oxide was investigated in this study. The adsorption was carried out under different operating conditions. The operating conditions were contact time, adsorbent dosage (10, 30, 50, 70 and 100 mg), initial dye concentration (10, 20, 30, 40, 50, 60 and 70 mg/L), the pH of the solution (2, 4, 6, 7, 8, 10 and 12) and temperature (20, 30, 40, 50 and 60°C). The remo val percentage of dye on ZnO decreases from 67% to 54% with increase in initial dye concentration from 10 to 70 mg/L, respectively. It was found that the increasing of ZnO dosage enhanced the dye removal. The increasing of temperature insignificantly enhanced the removal of dye. The study reports that the best pH of solution for the adsorption of AAB on ZnO were 7 and 8. The adsorption data have been analysed using Langmuir, Freundlich and Temkin. It is indicated that the adsorption of dye onto ZnO was endothermic. The uptake process of AAB obeyed the pseudo second order kinetic expression.
Zinc oxide (ZnO) has been used as heterogeneous catalyst for the degradation of Acid Alizarin Bla... more Zinc oxide (ZnO) has been used as heterogeneous catalyst for the degradation of Acid Alizarin Black S dye (AAB) in aqueous solutions using UV light irradiation. Experiments were conducted at various operating parameters. The operating parameters were amount of catalyst (50 mg, 100 mg and 150 mg), initial concentration of dye (30 mg/L, 50 mg/L and 70 mg/L), the pH of solution (2, 4, 6, 8, 10 and 12) and the UV light intensity (6 watt and 12 watt). The progress of the degradation reaction was monitored spectrophotometrically. It was found that the degradation process of AAB solution was accelerated with increased catalyst dosage and decreased initial concentration of AAB. It was also found that the removal efficiency of AAB significantly depend on pH value of solution. The results show that the degradation percent reaches the highest values with pH close to neutral. The data proved that removal percent of dye decreased when 6 watt lamp used instead of 12 watt lamp. The kinetic study confirmed that photocatalytic degradation of AAB dye follows a pseudo first order reaction rate.
The photocatalytic degradation of Toluidine Blue dye (TB) in aqueous solution was investigated un... more The photocatalytic degradation of Toluidine Blue dye (TB) in aqueous solution was investigated under UV light in the presence of magnesium oxide (MgO) as a photocatalyst at different operating parameters. The operating
conditions were photocatalyst dose, initial dye concentration and the pH of the solution. Increasing of photocatalyst dose from 10 to 70 mg enhanced the degradation rate of TB dye. However, the increasing of TB dye concentration from 2 to 8 mg/L negatively affected the degradation rate. It was found that the percent of dye
removal reached the maximum value at high acidic medium. In dark condition, 15 % of dye was adsorbed by MgO. Furthermore, the kinetics involved in the degradation of TB dye was examined and the degradation was found to follow pseudo first order kinetic model.
Photocatalytic degradation of Acid Alizarin Black S (AAB) dye (C.I. 21725) was studied, at differ... more Photocatalytic degradation of Acid Alizarin Black S (AAB) dye (C.I. 21725) was studied, at different operating conditions, in aqueous solution using UV light in the presence of two types of local clay (B1 and B2) as a catalysts. The operating conditions were catalysts dosage (10, 30 and 50 mg), initial concentration of AAB dye (10, 20 and 30 mg/L), pH (2, 4, 6, 9 and 11) and UV light intensity (6 and 12 watt). It was found that the increasing of catalyst dosage enhanced the removal percent of dye. Clays (B1 and B2) exerted positive effects on the AAB removal whilst the initial AAB concentration negatively affected its removal. It was also found that the removal efficiency of AAB significantly depend on pH value. In high pH values removal percent increase, while a reversed trend was observed in low pH value. The result shown that removal percent of dye decreased when 6 watt lamp used instead 12 watt lamp. The data proved that B2 was more efficient than B1 for removing AAB dye. B1 and B2 clays were analysed by X-Ray fluorescence to determine the metal oxides in clays.
Acid alizarin black (AAB) dye (C.I. 21725) was degraded in aqueous solution using UV light in the... more Acid alizarin black (AAB) dye (C.I. 21725) was degraded in aqueous solution using UV light in the presence of two types of clay (C1 and C2) as a catalyst at different operating conditions. The operating conditions were concentration of catalyst dosage (10, 30 and 50 mg), initial concentration of AAB dye (10, 20 and 30 mg/L), pH (2, 4, 6, 9 and 11) and intensity of UV light (6 and 12 watt). It was found that the increasing of catalyst concentration enhanced the dye decolourisation. C1 and C2 exerted positive effects on the AAB removal whilst the initial concentration of AAB negatively affected its removal. It was
also found that the removal efficiency of AAB significantly depend on pH value. In high and low pH values removal percent increase, while a reversed trend was observed at with the pH value close to neutral. The result shown that removal percent of dye increased when 12 watt lamp used instead 6 watt lamp. C1 and C2 clay were analysed by X-Ray fluorescence to determine the metal oxides in clays.
Multi-walled carbon nanotubes functionalized by plasma oxygen (CNTs) have been used as heterogene... more Multi-walled carbon nanotubes functionalized by plasma oxygen (CNTs) have been used as heterogeneous catalysts for the ozonation of methyl orange (MO) dye (CI 13025) in aqueous solutions. It was found that the addition of CNTs significantly enhanced the dye decolorization as compared to ozone alone or when activated carbon was used at the same dose as CNTs. Both the initial ozone concentration and catalyst dosage enhanced the removal of MO. However, ozone gas concentrations higher than 6 g/m3 NTP did not further improve the decolorization rates. The removal efficiency of MO increased with pH in the range 2 to 3, while a reverse trend was observed when the pH increased from 3 to 9. The addition of a radical scavenger resulted in only a limited change in the decolorization rates suggesting that molecular ozone was the main pathway by which MO decolorization occurred in solution. However, under favorable conditions for MO attraction to CNT surface (pH=3), the decolorization rate has significantly increased. At higher pH than the pKa value of MO (3.47) and the point of zero charge of CNT (3.87), a condition that favors the electrostatic repulsion of MO from CNT, the rates were reduced in the presence of CNT as compared to ozone alone possibly due to loss of part of the supplied ozone in un-useful parallel reactions.
Photocatalytic degradation of acid alizarin black (AAB) dye (C.I. 21725) in aqueous solution was ... more Photocatalytic degradation of acid alizarin black (AAB) dye (C.I. 21725) in aqueous solution was investigated using UV light in the presence of hydrogen peroxide (H2O2) as a catalyst at different operating conditions. The operating conditions were concentration of catalyst dosage (0.1, 0.2 and 0.3 mL of 30 % H2O2), initial concentration of AAB dye (100, 150 and 200 mg/L) and pH (3.3, 6.84 and 10.8). It was found that the increasing of catalyst concentration enhanced the dye decolourisation. Hydrogen peroxide exerted positive effects on the AAB removal whilst the initial concentration of AAB negatively affected its removal. It was also found that the removal efficiency of AAB increased with the pH value close to neutral (pH 7), while a reversed trend was observed at acidic and basic medium.
Photocatalytic degradation of acid alizarin black (AAB) dye (C.I. 21725) in aqueous solution was ... more Photocatalytic degradation of acid alizarin black (AAB) dye (C.I. 21725) in aqueous solution was investigated using UV light in the presence of powder of titanium dioxide (P- TiO2) and nanoparticles of titanium dioxide (N- TiO2) as a catalyst. The operating conditions were catalyst dosage (10 and 20 mg/L) and initial concentration of AAB dye (10 and 20 mg/L). It was found that the increasing of catalyst concentration enhanced the dye decolourisation. Both catalysts exerted positive effects on the AAB removal whilst the initial concentration of AAB negatively affected its removal.
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Papers by Haydar A. Mohammad Salim
conditions were photocatalyst dose, initial dye concentration and the pH of the solution. Increasing of photocatalyst dose from 10 to 70 mg enhanced the degradation rate of TB dye. However, the increasing of TB dye concentration from 2 to 8 mg/L negatively affected the degradation rate. It was found that the percent of dye
removal reached the maximum value at high acidic medium. In dark condition, 15 % of dye was adsorbed by MgO. Furthermore, the kinetics involved in the degradation of TB dye was examined and the degradation was found to follow pseudo first order kinetic model.
also found that the removal efficiency of AAB significantly depend on pH value. In high and low pH values removal percent increase, while a reversed trend was observed at with the pH value close to neutral. The result shown that removal percent of dye increased when 12 watt lamp used instead 6 watt lamp. C1 and C2 clay were analysed by X-Ray fluorescence to determine the metal oxides in clays.
conditions were photocatalyst dose, initial dye concentration and the pH of the solution. Increasing of photocatalyst dose from 10 to 70 mg enhanced the degradation rate of TB dye. However, the increasing of TB dye concentration from 2 to 8 mg/L negatively affected the degradation rate. It was found that the percent of dye
removal reached the maximum value at high acidic medium. In dark condition, 15 % of dye was adsorbed by MgO. Furthermore, the kinetics involved in the degradation of TB dye was examined and the degradation was found to follow pseudo first order kinetic model.
also found that the removal efficiency of AAB significantly depend on pH value. In high and low pH values removal percent increase, while a reversed trend was observed at with the pH value close to neutral. The result shown that removal percent of dye increased when 12 watt lamp used instead 6 watt lamp. C1 and C2 clay were analysed by X-Ray fluorescence to determine the metal oxides in clays.