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A comparative research on the effect of the ultrasound irradiation and peroxyacetic acid (PAA) desulfurization on sulfur forms in high sulfur coal samples (gathered from Tabas mine in Iran) was studied by reductive pyrolysis method. The total sulfur reduction after chemical desulfurization by PAA for sonicated samples is achieved in a range of 49-58%. Moreover, the studied sonicated-desulfurized samples showed that the pyritic and sulfate sulfur were mainly attacked by PAA. The maximum organic sulfur reduction was obtained for longer sonication treatment times (15 and 20 min) being around 42-44%. For the first time the role of advanced oxidation process (AOP) in the sonication treatment of coal samples has been considered. The profiles of m/z 48 (SO+) and 64 (SO2+) obtained by Atmospheric Pressure-Temperature Program Reduction on-line coupled with MS (AP-TPR/MS) experiments for sonicated and sonicated-desulfurized samples exhibited identical trends over the whole temperature range. This achievement demonstrated the presence of high amounts of oxidized sulfur functionalities as a function of sonication treatment and post-chemical PAA desulfurization. Furthermore, AP-TPR "off-line" coupled with TD-GC/MS showed quantitative changes in the refractory sulfur forms as a result of sonication settings before and after desulfurization. The Iranian authors like to thank the Tabas coal mine in helping the sampling and also the science and research branch of Islamic Azad University and Hasselt University for financial support of this research project.

The aim of this study was to evaluate the production of pyrolysis oil from three types of sewage sludges. The flash pyrolysis was performed at 500 degrees C, the maximum oil yield was 43.1%, and the water content in bio-oils obtained from secondary sludges was relatively low - 10.3% and 17.0%. GC-MS results showed that pyrolytic bio-oils of studied sludges dominantly contained fatty acids and nitrogenous compounds with potential added value. Obtained solids had high ash content and low calorific value which make them unattractive for use in incineration. FT-IR results showed that solids gave similar IR features as notified alumino silicates; utilization of these solids as adsorbents could be a potential valorization. (c) 2009 Elsevier Ltd. All rights reserved.