Phytoremediation applied to urban solid waste disposal sites

ABSTRACT

The environmental restoration of dumpsites, closed and/or abandoned landfills is a relevant issue nationally and globally, considering that about 40% of urban solid waste is still disposed of inappropriately in the world. Phytoremediation is a promising alternative for application in such areas, due to the low costs involved, ease of implementation, good public acceptance, landscape aspects and the fact that it is a non-invasive in situ technique. The present manuscript evaluated the application of phytoremediation to areas contaminated by solid urban waste, addressing techniques for the remediation of contaminated soils, implantation of evapotranspiration covers, construction of (phyto)hydraulic barriers and implementation of leachate treatment systems (wetlands). It was considered that the main pollutants of interest in these places are organic matter, ammonium, and low concentrations of heavy metals, which can undergo phytodegradation, phytoextraction, phytostabilization, rhizodegradation, and rhizofiltration. It is recommended that: Phreatophyte species be adopted for the construction of (phyto)hydraulic barriers around dumps; plant species that promote the phytoextraction and/or phytostabilization of metals and ammonium and the phytodegradation of organic compounds are planted on the surfaces of landfills and dumps; and that evapotranspiration covers be installed in landfills and dumps, contributing to the reduction in leachate production. Finally, it is recommended that abandoned dumps are subject to research by Brazilian educational institutions, seeking to develop phytoremediation techniques that allow environmental rehabilitation and the safe use of these areas.

Keywords:
dumps; hydraulic barriers; evapotranspiration covers