不同pH值条件下Cr^(6+)对小球藻和斜生栅藻的毒性效应  

Toxic effects of chromium(Cr^(6+)) on Chlorella vulgaris and Scenedesmus obliquus at different pH

作　　者：赵娜[1] 冯鸣凤[1] 朱琳[1] 

机构地区：[1]南开大学环境科学与工程学院环境污染过程与基准教育部重点实验室,天津300071

出　　处：《东南大学学报（医学版）》2010年第4期382-386,共5页Journal of Southeast University(Medical Science Edition)

基　　金：国家水体污染控制与治理科技重大专项(2008ZX08526-00)

摘　　要：目的:研究不同pH值条件下,重金属Cr6+对淡水绿藻小球藻和斜生栅藻生长的毒性效应,为我国水质量基准和标准的科学制定提供参考资料。方法:依据OECD-201藻类生长抑制实验指南,以72h藻生物量为测试终点进行藻类抑制实验。结果:两种藻在不同初始pH值条件下的生长潜势不同,小球藻的最适pH值为7.0,而斜生栅藻的最适pH值为9.0。在不同初始pH值条件下,Cr6+对小球藻和斜生栅藻的作用均为低浓度(<0.1mg·L-1)刺激而高浓度(>0.5mg·L-1)抑制,且浓度越大抑制率越高。对于小球藻Cr6+在pH值=7.0时毒性最小,在pH值=8.0时毒性最大;对于斜生栅藻Cr6+在pH值=9.0时毒性最小,在pH值=7.0时毒性最大。结论:Cr6+在藻的最适pH值条件下毒性最小。Objective：The toxicological effects of hexavalent chromium（Cr6＋） on the growth of freshwater green algae,Chlorella vulgaris（C.vulgaris） and Scenedesmus obliquus（S.obliquus） were investigated at different pH levels in order to provide references to the scientific establishment of water quality criteria and standard in China.Methods：According to the OECD guidelines for the testing of chemicals,freshwater alga and cyanobacteria growth inhibition test（OECD-201）,taking 72 h biomass as the endpoint,the algal inhibition tests were conducted.Results：The alga grew differently at different initial pH levels,and the optimal growth pH of C.vulgaris was pH = 7.0,while the optimal pH =9.0 for S.obliquus.At different initial pH levels,Cr6 ＋ had the stimulating effects on both C.vulgaris and S.obliquus when the concentrations were lower than 0.1 mg·L-1,and the inhibition effects were observed when the concentrations of Cr6 ＋ were higher than 0.5 mg·L-1.The inhibition effects grew stronger with the increasing of the Cr6 ＋ concentrations.For C.vulgaris,the toxicity of Cr6 ＋ was minimum at pH =7.0,and maximum at pH =8.0.For S.obliquus,the toxicity of Cr6 ＋ was minimum at pH = 9.0,and maximum at pH = 7.0.Conclusion：The toxicity of Cr6 ＋ is minimum at the optimal pH of the algae.

关 键 词：Cr6+ 小球藻 斜生栅藻 PH值 水质量基准 

分 类 号：X651[环境科学与工程]