This report from 1989 reviewed the emergency water treatment equipment from the US A.I.D. and its performance. It also suggests some valuable design criteria on specifications of water treatments units. However the market survey is obviously not up to date.
HOLLAND, F. GARLAND, M. (1989): Report on Mobile Emergency Water Treatment and Disinfection Units. (= WASH Field Report No. 271 ). Arlington: Water and Sanitation for Health Project URL [Accessed: 25.05.2011]