兰州市城关区七里河区污水中的原生动物及水质评价

STUDIES ON PROTOZOAN COMMUNITIES IN SEWAGE OF CHENGGUAN AND QILIHE DISTRICTS IN LANZHOU AND ASSESSMENT OF WATER QUALITY

1986—1987年5—6月间作者调查了甘肃省兰州市城关区和七里河区污水处理厂污水中的原生动物。在6个采样点中,其鉴定出原生动物82种,隶属植鞭毛纲、动鞭毛纲、根足纲、辐足纲、动基片纲、寡膜纲和多膜纲。根据其优势种、污生指数(Pantle—Buck,1955)和功能类群(Pratt等,1985)表明,这两个污水厂的排放水水质属于多污性—→α—中污性。在城关区污水厂的4个采样点中,随着污水处理工艺流程的进行,原生动物群体结构和优势种亦有明显变化,这种变化表明水质污染程度在递减。以上用原生动物对污水处理效应的评价与这两个污水厂的处理流程相一致。这一研究结果证明:原生动物可以作为宏观评价水质污染程度的指示生物。

An investigation of protozoan communities in sewage of Sevage Treatment Plant in Cheng-guan and Qilihe Districts in Lanzhou of Gansu has been made by the authors from May to June , 1986-1987. We have collected and made a microscopic examination into the specimens from 6 areas of different water qualities. We have found that 82 species of protozoa belong to seven classes (Phy-tomastigophorea, Zoomastigophorea, Rhizopoda, Actinopodea, Kinetofragminophorea, Oligohy-menophorea, Polyhymenophorea). The sewage quality belongs to polysaprobic zone to a-mesos- aprobic one which is indicated by the dominant species (P. caudatum, L, obtusum, A. klebsi and V. limex etc. ) and the pollution index about (3. 3 - 3. 06). The water body pollution has been progressively decreased and it is indicated by the change in dominant species of protozoan communities in 4 sample areas in sewage of Chengguan. This kind of evaluation is in agreement with the treatment of pollution sources and composition in sewage. The result shows that protozoan communities can be regarded as indicator organisms for judging the pollution of water quality.