Thallium contamination in agricultural soils and associated potential remediation via biochar utilization

Thallium(Tl)is an extremely harmful metal that is substantially distributed in the environment.It can threaten human health via consumption of food potentially derived from Tl-contaminated agricultural production.Little information is available on how to utilize biochar to remediate Tl contamination in agricultural soils.More efforts are urgently needed to be devoted to developing effective techniques to empower biochar with high selectivity of Tl in agricultural soils.In this review,we provided comprehensive information on Tl contamination in agricultural soils.We also discussed recent developments and assessed the current status of biochar applications.We briefly reviewed the bridge between biochar preparation technology and utilization wherein further developments can exhibit potential in terms of Tl remediation.Hence,biochar is expected to exhibit excellent Tl remediation performance in contaminated agricultural soils with promising application prospects.The obtained knowledge provides further insights into the remediation of Tl contamination in agricultural soils.

Insights into thallium adsorption onto the soil,bamboo-derived biochar,and biochar amended soil in Pomelo orchard

Little information is available on thallium(Tl)adsorption onto biochar amended soil for a relatively long term.In this study,bamboo-derived biochar(BDB),soil in pomelo orchard(SP),and biochar amended soil in pomelo orchard(BSP)were thus used to evaluate the potential remediation of thallium(Tl)using batch-adsorption techniques.Furthermore,we characterized the above-mentioned sorbents’properties related to Tl adsorption to understand Tl’s adsorption mechanisms.The results showed that BDB,SP,and BSP achieved equilibrium adsorption capacity of 96.9,95.43,and 96.76%,respectively,within the initial 15 min.This means that compared to other sorbents,BSP exhibited an efficient sorbent for Tl remediation even when applied in the agricultural field for one year.Multi-layer adsorption played a dominant role in the adsorption of Tl,which was supported by the suitability of Freundlich model for describing the adsorption behavior of Tl onto the selected sorbents.In addition,the pseudo-second kinetic order models strongly fitted Tl’s adsorption onto BDB,SP,and BSP,indicating that the process was accompanied by chemical adsorption.Observed on the surface of BDB by a Fourier Transform Infrared Spectrometer(FTIR)and an X-ray photoelectron spectroscopy(XPS),the presence of O-H groups and PO_(4)^(3−)might promote chemical adsorption of Tl onto BDB.Overall,these findings can provide insights into comprehensively developed bamboo-derived biochar technology to remediate Tl contamination in agricultural soils.