Abstract
Production temperature significantly affects biochar properties and consequently the removal mechanisms of heavy metals. In this study, rice straw biochars were produced at 300, 500 and 700 °C (RSB300, RSB500 and RSB700). The influence of production temperature on the adsorption characteristics and removal mechanisms of lead on this set of rice straw biochars were investigated by batch adsorption tests, micro-structural analyses and sequential metal extractions. Biochars produced at higher temperatures had significantly higher pH values and surface areas, resulting in higher metal removal capacities and faster uptake kinetics. Precipitation was a key mechanism for lead removal from solution for all biochars: lead oxalate was precipitated on RSB300, and hydrocerussite was precipitated on RSB500 and RSB700. The immobilized lead fraction on the biochars could be divided into exchangeable, acid soluble and non-available fractions. RSB300 had 11.34% of the total immobilized Pb attributed to the exchangeable fraction, whereas for RSB500 and RSB700, it was <1%. Immobilized Pb on RSB500 and RSB700 was almost exclusively attributable to the acid soluble and non-available fractions (>99%). Based on our results, RSB500 and RSB700 are likely much more appropriate for soil remediation of Pb as compared with RSB300.
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.
