00000ctm a22000004i 4500 UP-99796217612279760 Buklod 20161027170055.0 m |o d | ta 161027s2016 xx d r |||| u| (iLib)UPD-00259710686 DENG rda eng DMLUC LG 995 2016 E653 D43 De Castro, Maria Leah Flor A. author. Adsorption of methylene blue using EDTA-modified Philippine bentonite Maria Leah Flor A. De Castro ; Mark Daniel G. De Luna, adviser. Quezon City College of Engineering, University of the Philippines Diliman 2016. x, 58 leaves illustrations 28 cm text rdacontent unmediated rdamedia volume rdacarrier Thesis (M.S. Environmental Engineering)--University of the Philippines Diliman July 2016. Available to the general public. Dyes are hazardous and highly noticeable pollutants that are commonly found in industrial wastewaters. The removal of these pollutants can be complex and expensive This study evaluates the performance of adsorption using EDTA-modified Philippine bentonite as a low-cost, readily available treatment method for wastewater contaminated with methylene blue. The bentonite was modified using EDTA or ethylenediaminetetraacetic acid in basic conditions and subsequently characterized by SEM, FTIR, XRF-EDX, XRD and Dynamic Light Scattering analyses for surface morphology, presence of surface functional groups, elemental composition, chemical composition and particle size, respectively. The results showed that the EDTA-modified bentonite has better adsorption capacity than unmodified bentonite. At a dosage of 20 mg per 50 ml of 100 mg/L MB solution, the modified bentonite achieved its highest q of 162.29 mg g-1 while the unmodified adsorbent had a q of 116.13 mg g-1. Adsorption capacity increases with increasing initial solution pH and contact time, and decreases with increasing ionic strength of NaCl, KCl and NaNO3 in solution, initial dye concentration and temperature. The Langmuir isotherm model best describes the adsorption equilibrium of the process (qm 160.26 mg g-1, KL = 3.45 L mg-1, Rl = 0.0029, Adj R2 = 0.99808) while the Pseudo- Second Order kinetic model best describes its adsorption kinetics (qe = 172.71 mg g-1, k2 = 0.0011 g mg-1 min, Adj R2 = 0.99713). Thermodynamic study also shows that the process is a spontaneous (ΔG < 0), exothermic (ΔH< 0) and reversible (ΔS < 0) physisorption. Methylene blue. Bentonite. Adsorption. De Luna, Mark Daniel G. adviser. FI UP UPD DARCHIVES LG 995 2016 E653 D43 UPD DENG-II LG 995 2016 E653 D43 Thesis