[1] Watershed export of phosphorus (P) from anthropogenic sources has contributed to eutrophication in freshwater and coastal ecosystems. We explore impacts of watershed urbanization on the magnitude and export flow distribution of P along an urban-rural gradient in eight watersheds monitored as part of the Baltimore Ecosystem Study Long-Term Ecological Research site. Exports of soluble reactiv...

The effectiveness of alum (aluminum sulfate) in reducing the concentrations of potential pollutants in pond effluents was investigated in catfish production ponds. Application of alum at 50 mg/l to water remaining in ponds immediately after seining for harvest did not generally result in significantly greater removal of nutrients and solids than did settling alone, although removal rates of som...

A segmented flow automated method with on-line photo-oxidation for the determination of dissolved organic phosphorus+soluble reactive phosphorus (DOP+SRP) in seawater and fresh water is described here. A low-power lamp was used for a compact, easy-to-handle and low-ozone-producing manifold. The influence of seawater matrix components was studied in detail using natural seawater and salt solutio...

Water quality has become and important issue in the state of Iowa as well as across the entire United States. Two Iowa Lakes, Silver Lake and Casey Lake were chosen for study by a team of biologists, chemists, earth scientists and statisticians from the University of Northern Iowa. Our goals are to statistically compare the water quality in the two lakes in each year and examine whether or not ...

Microalgae in waste stabilization ponds (WSP) have been shown to accumulate polyphosphate. This luxury uptake of phosphorus is influenced by the wastewater phosphate concentration, light intensity and temperature, but the dynamics of how these factors affect luxury uptake with respect to time are not understood. With improved understanding of the dynamics of this mechanism and how it could be m...

salinity tolerance is one of the most important affecting factors on agricultural production in arid and semi-arid areas. in order to study the effects of saline and fresh water irrigation with application of organic and npk fertilizers on cumin, a split plot experiment based on randomized complete block design was carried out with three replications during 2011 and 2012, at the research farm o...