The paper analysed peak flood discharge data from records of South African rivers at 83 places and established that the country can be conveniently sub-divided into seven regions of reasonably similar mean flood characteristics. Frequency distributions appropriate to peak discharges in each of the regions were set up and the results presented in the form of a co-axial plot to facilitate their application.
The design of a water purification plant should, in order to be efficient, be based on that pre-determined treatment process which will deliver the best water in the most economical manner. This requires close co-operation between the chemist and the engineer.In this paper an attempt has been made to substantiate the foregoing statement, and it was shown why certain types of colloidal material are flocculated more effectively by some flocculants than by others. Basic data were given for use in the approach to water purification problems in the different regions of South Africa.