Sorption of Ni(II) on surface of bed grains used in iron and
manganese removal filters
Marta Tytkowska, Magdalena M. Michel, Lidia Reczek and Tadeusz Siwiec
ABSTRACT
This paper reports the results of determinations of crystalline phase type, specific surface area, point
of zero charge pH ( pH
pzc
), and Ni(II) sorption capacities of beds for groundwater treatment. Bed
materials from iron and manganese removal filters (FeRF, MnRF) as well as a catalytic bed (G1) were
investigated. The reference material was MnO
2
-coated quartz sand (MnQS). The efficiency of Ni(II)
sorption was investigated as a function of pH. It was found that the naturally formed coating on FeRF
was characterised by the highest sorption efficiency (80–88%) in the wide pH range (4–9) of the
solution. Sorption on MnRF was weaker (35–45%). G1 and MnQS, which contained only manganese
oxides, were characterised by a very low sorption efficiency of 0–6% and 3–8%, respectively. A lower
Ni(II) removal efficiency was observed at an initial pH close to the pH
pzc
values. During Ni(II) sorption,
the pH of the solution was not constant and tended towards the value of pH
pzc
for all tested
materials. The slightly pH-dependent sorption of Ni(II) indicates that its removal depends more on the
chemical composition and the specific surface area of the oxide coatings covering the bed materials.
Marta Tytkowska (corresponding author)
Magdalena M. Michel
Lidia Reczek
Tadeusz Siwiec
Faculty of Civil and Environmental Engineering,
Warsaw University of Life Sciences – SGGW,
Nowoursynowska 166, 02-787 Warszawa,
Poland
E-mail: marta_tytkowska@sggw.pl
Key words | iron oxides, manganese dioxide, pH
pzc
, surface properties
INTRODUCTION
The term ‘heavy metals’ is often used as a collective name
for metals and metalloids that have been associated with
contamination and potential toxicity or ecotoxicity (Duffus
). These elements can occur in excessive amounts in
groundwater as a result of local pollution, release of
sewage or expired plant protection agents from waste sto-
rage facilities, and metal leaching from rocks (Kowal &
S
´
widerska-Bróz ˙ ). The presence of mobile forms of
heavy metals in groundwater makes using it as a source
of high quality water difficult. Research done in the area
of the Ntem watershed in West Africa shows that the occur-
rence of higher than permissible levels of heavy metals (Pb,
Cd, Cr, and Ni) in groundwater poses a potential threat to
public health (Defo et al. ). The form and concentration
of heavy metals which occur in natural sources of water
depend on the physical and chemical composition of the
water and the various processes which take place in water
and ground environments. Heavy metals can accumulate
in living organisms causing pathological changes (Duffus
). For example, nickel, a heavy metal which is the
focus of this present study, may cause disturbances in the
development of living organisms and exert carcinogenic
effects (El-Dars et al. ). That is why the permissible con-
tent of nickel in water intended for human consumption is
very low at 20 μg dm
3
(Council Directive //EC).
To prevent the detrimental effects of heavy metals, includ-
ing nickel, on consumers’ health, they must be removed from
water intended for human consumption. Even amounts that
only slightly exceed the permissible concentration require
measures to be taken in the production of potable water
(Siwiec et al. ) and can cause problems in its distribution.
The processes which enable removal of heavy metal
elements from groundwater include adsorption, chemical
precipitation, and ion exchange. These processes often
815 © IWA Publishing 2019 Water Supply | 19.3 | 2019
doi: 10.2166/ws.2018.127
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