Exploring the use of Azorean native plants and rock material for sustainable wastewater treatment through constructed wetland systems

Abstract

The constructed wetlands (CWs) are natural engineered systems well suited for wastewater treatment from small agglomerations and individual houses. These systems are characterized by low energy and low chemical consumption, and the water treatment is due to biological, chemical and physical processes occurring in granular media, biofilms and plants. This study aimed at assessing the suitability of Azorean native plants, Bolboschoenus maritimus L. Palla and Juncus acutus L., and local pebbles for CWs used as complementary treatment for septic tank effluents or for polishing secondary effluents aiming at water reuse in the Azores Islands. Bolboschoenus maritimus L. Palla showed a good performance, identical and sometimes better than the conventional species, with 2.5 to 6.5-log reduction of faecal coliforms. Organic matter (expressed as dissolved organic carbon and absorbance at 254nm) and phosphorus concentrations in the CW effluent were lower than in the corresponding influent water. This exploratory assay suggests that Bolboschoenus maritimus L. Palla and the seashore pebbles can be successfully used in CWs in Azores."