Vetiver-Based Vertical Helophyte Filtration Systems for Sustainable Backyard Swine Wastewater Management: A Review

Swine wastewater, particularly from backyard production systems, represents a significant environmental challenge due to its high concentrations of organic matter, nutrients, and microbial contaminants. In many developing regions, including the Philippines, small-scale swine farmers often lack access to efficient and affordable wastewater treatment systems, leading to the discharge of untreated effluents into the environment. This review synthesizes current knowledge on the application of Vertical Helophyte Filtration Systems (VHFS) as a sustainable, nature-based solution for treating swine wastewater. VHFS integrates physical, chemical, and biological processes through the use of filter media, microbial communities, and helophytic plants to reduce pollutant loads. Particular emphasis is given to the role of vetiver grass (Chrysopogon zizanioides), which has demonstrated strong phytoremediation potential due to its extensive root system, high tolerance to environmental stress, and capacity for nutrient uptake and contaminant stabilization. Evidence from existing studies indicates that vetiver-based filtration systems can achieve substantial reductions in biochemical oxygen demand (BOD), chemical oxygen demand (COD), nutrients, suspended solids, and selected emerging contaminants. Additionally, treated effluent may be reused for agricultural purposes, contributing to improved water use efficiency and reduced freshwater demand. Despite these advantages, system performance is influenced by factors such as substrate composition, hydraulic retention time, plant density, and pollutant loading, highlighting the need for site-specific optimization. This review underscores the potential of vetiver-based VHFS as a cost-effective and environmentally sustainable wastewater management approach for backyard swine production, while also identifying key research gaps and opportunities for system improvement and wider adoption.