At present, industrial development is increasing pollution of soils, air and natural waters. These
pollutants have a negative effect on the health and life of living organisms. Metals which interfere with
the natural biological balance and inhibit self-cleaning processes in water bodies have particularly
toxic effects. Cobalt, which gets into the environment from industrial sewage from electrochemical
plants and the metallurgical industry, also belong to this group. This is also relatively rare and precious
element, so it is important to look for additional sources of its recovery. Chemical and physicochemical
methods such as: precipitation, extraction, membrane processes – nanofiltration, reverse
osmosis, sorption and ion exchange are used to recover cobalt. The choice of method depends on: the
kind and composition of wastewaters as well as on form and concentration of the pollutants.
Ion exchange resins produced by Purolite which were used to remove cobalt ions from solutions
with concentrations corresponding to its contents in galvanic wastewater was the subject of the study.
It has been shown that the C 160 ion exchange resin has the best the sorption properties for Co2+ ions
(54.7 mg/g). In case of this ion exchange resin, after sorption process carried out in one 50 minute cycle,
cobalt concentration decreased from about 30 g/L to about 9 g/L. The values of the sorption capacity
do not depend on the method of introducing the solution into an ion exchange column (pouring or dropping).
E ach of the tested ion exchange resins is characterized by a high degree of cobalt concentration
after regeneration using mineral acids, which can be advantageous in selecting the recovery method for
this metal.
The paper presents results of research on cobalt and nickel ions removal from monocomponent solutions
using Purolite ion exchange resins. It has been shown that C 160 ion exchange resin has the best
sorption properties for both ions (Qe – 72.5 mg Co/g and 88.2 mg Ni/g). Regeneration process of this
ion exchanger has high efficiency, achieving about 93% for cobalt ions and about 84% in case of nickel
ions. It has been shown that the use of ion exchange method with suitable ion exchange resins guarantees
effective removal of cobalt and nickel ions from solutions with very high concentrations corresponding
to contents of these metals in industrial wastewaters (e.g. galvanic). In case of C 160 ion exchange resin,
after the sorption process is carried out in one 50 minute cycle, the cobalt concentration decreased from
about 30 000 mg/L to about 9 500 mg/L (approx. 68%), whereas nickel concentration reached about
6 300 mg/L (approx. 79%). Studied chelating resins don’t have such high sorption capacities. In their
case, it is required to convert cobalt and nickel ions into complex forms. The kinetics of studied processes
were described by pseudo-second order equations.