Characterization of residual soil used for infiltration of reclaimed water

The effects of climate change and the growing demand for water for domestic, industrial, agricultural and recreational activities have been led the use of treated wastewater (reclaimed water) for such applications. The artificial recharge of aquifers with treated wastewater can be an alternative way for restoring underground water volumes that can be used for satisfying some activities, particularly in water shortage areas or where their quality is not suitable for use. After a two-year monitoring period in the Vila Fernando WWTP (Guarda, Portugal), the characteristics of the treated effluent suggest that it could be used for infiltration for aquifer recharge. A multi-criteria analysis based on GIS was developed for site location of infiltration sites. The procedure has involved the combination of six thematic maps and environmental, technical and economic criteria, over an area of 6687.1 ha. About 6.4 ha were selected for suitable sites for infiltration and one of these sites (Quinta de Gonçalo Martins, Guarda) was selected for collecting soil samples. The characterization of the soil indicates that is favorable to the infiltration of treated wastewater for artificial recharge of aquifers.

Optimization of ultrasound-assisted extraction to obtain mycosterols from Agaricus bisporus L. by response surface methodology and comparison with conventional Soxhlet extraction

Ergosterol, a molecule with high commercial value, is the most abundant mycosterol in Agaricus bisporus L. To replace common conventional extraction techniques (e.g. Soxhlet), the present study reports the optimal ultrasound-assisted extraction conditions for ergosterol. After preliminary tests, the results showed that solvents, time and ultrasound power altered the extraction efficiency. Using response surface methodology, models were developed to investigate the favourable experimental conditions that maximize the extraction efficiency. All statistical criteria demonstrated the validity of the proposed models. Overall, ultrasound-assisted extraction with ethanol at 375 W during 15 min proved to be as efficient as the Soxhlet extraction, yielding 671.5 ± 0.5mg ergosterol/100 g dw. However, with n-hexane extracts with higher purity (mg ergosterol/g extract) were obtained. Finally, it was proposed for the removal of the saponification step, which simplifies the extraction process and makes it more feasible for its industrial transference.