APPLICATION OF THE ORGANIC ACIDS SOLUTIONS FOR CLEANING THE MEMBRANE BLOCKS OF BAROMETRIC INSTALLASTIONS
Keywords:baromembrane units, membrane blocks, membrane pollutants, malic acid, acetic acid, photocolorimetry
Paper describes the experimental studies, using the solutions of food acids for the extraction of the iron compounds from the membrane blocks of barometric installations by means of maceration. Ferric iron compounds are typical and at the same time complex pollutants of the membrane blocs. Iron norms exceedance in the water may provoke allergic reactions and organic iron may cause stomach and duodenal ulcer. High concentration of iron in the water creates favorable conditions for the development of iron bacteria, especially in the warm water. Waste products of iron bacteria are canrcinogens.
Aim of the given research is searching of the optimal means of the membrane block cleaning from the ferric iron compounds. It is worth taking into account that this method must be ecologically safe and economically expedient that enables to use it in practice, increasing the service life of the membrane block of the units for barometric membrane purification of water.
Thus, after the analysis of the scientific sources, the decision was made to use the solution of hydroxy-succinic food acid for the elimination of the iron compounds from the surface of the membrane blocks. In the laboratory conditions the study of the efficiency of hydroxy-succinic acids solutions (malic acid formula, C4H6O5) and methane carboxylic (acetic acid, formula C2H4O2 ) acids impact on the extraction of Fe3+ ions was performed. A number of experiments were carried out, observation and assessment of optical density measurements of the standard and working solutions was performed at photo-colorimeter, clarification, filtration, preparation of the work solutions with malic and acetic acids. Identical experiment was performed, using citric acid but it did not give the desired results.
Results of the studies were summarized in the Table 2 and conclusions were made that the solution of dibasic 6% acid C4H6O5 is more efficient for fighting the precipitation of the compounds of the ferric iron on the membrane blocks of baromembrane water treatment units. This method is suitable for application in real conditions as the food solution of the malic acid is ecologically safe, financially accessible and in case of corresponding dilution can be discharged into the common drain, it also gives better results at short-term maceration.