clay and diethyl-ketone

The toxic effects of diethylketone (DEK) in aqueous solution with different concentrations of Al

Topics: Adsorption; Aluminum; Aluminum Silicates; Biodegradation, Environmental; Clay; Environmental Pollutants; Metals, Heavy; Pentanones; Pilot Projects; Streptococcus; Waste Disposal, Fluid

The performance of two bacteria, Arthrobacter viscosus and Streptococcus equisimilis, and the effect of the interaction of these bacteria with four different clays on the retention of diethylketone were investigated in batch experiments. The uptake, the removal percentages and the kinetics of the processes were determined. S. equisimilis, by itself, had the best performance in terms of removal percentage, for all the initial diethylketone concentrations tested: 200, 350 and 700 mg/L. The uptake values are similar for both bacteria. A possible mechanism to explain the removal of diethylketone includes its degradation by bacteria, followed by the adsorption of the intermediates/sub-products by the functional groups present on the cells' surfaces. The assays performed with bacteria and clays indicated that the uptake values are similar despite of the clay used, for the same microorganism and mass of clay, but in general, higher values are reached when S. equisimilis is used, compared to A. viscosus. Kinetic data were described by pseudo-first- and pseudo-second-order models.

Topics: Absorption; Aluminum Silicates; Arthrobacter; Bentonite; Biodegradation, Environmental; Clay; Environmental Restoration and Remediation; Kaolin; Magnesium Silicates; Pentanones; Streptococcus; Wastewater; Water Pollutants, Chemical

The ability of four different clays to adsorb diethylketone was investigated in batch experiments aiming to treat wastewater with low solvent concentrations. The adsorption performance in terms of uptake followed the sequence: vermiculite>sepiolite=kaolinite=bentonite, for all the adsorbent doses tested (from 0.1 to 1.5 g) in 150 mL of ketone solution (800 mg/L). The equilibrium data in the batch systems were described by Sips and Dubinin-Raduskevich isotherms. The best fits for bentonite and kaolinite clays were obtained with the Sips isotherm and for sepiolite and vermiculite the best fits were obtained with the Dubinin-Raduskevich model. Kinetic data were described by pseudo-first and pseudo-second order kinetics models. The best fit was obtained for the pseudo-first order model which assumed that the interaction rate was limited only by one process or mechanism on a single class of sorbing sites and that all sites were time dependent. The presence of functional groups on the clay surface that might have interacted with the solvent was confirmed by FTIR. XRD analysis was also performed. This study showed that the tested clays are very effective for the removal of diethylketone from industrial effluents.

Topics: Adsorption; Algorithms; Aluminum Silicates; Chromatography, Gas; Clay; Environmental Restoration and Remediation; Flame Ionization; Kinetics; Models, Chemical; Models, Statistical; Pentanones; Solutions; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Waste Disposal, Fluid; X-Ray Diffraction