Study On The Anerobic Biodegradatbility Of The Potassium Sorbate Production Wastewater Using Anaerobic Baffled Reactor

Potassium sorbate is an acidic preservative. Highly concentrated organic potassium sorbate wastewater from the production of sorbate process consists mostly of butenal wastewater, potassium sorbate wastewater, a small amount of carrier fluid and circulatory water. The potassium sorbate wastewater was composed of a number of unsaturated fatty acids, aldehyde ketone, lactone and inhibiting toxic substance. It is made up of a number of substances which has pH 3~5 and a CODcr between 20,000~40,000 mg/L. Existing aerobic treatment is unable to achieve the national discharge standards of this wastewater.To improve the anaerobic biodegradability of the potassium sorbate wastewater and provide advantageous operation condition for the aerobic treatment through the anaerobic treatment, this paper studies the anaerobic biodegradability of the potassium sorbate wastewater using biochemical methane potential (BMP) and anaerobic toxicity assay (ATA). This experiment studied the treatment of the potassium sorbate wastewater using anaerobic baffled reactor (ABR).(1) In the BMP test when the dilution was 51.9%, the experimental wastewater had a COD removal efficiency of 80.3% and anaerobic biodegradability rate of 20.9%.So the potassium sorbate wastewater could be treated using the anaerobic treatment.(2) In the ATA experiment, the COD concentration of experimental wastewater was about 5000mg/L.when the dilution was 40.0%, the experimental wastewater had a maximum COD removal efficiency of 97.9 %. It showed that the potassium sorbate wastewater contained biological inhibitory compounds, but its toxicity was weak to the anaerobic sludge.(3) The experiment of treatment the potassium sorbate wastewater using ABR started with a low organic loading rate (OLR) of 0.5 kgCODcr/m3d at ambient temperature. When the start-up of the ABR was finished, the OLR was up to 2.85 kgCODcr/m3d. The maximum CODcr removal efficiency could reach 97.9 % and granules generated in the all sixcompartments at the end of the experiment.So the potassium sorbate production wastewater could be treated using the anaerobic treatment. Its anaerobic biodegradability was improved after it was treated with ABR. This showed that subsequent wastewater could be treated under these conditions.