https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38044 2PO₄) (10 %, w/w) at 300 ℃, 500 ℃ and 700 ℃ to evaluate their potential lead [Pb(II)] adsorption. Effects of pH, contact time, and initial Pb(II) concentration on the Pb(II) adsorption capacity of the biochars were investigated. The physico-chemical, morphological, porous structure, crystallinity and spectroscopic characteristics of pre- and post-Pb-adsorbed biochars were analyzed to unravel the Pb(II) adsorption mechanism. Results showed that KH₂PO₄ reacted with biomass carbon to form stable C–P and/or C–O–P groups in BCP, and increased carbon retention and aromaticity of BCP. However, the addition of KH₂PO₄ led to an adverse effect on porous structure, e.g. surface area of biochars produced at 300 ℃, 500 ℃ and 700 ℃ were decreased by 41.53 %, 80.32 %, and 59.74 %, respectively. Adsorption experiments displayed that BCP produced at 300 ℃ exhibited the highest Pb(II) adsorption capacity (q_max = 154.7 mg g⁻¹), which was almost 6 times higher than the pristine biochar (q_max = 24.3 mg g⁻¹). Potassium polymetaphosphate [(KPO₃)_n] particles were attached on the surface of BCP, which facilitated the precipitation of Pb(II) to form [Pb(PO_3)2]n, Pb5(PO₄₎₃OH and PbHPO₄. This study thus demonstrated the effect of pyrolysis temperature on the enhancing removal capability of P-modified biochar for Pb(II) from aqueous solutions.]]> Wed 28 Jul 2021 15:18:58 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:52614 La-Euchar >goethite >HDPB-Z >HDPC-M. Birnessite exhibited great affinity for As and drastically reduced As extractability by more than 90% in all single extractions. The results revealed that HDPC-M, HDPB-Z, La-Euchar, birnessite, and goethite are promising immobilizing agents for in situ stabilization of As in terrestrial environments.]]> Wed 18 Oct 2023 13:47:13 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:39503 −1) and lead (Pb = 736.2 mg kg⁻¹). Soil properties, microbial activities, and the geochemical fractions and potential availabilities of As and Pb were determined in the non-treated (control) and biochar-treated soil. Modification of PB (pH = 10.6) and GWB (pH = 9.3) with Fe caused a decrease in their pH to 4.4 and 3.4, respectively. The application of PB and GWB significantly increased soil pH, while Fe-PB and Fe-GWB decreased soil pH, as compared to the control. Application of Fe-GWB and Fe-PB decreased the NH₄H₂PO₄-extractable As by 32.8 and 35.9%, which was more effective than addition of GWB and PB. However, PB and GWB were more effective than Fe-PB and Fe-GWB in Pb immobilization. Compared to the control, the DTPA-extractable Pb decreased by 20.6 and 21.7%, respectively, following PB and GWB application. Both biochars, particularly PB significantly increased the 16S rRNA bacterial gene copy numbers, indicating that biochar amendments enhanced the bacterial abundance, implying an alleviation of As and Pb bio-toxicity to soil bacteria. The results demonstrated that pristine pig carcass and green waste biochars were more effective in immobilizing Pb, while their Fe-engineered biochars were more effective in As immobilization in co-contaminated soils.]]> Wed 07 Feb 2024 16:39:44 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:39595 Ni2+ > Cd2+. Interestingly, in Cd2+–Cu2+ system the earlier adsorbed Cd2+ could be completely replaced by Cu2+ from the solution. Different competitive adsorption ability of those heavy metal were due to the characteristics of heavy metal and resultant affinity of the adsorption sites on E–CMBC. The adsorption mechanism indicated that chemical adsorption played a dominating role. Therefore, E–CMBC could be a potential adsorbent for wastewater treatment.]]> Thu 28 Jul 2022 15:24:26 AEST ]]>