IMPACT OF UNCONTROLLED WATER CONSUMPTION ON WASTE PRODUCTION IN A WATER TREATMENT PLANT. CASE STUDY: ITACOLOMI-WTP, OURO PRETO (MG), BRAZIL

Abstract

This study evaluated the waste production in the Itacolomi Water Treatent Plant (WTP) (Ouro Preto, MG), emphasizing its operational conditions. The WTP operates in overload conditions to guarantee the water supply to the population due the uncontrolled consumption, seen as the municipality does not have hydrometers to measure the water consumption, with only a minimum operating cost being charged. The volume and the mass of the waste were evaluated during 75 days, from the measurement of the volumes of water spent on washing the filters and settlers of the WTP, and the concentrations of the parameters turbidity, color, total solids (TS), volatile total solids (VTS) and chemical oxygen demand (COD). The volumetric production of sludge observed was 73.45 m3.day-1 and, in terms of mass of TS, was 32.10 kgTS.day-1. The data analysis revealed that the overload conditions cause a waste production 73% greater than what would be observed if the water consumption was controlled.