摘要:

Gas chromatographic analysis of extracts prepared from adult mayflies (Hexagenia bilineata) collected from the Mississippi River between Prescott, WI and McGregor, IA indicated that polychlorinated biphenyls (PCB's) were as widely distributed and as abundant in 1983 as they were in 1980. The ranges of total body burden of PCB (μg g−1wet weight) within this 300-kilometer section of the river were 0.17—2.10 in 1980 and 0.21—3.10 in 1983. The 1980 geographic distribution pattern of PCB concentrations was similar to that which others found in 1976 forH. bilineata, but the mayfly body burden was less at nearly all sites similarly sampled in 1980. This trend did not persist in 1983; PCB's were as abundant and as widely dispersed inH. bilineatain 1983 as they were in 1976.

ISSN:0270-5060    

DOI:10.1080/02705060.1984.9664644

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Long Lake, an impoundment of the Spokane River, was eutrophic prior to 1978. Extensive hypolimnetic anoxia, excessive summer algal growth and limited water clarity existed as a result of nutrient loading from the City of Spokane's primary sewage treatment plant. Advanced wastewater treatment (Am) began in the fall of 1977 with a process for 85 percent phosphorus removal. Investigations during post-AWT years (1978–1981) have shown significant reductions in phosphorus loading with corresponding declines in chlorophylla, phytoplankton biovolume, primary productivity and increased water clarity to levels characteristic of mesotrophy. Hokever, anoxia has continued to exist, although the degree of anoxia has been considerably less.

ISSN:0270-5060    

DOI:10.1080/02705060.1984.9664645

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0270-5060    

DOI:10.1080/02705060.1984.9664646

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0270-5060    

DOI:10.1080/02705060.1984.9664647

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

ISSN:0270-5060    

DOI:10.1080/02705060.1984.9664633

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor