| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent scale formation due to insolubilization of polyvalent inorganic ions in a membrane separator and deterioration of quantity and quality of water treated with the membrane separator due to the scale formation when nitrite/nitrate nitrogen and multiply-charged inorganic ion-containing wastewater is concentrated by the membrane separator and the concentrate is denitrified by a biological denitrification device. <P>SOLUTION: After an antiscaling agent for inhibiting the scale formation of the polyvalent inorganic ions is added to the nitrite/nitrate nitrogen and polyvalent inorganic ion-containing wastewater, the wastewater is separated into a permeate and a concentrate by membrane separation in the membrane separator 2, and the concentrate is denitrified by the biological denitrification device 3. The addition of the antiscaling agent for inhibiting the scale formation of the polyvalent inorganic ions before the membrane separation of the nitrite/nitrate nitrogen and polyvalent inorganic ion-containing wastewater in the membrane separator 2 prevents the scale formation of the polyvalent inorganic ions in the membrane separator 2 and enables a stable and efficient treatment for a long time without causing an increase in a membrane differential pressure due to deposition, a deterioration of a permeation flux (treated water quantity) of a membrane and deterioration of treated water quality. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
