Toward Sustainable Lagoon Wastewater Treatment: A Review of Nutrient Management Technologies and Their Suitability for Small Communities

Lagoon wastewater
systems are popular in small communities (<10,000
people) due to their cost-effectiveness and energy efficiency. However,
these systems struggle to meet regulatory discharge limits for ammonia,
total nitrogen, and total phosphorus, emphasizing the need for improved
nutrient management. Most existing reviews focus on large-scale mechanical
systems, leaving a gap for stand-alone lagoon systems in resource-limited
settings. This systematic review analyzed 1003 peer-reviewed articles
spanning five decades, evaluating nutrient management technologies
for municipal lagoons. Technologies were categorized by nutrient target,
process type, installation location, and development phase. Biological
processes dominate (79%) due to their adaptability and cost-effectiveness,
while advanced and hybrid systems are gaining traction. Performance
varied widely based on design, climate, and operational conditions,
highlighting the importance of site-specific considerations. To support
context-sensitive selection, this study developed the Suitability
Index (SIDX), a multicriteria framework incorporating complexity,
automation, availability, and operational feasibility. SIDX identified
several applicable and promising technologies for small-community
lagoons. The review also highlighted an evolving focus toward circularity,
resource recovery, and emissions reduction, moving beyond traditional
pollutant removal. These insights provide practical guidance to support
adaptive, context-appropriate nutrient management strategies aligned
with current regulatory standards and future environmental goals.