STUDY OF SORPTION OF NICKEL ION WITH FIBROUS ADSORBENTS

Technological processes of processing of metal products and galvanic production are characterized by large volumes of wastewater containing ions of heavy metals, in particular as a result of Nickel plating products in wastewater in the predominant amount fall ions Ni2+. To assess the possibility of removing pollution from this type of wastewater, the process of adsorption purification of model Nickel-containing wastewater was investigated. As adsorbents modified nitrogen-containing polyvinyl alcohol, polycaproamide, hydrocellulose fiber were used. Modification of this type of fibers allows fixing functionally active groups on the surface of adsorbent. It is established that the fibrous adsorbents have a high adsorption capacity towards Nickel ion(II), the magnitude of adsorption is in the range of 80-100 mg/g. The predominant mechanism is monomolecular chemisorption. Adsorption proceeds at high speeds, the balance is achieved in the first 20 minutes of the process. The effect of pH on complex formation in the phase of adsorbents is revealed. It is shown that in a strongly acidic medium the purification efficiency is small, the increase in pH leads to increased adsorption properties of fibers. The optimal value of the acidity of the solution are pH values above 5. A decrease in the amount of coordinated nitrogen with an increase in pH was determined. In assessing the selectivity of fibers with respect to Ni2+ in the presence of Zn2+ and Cu2+, the influence of matrix polymer effect was revealed. Adsorption on polyvinyl alcohol and polycaproamide fibers showed that the influence of zinc ions(II) on the adsorption of Nickel (II) increases with its concentration in the solution, and hydrate cellulose fiber has a higher selectivity with respect to Zn2+ion. The presence of Cu2+ leads to a significant decrease in the efficiency of model wastewater treatment from Nickel ions (II) on all types of adsorbents studied