Comparing the performance of Cyperus papyrus and Typha domingensis for the removal of heavy metals, roxithromycin, levofloxacin and pathogenic bacteria from wastewater

Abstract

Contamination of heavy metals and antibiotics would threaten the water and soil resources. Phytoremediation can be potentially used to remediate metal and antibiotics contaminated sites. The current study was carried out over a period of 12 months to assess the efficiency of the macrophytes Typha domingensis and Cyperus papyrus with different substrate materials to remove heavy metals and two antibiotics, roxithromycin and levofloxacin, from wastewater for reuse in agriculture. The concentrations of seven heavy metals (copper, nickel, iron, cadmium, zinc, lead, and chromium) in water and plant tissues were determined. The results showed that C. papyrus had a greater capacity than T. domingensis to remove biochemical oxygen demand (BOD) (80.69%), chemical oxygen demand (COD) (69.87%), and ammonium (NH4+) (69.69%). Cyperus papyrus was more effective in retaining solid pollutants. The bioaccumulation factors (BCF) roots of C. papyrus were higher levels of most metals than those of T. domingensis. The highest root–rhizome translocation factor (TF) values of C. papyrus were higher than T. domingensis. The bacterial indicators (total and fecal coliforms, as well as Faecal streptococci) and the potential pathogens (Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa) showed removal efficiencies ranging between 96.9% and 99.8%. The results indicated that the two systems could significantly reduce the concentration of antibiotics in wastewater, with roxithromycin showing higher elimination rates than levofloxacin. The results showed maximum removal of the heavy metals in constructed wetlands CWs planted with T. domingensis. The presence of zeolite and C. papyrus in the effluent of CWs significantly improved treatment capacity and increased pollutant removal efficiency.