Lignosulfonates from calcium spent sulfite liquor (CaSSL) recovery using ANIC ultrafiltration membranes

In this paper, some experimental results on treatment of calcium sulfite spent liquor by ultrafiltration are presented. The membranes were prepared by casting chemically modi- fied polyvinylidene fluoride, and showed interesting performance in comparison with other membranes usually used in this application. On the basis of the results obtained, the membranes showed (1) noticeable resistance towards temperature and pH; (2) good stability in long term performance.