Constructed Wetlands in Latin America and the Caribbean: A Review of Experiences during the Last Decade

Marco A. Rodriguez-Dominguez,Hans Brix,Carlos A. Arias,Dennis Konnerup

doi:10.3390/w12061744

Abstract

The review aims to report the state-of-the-art constructed wetlands (CW) in the Latin America and Caribbean (LAC) region not limited to national and local conditions. The aim is with a broader view, to bring updated and sufficient information, to facilitate the use of the CW technology in the different countries of LAC. Thus, 520 experiences extracted from the 169 reviewed documents in 20 countries were analyzed. According to the data, horizontal subsurface flow wetlands are the most reported CW in the region (62%), the second most common CW technology in the region is free water surface CW (17%), then vertical flow systems (9%), followed by intensified constructed wetlands (8%), and finally French systems (4%). The performance for nutrient removal is analyzed, finding that the mean of Chemical Oxygen Demand (COD), Total Nitrogen (TN), and Total Phosphorous (TP) removal efficiencies varies from 65% to 83%, 55% to 72%, and 30% to 84%, respectively. The results suggest a generally good performance for COD and TN removal, but a low performance for TP removal. Regarding plant species used for CWs, 114 different plant species were reported, being until now the most extensive report about plant species used in CWs in the LAC region.

Highlights

Intensified Constructed Wetlands (ICW) included in this review shows the use of hybrid systems in different configurations and operational schemes in the region; e.g., recirculation of Horizontal Subsurface Flow Constructed Wetlands (HSSFW) and Vertical Flow Constructed Wetlands (VF) systems [39,88], hybrid systems [41,140,161] aerated systems [67,103,121], using algae turf filters [89] and microalgae ponds [98], evapotranspirative systems [114], and the use electroactive bacteria-based constructed wetlands (METland) [58] in the region
It is possible to state, that the lack of use in the Latin America and the Caribbean region (LAC) region of the CW technology lies in a possible lack of communication between the local scientific communities and governments that delays the adoption of the technology
The LAC region is a heterogeneous territory, with a wide variety of environmental conditions that interact in many different ways with CWs

Summary

Introduction

The term Latin America and the Caribbean region (LAC) refers to 48 countries; 14 in continental. 21,111,500 km (~14% of the world surface), with an estimated population of 650 million inhabitants and is the most urbanized region in the world, producing in more than 30 km of wastewater each year the urban settlements [2]. Estimates the pollution in rivers and freshwater in the region has increased, and since 1990, up to one-third of the rivers, and one-seventh of the length of them are receiving untreated wastewater. Social status and wealth correlate with sanitization level and wastewater treatment coverage. The OMS/UNICEF (2016) [4] has estimated that the level of enhanced sanitization in the region reaches 88% in the urban areas and 64%

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