Pollutants Characterization of Spinning Effluents Containing Dimethyl Formamide from Dry-Spun Acrylic Fiber Manufacturing by Multi Scale Membrane Filtration

Abstract

Spinning effluents (SE) from dry-spun acrylic fiber manufacturing are hard to biodegrade due to the high concentration of dimethyl formamide (DMF). This paper evaluated the pollutant distribution characteristics of SE by means of multi scale membrane filtritions, including microfiltration, ultrafiltration, nanofiltration and reverse osmosis. Scanning electron microscopy (SEM) and nano particle size analyzer (NPSA) tests were also used as assistant measurements. The major pollutant diameters in SE range from 20 nm to 30 nm with a statistical median size of 300nm. The particulate, colloidal and soluble organic fractions contribute 8.44%, 37.13% and 54.43% to the initial COD. 11.4%, 13.67% and 71.92% of the initial DMF distributes in the particle, colloidal and soluble portion respectively. The data of ammonia are relevantly 22.17%, 11.45% and 56.38%, indicating that the soluble fraction, which is also poor in biodegradability, plays a key role in SE treatment. Beside, the majority of AN distributes in the soluble range while 90.98% of cyanide distributes in the particulate and supracolloidal portions.