VOCʹs removal from water with a hybrid system coupling a PTMSP membrane module with a stripper Original Research Article

The treatment of waste water streams containing low amounts of VOCʹs is still quite difficult to handle. In particular, for small or medium flow rates this problem remains most often unsolved by conventional techniques orcannot be treated directly at the source to authorize water recycling in the process. This study is concerned with thisaspect and has investigated theoretically and experimentally a hybrid system which should allow recovery of VOCʹs and recycling of purified waste water. This system is based on an initial VOCʹs stripping step followed by the removal of VOCʹs by membrane permeation. The simulation of the system was first carried out with experimental resultsconcerning only the membrane permeation step. Then a lab scale membrane module was constructed and combinedin a closed loop with a stripper to recycle, on one hand, the stripping gas and, on the other hand, the purified water. As typical cases, the removal of toluene and dichloromethane from water was simulated under the following conditions:waste water flux of ≈ 1 m3/h with a VOC concentration of 0.1–0.6 wt%, stripping column of 2 m height, inert gas flux of 400–1000 NL/h, module of 0.8 m2. The experimental results obtained were compared to the simulation ones and discussed in the light of original polymer properties (PTMSP).