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Papers by Angel Cruz
Chemical Engineering Journal, 2017
h i g h l i g h t s Fe(III)/alginate catalyst can be applied to circumneutral photo-Fenton. Fe(II... more h i g h l i g h t s Fe(III)/alginate catalyst can be applied to circumneutral photo-Fenton. Fe(III)/alginate stability strongly depends on pH. The reduction of pH under alginate pK a leads to the release of Fe from the catalyst. A Fe release mechanism for Fe(III)/ alginate catalysts is proposed. Alginate catalyst acts as a strong scavenger of the OHÅ generated on its surface.
Chemical Engineering Journal, 2014
The homogeneous advanced oxidation process UV/H 2 O 2 , using UV radiation (λ = 254 nm) at low H ... more The homogeneous advanced oxidation process UV/H 2 O 2 , using UV radiation (λ = 254 nm) at low H 2 O 2 concentration, was studied at bench scale for the treatment of secondary effluent spiked with atrazine. The transformation of the effluent organic matter in terms of its biodegradability, atrazine and dissolved organic carbon (DOC) removal was investigated. Hydroxyl radical (•OH) scavenging and radiation scattering are discussed, along with a rough estimation of treatment costs in terms of energy requirements. The results demonstrated that an UV/H 2 O 2 process at low H 2 O 2 initial dose ([H 2 O 2 ] 0 = 5 mg L-1 and photonic flow = 14.9μEinstein s-1) was effective in removing 100 µg L-1 of atrazine in secondary effluent, although hydroxyl radical scavenging was quantified at about 60% of the hydroxyl radical production. Effluent organic compounds were responsible for 85% of the total hydroxyl radical scavenging and for the 12-fold reduction of the atrazine removal rate. Moreover, the natural matrix affected directly the energy required by the lamps to produce •OH, which increased more than tenfold in relation to deionized water. Low doses of H 2 O 2 were unable to promote biodegradability increment in secondary effluents, although H 2 O 2 /DOC ratios over 3 achieved significant mineralization of effluent organic matter (higher than 50%). At a low H 2 O 2 concentration, the system removes micropollutants without any significant modification of secondary effluents (SE) physic-chemical parameters. However, there will be less elimination of more recalcitrant micropollutants, due to the greater •OH scavenging than when there are higher H 2 O 2 dosages.
Chemical Engineering & Technology, 2013
Alternative water sources, including effluents from municipal wastewater treatment plants (MWTP) ... more Alternative water sources, including effluents from municipal wastewater treatment plants (MWTP) are necessary to meet increasing water demand. Advanced oxidation processes based on the Fenton reaction were applied to remove atrazine from the secondary effluents of a MWTP that uses activated sludge. Fenton, UV-A photo-Fenton, and UV-C photo-Fenton treatments were tested. Atrazine removal percentages were around 20 % for Fenton, 60 % for UV-A photo-Fenton and 70 % for UV-C photo-Fenton treatments, respectively. Organic matter mineralization by Fenton treatment was monitored and no significant reduction was observed. However, organic matter oxidation in terms of COD reduction of around 30 and 40 % were achieved by Fenton and photo-Fenton processes, respectively. The photo-Fenton process with UV-C is a useful technique for atrazine degradation, leading to higher degradation than with UV-A while also being more attractive in an economic point of view.
Chemical Engineering Journal, 2017
h i g h l i g h t s Fe(III)/alginate catalyst can be applied to circumneutral photo-Fenton. Fe(II... more h i g h l i g h t s Fe(III)/alginate catalyst can be applied to circumneutral photo-Fenton. Fe(III)/alginate stability strongly depends on pH. The reduction of pH under alginate pK a leads to the release of Fe from the catalyst. A Fe release mechanism for Fe(III)/ alginate catalysts is proposed. Alginate catalyst acts as a strong scavenger of the OHÅ generated on its surface.
Chemical Engineering Journal, 2014
The homogeneous advanced oxidation process UV/H 2 O 2 , using UV radiation (λ = 254 nm) at low H ... more The homogeneous advanced oxidation process UV/H 2 O 2 , using UV radiation (λ = 254 nm) at low H 2 O 2 concentration, was studied at bench scale for the treatment of secondary effluent spiked with atrazine. The transformation of the effluent organic matter in terms of its biodegradability, atrazine and dissolved organic carbon (DOC) removal was investigated. Hydroxyl radical (•OH) scavenging and radiation scattering are discussed, along with a rough estimation of treatment costs in terms of energy requirements. The results demonstrated that an UV/H 2 O 2 process at low H 2 O 2 initial dose ([H 2 O 2 ] 0 = 5 mg L-1 and photonic flow = 14.9μEinstein s-1) was effective in removing 100 µg L-1 of atrazine in secondary effluent, although hydroxyl radical scavenging was quantified at about 60% of the hydroxyl radical production. Effluent organic compounds were responsible for 85% of the total hydroxyl radical scavenging and for the 12-fold reduction of the atrazine removal rate. Moreover, the natural matrix affected directly the energy required by the lamps to produce •OH, which increased more than tenfold in relation to deionized water. Low doses of H 2 O 2 were unable to promote biodegradability increment in secondary effluents, although H 2 O 2 /DOC ratios over 3 achieved significant mineralization of effluent organic matter (higher than 50%). At a low H 2 O 2 concentration, the system removes micropollutants without any significant modification of secondary effluents (SE) physic-chemical parameters. However, there will be less elimination of more recalcitrant micropollutants, due to the greater •OH scavenging than when there are higher H 2 O 2 dosages.
Chemical Engineering & Technology, 2013
Alternative water sources, including effluents from municipal wastewater treatment plants (MWTP) ... more Alternative water sources, including effluents from municipal wastewater treatment plants (MWTP) are necessary to meet increasing water demand. Advanced oxidation processes based on the Fenton reaction were applied to remove atrazine from the secondary effluents of a MWTP that uses activated sludge. Fenton, UV-A photo-Fenton, and UV-C photo-Fenton treatments were tested. Atrazine removal percentages were around 20 % for Fenton, 60 % for UV-A photo-Fenton and 70 % for UV-C photo-Fenton treatments, respectively. Organic matter mineralization by Fenton treatment was monitored and no significant reduction was observed. However, organic matter oxidation in terms of COD reduction of around 30 and 40 % were achieved by Fenton and photo-Fenton processes, respectively. The photo-Fenton process with UV-C is a useful technique for atrazine degradation, leading to higher degradation than with UV-A while also being more attractive in an economic point of view.