Virus inactivation during water treatment by a progressive ozonation unit

• Published in: Water research (Oxford) 1986-01, Vol.20 (7), p.871-876
• Main Authors: Joret, J C, Hassen, A, Bourbigot, M M, Agbalika, F, Hartemann, P, Foliguet, J M
• Format: Article
• Language: fre
• ISSN: 0043-1354
• DOI: 10.1016/0043-1354(86)90175-2

Studies on the removal and inactivation of viruses during treatment of water from the Seine river in a pilot plant and from the Oise river in a full-scale plant, are presented. A flow diagram of the full-scale plant at Mery sur Oise is included. Reduction in viral count achieved by conventional treatment in the pilot plant involving coagulation, sedimentation, and sand filtration, was much less than results reported in the literature. However, preliminary ozonation of the raw water in the pilot plant inactivated 64-97 per cent of viruses, and no viruses could be detected in the finished water. The treatment process for the industrial water supply at Mery sur Oise was preozonation, storage, coagulation-flocculation, settling, sand filtration, second stage ozonation, activated carbon filtration, postozonation and chlorine dioxide. Raw water samples showed relatively low viral counts (10-146 PFU per 1000 litres) compared with those in Seine river water (190-1420 PFU per 1000 litres). Preozonation efficiency was not evaluated before storage due to its intermittent operation. Enteroviruses were not detected after the second stage ozonation. Postozonation and chlorine dioxide treatment acted as an additional safeguard for safe drinking water. The principal viruses detected in the river waters were ECHO virus and Coxsackie B virus. A bibliography of 30 references is appended. (Full translation 54 pounds sterling).