Department of Earth and Environmental Science, Botswana International University of Science and Technology, Palapye, Botswana.
Department of Biology and Biotechnology, Faculty of Science, Botswana International University of Science and Technology, Palapye, Botswana.
Environ Sci Pollut Res Int. 2021 Apr;28(16):20637-20649. doi: 10.1007/s11356-020-11905-7. Epub 2021 Jan 6.
Discarding fly ash from a coal power plant into a dumpsite does not only contribute to deforestation and loss of productive land but also leads to contamination of air, soil, and groundwater. Therefore, fly ash should be managed properly to avoid the migration of contaminants. One management option is phytoremediation using adapted plants and as a prerequisite, there is a need to identify suitable plants that can be used for revegetation of fly ash dumpsites. To identify prospective plants, a survey was carried out by assessing the plants growing in Morupule B fly ash dumpsite based on their ability to accumulate heavy metals and their bioconcentration (BAF) and translocation factors (TF). Of the twenty-two-plant species growing in the fly ash dumpsite of Morupule B power plant station, N. glauca is a potential phytoextraction agent for Cu (TF = 1.02; BAF = 2.16) and Pb (TF = 1.38; BAF = 1.65); P. burchellii for Pb (TF = 1.61, BAF = 0.9) and Zn (TF = 1.35; BAF = 5.74); I. pes-tigridis for Pb (TF = 1.35; BAF = 1.56) and Zn (TF = 1.62; BAF = 7.43); A. pungens for Cr (TF = 1.22; BAF = 0.11), Cu (TF = 2.18; BAF = 1.14), and Zn (TF = 1.04; BAF = 1.44); E. hirta for Zn (TF = 1.54, BAF = 2.44); A. spinosus for Pb (TF = 1.29; BAF = 1.55); C. dactylon for Cu (TF = 1.86; BAF = 1.07) and Zn (TF = 1.00; BAF = 2.46); and D. aegyptium for Pb (TF = 1.19; BAF = 2.57). Other plants growing in the fly ash dumpsite are potential candidates for phytostabilization as they can tolerate a high concentration of metals and low essential nutrients. Also, different plant groups variably modified the pH, EC, OM, and exchangeable fractions of metals in the rhizosphere wherein grasses can increase the OM at higher rates, and it has a higher capacity to acidify and solubilize heavy metals in the rhizosphere leading to higher EC and available metals compared to other plant groups. Overall, the information presented is useful in identifying plants or their combinations for the phytoremediation of fly ash and other heavy metal-polluted environments.
将燃煤电厂的粉煤灰倾倒在垃圾场不仅会导致森林砍伐和生产性土地的丧失，还会导致空气、土壤和地下水受到污染。因此，应该妥善管理粉煤灰，以避免污染物的迁移。一种管理选项是使用适应性植物进行植物修复，作为前提条件，需要确定可用于粉煤灰堆填区植被恢复的合适植物。为了确定有前途的植物，通过评估生长在莫鲁普勒 B 粉煤灰堆填区的植物根据其积累重金属的能力及其生物浓缩（BAF）和迁移因子（TF），对该地区进行了调查。在莫鲁普勒 B 火力发电厂的粉煤灰堆填区生长的二十二种植物中，N. glauca 是 Cu 的潜在植物萃取剂（TF = 1.02；BAF = 2.16）和 Pb（TF = 1.38；BAF = 1.65）；P. burchellii 是 Pb（TF = 1.61，BAF = 0.9）和 Zn（TF = 1.35；BAF = 5.74）的潜在植物萃取剂；I. pes-tigridis 是 Pb（TF = 1.35；BAF = 1.56）和 Zn（TF = 1.62；BAF = 7.43）的潜在植物萃取剂；A. pungens 是 Cr（TF = 1.22；BAF = 0.11）、Cu（TF = 2.18；BAF = 1.14）和 Zn（TF = 1.04；BAF = 1.44）的潜在植物萃取剂；E. hirta 是 Zn（TF = 1.54，BAF = 2.44）的潜在植物萃取剂；A. spinosus 是 Pb（TF = 1.29；BAF = 1.55）的潜在植物萃取剂；C. dactylon 是 Cu（TF = 1.86；BAF = 1.07）和 Zn（TF = 1.00；BAF = 2.46）的潜在植物萃取剂；D. aegyptium 是 Pb（TF = 1.19；BAF = 2.57）的潜在植物萃取剂。在粉煤灰堆填区生长的其他植物是植物稳定化的潜在候选植物，因为它们可以耐受高浓度的金属和低必需养分。此外，不同的植物群落在根际中不同程度地改变了 pH 值、EC 值、OM 值和金属的可交换分数，其中草类可以以更高的速度增加 OM 值，并且具有更高的酸化和溶解根际中重金属的能力，导致与其他植物群相比，EC 值和可用金属更高。总的来说，所提供的信息有助于识别用于粉煤灰和其他重金属污染环境的植物修复的植物或其组合。
