Use of Plants for Remediation, Stabilization and Restoration of Aquatic and Terrestrial Ecosystems
Plants can be used to remediate polluted soil or water ( phytoremediation) by extracting and/or degrading pollutants and for stabilization of soils and sediments ( phytostabilization) in order to prevent erosion and to minimize the release of contaminants from the solid matrix. A broad range of inorganic and organic pollutants can thus be processed by using suitable plants that are tolerant of the pollutants, generate high biomass, and are effective in uptake. As an example, water hyacinths can be used for extracting and degrading cyanide from gold mining process water that usually contains cyanide species and heavy metals in concentrations of toxicological concern. We determined a lethal dose (LC50) of about 13 mg cya-nide/L for the water hyacinths and observed that under field conditions in a pilot scale wetland the plants became more effective after several applications in degrading cyanide even at high concentrations. Experiments with radio-labelled cyanide revealed that the carbon and nitrogen of cyanide in the plants were used to biosynthesize asparagine; thus the toxic cyanide was effectively transformed into a non-toxic, natural product . Waste disposal sites can be remediated with plants both with respect to leaching - the percolating water may contain high concentrations of pollutants - and with respect to the stabilization of slopes in order to reduce erosion. We used the concept of dense vegetation on an industrial waste site and grew douglas firs that perform high evapo-transpiration rates throughout the year and thus reduce the amount of leachate from the dump site. For stabilization of the slopes it is possible to first install a stable, diamond-shaped network of living plants (willows) , level up the network with soil and spray a mixture of suitable seeds of grass, shrubs or trees (truck wet application) which will further stabilize the soil during growth. This technique can be applied also to river banks for erosion control.
phytoremediation cyanide waste soil stabilization leachate reduction erosion control
Andreas SCHAEFFER CHEN Zhong-li Mathias EBEL Michael EVANGELOU Henner HOLLERT Martina ROB-NICKOLL Burkhard SCHMIDT Yuan Ye Gottfried LENNARTZ
RWTH Aachen University, Worringerweg 1 , 52076 Aachen, Germany GAIAC, Research Institute for Ecosystem Analysis and Assessment, 52072 Aachen, Germany
国际会议
重庆
英文
84-86
2011-10-01（万方平台首次上网日期，不代表论文的发表时间）