Abstract:
Disclosed herein are a treatment method and a treatment system which are capable of inexpensively, efficiently, and safely treating wastewater discharged from a gasification plant in large amounts and containing two or more persistent substances. The method for treating wastewater discharged by wet-cleaning of gas obtained by partial oxidation of fossil fuel includes: a free cyanide removal step 2 in which free cyanides contained in the wastewater are removed by acidifying and aerating the wastewater; a biological treatment step 3 in which the wastewater that has been treated in the free cyanide removal step 2 is biologically treated; and a decomposition treatment step 4 in which COD components contained in the wastewater that has been treated in the biological treatment step 3 are decomposed. The decomposition treatment step 4 is preferably performed by an advanced oxidation treatment means, and may include the step of crystallizing calcium sulfate by adding a calcium-based alkaline agent to the wastewater.
Abstract:
Disclosed herein is a method capable of economically treating water containing water-insoluble substance. The method for treating water containing water-insoluble substance, typified by produced water, using a porous material having functional groups on its surface and preferably made of an inorganic oxide includes: a first step of bringing an aqueous solution containing ions ion-exchangeable for the functional groups into contact with the surface to attach the ions to the surface; and a second step of allowing the water containing water-insoluble substance to pass through the porous material from the surface having the ions attached thereto to remove the water-insoluble substance from the water containing water-insoluble substance. The method may further include, after the first step but before the second step, the step of firing the porous material under a temperature condition of 300°C to 500°C for 1 to 5 hours.