Selection of plant species and substrates affect the removal rates of the metals from solid waste leachate in horizontal flow constructed wetlands?

Abstract

Abstract Present work reported a systematic assessment of treatment efficacy for two pilot-scale horizontal flow constructed wetlands for metal (zinc, copper and lead) removal over the course of one year in an outdoor study to evaluate the effects of plant and substrates. The systems consisted of horizontal flow wetland with 0.3m depth, filled with sand and zeolite. One system was planted with Vetiveria zizanioides and Chloris gayna and other was planted with Eucalyptus globulus, while one left unplanted as control. Percentage removal rates with respect to the performance of plants and substrates for both HF systems were discussed. The HF1 wetland removed Zn, Cu and Pb by 50–93%, 67–98% and 77–99%, respectively. Whereas, HF2 wetland removed Zn, Cu and Pb by 60–99%, 78–99% and 78–99% respectively. Plants and substrates clearly enhanced treatment efficacy (p<0.05) despite of fluctuation in temperature and influent concentration and also improved the performance of plants for removal of metals without exerting stress on their proliferation within wetlands.