Phosphorus In Aqueous Solution Research Articles

Determination of phosphorus in waste water by EDXRF

In a method developed for the determination of phosphorus in aqueous solutions, phosphorus was changed to the phosphate form, coprecipitated with hydrated iron(III) oxide, bound with activated charcoal and measured by EDXRF. The detection limit was 0.89 mg P/g activated charcoal. The method was used to determine the total phosphorus content of a waste water sample from a paper mill. Investigation of two sample destruction methods, dry ashing/HCl digestion and persulphate oxidation, showed the former to be more suitable for our purpose.

Trace analysis for sulphur and phosphorus in aqueous solution by a carbon filament atom reservoir technique

The chemiluminescent emissions of S 2 and HPO are excited around a resistively heated carbon filament in a hydrogen-nitrogen diffusion flame. Detection limits of 5 · lO -10 g and 4 · 10 -9 g were obtained, respectively, for sulphur and phosphorus for 1-μl samples of sulphuric and phosphoric acid solutions. Interference effects were studied; there are numerous cationic interferences but few anionic interferences.

Gel chromatographic behavior of the oxo acids of phosphorus

A number of oxo anions of phosphorus which contain one to four phosphorus atoms in the molecule were eluted with potassium chloride solutions on Sephadex columns. The K d values of the oxo anions of phosphorus were measured as functions of the concentration and pH of the eluents, sample concentration and gel prosoity. K d values obtained by both the column and batch method were compared to each other. The main conclusions are as follows. (1) When pure water was used as an eluent, extremely low K d values were observed because of the electrostatic repulsion between the sample anions and the negatively charged gel matrix. (2) The K d values increased with increasing concentration of potassium chloride. This may be due to the variation in the degree of hydration of sample anions. (3) At sample concentrations lower than 10 −2 gram atom P per 1 the elution curves were symmetrical, while unsymmetrical elution curves were obtained at the higher sample concentrations. (4) The K d values did not depend on the pH values of the eluent. (5) The most satisfactory separation of ortho-, di- and triphosphate anions was carried out on a Sephadex G-25 column. (6) The effective sizes of the oxo anions of phosphorus in aqueous solution were stimated from the gel chromatographic data.