银对几种藻类的毒性浓度及其积累

银对水生生物是一种有毒金属.本文以不同浓度的AgNO_3加入培养液中,通过对藻类生长的测定研究了银对三种常见藻类的毒性浓度.1-2.5ppm的银对球衣藻和斜生栅藻是安全浓度范围,当银增至10ppm时,这两种藻类被明显致毒,生长繁殖被完全抑止.颤藻在10~3ppm银浓度中生长正常,对银具有较大的耐性,同时,以原子吸收光谱测定证明每0.2克(干重)颤藻可从这一浓度的含银水体中吸收10.17微克银,对银具有一定的积累能力.本文试验结果可供考虑含银水质排放标准、含银水体的生物净化及银的生物回收可能性之参考.

TOXIC CONCENTRATION AND ACCUMULATION OF SILVER IN SOME ALGAE

Silver is one of the toxic elements for hydrobios. In this paper, we study the toxic concentration of silver for three common algae. A non-toxic concentaration of 1-2.5 ppm silver was presented to Chlamydomonas globosa and Scenedesmus obliquus. But when the concentration of silver was increased to 10 ppm. the algal growth was inhibited complctly. The Oscillatoria sp., a green alga, had higher resistance to silver toxicity. This alga not only grew normally at a concentration of silver as high as 10~3ppm in the medium but also absorbed 10.17 micrograms of silver in six days per 0.2 grams (day weight).