STATE OF THE ART OF WETLANDS SYSTEMS FOR THE TREATMENT OF EFFLUENTS FROM LANDFILLS

Abstract

Landfill leachate is an effluent with a high polluting load, characterized by high concentrations of persistent organic matter, ammonia and heavy metals. Conventional treatment of these wastes involves high energy and operational costs, demanding more sustainable alternatives. This paper presents a state-of-the-art review on the use of Constructed Wetlands (CW) as a Nature-Based Solution for leachate treatment. The methodology consisted of a systematic literature review across scientific databases, covering studies published in the last years. The results indicated a significant growth in publications in recent years, with a higher concentration starting in 2021. Journal analysis highlighted Science of the Total Environment, Ecological Engineering, and Journal of Environmental Management. The most recurrent keywords indicated a focus on wastewater treatment and the use of constructed wetlands for leachate treatment, in addition to a growing interest in the removal of emerging contaminants and the understanding of microbiological processes involved in the efficiency of these systems. It is concluded that CW systems represent a consolidated, low-cost technology for the post-treatment or complementary treatment of landfills, although challenges such as the acute toxicity of raw leachate still require integrated pre-treatment strategies.