| dc.description.abstract | Nichrome is a composite of nickel chromium alloys and commonly used as resistance wire for heating equipment. In this study, ability of multilayered heterojunctions between Cr+3-TiO2 and Ni2+-TiO2 nanoparticles to disintegrate acidified slurry sludge was investigated experimentally. Recombination and photoactivity of the Cr3+ and Ni2+ nanoparticles were optimized alternating their atomic mass fractions in the nanocomposites by their heating ability, using a central composite statistical design approach. Effects of the applied method on sludge conditioning, stabilization, and drying behaviors were systematically investigated. Temperature increase (Delta T) at the highest volatile suspended solids (VSS) oxidation level in the treated sludge samples were 2 +/- 1 degrees C, 5 +/- 1 degrees C, and 20 +/- 1 degrees C for UV C + H2O2-no catalyst, pure and Cr-Ni-TiO2 thin films (TFs), respectively. Obtained results also indicated that the modified TiO2 nanoparticles were able to decrease sludge bound water content by 45 +/- 1% efficiency. Cr3+ and Ni+2 co-doped TF functioned to decrease the unit drying energy from 236 +/- 10 kJ kg(-1) H2Oevaporated to 140 +/- 10 kJ kg(-1) H2Oevaporated. Drying profiles of raw and treated the sludge samples were fitted to Henderson and Pabis Model. Drying constants (k) for raw and treated sludge samples by pure TiO2 and Cr-Ni-TiO2 TFs were found to be 0.11 +/- 0.01 min(-1), 0.12 +/- 0.01 min(-1), and 0.19 +/- 0.01 min(-1), respectively. VSS degradation followed pseudo-first-order reaction kinetics in the all assayed conditions and pseudo-first-order reaction rates (k(obs)) for pure and the modified TFs were determined as 6 x 10(-4) min(-1) and 4 x 10(-3) min(-1), respectively. 2,2 ',5-Trichlorobphennyl, 2,2 ',5,5 '-Tetrachlorobiphenyl, 2,3 ',4,4 ',5-Pentachlorobiphenyl, and 2,2 ',3,4,4,5,5 '-Heptachlorobiphenyl were detected in raw sludge and after the photocatalytic oxidation through Cr3+ and Ni2+ co-doped TiO2 TF reactor, their total concentration was reduced from 4.36 mg kg(-1) to 9.76 x 10(-3 )mg kg(-1). | en_US |
