Tu S, Ma Lena Q, Fayiga Abioye O, Zillioux Edward J
Soil and Water Science Department, University of Florida, Gainesville, Florida 32611-0290, USA.
Int J Phytoremediation. 2004;6(1):35-47. doi: 10.1080/16226510490439972.
Arsenic concentrations in a much larger fraction of U.S. groundwater sources will exceed the maximum contaminant limit when the new 10 microg L(-1) EPA standard for drinking water takes effect in 2006. Thus, it is important to develop remediation technologies that can meet this new standard. Phytoremediation of arsenic-contaminated groundwater is a relatively new idea. In this research, an arsenic-hyperaccumulating fern, commonly known as Chinese Brake fern (Pteris vittata L.), was grown hydroponically to examine its effectiveness in arsenic removal from what is believed to be herbicide-contaminated groundwater. One plant grown in 600 mL of groundwater effectively reduced the arsenic concentration from 46 to less than 10 microg L(-1) in 3 days. Re-used plants continued to take up arsenic from the groundwater, albeit at a slower rate (from 46 to 20 microg L(-1) during the same time). Young fern plants were more efficient in removing arsenic than were older fern plants of similar size. The addition of a supplement of phosphate-free Hoagland nutrition to the groundwater had little effect on arsenic removal, but the addition of phosphate nutrition significantly reduced its arsenic affinity and, thus, inhibited the arsenic removal. This study suggested that Chinese Brake has some potential to remove arsenic from groundwater.
当美国新的饮用水中砷含量最高污染物限量标准（10微克/升）于2006年生效时，美国很大一部分地下水源中的砷含量将超过该标准。因此，开发能够满足这一新标准的修复技术至关重要。对受砷污染的地下水进行植物修复是一个相对较新的概念。在本研究中，一种砷超富集蕨类植物，通常称为蜈蚣草（Pteris vittata L.），采用水培方式种植，以检验其从被认为受除草剂污染的地下水中去除砷的效果。一株生长在600毫升地下水中的植物在3天内有效地将砷浓度从46微克/升降至低于10微克/升。重复使用的植物继续从地下水中吸收砷，尽管速度较慢（在相同时间内从46微克/升降至20微克/升）。幼小的蕨类植物比大小相似的 older蕨类植物在去除砷方面更有效。向地下水中添加不含磷的霍格兰营养液对砷的去除影响不大，但添加磷营养显著降低了其对砷的亲和力，从而抑制了砷的去除。本研究表明，蜈蚣草具有从地下水中去除砷的潜力。
