URINE EXPERIMENT

Urine Experiment

Urine Experiment

Introduction

When testing urine the test results may provide information regarding the status of carbohydrate metabolism and kidney function.

The kidney glomeruli act as ultrafilters for the plasma protein; however as much as 150 mg/dl of protein may normally be excreted into the urine. In glomerular proteinuria, an increase in glomerular permeability occurs, resulting in an increase of urine proteins. High urine protein concentration therefore may indicate proteinuria.

Blood glucose concentration above the renal threshold will overflow into the urine. This situation normally arises in diabetes patients. In renal diabetes, the renal threshold is reduced to the point where sugar appears in the urine despite normal levels being present in the blood. In both situations, monitoring of urine glucose becomes important.

The concern for diminishing phosphorus reserves are being expressed progressively. Supplies, particularly for high-grade phosphate ores, were reported low over 2007 and continuing into 2008, leading to drastic price increases. Phosphorus demand is projected to increase even further with a global peak in phosphorus production predicted to occur around 2030. Phosphorus is not only indispensable for a secure food production to feed an increasing world population; the growing production of crops for bio fuel production places an additional burden on the global P reserves. At the same time, phosphorus forms a problematic waste stream in those areas where there is no adequate wastewater treatment, or is responsible for extra costs when it needs to be disposed of in landfills as incineration ash. In view of a more sustainable future, we need to look at alternative sources of phosphorus. In other words, we need to recycle.

Within conventional wastewater treatment, several pathways are known to remove phosphorus out of the wastewater; the recovery product then being a phosphorus-rich water or sludge stream. Within the concept of wastewater design, we find a stream that is very low in volume, yet very high in phosphorus: human urine. A technique proven to be a successful method to recover phosphorus from high strength phosphorus-rich streams is the precipitation of struvite (MgNH4PO4·6H2O). Struvite is a known and applied slow-release fertiliser, well applicable to crops in soils with relatively low pH. For plants that need an initial high dose of P followed by a continued slow P release, for example container plants, a product called enhanced struvite is already on the market: struvite treated with phosphoric acid to achieve a modified form of DAP (diammonium phosphate, one of the most applied fertilisers in the world). Phosphorus recovery in the form of struvite is technically feasible and economically viable.

Objectives

The examination of the urine remains one of the most commonly performed test in laboratory practice. In most laboratories, the procedure consists of analysis by test strips and by the microscopy of urine sediment when test strips are positive. The test strip procedure, however, has significant false negative and false positive rates when compared to precise particle counts [1 and 2]. Furthermore, urine particle counting by visual microscopy has gained a reputation for unreliability [3, 4 and ...