Full-scale vibrating pervaporation membrane unit: VOC removal from water and surfactant solutions

Abstract

A commercial-scale vibrating membrane system was evaluated for the separation of volatile organic compounds (VOCs) from aqueous solutions by pervaporation. Experiments with surrogate solutions of up to five VOCs in the presence and absence of a surfactant were performed to compare performance of the full-scale vibrating system with that previously observed at the laboratory-scale as well as the performance of the same full-scale system during a recent field demonstration project. The primary process variables studied were amplitude of vibration, temperature, liquid flow rate, and permeate pressure. Data were obtained with two types of silicone rubber membranes-a thick (254 m) fiberglass reinforced silicone membrane and a more typical pervaporation membrane consisting of a 10 m silicone layer on a microporous support. The full-scale vibrating system delivered mass transfer coefficients comparable to those observed at the laboratory-scale and, under certain conditions, were comparable to those obtained with spiral wound pervaporation modules.

Pervaporative recovery of volatile aroma compounds from fruit juices

“…In fact, Baker et al [90] state that, for highly hydrophobic VOC's, such as most aroma compounds, concentration polarization in pervaporation is often so severe that it cannot be overcome even at the highest practical turbulence. In order to minimize this problem, some authors have focused on module design, proposing the use of transverse flow configuration [207][208][209], turbulence-enhancing spacers [172,210] and even vibrating units [211,212]. Bearing in mind that pervaporation and vapor permeation are rather similar membrane process and that the latter is less sensitive to concentration polarization, Ribeiro et al [213] proposed an alternative aroma recovery process, in which aroma extraction is brought about by gas stripping in a bubble column and aroma concentration is performed by vapor permeation.…”

Modeling and multi-response optimization of pervaporation of organic aqueous solutions using desirability function approach

“…In this case, the overall desirability D is also equal to 1. In a real situation, we are interested in maximizing the overall desirability function D (x), which may be computed as geometric mean of the individual desirability functions d i ŷ i (x) as shown in the following equation [40][41][42][43]: (14) where m denotes the number of responses. Note that if an individual desirability function is completely undesirable, i.e.…”

“…For example, vacuum membrane distillation has been tested for the removal of VOCs from water [5][6][7][8]. Furthermore, pervaporation has been proved as a promising separation process for VOCs removal from aqueous feed solution using different types of membranes [5,[9][10][11][12][13][14][15][16][17][18] and has the potential to be one of the most common techniques in environmental engineering for water purification. The performance of both separation processes, i.e.…”

Multipass membrane air-stripping (MAS) for removing volatile organic compounds (VOCs) from surfactant micellar solutions

“…Over the years, many contaminant-surfactant separation methods have been developed, such as air-stripping [20][21][22][23], vacuum stripping [24], pervaporation [25,26], solvent extraction [20,[27][28][29][30], ion exchange [31], activated carbon adsorption [17,32], reverse micellar extraction [33], precipitation [34,35], and phase behavior manipulation [36]. The advantages and limitations of these technologies have been discussed in a recent review [37].…”