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The corncob hydrochar is prepared by using a stainless autoclave at 230˚C for 8 h. The products are characterized by elemental analyzer, Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The effects of hydrochar dosage, pH, adsorption time and phenol concentration on the adsorption performance of hydrochar are investigated by means of single-factor experimental analysis. Based on the experiments the adsorption thermodynamic and kinetics are tentatively discussed. The results show that abundant oxygen-containing functional groups are scattered on the surface of the corncob hydrochar. The adsorption kinetics of phenol on the hydrochar corresponds well with pseudo-second-order kinetic model. Thermodynamic studies indicate that Freundlich adsorption isotherm model is much better than Langmuir model in describing the adsorption of phenol on the corncob hydrochar at 25˚C-45˚C. This study provides scientific basis for the development of cheap and efficient adsorbents for the removal of phenols derived from oilfield wastewater.

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The kinetic characteristics of alkenes involved in thermochemical sulfate reduction (TSR) have been never reported in geological literature. In this study, TSR by ethene under hydrothermal conditions was performed in the constrained simulation experiments. Typical TSR products consisted of H 2 S, CO 2 , mercaptans, sulfides, thiophenes derivatives and benzothiophene. The apparent activation energy E and apparent frequency factor A for TSR by ethene were determined as 76.370 kJ/mol and 4.579 s −1 , respectively. The lower activation energy for ethene involved in TSR relative to ethane suggested that the reactivity of ethene is much higher than that of ethane, in accordance with the thermodynamic analysis. Rate constants were determined experimentally using first-order kinetics extrapolate to MgSO 4 half-lives of 67.329 years -3.053 years in deep burial diagenetic settings (120˚C -180˚C). These values demonstrate that the reaction rate for TSR by ethene is extraordinarily fast in high-temperature gas reservoirs (120˚C -180˚C). Consequently, the newly formed ethene from thermal cracking and TSR alteration of natural gas and/or petroleum could not survive after TSR process and were rarely detected in natural TSR reservoirs.

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