Phytoremediation potential of sewage sludge using native plants: Gossypium hirsutum L. and Solanum lycopersicum L.

Abstract

The aim of the study was to evaluate the potential of Gossypium hirsutum L. and Solanum lycopersicum L. plants for sewage sludge stabilization. The plants were cultured for 120 days in two plastic beds of 30 cm × 60 cm × 50 cm (W. L. H) in dimension. The highest removal efficiency of organic carbon, total Kjeldahl nitrogen, total phosphorous, lead and cadmium was obtained 36, 33.6, 23, 74.29 and 91.2%, respectively. The removal rate of above parameters was considerably higher than control (P < 0.05), and in Solanum lycopersicum L., it was higher than Gossypium hirsutum L. (P < 0.05). The pH, electrical conductivity and sodium absorption ratio variation in control with plants were significant (P < 0.05). By increasing electrical conductivity and sodium absorption ratio, the removal efficiency of heavy metals increased. The highest translocation factor (2.44) and bio-concentration factor (1.63) were observed in the Solanum lycopersicum L. for lead. Maximum and minimum cadmium concentrations in the shoot parts of Solanum lycopersicum L. and Gossypium hirsutum L. plants were 1.21 and 0.03 mg/kg, respectively. TF mean for lead and cadmium in Gossypium hirsutum L. was and 0.65 and 1.77; in Solanum lycopersicum L., it was 0.44 and 1.5, respectively. The results showed that the mean of bio-concentration factor in Solanum lycopersicum L. bed for Cd and Pb was 0.39 and 0.63, and for Gossypium hirsutum L., it was 0.3 and 0.58, respectively. The changes in organic carbon, nutrients and heavy metal in sludge were showed that Solanum lycopersicum L and Gossypium hirsutum L. can be used properly to stabilize sewage sludge.