Cheng C Y, Chu L M
Department of Biology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China.
Environ Pollut. 2007 Jan;145(1):195-202. doi: 10.1016/j.envpol.2006.03.020. Epub 2006 May 15.
Leachates from an operating and a closed landfill were examined for their phytotoxicity by seed germination/root elongation tests using seeds of Brassica chinensis and Lolium perenne. Their EC50s ranged from 3% to 46% v/v, which varied remarkably with the operating status of the landfills. Seedlings of twelve tree species were grown in pots, which were irrigated with landfill leachate at the EC50 levels, with tap water as control. No tree mortality or growth inhibition was observed after 90 days of leachate application. Chlorophyll fluorescence measurement also showed that plants receiving leachate did not suffer from a decline in photosynthetic efficiency. Litsea glutinosa and Hibiscus tiliaceus had remarkable growth, and other non-N-fixers were not inferior to the N-fixing Acacia auriculiformis. Leachate irrigation improved soil N content, though P deficiency is still a problem. The seed bioassay provided a conservative estimate of the phytotoxicity of landfill leachate. Plants irrigated can be protected from growth inhibition when the leachate irrigation plan is designed with reference to phytotoxicity data.
通过使用小白菜和黑麦草种子进行种子发芽/根伸长试验，对一个正在运营的垃圾填埋场和一个封闭垃圾填埋场的渗滤液的植物毒性进行了检测。它们的半数有效浓度（EC50）范围为3%至46%（体积/体积），这随垃圾填埋场的运营状况有显著变化。将12种树种的幼苗种植在花盆中，用半数有效浓度水平的垃圾填埋场渗滤液进行灌溉，以自来水作为对照。在施加渗滤液90天后，未观察到树木死亡或生长受抑制的情况。叶绿素荧光测量还表明，接受渗滤液的植物光合作用效率并未下降。潺槁木姜子和黄槿生长显著，其他非固氮树种并不比固氮的大叶相思差。渗滤液灌溉提高了土壤氮含量，不过磷缺乏仍是一个问题。种子生物测定对垃圾填埋场渗滤液的植物毒性提供了一个保守估计。当参照植物毒性数据设计渗滤液灌溉方案时，灌溉的植物可以免受生长抑制。
