engleski

Detrmination of iron in raw materials, during fabric processing, and in wastewaters of the textile industry

The Schiff base2-(2-pyridylmethyleneamino)phenol (PMAP) was investigated as a spestrophotometric reagent for determinationof iron in caustic soda, cotton yarn and fabric, woolen fabric, and industrial water. The solution properties of Fe(III)-PMAPcomplexes were determined. At pH 4.4 and 5.6, Fe(III)forms stable complexes with PMAP, with molar absorption coeffients ( ) of 3.00 x 103 and 7.44 x 103 /Mcm, respectively. Composition and cumulative stability constants were determined by the mole ratio method (MRM) and the mole fraction variation method (MFVM). At the lower pH (4.4), the predominant complex species in the solution obtained with both methods are ML2, with fairly good agreement of stability constants: log  ML2 = 7.00  0.04 vith MRM and 7.31 +/- 0.01 with MFVM. At the higher pH (5.6), the composition and stability constants of predomonant complex species in the solution obtained with the 2 methods were not good agreement, perhaps because of the coexistence of several species, such as Fe-PMAP, Fe-hydroxo, and Fe-acetate complexes. Pmam is sensitive reagent for determination of Fe(III). The detection limit of 0.4  g/mL is lower than those of other frequently used spectrophotometric reagents for Fe. The reagent is ecologically more acceptable, because extraction with organicsolvents is avioded. All measurements were made at pH 5.6 because sensitivity was higher at this pH. The high Fe values obtained for industrial water (38.8  g/mL) indicate that some modifications in the process have to be done. Concentration of Fe in wastewaters was much lower (15.9  g/mL). The results for cotton and woolen fabric indicate that accumulation of Fe in wool is much higher than in cotton (84.4  g/mL and 29.3 � 53.1  g/mL, respectively).

iron; wastewaters; textile

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