Study of fouling mechanism in pineapple juice clarification by ultrafiltration

Improvement on the concentrated grape juice physico-chemical characteristics by an enzymatic treatment and Membrane Separation Processes

“…The physico-chemical interactions of the layer of rejected particulates with the membrane have been referred to another aspect of concentration polarization phenomenon. Another adversely phenomenon causing fouling at the interface is related to the adsorption on the membrane pore walls and pore plugging by solute penetrate (Barros et al 2003). The membrane fouling is considered the main disadvantage of MPS application, due to the frequent cleanings or replacements of membranes and especially by increased operating costs caused by the higher power consumption, caused by the reduced permeate fl ux along time (Giorno et al 1998).…”

“…Regarding constant pressure blocking fi ltration laws, earlier proposed by Hérmia (Hérmia 1982) who applied to power-law non-Newtonian fl uids, and reformulated by Field et al (1995) for crossfl ow microfi ltration in critical fl ux, the decay on the permeate fl ux in cross-fl ow fi ltration at constant pressure was proposed by Barros et al (2003), being mathematical expressed by the Eq. 1.…”

“…Many works on the optimization of enzymatic pretreatment for clarification of fruit juice have been reported in this regard (Lee et al 2006, Rai et al 2004, Sin et al 2006). In addition, performing a pectin degradation, it is expected to reduce the membrane fouling, which is mainly caused by the colloidal constituents of the fi ltered media, resulting in a consequently drop on the fl ux in fi ltration processes (Balischi et al 2002, Barros et al 2003, Habert et al 2006, Peter-Verbanets et al 2011, Qu et al 2012). Many efforts have been devoted to improve methods such as freeze concentration, sublimation concentration and membranes for concentrated juice processing (Chen et al 1993, Köseóglu et al 1990).…”

Destabilization and removal of immobilized enzymes adsorbed onto polyethersulfone ultrafiltration membranes by salt solutions

“…Several authors [9][10][11]32] adapted these models to crossflow configuration by incorporating the flux associated with the back-transport mass transfer, which is evaluated at the steady-state [33]. Eq.…”

“…They concluded that the intermediate and complete blocking mechanisms were the models with the highest fitting accuracy for most of the operating conditions tested. De Barros et al [10] identified the fouling mechanism as a function of the membrane material used during the crossflow UF of pineapple juice previously treated with enzymes. Results after fitting the Hermia's models adapted to crossflow showed that complete pore blocking and cake formation were the predominant mechanisms when using the ceramic and polymeric membranes, respectively.…”