SEPARATION OF NITROCELLULOSE USING INORGANIC MEMBRANE (MF/NF ) SEPARATION SYSTEM
Nitrocellulose (NC) is a basic constituent for military gun propellants and has civilian applications in photographic films and paints. NC wastewater is a by-product of the NC manufacturing process. The environmental impact of NC is currently a major concern, mainly due to its higher reactivity and toxicity, a fact that makes this compound highly harmful. A pilotscale microfiltration and nanoflitration (MF/ NF) filtration system was constructed to study the feasibility of NC recovery from the industrial wastewater generated from NC manufacture process. Batch concentration mode experiments were performed on the synthetic and real wastewater at different operating parameters. The performance of the MF and NF membranes was evaluated in terms of TSS, TDS, TOC, COD and UV absorbance, conductivity and turbidity. The scanning electron microscope (SEM) for both the original and used membranes showed that the MF membrane was fouled only by NC fines the MF/NF process, allowed the recovery of NC fine from industrial wastewater and reuse more than 80% of the original wastewater. The quality of NF permeates obtained at trans membrane pressure of 5 bar and crossflow velocity 7 m/s showed low values of salts: 300 mg/L, conductivity: 290 μS/cm, COD less than 5 mg/L. and non-detected TOC. The permeate quality obtained from MF/NF system in the present work satisfied with the Egyptian Environmental Law (Law 4/1994). Empirical correlations have been developed to permit quantitative estimation of flux based on prevailing operating conditions. Further, quantitative analysis of fouling resistance has been developed with emphasis on the contribution of the different components of the resistance namely Rc, Rm, Ri and Rt. The results in general confirm that technical feasibility of concentration and recycling of NC fines and the recovery of high quality clean water based on MF, NF inorganic membranes.
AA ISMAIL, YA ABDELAZIZ AND L. GIORNO