Impact of olive and olive oil waste biochars on bioavailability and leaching of Pb and Cd
摘要
In the study, impacts of olive and olive oil waste biochars on the bioavailability and leaching of Pb and Cd, as well as the effects of biochar, Pb, and Cd applications on cress seed germination and phytotoxicity, were investigated. The soil sample was spiked with 500 mg/kg Pb(NO3)2 and 12 mg/kg Cd(NO3)2, then incubated for 60 days. For the bioavailability study, BCs (0%, 0.5%, 1%) and 10 g contaminated soil (CS) were incubated for 1, 2, 3, 4, 5, 6, 7, and 8 weeks, respectively. For the leaching study, 50 g CS and BCs (0%, 0.5%, 1%) were incubated 60 days. For the phytotoxicity study, 0.5 g BCs and 20 cress seeds with Pb (0, 250, 500, 750, 1000 mg/L) and Cd (0, 6, 12, 24, 48 mg/L) solutions were incubated separately for 8 days. The results revealed the potential of BCs to improve soil properties and reduce Cd and Pb, which can be removed and leached from CS. EC, pH, and CEC increased, and Pb and Cd amounts decreased. The lowest Cd and Pb leaching was observed at 1% BC application. Shoot and root length were decreased without BCs, and the highest toxicities were observed at 1000 mg/L Pb and 48 mg/L Cd applications. PT decreased with BCs, and the most effective PT reduction was observed in BCPW. As a result, BCs produced from olive waste controlled the immobilization of Pb and Cd at soil interfaces, significantly reduced phytotoxicity by promoting shoot and root development, and improved plant growth characteristics.