Department of Soil Science, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, Brazil.
Department of Soil Science, Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo (USP), Piracicaba, Brazil.
Chemosphere. 2022 Jan;287(Pt 1):132102. doi: 10.1016/j.chemosphere.2021.132102. Epub 2021 Sep 1.
Globally, tons of soils and sediments are experiencing degradation due to the presence of high concentrations of potentially toxic elements (PTEs), such as arsenic (As) and lead (Pb), in areas in the vicinity of metal mining activities. The addition of biochar to contaminated sediments is a promising in situ remediation approach, and the effects of pyrolysis temperature and biochar aging are important factors for the immobilization and fate of PTEs. In this study, we evaluated the temporal changes in pools of As and Pb in sediment amended with biochars produced from sugarcane (Saccharum officinarum) pyrolyzed at 350 (BC350), 550 (BC550), and 750 °C (BC750). Biochars were aged by natural process (without additional acid or heat), and changes in As and Pb pools were evaluated every 45 days until completing 180 days of incubation. Changes in the As and Pb pools were extracted with water (bioavailable), magnesium chloride (exchangeable), nitric acid (active geochemical fraction), and exchangeable Mehlich-3 (associated with organic matter). As and Pb available contents have increased over time. BC750 was more effective in reducing the bioavailable and exchangeable As contents, while BC550 and BC350 were more effective in reducing the contents of bioavailable and exchangeable Pb.
全球范围内，由于金属采矿活动附近地区存在高浓度的潜在有毒元素（PTEs），如砷（As）和铅（Pb），大量土壤和沉积物正在遭受退化。向污染沉积物中添加生物炭是一种很有前途的原位修复方法，而热解温度和生物炭老化的影响是固定和 PTEs 归宿的重要因素。在这项研究中，我们评估了用甘蔗（Saccharum officinarum）在 350°C（BC350）、550°C（BC550）和 750°C（BC750）下热解生成的生物炭改良沉积物中砷和铅库的时间变化。生物炭通过自然过程（没有额外的酸或热）老化，并且在完成 180 天的孵育之前，每 45 天评估一次砷和铅库的变化。使用水（生物可利用）、氯化镁（可交换）、硝酸（活性地球化学部分）和 Mehlich-3 可交换（与有机物相关）提取砷和铅库的变化。随着时间的推移，砷和铅的可用含量增加了。BC750 更有效地降低了生物可利用和可交换的 As 含量，而 BC550 和 BC350 更有效地降低了生物可利用和可交换的 Pb 含量。
