ANAEROBIC TREATABILITY OF SELECTED ORGANIC TOXICANTS IN PETROCHEMICALWASTES

The objective of this research was to study the biodegradability of et hylene glycol, acrylic acid. acrolein and allyl alcohol using a methan ogenic acetate enrichment culture. Anaerobic Toxicity Assays (ATA) and Biochemical Methane Potential (BMP) studies were performed with serum bottles. Ethylene glycol was found to be degraded to less than 5 mg/l with spikes up to 10,000 mg/l. Higher concentrations led to pH inhibi tion even with a design initial bicarbonate alkalinity of 6000 mg/l as CaCO3. Acrylic acid was degraded with almost no effect on methanogens with spikes up to 100 mg/l. However, concentrations of 500, 1000 and 1500 mg/l were found to inhibit the methanogens for several days befor e recovery. Acrylic acid was eventually degraded to less than 1 mg/l i n all cases. Acrolein was inhibitory at concentrations as low as 10 mg /l. However, recovery of the culture was observed at concentrations up to 150 mg/l. Allyl alcohol was cometabolized when acetate was supplie d to the bottles in the ATA; it was not degraded well when supplied as the sole carbon source in the BMP study. Ethylene glycol and acrylic acid were found to be suitable for anaerobic treatment whereas allyl a lcohol and acrolein were not suitable at the selected concentrations u sing a methanogenic culture.