| Supercritical water oxidation(SCWO) is a promising technique for the treatment of organic wastes. The properties of supercritical water(SCW) were presented, the advantages and disadvantages of SCWO were discussed in detail, and the universal research works on the degradation efficiency, oxidation kinetics and reaction pathway of organic pollutant were reviewed in this paper. A apparatus for the oxidative decomposition of organic compounds in SCW was established, and in which the oxidation of hydroxy-naphthalenesulfonic acid and amino-naphthalenesulfonic acid were carried out at different conditions. The results demonstrated that: I. Organic pollutant can be destroyed effectively by SCWO, and the COD removal rate of high- concentration pollutant reach up to 99% under the experimental conditions, which showed that SCWO is a high-efficiency water treatment technique. 2. The COD removal rate of organic pollutants will increase with the increment of reaction temperature, pressure, residence time, concentration of organic pollutants or added some catalysts, among which temperature and residence time are the main factors effecting the COD removal rate of organic pollutants. Pressure has little influence on the oxidative decomposition of organic pollutants. 3 After treated by SCWO, the biodegradability of organic pollutant rised increasingly. 4. The kinetics of oxidative degradation of hydroxy-naphthalenesulfonic acid and amino- naphthalenesulfonic acid in SCW were studied systematically. The results were as follows: Reaction order Residue Pollutanttemperature pressure E3 A square N4Pa ki/mol organics oxygen differencehydroxy- nic acid(COD) amino- nic acid(COD) 5. The residual products of naphthol and amino-naphthalenesulfonic acid were studied and the degradation pathway of naphthol organic pollutant in SCWO was inferred: Single Ring product (IA) naphthyl pollutnats phenol short-chain acid ?C02. 1-120 coupled product... |
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