Modeling and experimental validation of direct contact membrane distillation applied to synthetic dye solutions

Abstract

AbstractBACKGROUNDIn order to protect water resources and reduce the harmful effects of releasing contaminated wastewater to the environment, the textile industry has increasingly demanded improved water reclamation technologies, such as membrane distillation. In this work, theoretical and experimental investigations were carried out to evaluate the behavior of the operational parameters of a direct contact membrane distillation (DCMD) setting with a commercial membrane applied to synthetic dye solutions, simulating textile wastewater from the fabric dyeing stage.RESULTSThe analytical model based on heat and mass transfer correlations specific to textile effluents implemented using Matlab® predicted the permeate flux with good agreement, with errors less than 10% when compared with the experimental values. There was a different trend for reactive and disperse dyes when input variables were changed. In general, increasing all variables led to an increase in permeate flux. An increase of 30 °C in the feed temperature increased by 2.0‐ to 2.3‐fold the permeate flux. Moreover, the simulation showed the influence of the permeate temperature and the membrane interface temperature on the permeate flux, which is not commonly achieved experimentally.CONCLUSIONSThe hybrid modeling supported by extensive experimental validation accurately predicted the permeate flux in DCMD to recover water from synthetic dye solutions containing reactive and disperse black dyes. DCMD is a promising technology for recovering textile wastewater containing these dyes, as it can use the waste heat from the hot effluent discharge. Therefore, this work can contribute towards the scaling up of DCMD, aiding in predicting and optimizing the operational variables. © 2020 Society of Chemical Industry (SCI)