SEWAGE RE‐USE IN MAURITIUS

In: Water and environment journal, Band 18, Heft 3, S. 171-176

Abstract

ABSTRACTWhen completed, the sewage‐treatment works at St. Martin will serve nearly a third of Mauritius'1.1 million population. In addition to protecting the marine environment, it will provide a valuable source of water to supplement irrigation supplies to west‐coast sugar‐cane plantations.This paper explains (i) the treatment‐process selection which favoured conventional activated sludge over extended aeration, (ii) the need for nutrient removal, (iii) the choice of UV treatment for disinfection, and (iv) the problem of dye discharges from the textile industry. It also describes the complexity of the control system which is designed to (a) supply tertiary effluent to the irrigation canals blended with surface‐water supplies to avoid sodium accumulation in the soils. (b) avoid flooding of the canals, and (c) provide an emergency stormoverflow discharge via the same common outfall pipe to the sea.