Abstract: The wastewater treatment systems have a plurality of treatment modules between the inlet and the outlet, each for treating water with a selected process. Influent is directed to a covered anaerobic reactor, and then to an attached growth pretreatment filter that is at least intermittently exposed to atmospheric oxygen. Following the filter is a hydroponic reactor followed by a vertical-flow wetland. A second embodiment includes, following the filter, a tidal vertical-flow wetland and a pump for recycling water exiting the wetland upstream of the filter.

Abstract: The wastewater treatment systems have a plurality of treatment zones including a first reactor for supporting biofilms for reducing a concentration of organics and solids from wastewater to be treated and for cyclically nitrifying and denitrifying the wastewater therein. A second reactor is for supporting biosolids, the supporting means including elements for digesting suspended solids in water exiting the first reactor. A portion of the water exiting the second reactor is recycled to the first reactor.