Phytoremediation of Anionic Surfactants in Urban Wastewater using Terrestrial Plants: A Comparative Study of Asystasia Gangetica, Calotropis Gigantea, and Phyllanthus Urinaria

Abstract

Surfactants in urban wastewater are persistent and toxic, while conventional treatments may not fully remove them. Physicochemical methods are effective but costly and energy intensive, limiting their use in developing regions. Aims: This study conducted the first comparative evaluation of widely available terrestrial plant species in the surrounding environment, namely Asystasia gangetica, Calotropis gigantea, and Phyllanthus urinaria, for the phytoremediation of anionic surfactants under controlled hydroponic conditions. Methodology and Results: The research design was carried out using each plant placed at three initial surfactant concentrations (0.049, 0.270, and 0.653 mg/L) and a control without plants. The experiment was carried out for 20 days and surfactant concentrations were measured every five days using the Methylene Blue Active Substances (MBAS) method. The results showed that A. gangetica had the highest remediation efficiency with the ability to reduce surfactant concentrations from 0.653 to 0.145 mg/L (77.8%) and consistently achieved concentrations below the Indonesian regulatory threshold (0.2 mg/L MBAS). Furthermore, C. gigantea showed moderate remediation efficiency and P. urinaria was relatively less effective. Conclusion, Significance, and Impact of the Study: These findings provide comparative evidence that each plant species influences the efficiency of surfactant phytoremediation and identify A. gangetica as the most promising candidate among the evaluated species. This study provides preliminary scientific evidence supporting terrestrial phytoremediation as an environmentally available natural resource approach for decentralized urban wastewater management, with further research required for pilot and field-scale validation before practical implementation.