Removal of metal ions from wastewater using EB irradiation in combination with HA/TiO2/UV treatment

The electron beam (EB) irradiation technology was applied for removal of Cu2+, Sr2+, and Co2+ ions from wastewater. The aim of this study is to achieve an efficient treatment process of wastewater using EB and introducing a combination of humic acid (HA) as a natural organic polymer and ultraviolet irradiation of a TiO2 (TiO2/UV), as a suspended catalyst in the treatment of wastewater solutions (TiO2/UV+HA). The experimental results showed that the percentage removal of Cu2+, Sr2+, and Co2+ ions was 41%, 87% and 75% respectively, at 125 kGy. In the presence of TiO2 photocatalyst and exposure of the investigated wastewater to ultraviolet rays before irradiation by the EB the percentage removal of Cu2+ ions became 51%, while the percentage removal of both Sr2+ and Co2+ ions was slightly improved; was 87% and 75%, respectively at the same EB dose. On the other hand, by introducing the combination of TiO2/UV+HA, only an irradiation dose of about 50 kGy led to removal of Cu2+, Sr2+, and Co2+ completely from the wastewater. Mechanisms of interactions between HA and Cu2+, Co2+ and Sr2+ metal ions were suggested and discussed. (C) 2014 Elsevier B.V. All rights reserved.