Aerobic and anaerobic treatment of DMAc and NMP - Treatment options for membrane production

N,N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP) are solvents that are used for the production of polysulfone-based membranes. The resulting solvent-containing wastewater is treated or disposed of externally. The associated effort can be reduced by treating the wastewater on site. Laboratory tests using moving bed biofilm reactors (MBBR), two-stage vertical flow constructed wetlands (VFCW) and anaerobic processes were conducted to select a suitable technology for this purpose.The results showed that the solvents DMAc and NMP were well aerobically degradable. The MBBR and VFCWs achieved in average DOC removal efficiencies of 95 % and 98 %, respectively. The nitrogen contained in the solvents was completely nitrified in the VFCWs, whereas nitrification in the MBBRs was dependent on the load. The results of the anaerobic tests differed significantly. DMAc was almost completely degraded. NMP, on the other hand, was slowly degradable under anaerobic conditions.