A Combined System Using Lagoons and Constructed Wetlands for Swine Wastewater Treatment

This study evaluates the depuration efficiency of a combined system consisting of lagoons (with aerated and non-aerated tanks) and CWs (with Typha latifolia L.) working at pilot scale for treating SW under two recirculation rates (RRs, 4:1 and 10:1) of the CW effluent. The combined system removed about 99% of the total suspended solids and organic matter, and from 80% to 95% of the total nitrogen at both tested RRs. The lagoon system was effective as a pre-treatment of SW, particularly for nitrogen removal. It is convenient to adopt the higher RR, since nitrogen removal can be increased by approximately 20%. The irrigation of the CWs with SW did not generally determine the phyto-toxic effects on Typha latifolia L., except at the start of the experiment and under the lower RR. Despite the limited spatial and temporal scale of this investigation, these results provide a starting point for the use of V-SSF CWs to treat livestock wastewater with a high pollution potential (such as SW).