Catalytic treatment, technology

Wastewaters containing chlorinated hydrocarbons (CHCs) are very toxic for aquatic system even at concentrations of ppm levels [1] thus, appropriate treatment technologies are required for processing them to non-toxic or more biologically amenable intermediates. Catalytic wet oxidation can offer an alternative approach to remove a variety of such toxic organic materials in wet streams. Numerous supported catalysts have been applied for the removal of aqueous organic wastes via heterogeneous wet catalysis [1,2]. 

The in situ nature of this treatment also minimizes potential exposure to humans and the environment. Ex situ options like excavation require repeated worker handhng of the contaminated soil and increased opportunity for volatilization of contaminants (leading to off-site contamination). The off-gas stream generated as part of the SPSH process can be treated using conventional off-gas treatment technologies such as catalytic oxidation, thermal oxidation, condensation, and granular activated carbon (GAC). 

Aki SNVK, Abraham MA. An economical evaluation of catalytic supercritical water oxidation comparison with alternative waste treatment technologies. Environ Prog 1998 17(4) 246-255. 

Granger P, Parvulescu VI. Catalytic NOx abatement systems for mobile sources From three-way to lean burn after-treatment technologies. Chemical Reviews. 2011 111(5) 3155—3207. 

L.J. Pettersson, Catalytic Treatment of Emissions. State of the Art for Alcohol and Natural Gas-Fueled Vehicles, Department of Chemical Technology, Royal Institute of Technology, Stockholm, Sweden, ISRN KTH/KT/FR-91/9—SE, 1991. 

It seems that Katzer etal. were the first to evaluate the catalytic WO as a potential wastewater treatment technology. They have shown that catalytic oxidation may not be economically feasible for waste streams containing small amounts of organic material, as is the case with the conventional WO process. For dilute or very dilute wastes the... 

Granger P, Parvulescu VI (2011) Catalytic NO Abatement Systems ftn Mobile Sources From Three-Way to Lean Bum after-Treatment Technologies. Chem Rev 111 3155-3207... 

Currently, the major deNOx after-treatment technologies under consideration include the so-called Lean-NOx Traps (LNT), which are used with direct injection gasoline and Diesel engines, and the Selective Catalytic Reduction (urea-SCR) process. 

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