School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China.
School of Ecology and Environment, Zhengzhou University, Zhengzhou, 450001, China; Yellow River Institute of Hydraulic Research, Zhengzhou, 450003, China.
Environ Pollut. 2020 Oct;265(Pt A):114887. doi: 10.1016/j.envpol.2020.114887. Epub 2020 May 30.
Organic contaminations and heavy metals in soils cause large harm to human and environment, which could be remedied by planting specific plants. The biochars produced by crop straws could provide substantial benefits as a soil amendment. In the present study, biochars based on wheat, corn, soybean, cotton and eggplant straws were produced. The eggplant straws based biochar (ESBC) represented higher Cd and pyrene adsorption capacity than others, which was probably owing to the higher specific surface area and total pore volume, more functional groups and excellent crystallization. And then, ESBC amendment hybrid Ryegrass (Lolium perenne L.) cultivation were investigated to remediate the Cd and pyrene co-contaminated soil. With the leaching amount of 100% (v/w, mL water/g soil) and Cd content of 16.8 mg/kg soil, dosing 3% ESBC (wt%, biochar/soil) could keep 96.2% of the Cd in the 10 cm depth soil layer where the ryegrass root could reach, and it positively help root adsorb contaminations. Compared with the single planting ryegrass, the Cd and pyrene removal efficiencies significantly increased to 22.8% and 76.9% by dosing 3% ESBC, which was mainly related with the increased plant germination of 80% and biomass of 1.29 g after 70 days culture. When the ESBC dosage increased to 5%, more free radicals were injected and the ryegrass germination and biomass decreased to 65% and 0.986 g. Furthermore, when the ESBC was added into the ryegrass culture soil, the proportion of Cd and pyrene degrading bacteria Pseudomonas and Enterobacter significantly increased to 4.46% and 3.85%, which promoted the co-contaminations removal. It is suggested that biochar amendment hybrid ryegrass cultivation would be an effective method to remediate the Cd and pyrene co-contaminated soil.
土壤中的有机污染物和重金属对人类和环境造成了极大的危害，可以通过种植特定的植物来修复。农作物秸秆制成的生物炭作为土壤改良剂可以提供巨大的好处。本研究以小麦、玉米、大豆、棉花和茄子秸秆为原料制备生物炭。茄子秸秆基生物炭（ESBC）对 Cd 和芘的吸附能力高于其他生物炭，这可能是由于其具有更高的比表面积和总孔体积、更多的官能团和良好的结晶度。然后，通过混合黑麦草（Lolium perenne L.）栽培来研究 ESBC 对修复 Cd 和芘复合污染土壤的效果。在淋洗量为 100%（v/w，mL 水/g 土）和 Cd 含量为 16.8 mg/kg 土的条件下，添加 3%的 ESBC（wt%，生物炭/土）可以使 96.2%的 Cd 留在黑麦草根可到达的 10 cm 土壤层中，并且有助于根对污染物的吸附。与单独种植黑麦草相比，添加 3%的 ESBC 可使 Cd 和芘的去除效率分别显著提高 22.8%和 76.9%，这主要与 70 天培养后植物发芽率提高 80%和生物量增加 1.29 g 有关。当 ESBC 用量增加到 5%时，注入的自由基更多，黑麦草发芽率和生物量分别降低到 65%和 0.986 g。此外，当 ESBC 被添加到黑麦草培养土壤中时，Cd 和芘降解菌假单胞菌和肠杆菌的比例显著增加到 4.46%和 3.85%，这促进了复合污染物的去除。因此，生物炭改良剂混合黑麦草栽培是修复 Cd 和芘复合污染土壤的有效方法。
