Chlorine dioxide for waste water treatment is formed by reaction of sodium chlorate, sodium chloride and sulphuric acid at high acidity while the reaction zone is subjected to subatmospheric pressure and spent reaction medium overflows from the reaction zone. The subatmospheric pressure preferably is applied using a water eductor to which the water to be treated is fed, so that direct contact between the produced gases and the water to be treated is effected.
展开▼