School of Forest and Resources Conservation, National Taiwan University, Taipei 10617, Taiwan.
School of Forest and Resources Conservation, National Taiwan University, Taipei 10617, Taiwan.
J Environ Manage. 2017 Dec 1;203(Pt 3):1005-1010. doi: 10.1016/j.jenvman.2017.04.049. Epub 2017 May 11.
Using plants to absorb and accumulate heavy metals from polluted soil, followed by the recycling of explants containing heavy metals, can help achieve the goal of reverting contaminated soil to low heavy-metal content soil. However, the re-use of recovered explants can also be problematic. Meanwhile, bioethanol has become a popular energy source. In this study, napier grass was used for the remediation of soil contaminated with heavy metals (artificially contaminated soil). The influence of bioethanol production from napier grass after phytoremediation was also investigated. The concentration of Zn, Cd, and Cr in the contaminated soil was 1000, 100, and 250 mg/kg, respectively. After napier grass phytoremediation, the concentration (dry biomass) of Zn, Cd, and Cr in the explants was 2701.97 ± 173.49, 6.1 ± 2.3, and 74.24 ± 1.42 mg/kg, respectively. Biomass production in the unpolluted soil was 861.13 ± 4.23 g. The biomass production ratio in high Zn-polluted soil was only 3.89%, while it was 4.68% for Cd and 21.4% for Cr. The biomass obtained after napier grass phytoremediation was pretreated using the steam explosion conditions of 180 °C, for 10 min, with 1.5% HSO, followed by enzymatic hydrolysis. The efficiency of enzymatic hydrolysis for Zn-polluted biomass was 90% of the unpolluted biomass, while it was 77% for Cd, and approximately the same for Cr. The fermentation efficiency of the heavy-metal-containing biomass was higher than the control biomass. The fermentation ethanol concentration obtained was 8.69-12.68, 13.03-15.50, and 18.48-19.31 g/L in Zn, Cd, and Cr environments, respectively. Results show that the heavy metals had a positive effect on bacteria fermentation. However, the fermentation efficiency was lower for biomass with severe heavy metal pollution. Thus, the utilization of napier grass phytoremediation for bioethanol production has a positive effect on the sustainability of environmental resources.
利用植物吸收和积累受污染土壤中的重金属，然后回收含有重金属的外植体，可以帮助实现将污染土壤恢复到低重金属含量土壤的目标。然而，回收外植体的再利用也可能存在问题。同时，生物乙醇已成为一种流行的能源。在这项研究中，采用象草修复受重金属污染的土壤（人为污染土壤）。还研究了象草植物修复后用于生产生物乙醇的影响。受污染土壤中 Zn、Cd 和 Cr 的浓度分别为 1000、100 和 250mg/kg。经过象草植物修复后，外植体中 Zn、Cd 和 Cr 的浓度（干生物量）分别为 2701.97±173.49、6.1±2.3 和 74.24±1.42mg/kg。未污染土壤中的生物量产量为 861.13±4.23g。高 Zn 污染土壤中的生物量产量仅为 3.89%，而 Cd 为 4.68%，Cr 为 21.4%。象草植物修复后获得的生物量先用 180°C、10min 和 1.5% HSO4 的蒸汽爆破条件预处理，然后进行酶水解。Zn 污染生物量的酶水解效率为未污染生物量的 90%，Cd 为 77%，Cr 则大致相同。含重金属生物量的发酵效率高于对照生物量。含重金属生物量发酵得到的乙醇浓度分别为 Zn、Cd 和 Cr 环境中的 8.69-12.68、13.03-15.50 和 18.48-19.31g/L。结果表明，重金属对细菌发酵有积极影响。然而，对于重金属污染严重的生物量，发酵效率较低。因此，利用象草植物修复来生产生物乙醇对环境资源的可持续性具有积极影响。
