Wet air oxidation (WAO) on sludge treatment and its first industrial application in China

Abstract Typical commercial application of WAO on sludge treatment is first used in China, system design and debugging, and effect and cost performance is illustrated in this article. It reduces the temperature and pressure of a typical wet oxidation reaction, and the oxygen supplied is only 30- 50 % of the COD, which is specifically used to treat sludge. After the treatment, the sludge moisture content from 80 % to 45-48 %, and become harmless and stabilized, so it can be used as soil for gardens directly or mixed with other materials. As a supplementary carbon source for the nitrogen removal and phosphorus removal process, the separation solution is rich in organic acids and returned to the sewage plant after the heavy metal removal process. The operating cost of the entire process is 180-200 yuan per ton (80 % moisture content), mainly for electricity consumption.