Removal of nitrogen containing hydrocarbons from wastewater by catalytic and non-catalytic hydrothermal oxidation, in sub- and supercritical conditions

[摘要] The results of the hydrothermal oxidation of 1,8 diazabicyclo[5.4.0]undec-7-ene (DBU), a toxic nitrogen-containing organic compound by different processes is presented here. Subcritical experiments (wet air oxidation (WAO) and catalytic wet air oxidation(CWAO)), were conducted in a batch reactor and supercritical water oxidation (SCWO) experiments were conducted in a tubular reactor. The key operating parameters investigated were temperature, pressure, initial organic concentration; for catalytic experiments, the effect of catalyst metal loading and weight were also investigated. Commercially available Ru/Al\(_2\)O\(_3\) pellets were selected for catalytic study after various catalysts were screened. Results indicated that temperature was the key operating parameter in all 3 processes that affected DBU removal, TOC removal and ammonia yield. Ru/Al\(_2\)O\(_3\) pellets enhanced the DBU removal, TOC removal and decreased ammonia yield compared to WAO. Complete DBU removal was achieved by catalytic wet air oxidation and supercritical water oxidation. Kinetic data was acquired and a pseudo first order kinetic model was used to quantify the oxidation rate. WAO and CWAO were investigated for the treatment of hazardous industrial effluent with a high initial ammonia concentration and complete ammonia removal was achieved using Ru/Al\(_2\)O\(_3\) pellets. A novel ruthenium coated reticulated foam monolith was investigated as an alternative for heterogeneous catalyst instead of Ru/Al\(_2\)O\(_3\) pellets, the results show that it improved catalyst stability and could be an alternative to pellets for wastewater treatment.

[发布机构] University:University of Birmingham;Department:School of Chemical Engineering

[关键词] T Technology;TP Chemical technology