Improving the remediation capacity of a landfill leachate channel by selecting suitable macrophytes

To assess the remediation capacity of a leachate channel, we monitored basic environmental parameters such as bathymetry, leachate, and soil characteristics and vegetation coverage. Based on our results, we designed a series of experiments to determine the most suitable remediating plant species for sustainable wastewater treatment. We found that adaptability to water depth may be a prime driver of reduced remediation capacity. Large portions of the leachate channel were deeper than the maximum tolerance range of many candidate emergent macrophytes, resulting in only 16% total vegetation coverage. Among tested species, Typha angustifolia showed the most promising potential for remediation, reaching the highest aboveground biomass (3300 g/m2) and demonstrating maximum concentrations in tissues (34,600 mg/kg of Na, 4013 mg/kg of Mg, 904 mg/kg of P, 639 mg/kg of Mn, 191 mg/kg of Fe and 62 mg/kg of Zn) when grown in leachate filled tank for six months. Typha angustifolia also showed greater tolerance of water depth than Phragmites australis, which previously was planted in leachate channels. Thus, T. angustifolia should be more suitable for the actual water depth of the channel. Additional planting of T. angustifolia will improve the vegetation coverage, the total remediation capacity and sustainability of the leachate channel. Considering water depths of target wetlands when selecting remediation plant will improve remediation ability and sustainability of remediation wetlands.