The influence of water filtration rate on the efficiency of its oxidization on iron-containing redoxite

Abstract

Experimet to determine the effectiveness of iron-containing redoxites on the efficiency of water deoxidation. In the course of the study, the dependence of the efficiency of water deoxidation on the filtration rate was determined. 
 The filtration rate was varied in the range from 5 to 25 mph. The residual oxygen content and the dissolved iron content in the water were determined. It was shown that with increasing filtration rate within these limits, the residual oxygen concentration increases from 0.1-0.2 mg/dm3 to 0.9-1.0 mg/dm3. The residual oxygen content depends not only on the filtration rate but also on the reaction of the medium. An increase in the residual oxygen concentration with increasing pH of the medium from 6.7 to 10.0.
 Residual iron content depends little on both the filtration rate and the reaction medium and in all cases did not exceed 0.2 mg / dm3. In this work, the dissolution of iron in general was determined by preliminary preparation for the work of iron-containing redoxite.
 When used in the installation scheme, in addition to the column with iron-containing redoxite, also columns with cation exchange resin KU-2-8 in Na-form, almost complete removal of iron ions from the water and natriation softening of tap water was noted. In the case of sodium-cationized water, the extraction of iron from water will be observed for a long time, given the low concentration of iron ions in the water and the high capacity of the cation exchange resin in iron ions. In addition, sorbed iron (II) ions on the cation exchange resin are oxidized by oxygen residues to iron (III). The latter, at elevated pH, are hydrolyzed, which is the reason for the restoration of capacity and cation exchange resin by divalent iron cations.
 In the case when after the column with iron-containing redoxite used anion exchange resin AB-17-8 in sulfite form, complete extraction of oxygen from water was achieved.
 Given that the oxygen concentration in water with the use of iron-containing composite decreased by 10-40 times, the load on the anion exchange redox will decrease proportionally, which means that the duration of the anion exchange redox filter cycle will increase in the same proportion.
 The use of iron in the second stage of the anion exchange resin in the SO32- form remained unchanged, but complete oxygen extraction was achieved. The option is quite promising for implementation.