Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Box 191, Beijing 100083, China.
Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Box 191, Beijing 100083, China.
Bioresour Technol. 2019 Feb;273:70-76. doi: 10.1016/j.biortech.2018.10.065. Epub 2018 Oct 26.
Straw biomass is a promising adsorbent for the removal of heavy metals. To improve its Pb(II) adsorption capacity and elucidate competition of adsorption mechanisms (e.g., ion exchange and precipitation), the Pb(II) adsorption mechanisms for wheat straw (WS-CK), wheat straw-biochar (WS-BC), and ball-milled wheat straw-biochar (WS-BC + BM) samples were investigated in detail by EDX, XRD, and FTIR. The results implied that the Pb(II) adsorption capacities at an adsorbent dosage of 0.2 g/L onto WS-CK, WS-BC, and WS-BC + BM were 46.33, 119.55, and 134.68 mg/g, respectively. This indicates that carbonization and ball milling are efficient techniques for improving the adsorption capacity of Pb(II) onto wheat straw, as WS-BC and WS-BC + BM exhibited adsorption capacities comparable to other commonly used bioadsorbents. Carbonization contributed significantly to precipitation (e.g., PbCO and Pb(CO)(OH)). Furthermore, competition existed between ion exchange and precipitation during the Pb(II) adsorption process. With relative lower adsorbent dosages, carbonization and ball milling enhanced ion exchange capacity.
秸秆生物质是一种很有前途的重金属吸附剂。为了提高其对 Pb(II)的吸附能力，并阐明吸附机制（如离子交换和沉淀）的竞争，通过 EDX、XRD 和 FTIR 详细研究了小麦秸秆（WS-CK）、小麦秸秆生物炭（WS-BC）和球磨小麦秸秆生物炭（WS-BC+BM）样品的 Pb(II)吸附机制。结果表明，在吸附剂用量为 0.2 g/L 时，WS-CK、WS-BC 和 WS-BC+BM 对 Pb(II)的吸附容量分别为 46.33、119.55 和 134.68 mg/g。这表明碳化和球磨是提高小麦秸秆对 Pb(II)吸附能力的有效技术，因为 WS-BC 和 WS-BC+BM 的吸附容量可与其他常用的生物吸附剂相媲美。碳化对沉淀（例如 PbCO 和 Pb(CO)(OH)）有重要贡献。此外，在 Pb(II)吸附过程中，离子交换和沉淀之间存在竞争。在相对较低的吸附剂用量下，碳化和球磨提高了离子交换能力。
