44 documents found, page 1 of 5
Selective denitrification of simulated oily wastewater by oxidation using Janus...
Roman, Fernanda; Díaz de Tuesta, Jose Luis; Sanches, Flávia Kim; Silva, Adriano S.; Marin, Pricila; Machado, Bruno F.; Serp, Philippe; Pedrosa, MartaThe intense industrial development has resulted in several consequences for human and environmental health, including the increased discharge of oily products in water bodies. Oily products are widely used in industry, often bearing an associated high cost. Finding alternatives to treat oily wastewater aiming at recovering oily and water phases is an approach allowing recovery of products of economic interest. ...
Selective denitrification of a simulated oily wastewater using Janus-structured...
Roman, Fernanda; Sanches, Flávia Kim; Silva, Adriano S.; Díaz de Tuesta, Jose Luis; Marin, Pricila; Machado, Bruno; Serp, Philippe; Silva, AdriánCarbon nanotubes (CNTs) bearing a Janus-like structure were synthesized by chemical vapor deposition considering ethylene and acetonitrile as carbon and nitrogen sources. The developed materials were applied as catalyst in the oxidation of 4-nitrophenol (4-NP) dissolved in a biphasic medium (water/2,2,4-trimeylpentane) simulating a contaminated oily wastewater. The CNT prepared using both ethylene and acetonitr...
Selective oxidation of 4-nitrophenol with H2O2 in a biphasic system by janus-li...
Sanches, Flávia Kim; Roman, Fernanda; Silva, Adriano S.; Díaz de Tuesta, Jose Luis; Silva, Adrián; Faria, Joaquim; Machado, Bruno; Serp, PhilippeThe use of petroleum-based products has increased drastically with the increase in population, resulting in the deposition of oily products in aquatic systems. It is estimated that for each ton of petroleum that undergoes refinement processes, between 0.5 and 1 ton of oily wastewaters are generated, bearing an oil concentration that may reach 40 g L-1 [1,2]. Hazardous pollutants dissolved both in oily and aqueo...
Amphiphilic carbon nanotubes for catalytic wet peroxide oxidation of 4-nitrophenol
Roman, Fernanda; Sanches, Flávia Kim; Díaz de Tuesta, Jose Luis; Marin, Pricila; Machado, Bruno; Serp, Philippe; Silva, Adrián; Faria, JoaquimCarbon nanotubes (CNTs) were synthesized via chemical vapor deposition (CVD) over an AlCoFeO4 catalyst by a sequential feed of ethylene (E, as carbon source) and acetonitrile (A, as nitrogen source). The resulting samples were noted E20 (hydrophobic), E10A10 (amphiphilic), and A20 (hydrophilic), the number referring to the feed time (minutes) of each precursor, as reported elsewhere1. These materials were teste...
Selective denitrification of lipophilic pollutants from oily wastewater by pero...
Sanches, Flávia Kim; Roman, Fernanda; Silva, Adriano S.; Díaz de Tuesta, Jose Luis; Marin, Pricila; Machado, Bruno; Serp, Philippe; Silva, AdriánCarbon nanotubes (CNTs) were tested as catalysts in the selective denitrification of 4-nitrophenol (4-NP) from oily wastewater by catalytic wet peroxide oxidation (CWPO). The CNTs were prepared by chemical vapor deposition, feeding sequentially ethylene (E) and/or acetonitrile (A) during different times until 20 min, resulting in samples E20, A20 and E10A10, the number denoting the time feeding of each precurso...
Carbon nanotubes as catalysts for wet peroxide oxidation: the effect of surface...
Martin-Martinez, Maria; Machado, Bruno; Serp, Philippe; Morales-Torres, Sergio; Silva, Adrián; Figueiredo, José; Faria, Joaquim; Gomes, HelderThree magnetic carbon nanotube (CNT) samples, named A30 (N-doped), E30 (undoped) and E10A20 (selectively N-doped), synthesized by catalytic chemical vapor deposition, were modified by introducing oxygenated surface groups (oxidation with HNO3, samples CNT-N), and by heat treatment at 800 °C for the removal of surface functionalities (samples CNT-HT). Both treatments lead to higher specific surface areas. The ac...
Janus amphiphilic carbon nanotubes as Pickering interfacial catalysts for the t...
Díaz de Tuesta, Jose Luis; Machado, Bruno; Serp, Philippe; Silva, Adrián; Faria, Joaquim; Gomes, HelderJanus-like amphiphilic carbon nanotubes (CNTs) were tested as catalysts in the oxidation of 2-nitrophenol (2- NP) with hydrogen peroxide. A biphasic oil-water medium was used to simulate oily wastewater contaminated with the lipophilic model pollutant 2-NP. The CNTs were synthesized by sequentially feeding ethylene and/or acetonitrile, used as carbon and carbon/nitrogen precursors, respectively. The results obt...
Carbon nanotube catalysts for the cwpo of 2-nitrophenol in biphasic systems: ki...
Díaz de Tuesta, Jose Luis; Machado, Bruno; Serp, Philippe; Silva, Adrián; Faria, Joaquim; Gomes, HelderCarbon nanotubes (CNTs) were used as catalysts in the removal of 2-nitrophenol (2-NP) by catalytic wet peroxide oxidation (CWPO). Different CNTs were synthesized by catalytic chemical vapour deposition (CVD) using Fe/γ-Al2O3, as described elsewhere (Purceno et al., 2015 and Martin-Martinez et al., 2016). A fluidized-bed reactor was employed by feeding a gas mixture of hydrogen and: i) ethylene alone for 30 min ...
Kinetic modelling of wet peroxide oxidation with N-doped carbon nanotubes
Díaz de Tuesta, Jose Luis; Machado, Bruno; Serp, Philippe; Silva, Adrián; Faria, Joaquim; Gomes, HelderCarbon nanotubes (CNT) were tested as catalysts in the removal of 2-nitrophenol (2-NP) by catalytic wet peroxide oxidation (CWPO). The CNT materials were synthesized by catalytic chemical vapour deposition in a fluidized-bed reactor, as described elsewhere [1,2]. In order to synthesize a CNT with different characteristics, ethylene and acetylene were feeding as follows: 1) ethylene for 30 min (resulting in cata...
Catalytic wet peroxide oxidation with modified carbon nanotubes
Martin-Martinez, Maria; Machado, Bruno; Serp, Philippe; Morales-Torres, Sergio; Silva, Adrián; Figueiredo, José; Faria, Joaquim; Gomes, HelderCatalytic wet peroxide oxidation (CWPO) uses H2O2 as a source of hydroxyl radicals (HO) for the oxidation of organic species. This process is regarded as a potential solution for the treatment of aqueous effluents containing recalcitrant and toxic organic pollutants, difficult to remove by conventional biological processes, mainly if present at high concentrations (1- 10 g L-1) [1]. In a recent study, three ma...