Multipurpose use of Colocasia esculenta for COD and iron leachate treatment in constructed wetlands optimized by response surface methodology

This study explores the versatile application of Colocasia esculenta (L.) Schott (taro) in the treatment of contaminated water, focusing on its dual role as a natural component of constructed wetlands and as an adsorbent for the removal of chemical oxygen demand (COD) and iron (Fe) from landfill leachate. Constructed wetlands (CW) planted with C. esculenta achieved an Fe removal efficiency of 77.97 % (from 0.59 mg/L to 0.13 mg/L), while COD removal was limited to 33.37 % (from 1531 mg/L to 1020 mg/L). To improve pollutant reduction, activated carbon derived from C. esculenta was tested using batch adsorption experiments. Response surface methodology (RSM) was employed to optimize key parameters, including pH 6 and a contact time of 53 min, resulting in 46.37 % COD removal and 84.62 % Fe removal. These findings demonstrate the promising potential of C. esculenta as both a phytoremediator and a bio adsorbent, providing an eco-friendly and sustainable solution for leachate treatment in agricultural, industrial and municipal wastewater applications. This research contributes to the development of low-cost, environmentally sound strategies for pollutant removal and resource recovery in sustainable water management.