Study On Treatment Technologies Of Wastewater From Butanol And Octanol Production

The aldol wastewater produced during the production of butanol and octanol in theNo. 2 Fertilizer Factory, Qilu Petrochemical Company, whose COD concentration isup to 40000mg/L, is the major pollutant source affecting the main sewage COD indexof the No. 2 Fertilizer Factory and Ethylene Sewage Disposal Plant. And thus the cost ofsewage treatment is more than￥4.8 million. This paper proposed the method treatingthis high concentration organic wastewater with acidification and extraction on the basisof wastewater treatment technologies and research works home and abroad. This paperstudied the effect of pH value, temperature, extractants and their dosage on extractionefficiency. The experiment results showed that the solvent extraction is a very validmethod for treating high concentration wastewater from butanol and octanol production.The organic substances in the wastewater can be separated and recovered. Acidificationis the essential condition of extraction. By acidification, sodium butyrate in the basicwastewater can be converted into butyric acid. The solubility of extractant, butylaldehyde and butanol in water can also be reduced greatly. Therefore, they can beextracted and separated easily. Using octanol, octanol residue and octylene aldehyderesidue as extractants, extracting the aldol wastewater under the condition of pH 1～3,the volume ratio of extractant to wastewater 1:(1～12), temperature 25～60℃, quite gooddisposal effect can be obtained. The removal efficiency of COD can be up to 83～94%.The COD concentration of main sewage of the No. 2 Fertilizer Factory can be reducedfrom 2209mg/L to 704mg/L. Considering economical during extraction, octylenealdehyde residue is recommended. Combining with the actual production, the volumeratio of extractant to wastewater had better be 1: (4～5). Under this condition, high CODremoval efficiency can be made sure with as few extraction stages as possible. Underthe scope of experiment, the effect of extractant dosage and the temperature on thewastewater treatment is not very great, the COD removal efficiency increase slowlywith the increase of extractant dosage and the temperature. So, in the process ofextraction, do not need to control the temperature of extraction system designedly, buthad better adapt to the original temperature of production system only.