22 In this research an electrochemical technique in combination with powdered activated carbon 23 (PAC) for the removal of micropollutants by adsorption as an advanced stage purification step 24 from effluents of pilot plant wastewater treatment plants (WWTP). The effluents of sedimentation 25 tank comprised of wastewater plus PAC (WWPAC). The pilot plant mainly consists of two parts; 26 the first one consists of electrocoagulation (EC) reactor and the second consists of electrophoretic 27 deposition (EPD) discs and electroflotation (EF) setup. The electrocoagulation (EC) reactor is a 28 fiber box consisting of two chambers and thirty four plates of one material (either Fe or Al) on the 29 whole in one EC reactor while one cell has seventeen plates. Both entered into the EC reactor for the determination of EC reactor efficacy for the successful 32 accomplishment of EC process at the designed pilot plant for WW treatment. The effect of 33 different operational parameters; PAC dosage (20 mg), electrode nature (Fe and Al), current 34 density (0.34–2.02 A/m 2 ) has been studied to find out the optimum conditions. Sludge volume 35 index (SVI) of the sludge, thermogravimetric (TG), differential thermal analyses (DTA) and 36 particle size distribution (PSD) of the flocs generated after the EC process has also been studied. 37 The turbidity, pH and conductivity of effluents before and after EC treatment has also been carried 38 out. This pilot plant research gave promising results for future work in advance wastewater 39 treatment direction. 40

Abstract Simultaneous adsorption of heavy metals in complex multi metal system is insufficiently explored. This research gives results of key process parameters optimization for simultaneous removal of Cd(II), Co(II), Cr(III), Cu(II), Mn(II), Ni(II) and Pb(II) from aqueous solution (batch system). New lemon peel-based biomaterial was prepared and characterized by infrared spectroscopy with Fourier transformation (FTIR), scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), while the quantification of metals was made by atomic absorption spectrometry (AAS). Simultaneous removal of seven metals ions was favorable at pH 5 with 300 mg/50 mL solid-liquid phase ratio, within 60 min at room temperature with total obtained adsorption capacity of 46.77 mg g−1. Kinetic modeling showed that pseudo-second order kinetic and Weber-Morris diffusion models best describe the adsorption mechanism of all seven heavy metals onto lemon peel.

Abstract Simultaneous adsorption of heavy metals in complex multi metal system is insufficiently explored. This research gives results of key process parameters optimization for simultaneous removal of Cd(II), Co(II), Cr(III), Cu(II), Mn(II), Ni(II) and Pb(II) from aqueous solution (batch system). New lemon peel-based biomaterial was prepared and characterized by infrared spectroscopy with Fourier transformation (FTIR), scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), while the quantification of metals was made by atomic absorption spectrometry (AAS). Simultaneous removal of seven metals ions was favorable at pH 5 with 300 mg/50 mL solid-liquid phase ratio, within 60 min at room temperature with total obtained adsorption capacity of 46.77 mg g−1. Kinetic modeling showed that pseudo-second order kinetic and Weber-Morris diffusion models best describe the adsorption mechanism of all seven heavy metals onto lemon peel.

This article reports on an investigation into the ability of SiO2–Ta2O5 as a new sorbent for simultaneous preconcentration of Cd(ii), Co(ii), Cr(iii), Cu(ii), Fe(iii), Mn(ii), Ni(ii) and Pb(ii) ions from water by the column method and the parameters involved in this process.

Abstract A silica-based inorganic sorbent was synthesized by the thermal decomposition of ammonium heptamolybdate on silica and applied for the preconcentration and simultaneous determination of Cd, Co, Cr, Cu, Fe, Mn, Ni, and Pb in river water samples using a column system with flame atomic absorption spectrometry. Attenuated total reflection-Fourier transformation infrared spectroscopy, scanning electron microscopy, and electron dispersive spectroscopy were used for sorbent characterization. The effects of pH, sample volume, eluent type, eluent concentration, eluent volume, sample flow rate, and matrix ions (Al, Bi, Ca, Mg, and Zn) on the recovery of the metals in model solutions were investigated. The adsorption capacities (µmol g−1) of SiO2-MoO3 were 88.96 (Cd), 169.69 (Co), 153.85 (Cr), 188.88 (Cu), 179.05 (Fe), 163.81 (Mn), 136.31 (Ni), and 38.61 (Pb). The detection limits of the method were 9.09, 10.82, 10.77, 49.57, 31.64, 6.40, 8.86, 19.15 µg L−1 for Cd, Co, Cr, Cu, Fe, Mn, Ni, and Pb, respectively, with a preconcentration factor of 25. The developed method was used for the determination of the target metals in real samples and the recoveries for spiked samples were found to be from 91.2% to 102.9%.

ABSTRACT The pulverized peel of unmodified and modified pumpkin (Cucurbita pepo L.) was used as sorbent for the determination of Cd, Co, Cr, Fe, Mn, Ni, and Pb by flame atomic absorption spectrometry. The parameters affecting the preconcentration efficiency were investigated. The optimal conditions for preconcentration on unmodified pumpkin peel were identical to those using modified peel: a pH of 8, a preconcentration factor of 10, a flow rate of 3 mL min−1, and an eluent concentration of 1 mol L−1 for all analytes. The detection limits of the method were 9.2, 8.8, 13.2, 28.7, 6.6, 7.6, and 16.5 µ g L−1, while the quantification limits were 30.6, 29.2, 43.9, 95.5, 22.1, 25.4, and 55.1 µ g L−1 for Cd, Co, Cr, Fe, Mn, Ni, and Pb, respectively. The accuracy of the method was verified with a certified reference material. The relative standard deviation was less than 4% based on 12 measurements. Under the optimum conditions of preconcentration, the recovery values exceeded 94%. The following capacity order was obtained for the analytes (µmol g−1): Ni2+ > Co2+ > Fe3+ > Mn2+ > Cr3+ > Cd2+ > Pb2+.