Chemical Activation of Sludge from Drinking Water Treatment Plant for Adsorption of Methylene Blue Dye

AbstractThe objective of this study is to explore the preparation and application of sludge produced in plants of drinking water treatment, to remove methylene blue (MB) dye from polluted water. Adsorbate (methylene blue) is prepared in the lab. as a stock solution. To create new adsorbents, chemical activation of the used sludge has been carried out. The activation is performed by HCl and H2O2 and a mixture of HCl and H2O2. The experiments were carried out under different boundary conditions, like the initial concentration of dye, dosage of adsorbent, solution pH, contact time, and temperature of the adsorption, to determine the optimum boundary conditions for operation. All of the experiments in this study were carried out in a batch system. The results show that sludge activation by a mixture of 2:1 HCl/ H2O2 was selected as the best chemically activated adsorbent (removal of 99.9%). For the best MB adsorption results, the following criteria must be met: 50 ppm initial dye concentration, 90 min of contact time, pH 7, and a dosage of 0.25 g of the adsorbent. Adsorbents suit the Langmuir and Freundlich models well, according to applications of the Freundlich Isotherm and Langmuir models.</jats:p

Efficiency of chemically activated raw and calcined fish bone for the Adsorption of Cd(II) and Pb(II) from polluted water

Abstract Background: Bone biochare is used widely as an adsorbent in water pollution control; because of its high surface area and pore volumes . This study is attempting to prepare a low cost adsorbent (biochare) from the waste fish bone by chemical activation, and uses it for the removal of Pb and Cd from wastewater. Fish bone adsorbent was prepared by two methods, one by activation with different chemical activators include 0.001 M HNO3, 0.1 M NaOH, 0.5 % H2O2, and ethanol ( FB) . The other method by calcination after the chemical activation at 600oC (FB-Hy). The synthesized fish biochare adsorbents were characterized by electron microscopy (SEM), x-ray diffractometer (XRD), x-ray fluorescence (XRF), BET surface area, and Fourier transform infrared (FT-IR). The efficiency of the prepared adsorbents for removal Pb and Cd were investigated as a function of contact time, pH,solution temperature, initial metal concentration, and adsorbent dose. Metal concentrations were determined by atomic absorption spectroscopy .Results: The results reveal that activation of the fish bone by 0.1 M NaOH is the suitable for the higher adsorption of Pb and Cd than with the other activators. The chemically treated bone adsorbent by 0.1 M NaOH (FB) shows higher removal of Pb and Cd than with that chemically calcinated adsorbent (FB-Hy). The maximum adsorption of Pb and Cd on the chemically prepared adsorbent(FB) were 99.74 and 99.35 % , respectively at optimum conditions. The results of kinetic adsorption obeyed a pseudo-second-order model. Freundlich and Langmuir isotherms were applied in which the adsorption fitted with the Langmuir isothermConclusion: This study ended with the success for preparing an ecofriendly and low cost fish bone adsorbent from the waste fish bone, and used it for the removal of Pb and Cd from polluted water</jats:p