Reverse osmosis concentration of press liquid from orange juice solid wastes:flux decline mechanisms

Orange juice production produces high amount of solid waste. An alternative for these wastes is their pressing with lime to obtain a press liquor stream and a dried solid for cattle feeding. The press liquor (around 10 °Brix) is traditionally concentrated up to 70 °Brix (citrus molasses) by multiple effect evaporation. In this investigation, reverse osmosis is evaluated as an alternative for press liquor preconcentration. Two synthetic feed solutions were studied, one included pectin in its composition (WP) and the other lacked pectin (WOP) to simulate a previous depectinization of WP. The concentration process was evaluated in terms of some selected parameters (chemical oxygen demand, total soluble solids, total dissolved solids and osmotic pressure). The fouling mechanism as well as the membrane resistance to the permeate pass were assessed. It was found that for later stages of concentration cake filtration was the dominant fouling mechanism while for earlier stages, the mechanism found was the complete pore blocking. The presence of pectin not only maximized the membrane fouling but also led to worse permeate quality. © 2011 Elsevier Ltd. All rights reserved.Authors acknoweledge the Universidad Politecnica de Valencia for the financial support from the call "Primeros Proyectos de Investigacion (PAID-06-07)" included in the funding program "Programas de Apoyo a la Investigacion I+D+i". Authors also acknowledge Dr. Juan Francisco Asturiano Nemesio, from the "Grupo de Acuicultura y Biodiversidad, Institut de Ciencia y Tecnologia Animal" at the Universidad Politecnica de Valencia for his help in the osmotic pressure measurements.Garcia-Castello, EM.; Mayor López, L.; Chorques, S.; Argüelles Foix, AL.; Vidal Brotons, DJ.; Gras Romero, ML. (2011). Reverse osmosis concentration of press liquid from orange juice solid wastes:flux decline mechanisms. Journal of Food Engineering. 106(3):199-205. https://doi.org/10.1016/j.jfoodeng.2011.05.005199205106