Sulfate removal from industrial wastewater in a hydroponic system planted with Bidens pilosa L

Sulfate-reducing bacteria and macrophytes play an essential role in sulfate degradation in constructed wetlands. This study provides an evaluation of sulfate removal in a hydropond planted with B. pilosa. Two hydroponds, the experimental (planted with B. pilosa) and reference sections (unplanted) were tested for their ability to remove sulfate from industrial wastewater. Wastewater containing the concentrations of sulfate (mean = 705 mg/l) was run in both systems. The samples were collected at 24 h' intervals and were analysed for pH, dissolved oxygen, temperature, chemical oxygen demand (COD) and sulfate. After 288 h, the final concentration of sulfate was 169 mg/l (mean value), representing 76% removal in the planted section and was 309 mg/l (mean value), representing 56% in the reference section. The removal in the planted section was found to be within the acceptable limits (