Constructed wetlands as alternatives for swine sustainability

Abstract

Objective: Analyze available information about constructed wetlands and identify the advantages of designs, substrates and vegetation that could be used as alternative solutions for wastewater from pig production systems.

Design/methodology/approach: A broad literature review was conducted to identify the primary characteristics of constructed wetlands (CWs), as well as the various plant species associated with these systems, and the substrates used as filter beds.

Results: Vertical CWs have provided the best results regarding organic matter removal, estimated indirectly through chemical oxygen demand (COD), and nitrogen derivatives such as total nitrogen (TN), ammonium (NH₃), nitrate (NO₃) and nitrite (NO₂). Various substrates are used as filter beds, but they must be evaluated according to their availability, cost, and feasibility for colonization by nitrifying and denitrifying bacteria to degrade the dissolved pollutants. Combinations of plant species can reduce more than 10% of nitrogen products and organic matter present.

Limitations of the study/implications: The lack of monitoring for the satisfactory application of water care standards by small backyard and transition producers limits the adoption of environmental technologies for livestock sustainability in Mexico.

Findings/conclusions: Constructed wetlands are inexpensive, easy-to-use and adaptive systems that can be feasible alternatives for reducing contamination from pig wastewater generated by backyard producers.