To bleach wastewater containing coloring matters easily and economically by a method in which in treating wastewater containing coloring matters, ozone is introduced into wastewater at a specified wastewater temperature and in the presence of sulfuric acid and/or hydrochloric acid to decolor the wastewater.
Wastewater having an absorbance of 50 (400nm) is, for example, passed through a heat exchanger 12 to adjust its temperature to 0-100°C, for example at 25°C and supplied to the bottom part of a column 1 filled with a catalyst, and 1-200mmol/liter of hydrochloric acid is added to the wastewater from an acid addition line 11. Additionally, ozone from an ozone generator 4 the flow rate of which is, for example, 75 liter/hr is supplied from an ozone line 8 equipped with a control valve 5 into the column 1 to be contacted with the wastewater. In the column, about 0.5 liter of a catalyst is packed in the upper part of an air diffusion pipe 6, where the wastewater is reacted. Gas after the reaction is discharged from an exhaust gas line 9 outside a system. Besides, the treated water after bleaching is discharged through the heat exchanger 12 and a line 10.
| WO/2022/245945 | CARTRIDGE FILTER AND METHOD OF MAKING THE SAME |
| WO/2006/135500 | METHOD AND APPARATUS FOR CONTROLLING SULFIDE GENERATION |
IKEDA MITSUAKI
ISHII TORU
