PHOTOOXIDATION OF EXHAUST POLLUTANTS .4. PHOTOCATALYTIC AND THERMAL-DECOMPOSITION OF TRICHLOROACETIC-ACID - DEGRADATION EFFICIENCIES AND PRODUCTS

The photocatalytical and thermal decomposition as well as the oxidatio n of trichloroacetic acid (TCA) was investigated in the aqueous phase by irradiation with a low pressure mercury lamp in the presence of tit anium dioxide (TiO2). In addition, the thermal decomposition without i rradiation was examined in dependence of pH, temperature and oxidizing agents. In all experiments TCA was mineralized and decomposed totally with chloride as main product. Chloroform could be identified in trac es by GC-MS. Heating to 90 degrees C in alkaline solution is the faste st way to destroy TCA. At high temperatures the half-life is recogniza bly larger at photocatalytical decomposition and could almost not be i nfluenced by change of reaction terms. Degradation products of TCA, th eir kinetics and mechanism of formation are discussed in detail. Copyr ight (C) 1996 Elsevier Science Ltd