Trophic state is the property of energy availability to the food web and defines the foundation of community integrity and ecosystem function. Describing trophic state in streams requires a stoichiometric (nutrient ratio) approach because carbon input rates are linked to nitrogen and phosphorus supply rates. Light determines the source of carbon. Cross system analyses, small experiments and eco...

Prior to 1935, studies on the absorption of phosphorus were carried out either by the use of intestinal fistulas, or by the addition of an inactive unabsorbed marker to the food, such as iron oxide in the method of Bergeim (1). Recently the excretion of calcium and phosphorus into the large intestine of the rabbit has been studied by Cowell (2) by means of the differential analysis of fecal pel...

By combining electron tomography with energy-filtered electron microscopy, we have shown the feasibility of determining the three-dimensional distributions of phosphorus in biological specimens. Thin sections of the nematode, Caenorhabditis elegans were prepared by high-pressure freezing, freeze-substitution and plastic embedding. Images were recorded at energy losses above and below the phosph...

The bioavailability of phosphorus (P) in sediments from West Lake and Lake Tai (China) and Lough Erne (Northern Ireland) was evaluated using total P (TP), water soluble P (WSP), readily desorbable P (RDP), algal available P (AAP) and Olsen-P. The results indicated that the TP content, the amounts of phosphorus extracted by each method and their proportions to TP varied widely between sediments ...

A number of studies have reported the beneficial effects of the organic matter on the bioavailability of P in different soil types. These effects have been attributed to several factors, including the possible formation of phospho-metal-humic complexes, which could protect P from retrogradation in both acid and alkaline-calcareous soils. However, the experimental evidence supporting the existen...

Phosphorus (P) is an essential element for life. It occurs in living beings in the form of phosphate, which is ubiquitous in biochemistry, chiefly in the form of C-O-P (carbon, oxygen and phosphorus), C-P, or P-O-P linkages to form life. Within prebiotic chemistry, several key questions concerning phosphorus chemistry have developed: what were the most likely sources of P on the early Earth? Ho...

dity increases the need to chlorinate drinking water, which, in -products that have been shown to increase the risk of cancer. The ry agencies based on issues of and aerated/unaerated mass fractions are identified reasingly being seen as tand the relevant factors which differentiate competing to recover nutrients as process, sewage treatment plant Phosphorus: Total phosphorus (TP) in domestic w...

There are two biological systems available for removing phosphorus from waste water, conventional phosphorus removal (CPR) and denitrifying phosphorus removal (DPR) systems, and each is characterized by the type of sludge used in the process. In this study, we compared the characteristics associated with the efficiency of carbon utilization between CPR and DPR sludge using acetate as a carbon s...

soil enzyme activities are considered as one of the most important biological indicators and reflect the soil quality and fertility. current study was conducted to investigate the relationship between urease, invertase, alkaline phosphatase and aryl sulphatase activities of two histosols (located in kerman and shahrekord provence) and some of the soil chemical and biological properties. soil sa...

An approach is presented for the on-site treatment of diluted swine waste. The approach (1) incorporates anaerobic digestion with an anaerobic sequencing batch reactor (ASBR) to stabilize waste, reduce odor, and reduce solids and organic compounds, while producing biogas; (2) increases the ortho-phosphate concentration of the anaerobic digester effluent by enhanced biological phosphorus removal...