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Chlorpyrifos Removal from Aqueous Solutions by Emulsion Liquid Membrane: Stability, Extraction, and Stripping Studies

Al-Damluji Farrah Emad, Mohammed Ahmed A.

Journal of Ecological Engineering

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2023

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Vol. 24, nr 2

101--111

EN

The current paper focuses on assessing key parameters affecting the extraction of Chlorpyrifos as well as emulsion stability using the emulsion liquid membrane technology. Five parameters affecting the extraction have been studied: homogenizer speed, emulsification time, agitating time, surfactant concentration, and stripping phase concentration taking into consideration the emulsion breaking. Experiments proved that using the resulting optimum values will maximize both extraction and stripping efficiencies (93.8% and 94.7% respectively), while minimizing the emulsion breakage (increasing the stability of emulsion) to 0.73% with no need to employ a carrier agent. A 10 min agitating time, 3% (v/v) Span 80 as a surfactant, 12700-rpm homogenizer speed, 0.25 M HCl as an internal phase concentration, and 5 min emulsification time are chosen to be the optimum parameters’ values. A study of extraction kinetics and estimation of mass transfer coefficient was also accomplished (3.89×10-9m/s). The conclusions of this work can be extended to the removal of other types of pesticides from water.

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Optimization of Acetaminophen and Methylparaben Removal within Subsurface Batch Constructed Wetland Systems

Mutar Zahraa Hasan, Mohammed Ahmed A., Al-Baldawi Israa Abdulwahab

Journal of Ecological Engineering

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2022

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Vol. 23, nr 1

228--239

EN

The response surface methodology accompanied by Central Composite Design (CCD) was employed in this study to optimize the Alternanthera spp-based phytoremediation process for the individual removal of acetaminophen and methylparaben. Two operational variables, including concentration (A) (20, 60,100 mg/L) and sampling time (B) (7, 14, 21, and 35 days) were involved in the study for removal efficiency (Y) as response. CCD had required a total of 18 experiments for each compound. Analysis of variance (ANOVA) was conducted to verify the adequacy of the proposed mathematical models and revealed good agreement with the experimental data. The observed R2 values (0.9732 and 0.9870), adjusted R2 (0.9620 and 0.9816) and predicted R2 (0.9383 and 0.9721) for AC and MP, respectively, indicated that the developed models were significant at the 95% probability level. Concentration factor was found to be insignificant in the mathematical models; in contrast, sampling time was found to be of a crucial role. The removal of AC and MP were 89.23% and 64.48% under optimum conditions of A = 100 mg/L and B = 35 days respectively. The validation test confirmed the predicted results obtained by Central Composite Design, as the removals achieved under optimum conditions were 91.04% and 59.17% for AC and MP, respectively, which were in good agreement with the results proposed by the theoretical design.

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Application of Emulsion Liquid Membrane Using Green Surfactant for Removing Phenol from Aqueous Solution: Extraction, Stability and Breakage Studies

Mohammed Ahmed A., Al-Khateeb Rasha Waleed

Journal of Ecological Engineering

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2022

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Vol. 23, nr 1

305--314

EN

Emulsion Liquid Membrane (ELM) has garnered much attention, for its simple operation and high selectivity for the target solute. For an ELM process to be successful, emulsion stability and formulation of liquid membrane are the two main criteria. This study investigated an ELM formulation to identify a suitable green surfactant over the ordinary ones to reduce the utilization of chemicals. The stability of water-in-oil-in-water (w/o/w) was assessed in the following ways, by altering the concentrations of the egg yolk and NaOH, homogenizer speed, and emulsification time. To ascertain the favorable conditions for phenol extraction, several experiments were performed, adopting the batch process, which included many parameters, like the influence exerted by the pH of the external feed, concentration of surfactant, concentration of the internal phase, time of emulsification, homogenization speed and mixing time. Lower breakage and greater extraction efficiency (0.83% and 82.06%, respectively) were attained at 3.5 pH of the external feed, 4% (v/v) of the surfactant, 0.1 M of NaOH, 7 min of emulsification time, 5800 rpm of homogenizer speed and 3 minutes of mixing time. From the results of this study, egg yolk emerged as a good green surfactant. Thus, the ELM process holds promise as an effective technology for stripping phenol from aqueous solutions.