Use of coalescer with a bed made of cationic exchange resins for pre-treatment of emulsified oil from oily wastewater

O tratamento de efluentes com coalescedor de leito consiste em induzir o aumento das gotas de óleo, pela passagem da emulsão por um leito poroso, para que elas possam, posteriormente, flotar por processo de separação gravitacional. O objetivo deste artigo foi apresentar considerações técnicas e experimentais sobre o uso do coalescedor de leito granular, com leito constituído por resinas de trocas catiônicas, visando o pré-tratamento de óleo emulsionado em efluentes líquidos. Os testes ocorreram em uma unidade em escala de bancada alimentada com emulsão óleo em água (O/A) com um teor de óleos e graxas (TOG) entre 200 e 400 mg.L-1 e diâmetro de gotas entre 3 a 8 μm. As velocidades do fluido (v) testadas foram entre 4,4 e 17,4 m.h-1. A altura do leito do coalescedor foi fixada em 5 cm. Os parâmetros usados para avaliar a eficiência dos testes foram eficiência de remoção de óleo (%E), pressão diferencial através do leito (Δp) e permeabilidade do leito (ko). Os resultados mostraram que o processo operou em estado estacionário e que os valores de TOG testados influenciaram no processo, bem como as velocidades do fluido, cuja elevação reduziu a eficiência significativamente. Os valores aproximados de %E obtidos foram 50 e 20-30%, para valores de v de 4,4 e 17,4 m.h-1, respectivamente202235242The wastewater treatment with a bed coalescer consists of inducing the increase of oil droplets by passing the emulsion through a porous bed, so they can flote by gravitational separation process. The objective of this paper is to present technical and experimental considerations on the use of a granular bed coalescer, with a bed made of cationic exchange resins, for pre-treatment of emulsified oil from oily wastewater. Tests were conducted on a bench scale unit, which was fed with oil in water emulsion with oil and grease concentration (O & G) between 200 and 400 mg.L-1 and oil droplet diameter between 3 and 8 μm. The fluid velocities (v) tested were between 4.4 and 17.4 m.h-1. The coalescer bed height was fixed at 5 cm. The parameters used for assessing the tests efficiency were oil removal efficiency percentage (%E), differential pressure across the bed and, bed permeability. Results showed that the process operates in a steady-state condition and that the influent O&G affected the process efficiency, as well as the fluid velocities which reduced the efficiency significantly, with its increasing. The %E values obtained ​​were between 50 and 20-30% to v between 4.4 and 17.4 m.h-1, respectivel

Processo combinado de evaporação por contato direto e permeação de vapor para tratamento de sucos de frutas

Em 19/12/2016:Restauração de pedido, patente ou certificado de adição de invençãoConcedidaApresenta-se uma rota de processamento em duas etapas para a obtenção de sucos de frutas concentrados com elevados teores de sólidos solúveis e melhores qualidades sensoriais. Na primeira etapa, efetua-se o arraste por gás inerte dos compostos voláteis de aroma do suco e sua subsequente recuperação em um módulo de permeação de vapor com uma membrana organofílica. O suco, desprovido dos compostos voláteis de aroma, segue para a etapa de concentração em um evaporador por contato direto, no qual, basicamente, borbulha-se um gás inerte superaquecido através do suco. Ao final do processo, os aromas recuperados no módulo de membrana podem ser re-adicionados ao suco concentrado para a obtenção do produto final

Bacuri and macaxeira waste: physical-chemical characterization and production of coconut bioaroma by solid-state fermentation

Agro-industrial waste is considered a global concern. Many of these residues are composed of considerable amounts of lipids and starch that can potentially be applied in bioprocesses, as is the case with residues from the bacuri fruit (Platonia insignis Mart.) and sweet cassava (Manihot esculenta Crantz), practically unexploited in the bioproduction of aromas. This work aimed to characterize these residues and evaluate the bioproduction of coconut aroma 6-pentyl-α-pyrone from solid-state fermentation using the fungi Trichoderma harzianum. The waste underwent characterization. Fermentations were conducted under different humidification conditions (water, nutrient solution without additives, and nutrient solutions with glucose or sucrose) for nine days. Aromatic compounds were extracted by solid-phase microextraction and subsequently quantified by gas chromatography. Analyses with bacuri residue revealed the presence of some compounds with nutritional potential for the fungus. Still, the inhibition halo detected for Trichodermaproved others, such as resinous derivatives that were probably responsible for the lack of growth and bioproduction. In sweet cassava, the compounds detected were not growth inhibitors and had low aroma production, not exceeding 7 ppm (weight/weight). Strategically, these residues were mixed and, in the presence of a nutrient solution with sucrose, a maximum production of 202.46±1.30 ppm (w/w) of 6-pentyl-α-pyrone was achieved, proving an excellent alternative. Cassava probably served as an environment for easy germination of fungal spores and bacuri, as an important source for bioexploitation of nutrients, especially lipids, resulting in increased production of 6-pentyl-α-pyrone

Performance evaluation of composite and microporous gas–liquid membrane contactors for CO2 removal from a gas mixture

Hollow fiber membrane contactors with microporous polypropylene (PP) and composite polytetrafluoro- ethylene/polyethersulfone (PTFE/PES) were used for carbon dioxide (CO2) removal from a gas mixture. The composite membranes exhibited higher efficiency than the microporous membranes, which was related to prevention of pore wetting due to the PTFE present in the top layer of the membrane. For both type of contactors, it was investigated the influence of liquid flow rate, temperature and kind of absorbent on the CO2 removal. A better performance of CO2 transfer into the liquid phase was observed by increasing the liquid flow rate, by using a reacting absorbent (sodium hydroxide) and by decreasing the liquid temperature

Evaluation of membranes for the treatment of oilfield-produced water

Large quantities of water are generated during oil extraction. Reinjection of this effluent is frequently the most suitable option for environmental considerations. For this purpose, the water produced must have characteristics that will prevent the plugging of the reservoir rocks, i.e., suspended solids and oil and grease content must be lower than 5 mg L-1. This work evaluated the performance of membranes for water treatment, based upon long-term experiments with real effluent, evaluating the permeate flux over time and the effluent characteristics. The results indicated that it is possible to obtain a permeate flux with suspended solids content with less than 1 mg L-1 oil and a grease concentration in the range of 1 to 3 mg L-1 using membranes with a pore size of 0,1 m. After 50 hours of permeation, the permeate fluxes obtained with the polymeric and ceramic membranes were equal to 50 and 300 L h-1 m-2, respectively. With a chemical regeneration procedure, it was possible to recover 95% of the ceramic membrane’s original permeability and 30% of the polymeric membrane’s permeability. Considering the permeate quality, the regeneration efficiency of the membrane and the fluxes achieved, it is possible to point out the use of ceramic membranes as a potential technology for treating oilfield-produced water, and it has the advantage of being a compact and robust process

Dual-layer hollow fibers for gas separation processes produced by quadruple spinning

A novel quadruple spinneret to produce dual-layer hollow fiber membranes by simultaneous spinning of two polymer solutions, using the dual precipitation bath technique is proposed. Hollow fibers aimed at gas separation processes were prepared in extrusion system specifically designed and built for this purpose. A polyurethane polymer was selected as the selective layer (outer-layer), while polyethersulfone was defined as the support (inner-layer). Activated carbon powder was added into the PU solution for further improvement of the transport properties. The hollow fibers showed good adhesion between the polymer layers and a defect-free selective layer. Representative results include a CO2/N2 selectivity of 43