Akademik Veri Yönetim Sistemi
International Journal of Engineering Inventions , cilt.14, sa.12, ss.73-82, 2025 (Hakemli Dergi)
In this
study, we present a simple and effective two-step process combining adsorption
and photoreduction for the removal, separation, and recovery of Cu(II) and
Cr(VI) from mixed heavy-metal wastewater. First, a TiO₂–ZrO₂ solid-solution
photocatalyst was applied to reduce Cr(VI) in the absence of a sacrificial
agent, achieving a removal efficiency of 95%, while Cu(II) remained
predominantly in the aqueous phase. Second, a commercial cation-exchange resin
(Lewatit TP207) was used to selectively adsorb Cu(II) without significantly
altering Cr(VI) concentrations. When these processes were combined—regardless
of the sequence—both Cu(II) and Cr(VI) were reduced to levels meeting typical
discharge standards. The most effective treatment sequence was found to be ion
exchange followed by photocatalysis: residual Cu(II) was reduced to 0.06 mg L⁻¹,
and total Cr (with no detectable Cr(VI)) was 0.74 mg L⁻¹. The separation factor
for Cu(II)/Cr(VI) reached 11,949, with recovery efficiencies of 99.17 % for
Cu(II) and 96.29 % for Cr(VI). This work demonstrates a promising dual-process
strategy for the selective removal and recovery of heavy metals in complex
wastewater streams.