Pollutants characterization of refining effluents effluents from acrylonitrile manufacturing by multi scale membrane filtration

Refining effluents from acrylonitrile manufacturing are very refractory to biodegradation. This paper evaluated the pollutant distribution characteristics of ANRE by means of multi scale membrane filtrations, including micro filtration (0.1 μm ~ 1 μm), 3-scale ultrafiltration (50 KD, 10 KD and 6 KD), nanofiltration and reverse osmosis. Laser particle size analyzer and nano particle size analyzer tests were also utilized as assistant measurements. The global size distribution of pollutants is below 1 μm with a median diameter of particles is 0.58 μm. More accurately, the majority of particles are distributed in ranges of 40 nm~100 nm and 180 nm~240 nm. Particulate, colloidal and soluble fractions contribute 1.4%, 9.8% and 88.2% to the initial COD. Among the soluble portions, RO rejection plays a key in limiting the biodegradability of ANRE and should be treated seriously. Contributions of the three portions to the initial ammonia are 4.4%, 6.7% and 89.0% respectively. And the soluble fraction appears to be the key element for denitrification. Contributions to the initial cyanide of the three fractions are 2.2%, 20.0% and 77.8%.