The effect of carbon source on nitrate and ammonium removal from drinking water by immobilised Chlorella sorokiniana|
Petrovič, A. & Simonič, M.
The feasibility of alginate-immobilised
Chlorella sorokiniana for nitrate and ammonium removal from
drinking water in regard to carbon source effects was
studied in this paper. Three different natural carbon sources
were tested in batch experiments with nitrate as nitrogen
source: sucrose, grape juice and acacia honey. The nitrate
removal efficiencies achieved at 50 mg/L of initial nitrate
concentration under sucrose, grape juice and acacia honey
were 93, 99 and 94 %, respectively. At 100 mg/L of
nitrate, comparable efficiencies were obtained after
approximately 3 days, whilst for acacia honey at 50 mg/L,
it took only 2 days of cultivation and 3 days for the other
two carbon sources. Grape juice and acacia honey showed
better performances than sucrose, which must be linked to
their chemical compositions. The study of the impact of
biosorbent quantity on nitrate removal efficiency showed
that sufficient nitrate removal efficiencies could be
achieved with a beads/water ratio of 1:6.7 (v/v) or smaller.
In addition, the beads’ ages significantly impacted the
nitrate removal. The removal of ammonium was studied in
the presence of nitrate with acacia honey as carbon source.
At the highest concentrations being tested (ammonium-
30 mg/L and nitrate-50 mg/L), ammonium was completely
removed in <3 days and nitrate by 81 % in 4 days,
whereby the suitable beads/water ratio was 1:5. The priority
of ammonium assimilation was noticed when compared
to nitrate. According to the results, the alginateimmobilised
C. sorokiniana represents a promising tool for
the removal of nitrogen from drinking water sources.
Algae; Ammonium; Carbon source; Chlorella sorokiniana; Drinking water; Nitrate