Institutes of Green Bio Science and Technology, Seoul National University, Gangwon-do, 25354, Republic of Korea.
Department of Energy and Resource Engineering, Chosun University, Gwangju, 61452, Republic of Korea.
Chemosphere. 2024 Sep;364:143203. doi: 10.1016/j.chemosphere.2024.143203. Epub 2024 Aug 28.
Microalgae can be collected in large quantities and hold significant potential for environmental remediation, offering a cost-effective solution. This study explores the use of Spirulina platensis (SP) as feedstock for biochar production. SP contains abundant nitrogen-rich components, such as proteins, which can serve as nitrogen sources. We prepared SP-derived biochar through pyrolysis for the adsorption of Pb and Zn from aqueous solutions and used it as an amending agent to remediate heavy metal-contaminated agricultural soil. Pyrolysis of proteins in SP introduces nitrogen-functional groups, resulting in nitrogen-doped biochar. We investigated the surface chemical behavior of thermally treated SP using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. Surface analysis revealed the presence of pyridine-N and pyrrole-N from protein pyrolysis products. The study also demonstrated that these functional groups affect interactions with heavy metals. Batch experiments examined the effects of pH and initial concentration on the adsorption of Pb and Zn using SP400 and SP600. Both types of biochar showed satisfactory performance in adsorbing Pb and Zn. The effect of SP400 and SP600 on the removal of Pb and Zn through the physicochemical properties and surface functional groups was investigated. Analysis of SP400 and SP600 highlighted that electrostatic interactions, cation exchange, complexation, and mineral precipitation contributed to Pb and Zn adsorption. The study concludes that SP-derived biochar, particularly SP600, is effective for immobilizing Pb and Zn in contaminated agricultural soil, with SP600 showing superior performance.
微藻可以大量采集，并且在环境修复方面具有很大的潜力，是一种具有成本效益的解决方案。本研究探索了使用螺旋藻（SP）作为生物炭生产的原料。SP 含有丰富的富氮成分，如蛋白质，可以作为氮源。我们通过热解制备了 SP 衍生的生物炭，用于从水溶液中吸附 Pb 和 Zn，并将其用作改良剂来修复重金属污染的农业土壤。SP 中蛋白质的热解会引入氮官能团，从而产生氮掺杂生物炭。我们使用 X 射线光电子能谱和傅里叶变换红外光谱研究了热处理 SP 的表面化学行为。表面分析表明存在来自蛋白质热解产物的吡啶-N 和吡咯-N。该研究还表明，这些官能团会影响与重金属的相互作用。批实验考察了 pH 值和初始浓度对 SP400 和 SP600 吸附 Pb 和 Zn 的影响。这两种生物炭在吸附 Pb 和 Zn 方面都表现出了良好的性能。通过物理化学性质和表面官能团研究了 SP400 和 SP600 对去除 Pb 和 Zn 的影响。对 SP400 和 SP600 的分析表明，静电相互作用、阳离子交换、络合和矿物沉淀有助于 Pb 和 Zn 的吸附。本研究得出结论，SP 衍生的生物炭，特别是 SP600，可有效固定污染农业土壤中的 Pb 和 Zn，SP600 的性能更优。
