Growth and biomass production of herbaceous species exposed to raw sewage in phytoremediation.

Abstract

The growth and phytomass production of four herbaceous species were examined using raw sewage from the Glória WWTP in Campina Grande, Paraíba, Brazil, in a bioassay conducted under two lighting conditions: sunlight and shade. The objective was to explore economical and sustainable alternatives for treating effluents. The plants were grown in plastic bottles, and their height and growth rates were recorded after 85 and 150 days. At 85 days, Canna indica thrived only in sunlight, reaching 40.1 cm, but died in the shade. Xanthosoma sagittifolium exhibited the highest average heights, measuring 34.70 cm in sunlight and 72.33 cm in shade. A subsequent decline in height due to senescence was noted. Heliconia psittacorum only reached 5.0 cm in sunlight and also perished in the shade. Tradescantia pallida had its highest average height of 12.7 cm in the shade. After 150 days, C. indica accumulated 278.52 g of phytomass in sunlight, while X. sagittifolium reached 279.34 and 307.84 g in both conditions. The statistical differences among the species highlighted the importance of their selection for successful phytoremediation as an efficient alternative for wastewater treatment when species are selected based on local conditions and effluent characteristics.