Abbas H. Sulaymon

Competitive biosorption of lead, cadmium, copper, and arsenic ions using algae.

The present study aims to evaluate the competitive biosorption of lead, cadmium, copper, and arsenic ions by using native algae. A series of experiments were carried out in a batch reactor to obtain equilibrium data for adsorption of single, binary, ternary, and quaternary metal solutions. The biosorption of these metals is based on ion exchange mechanism accompanied by the release of light metals such as calcium, magnesium, and sodium. Experimental parameters such as pH, initial metal concentrations, and temperature were studied. The optimum pH found for removal were 5 for Cd2+ and As3+ and 3 and 4 for Pb2+ and Cu2+, respectively. Fourier transformation infrared spectroscopy analysis was used to find the effects of functional groups of algae in biosorption process. The results showed that Pb2+ made a greater change in the functional groups of algal biomass due to high affinity to this metal. An ion exchange model was found suitable for describing the biosorption process. The affinity constants sequence calculated for single system was KPb > KCu > KCd > KAs; these values reduced in binary, ternary, and quaternary systems. In addition, the experimental data showed that the biosorption of the four metals fitted well the pseudo-second-order kinetics model.

Removal of lead, cadmium, copper, and arsenic ions using biosorption: equilibrium and kinetic studies

Abstract Biosorption of lead, cadmium, copper, and arsenic ions by using native algae was investigated. Experiments were carried out in a batch reactor to obtain equilibrium and kinetic data. Experimental parameters affecting the biosorption process such as pH, shaking time, initial metal concentrations, and temperature were studied. The optimum pH for removal was found to be 3, 5, 4, and 5 for Pb2+, Cd2+, Cu2+, and As3+, respectively. Biosorption of these metals is based on ion-exchange mechanism accompanied by release of light metals such as calcium, magnesium, potassium, and sodium. Experimental isotherms data well fitted an ion-exchange model and the affinity constant was calculated for each metal. The results showed the ion-exchange model was found suitable for describing the biosorption process. Fourier Transformation Infrared Spectroscopy analysis was used to find the effects of functional groups of algae in biosorption process. The results showed that Pb2+ had a greater difference in the peak valu...

A comparative adsorption/biosorption for the removal of phenol and lead onto granular activated carbon and dried anaerobic sludge

ABSTRACT The potential use of dried anaerobic granular sludge (DAGS) as a substitute for granular activated carbon (GAC) for removing phenol and lead from aqueous solution was examined in a batch system. To make the comparison between adsorption/biosorption process fair, the working sorption pH, temperature, mixing speed and contact time were fixed at 4, 30°C, 250 rpm and 24 h, respectively for both the sorbents. Adsorption/biosorption isotherms were developed for both the single and binary component systems and expressed by four models. Model parameters were estimated by the nonlinear regression method using STATISTICA version 6 and EXCEL 2007 software. The maximum loading capacity (q m) of the phenol was 66.8234 and 37.0370 mg/g for lead onto GAC, while it was 70.0183 mg/g for phenol and 89.8783 mg/g for lead onto DAGS in single system. However, in binary system, the loading capacity decreased because of competition between compounds to binding sites of adsorbent/biosorbent.

Comparative Study of Removal of Cadmium (II) and Chromium (III) Ions from Aqueous Solution Using Low-Cost Biosorbent

Abstract This study aims to evaluate the ability of abundant low-cost garden grass to remove cadmium and chromium ions from aqueous solutions. Batch biosorption studies were carried out to examine the biosorption capacity, pH value, temperature, agitation speed, and metal ions concentration. The biosorption process revealed that the garden grass was an effective biosorbent of cadmium and chromium. The maximum chromium and cadmium removal rate was 90 and 80% at pH 4, respectively. FTIR spectroscopy analysis showed that the hydroxyl, amine, and carboxyl groups were the major groups responsible for the biosorption process. The maximum biosorption capacity was 18.19 and 19.4 mg/g for cadmium and chromium, respectively. The biosorption isotherm data fitted well the Langmuir model. Kinetic data were adequately fitted by the pseudo-second-order kinetic model.

Column Biosorption of Lead, Cadmium, Copper, and Arsenic ions onto Algae

A mixture of green and blue-green algae was used as an adsorbant material for biosorption of lead, cadmium, copper, and arsenic ions in fluidized bed reactor. Batch experiments showed that the algal biomass was successfully used for the removal of these metal ions from wastewater. The maximum percentage removal for 1 g dose was 89, 82, 79, and 70 for Pb2+, Cu2+, Cd2+ and As3+, respectively. The experimental data fit well to an ion exchange equilibrium model. Affinity constants were calculated for each metal. A higher affinity of the biomass towards lead (Pb2+) was observed due to the high electronegativity of this metal. FTIR analyses showed that hydroxyl and carboxyl groups could be very effective for capturing these metals. An ideal plug flow model was adopted to characterize the fluidized bed reactor and solved numerically using MATLAB version (R2009b), which fit well to the experimental breakthrough data. The effects of different operating conditions such as: static bed height, superficial velocity and particle diameter on the removal process were investigated. Lead showed the largest operating time compared with others.

Removal of phenol and lead from synthetic wastewater by adsorption onto granular activated carbon in fixed bed adsorbers: prediction of breakthrough curves

Abstract The adsorption of phenol and lead (II) onto granular activated carbon (GAC) in single and binary system has been studied using fixed bed adsorber. A general rate multi-component model has been utilized to predict the fixed bed breakthrough curves for dual-component system. This model considers both external and internal mass transfer resistances as well as axial dispersion with non-liner multi-component isotherm. The effect of important parameters, such as flow rate, bed height and initial concentration on the behavior of breakthrough curves have been studied. The equilibrium isotherm model parameters such as isotherm model constants, pore diffusion coefficients (D p ) were obtained from batch experiments, while the external mass transfer coefficients and axial dispersion (k f , D z ) were calculated from empirical correlations. The results show that the general rate model was found suitable for describing the adsorption process of the dynamic behavior of the GAC adsorber column.

Removal of reactive yellow dye by adsorption onto activated carbon using simulated wastewater

AbstractReactive yellow dye was investigated as an adsorbate to be removed onto activated carbon during batch and continuous processes. A Fourier transform infrared (FTIR) analysis was carried out before and after onto the activated carbon adsorption. Thermodynamic parameters: Gibbs free energy, enthalpy change, and entropy change were found at different temperatures. Isotherm experiments were carried out at different conditions: adsorbent dosage (0.1–0.5 g), temperature (20–50°C), pH (2.5–9), and initial concentration (50–150 mg/l). Langmuir, Freundlich, and (Brunauer, Emmet, and Teller) BET isotherm model were used to fit the results. Kinetics mechanism of mass transfer pseudo-first-order, pseudo-second-order, and intraparticale diffusion models were studied. Fixed bed column experiments were carried out at different bed heights (0.05–0.15 m), initial concentration (10–50 mg/l), and flow rate (4–12) 10−6 m3/min to find empty bed contact time at break though point. Bed depth service time model was used a...

Competitive biosorption of phenol and lead from synthetic wastewater onto live and dead microorganisms

Abstract The comparison between the living and dead microorganisms for removing phenol and lead from aqueous solution was examined in a batch system. The working sorption pH, temperature, mixing speed and contact time were fixed at 4, 30°C, 250 rpm and 24 h respectively. Biosorption isotherms were developed for both the single and binary component systems and expressed by four models. Model parameters were estimated by the non-linear regression method using STATISTICA version-6 and EXCEEL-2007 software. The maximum loading capacity (q m) of the phenol was 30.2018 and 70.0183 mg g−1 and for lead was 36.7888 and 89.8783 mg g−1 onto live and dead microorganisms in single system respectively. However, in binay system the loading capacity decreased because of competition between compounds to binding sites of biosorbents. Desorption efficiency from living microorganisms was 85.974% and 80.096% under 0.1 M of Na2CO3 and HCl, while it was 95.352% and 96.632% from dead microorganisms for phenol and lead respectively.

Experimental investigation and numerical modeling of light nonaqueous phase liquid dissolution and transport in a saturated zone of the soil.

The present research aims at studying the dissolution and transport process of benzene as a light nonaqueous phase liquid (LNAPL) in saturated porous media. This process is studied under unidirectional flow at different water velocities ranging from 0.90 to 3.60 cm/h in a three-dimensional saturated sand tank (100 cm × 40 cm × 35 cm). This tank represents a laboratory-scale aquifer. The dispersion parameters of the sand tank are based on an independent tracer experiments. The experimental aquifer is simulated by developing a three-dimensional finite element numerical model. This model assumes that the dissolved concentration along the LNAPL-water interface is equal to the solubility concentration. The numerical model results overpredict the experimental within factor 1.6 and 2.29 at depths of 1 cm and 3 cm, respectively, during eight days. The correlation coefficient is ranging from 0.8485 to 0.9986. The time invariant average mass transfer coefficient is determined at each interstitial velocity. The values are ranged from 0.016 to 0.061 cm/h (i.e. increased with velocity toward a limiting value). For a circular benzene pool, two linear relationships are found; the first between the overall Sherwood number (Sh(e)(*)) with average Peclet number in x-direction (Pe(x(e))(*)); and the second between the overall Sherwood number (Sh(e)(*)) with average Peclet number in y-direction (Pe(y(e))(*)).

Competitive biosorption of Pb(II), Cr(III), and Cd(II) from synthetic wastewater onto heterogeneous anaerobic biomass in single, binary, and ternary batch systems

Biosorption of lead, chromium, and cadmium ions from aqueous solution by dead anaerobic biomass (DAB) was studied in single, binary, and ternary systems with initial concentration of 50mg/l. The metal-DAB affinity was the same for all systems. The main biosorption mechanisms were complexation and physical adsorption of metallic cations onto natural active functional groups on the cell wall matrix of the DAB. It was found that biosorption of the metallic cations onto DAB cell wall component was a surface process. The main functional groups involved in the metallic cation biosorption were apparently carboxyl, amino, hydroxyle, sulfhydryl, and sulfonate. These groups were part of the DAB cell wall structural polymers. Hydroxyle groups (‐OH) were responsible for 37, 52, and 31% of the removal of Pb(II), Cr(III), and Cd(II) by DAB through complexation mechanisms; whereas carboxylic groups (C=O) were responsible for 21, 14, and for 34%of the removal of Pb(II), Cr(III), and Cd(II), respectively. Biosorption data were fitted to four isotherm models. Langmuir model was best fitted to the experimental data than Freundlich, Sips, and Redlich‐Peterson models for single system. While for binary and ternary metal systems, extended Langmuir model were fitted experimental data better than interaction factor, a combination of Langmuir‐Freundlich and Redlich‐Peterson models. The maximum uptake capacities were 54.92, 34.78, and 29.99mg/g for Pb(II), Cr(III), and Cd(II), respectively. Optimum pH was found to be 4.