A pilot plant study on reclamation of sewage effluent by radiation treatment

A pilot plant was developed for the reclamation and reuse of secondary effluent from a sewage treatment plant. The plant system consists of sand filtration, gamma-irradiation, ozonation and ion-exchange. Gamma-irradiation showed effective organic contaminant decomposition and this resulted in the reduction of 5-day biochemical oxygen demand (BOD₅), color, chemical oxygen demand (COD_Cr) and total organic carbon (TOC). Ion-exchange significantly removed inorganic ions, and thus reduced total nitrogen (TN) and total phosphorus (TP). The average reduction in color, COD_Cr, BOD₅, TOC, TN and TP, which was obtained after 12 operations, was 64, 52, 67, 61, 95 and 92%, respectively. Irrespective of applied radiation dose, the treated water fully satisfied the quality requirements of household water that can be used for all home uses except for drinking and human contact uses. This revised version was published online in August 2006 with corrections to the Cover Date.