Abstract
Soil contamination with trace elements is an important and global environmental concern. This study examined the potential of biochars derived from rice husk (RHB), olive pit (OPB), and a certified biochar produced from wood chips (CWB) to immobilize copper (Cu2+) and lead (Pb2+) in aqueous solution to avoid its leaching and in a pot experiment with acidic Xerofluvent soils multicontaminated with trace elements. After assessing the adsorption potential of Cu2+ and Pb2+ from an aqueous solution of the three studied biochars, the development of Brassica rapa pekinensis plants was monitored on polluted soils amended with the same biochars, to determine their capability to boost plant growth in a soil contaminated with several trace elements. RHB and CWB removed the maximum amounts of Cu2+ and Pb2+ from aqueous solution in the adsorption experiment. The adsorption capacity increased with initial metal concentrations for all biochars. The efficiency in the adsorption of cationic metals by biochars was clearly affected by biochar chemical properties, whereas total specific surface area seemed to not correlate with the adsorption capacity. Among the isotherm models, the Langmuir model was in the best agreement with the experimental data for both cations for CWB and RHB. The maximum adsorption capacity of Cu2+ was 30.77 and 58.82 mg g−1 for RHB and CWB, respectively, and of Pb2+ was 19.34 and 77.52 mg g−1 for RHB and CWB, respectively. The application of 5% of RHB and CWB to the acidic polluted soils improved soil physico-chemical properties, which permitted the development of Brassica rapa pekinensis plants. RHB and CWB have been shown to be effective for the removal of Cu2+ and Pb2+, and the results obtained regarding plant development in the soils contaminated with trace elements indicated that the soil amendments have promising potential for the recovery of land polluted with heavy metals.
Highlights
The contamination by toxic heavy metals is a worldwide environmental problem
This study examined the potential of biochars derived from rice husk (RHB), olive pit (OPB), and a certified biochar produced from wood chips (CWB) to immobilize copper (Cu2+) and lead (Pb2+) in aqueous solution to avoid its leaching and in a pot experiment with acidic Xerofluvent soils multicontaminated with trace elements
This study showed that the certified wood biochar (CWB) and RHB biochars have a great capability for the adsorption of Cu2+ and Pb2+
Summary
The contamination by toxic heavy metals is a worldwide environmental problem. It encompasses great concerns, such as the pollution of water bodies by the discharge of industrial wastewaters and the pollution of soils by natural processes or anthropogenic activities (including mining). The solid carbonaceous residue produced by thermal treatment of biomasses in the absence of oxygen [3], typically considered an organic ameliorant for the restoration of degraded soils [4], has been proven to be effective in the removal of heavy metals in aqueous solution [5]. Biochar properties, such as its highly porous structure, high specific surface area, cation exchange capacity, and abundant surface functional groups, make it an ideal adsorbent. There is a lack of understanding regarding the relation of trace element adsorption between aqueous solution and the real immobilization potential when biochar is mixed with soil
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
