Qualitative aspects of the infiltration of sugar cane molasses into the Bauru Aquifer

Abstract

The study area is located in Novo Horizonte in central west São Paulo. The geology of the area comprises Cretaceous deposits of the Bauru Group underlain by The Serra Geral Formation. The Cretaceous aquifer in the state of São Paulo has 104.000 km² and is therefore exploitable. It is used for domestic and industrial water supplies. Sugar cane milling is a major economic activity in the region and sugar cane is widely cultivated over the aquifer. Groundwater may become polluted from the infiltration of molasses (alcohool production residues), which may reach large volumes; groundwater pollution, from molasses infiltration, is considered high in these areas. This article focuses on the problem of molasses infiltration in the pilot area of Bauru Aquifer. Molasses infiltration has caused the groundwater to become polluted making it inadequate for human consumption. The following measurements were made in water which exceeded drinking water standards; ammonia nitrogen >;0.005 to 9.8 mg/l; magnesium 12.0 to 210.0 mg/l; aluminum >;0.02 to 23.0 mg/l; iron >;0.005 to 60.0 mg/l; manganese 5.0 to 60.0 mg/l and chloride 4.0 to 640,0 mg/l.