Department of Civil and Environmental Engineering, Universidad de los Andes, Carrera 1Este #19A-40, 111711, Bogotá, Colombia.
Facultad de Arquitectura e Ingeniería, Institución Universitaria Colegio Mayor de Antioquia, Carrera 78 #65-46, 050034, Medellín, Colombia.
Sci Rep. 2023 Jan 30;13(1):1657. doi: 10.1038/s41598-022-27043-8.
Soil contamination by Pb can result from different anthropogenic sources such as lead-based paints, gasoline, pesticides, coal burning, mining, among others. This work aimed to evaluate the potential of P-loaded biochar (Biochar-based slow-release P fertilizer) to remediate a Pb-contaminated soil. In addition, we aim to propose a biomonitoring alternative after soil remediation. First, rice husk-derived biochar was obtained at different temperatures (450, 500, 550, and 600 °C) (raw biochars). Then, part of the resulting material was activated. Later, the raw biochars and activated biochars were immersed in a saturated KHPO solution to produce P-loaded biochars. The ability of materials to immobilize Pb and increase the bioavailability of P in the soil was evaluated by an incubation test. The materials were incorporated into doses of 0.5, 1.0, and 2.0%. After 45 days, soil samples were taken to biomonitor the remediation process using two bioindicators: a phytotoxicity test and enzyme soil activity. Activated P-loaded biochar produced at 500 °C has been found to present the best conditions for soil Pb remediation. This material significantly reduced the bioavailability of Pb and increased the bioavailability of P. The phytotoxicity test and the soil enzymatic activity were significantly correlated with the decrease in bioavailable Pb but not with the increase in bioavailable P. Biomonitoring using the phytotoxicity test is a promising alternative for the evaluation of soils after remediation processes.
土壤中的铅污染可能来自不同的人为来源，如含铅涂料、汽油、农药、煤炭燃烧、采矿等。本研究旨在评估负载磷的生物炭（基于生物炭的缓效磷肥）修复铅污染土壤的潜力。此外，我们旨在提出土壤修复后的生物监测替代方法。首先，在不同温度（450、500、550 和 600°C）下获得稻壳衍生的生物炭（原生物炭）。然后，部分得到的材料被激活。之后，将原生物炭和活化生物炭浸入饱和 KHPO 溶液中，制备负载磷的生物炭。通过孵化试验评估材料固定 Pb 和增加土壤中 P 生物有效性的能力。将材料以 0.5、1.0 和 2.0%的剂量掺入土壤中。45 天后，采集土壤样品，使用两种生物标志物：植物毒性试验和土壤酶活性，对修复过程进行生物监测。在 500°C 下制备的活化负载磷生物炭具有最佳的土壤 Pb 修复条件。该材料显著降低了 Pb 的生物有效性，增加了 P 的生物有效性。植物毒性试验和土壤酶活性与生物可利用性 Pb 的降低显著相关，但与生物可利用性 P 的增加无关。使用植物毒性试验进行生物监测是评估修复后土壤的一种很有前途的替代方法。
