Application of reverse osmosis to remove aniline from wastewater

The presence of organic toxic solutes in industrial wastewater is a common environmental problem. Aniline is known to be a harmful and persistent pollutant and its presence in wastewater requires treatment before disposal. The performance of reverse osmosis to remove aniline from aqueous solutions is studied in this paper. The study has been carried out in a flat membrane test module using three thin layer composite membranes, two of polyamide, HR98PP and SEPA-MS05, and one of polyether sulphone, DESAL-3B. Recycling of both concentrate and permeate has been carried out in order to keep the feed concentration practically constant and so simulate a continuous process in a quasi-stationary state. The influence of different operational variables (pressure, feed volumetric flow rate, feed concentration and pH) on the performance of the aniline removal process is analyzed.

The performance of reverse osmosis to remove aniline from aqueous solutions is studied in this paper. Three thin layer composite membranes, two of polyamide, HR98PP and SEPAMS05, and one of polyether sulphone, DESAL-3B, has been used. The influence of operational variables such as pressure, feed volumetric flow rate, feed concentration and pH on the rejection and permeate flow rate has been analyzed. The highest rejections are obtained with HR98PP membrane (91.8%) and the lowest rejections with MS05 membrane (79.0%). Aniline rejection slightly increases with pressure and feed aniline concentration for the three tested membranes. The observed changes in aniline rejection with pH are related to the charge of ionizables groups in the membrane structure and to the net charge of aniline molecule as a result of its dissociation equilibrium. Permeation rate increases with operation pressure, but no significant variations with feed aniline concentration and pH are observed. No discernable trend of feed volumetric flow rate on performance is obtained for all three membranes tested.