00000ctm a22000004a 4500 UP-99796217610865469 Buklod 20130722112238.0 m |o d | ta 130722s2013 xx d r |||| u| (iLib)UPD-00199209535 DENG rda eng DMLUC LG 995 2013 E653 S86 Sumalinog, Mario Jose R. II author. Synthesis and characterization of iron-manganese oxide adsorbents from actual drinking water treatment residuals for hexavalent chromium removal Mario Jose R. Sumalinog II. Quezon City College of Engineering, University of the Philippines Diliman 2013. x, 60 leaves illustrations 28 cm text rdacontent unmediated rdamedia volume rdacarrier Thesis (M.S. Environmental Engineering)--University of the Philippines, Diliman. Available only to those bound by confidentiality agreement. Approved written permission required. Waste streams are discharged from electroplating units and similar industrial operations containing high concentrations of toxic hexavalent chromium *Cr VI) ions. In this study, novel adsorbents for Cr (VI) removal were synthesized by coating sand with drinking water treatment (DWT) residuals. The effects of the residual-coated sand (RCS) synthesis parameters, namely: acid concentration, acid type and ratio, ultrasonication time, and heating duration, to the adsorption capacities of RCS were investigated. Compared to adsorbents treated with pure acid solutions, acid treatment using dual-acid solutions yielded lower adsorption capacities. The RCS adsorption capacity increased with ultrasonication time and heating duration. The highest adsorption capacity (641.2 mg/kg) was obtained by RCS synthesized using the following conditions: 0.5% w/w H₂SO₄, 30 min ultrasonication to the Freundlich isotherm (R² = 0.9607). Energy Dispersive X-ray (EDX) analysis confirmed the predominance of Fe and Mn oxides on RCS surface while Fourier Transform Infrared Spectroscopy (FTIR) spectra revealed the involvement of these metal oxides in the adsorption of Cr (VI) ions. The findings of this study demonstrated the potential of RCS in removing Cr (VI) for industrial wastewaters. Adsorption. Water Purification Chromium removal. FI UP UPD DARCHIVES LG 995 2013 E653 S86 UPD DENG-II LG 995 2013 E653 S86 Thesis