Aldo da Cunha Rebouças

Aspectos qualitativos da infiltração da vinhaça de cana no aqüífero Bauru

The study area is located in Novo Horizonte in central west Sao 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 Sao 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.

Aplicação de sondagem elétrica vertical na estimativa do topo e da espessura de unidades geológicas da bacia do Paraná na cidade de Rondonópolis-MT

The research was carried out in Rondonopolis city, Mato Grosso State, Brazil, to estimate the depth and thickness of geological formations occurring in the area, using vertical electrical sounding (VES). The results show that the maximum thickness of Ponta Grossa Formation is 63 m, and that the joint thickness of Furnas/Ponta Grossa transition and the Furnas Formation is greater to 700 m. The thickness of Furnas/Ponta Grossa transition could not be estimated due to lack of evidence in VES curves. It was observed a considerable litological variation in Furnas Formation. Geological data from wells used in the interpretation of VES allows greater reliability for the obtained results.