State Key Laboratory of Water Resources and Hydropower Engineering Sciences, Wuhan University, Wuhan 430072, China.
State Key Laboratory of Water Resources and Hydropower Engineering Sciences, Wuhan University, Wuhan 430072, China.
Bioresour Technol. 2020 May;303:122853. doi: 10.1016/j.biortech.2020.122853. Epub 2020 Jan 22.
In this study, competitive adsorption behaviour and mechanisms of Cd, Ni and NH by fresh and artificially ageing biochars produced from rice straw at 400 and 700 °C (RB400, RB700, HRB400 and HRB700) were investigated. Cd competed with Ni and NH for the overlapped adsorption sites on the biochars. For Cd and Ni adsorption, cation exchange (Q) and mineral co-precipitation (Q) were the primary mechanisms for the low-temperature and high-temperature biochars, respectively. However, the other potential mechanisms (Q) made the greatest contributions to NH adsorption (>60%). Cd and Ni competition increased the proportions of mineral co-precipitation (Q) and other potential mechanisms (Q) but decreased that of cation exchange (Q) mechanism. Biochar ageing increased the contribution of surface complexation (Q) mechanism, especially for the low-temperature biochars. This study indicated that biochar aging and types and states of adsorbates should be considered when biochars were applied to remove contaminants.
本研究考察了在 400 和 700°C 下由稻草制成的新鲜和人工老化生物炭（RB400、RB700、HRB400 和 HRB700）对 Cd、Ni 和 NH 的竞争吸附行为和机制。Cd 与 Ni 和 NH 在生物炭上的重叠吸附位点发生竞争。对于 Cd 和 Ni 的吸附，离子交换（Q）和矿物共沉淀（Q）分别是低温和高温生物炭的主要机制。然而，其他潜在机制（Q）对 NH 吸附的贡献最大（>60%）。Cd 和 Ni 的竞争增加了矿物共沉淀（Q）和其他潜在机制（Q）的比例，但降低了离子交换（Q）机制的比例。生物炭老化增加了表面络合（Q）机制的贡献，特别是对于低温生物炭。本研究表明，在应用生物炭去除污染物时，应考虑生物炭老化以及吸附质的类型和状态。
