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Presently, the treatment of dye-polluted water is a challenging task worldwide. In this study, the adsorptive removal of Auramine-O (AO) dye by magnetite nanoparticles (MNs) and sodium dodecyl sulfate (SDS) functionalized MNs (SFMNs) were investigated. FESEM, HRTEM, EDX, and XRD were employed to characterize the MNs. In batch optimization, dye removal efficiency of 74% was obtained at contact time (40min), pH 6.5, sorbent dosage (20mg), and initial dye concentration (20mg/L). The maximum adsorption capacity of 55.56mg/g was estimated from Langmuir model and the isotherm data were fitted with Freundlich model ($R^2=0.994$) for SFMNs. Pseudo-second-order kinetics was followed by both MNs and SFMNs for the adsorption of AO dye. The continuous AO dye adsorption was studied in fixed-bed column and the effects of bed height, influent flow rate, and initial dye concentration were investigated. The column performance was evaluated by breakthrough kinetic modeling and Yoon–Nelson model was fitted with the data. The results of this study showed that the surface modification of MNs using SDS enhanced the AO dye removal efficiency and SFMNs can be employed as an efficient nanoadsorbent for AO dye removal in batch and continuous mode of operation.

In this paper, the pyrolysis treatment of sewage sludge was studied in a laboratory fixed bed reactor at temperature range of 400~600 ⁰C. Meanwhile, the influences of the final pyrolysis temperature, the heating rate and ZnO additive on the characteristics of the resulting bio-oil were also investigated. The experimental results indicated that more than 35% bio-oil yield was achieved at a pyrolysis temperature range of 500~600 ⁰C and a heating rate of 5 ⁰C/min. Meanwhile, ZnO has some contributions to the vaporation of the volatile in the sewage sludge. Moreover, heavy oxygenated hydrocarbons in the bio-oil are as high as 90%, which should be updated and then reused as fuel.