PROCESS OF TREATING WASTE WATER OR SEWAGE AND THE APPLICATION THEREOF

The present invention relates to a process for decreasing the content of organic chemical substances in waste waters by chemical oxidation, preferably in the presence of chlorine, and, if required, additional alkaline thermal treatment of the waste water, the waste water (effluent), which has a COD content (chemical oxygen demand) and an alkalinity or is made alkaline, being passed into at least one reactor and being treated at a temperature of above 15@C with a chlorine-containing and/or chlorine-releasing chemical substance, the chlorine input being in an amount of more than 1 g of chlorine/g of COD (based on the chlorine content of the chlorine-containing and/or chlorine-releasing chemical substance) and a molar ratio of OH to chlorine of greater than 1.5 and a pH of the waste water of >/= 5, preferably >/= 6, being maintained or established, and the chlorine-treated waste water being subjected to a reaction time of more than 0.25 hours, preferably more than 0.4 hours, the organic compounds being at least partially oxidised and the waste water then being further treated and/or discharged or drained from the reactor.