Study on facultative biodegradability of terephthalic acid in polyester fabric alkali-peeling process wastewater

Key words: 
• facultative biodegradation /
• hydrolysis-acidification /
• terephthalic acid /
• polyester fabric alkali-peeling process wastewater (PAP-wastewater)

Abstract: Aimed at the negative influence of ethylene glycol (EG) on the aerobic biodegradation of terephthalic acid (TA) in the polyester fabric alkali-peeling process wastewater (PAPwastewater), the facultative biodegradability of terephthalic acid (TA) and ethylene glycol (EG), especially the facultative biodegradability of TA in the presence of EG, were studied under the lab conditions by hydrolysis-acidification process. Under the anoxic condition there was a low biodegradability of TA with a mean removal rate of 6.11% when TA was served as the sole carbon source, while the removal rate of EG was 58.9%～71.5% when EG and TA were served as the feed under the same condition. The experimental results indicated that the facultative aerobe had a very low activity for TA, but higher for EG. EG could not enhance the facultative biodegradability of TA when EG was added to TA artificial wastewater. TA began to degrade gradually after EG was depleted, and the removal rate of TA was equal to that before EG was added. From these observations it was concluded that the aerobic biological treatment process should be employed in the treatment of PAP-wastewater, coupled with facultative or anaerobic biological treatment process.