In 2020, TAUW Germany safely and sustainably remediated contaminated soil at a former industrial site in the São Paulo (Brazil) Metropolitan area using a thermal activation mechanism. In 2000 this area had already been rezoned and had become part of an educational centre. A soil and groundwater investigation, however, revealed substantial contamination with chlorinated volatile organic hydrocarbons. The relatively high groundwater temperatures in this region and the relatively high solar energy opportunities offered very favourable conditions for developing green energy solutions and facilitating a highly sustainable remediation process.
In the contamination and remediation zone, we installed a dense injection and extraction system consisting of 70 wells in two different soil layers. The groundwater wells are operated after each injection and incubation phase and the oxidant solution is prepared within a mixing station outside of the remediation zone to prevent any health and safety risks in the sensitive used area of the educational centre. The injection fluid was heated with a solar collector system. A buffer tank of 2 m³ acts as a heat storage tank within the remediation zone.
This project shows that green energy applications can successfully contribute to the sustainability of remediation projects which otherwise require massive amounts of conventional energy.