Managed Artificial Recharge into a Karstic Aquifer, Soil Treatment Studies from Small-Scale Laboratory to Field Scale Basin Infiltrations

This paper aims to present methodologies on improving the water quality in a Wastewater treatment plant, in the Algarve south of Portugal. The research was based on soil aquifer treatment, soil column laboratory experiments to obtain the best soil in contaminants retention for the infiltration basins, as a second wastewater treatment process. The water from the wastewater treatment plant after being treated flows directly into a river that is recharging a karstic aquifer. Good water quality of the river, prior to its recharge into the aquifer, was the main objective of this research. Two infiltration basins were built at San Bartolomeo de Messines, and a real-time water monitoring system was used in input and in output, understanding immediately the results from the soil basins and the water parameters as the potential of hydrogen, electrical conductivity, temperature, and oxidation-reduction potential. As results showed that the soil column, more than one-month laboratory experiment, presented almost the same average water parameter values as in the field scale basin infiltrations, more than two-month field experiment. As contaminants we focused on ammonia, nitrates, nitrites, boron, copper and zinc values, the results showed good contaminant retention for ammonia and copper.