Abstract: In the process for preparation of sisal fiber,waste liquor that containing sisal saponin is by-produced.In order to make use of the saponin,enrichment process is to be performed.Traditional enrichment process was based upon extraction with an organic solvent.A new approach using a surfactant was tested via a series of experiment.Suitable process conditions were obtained as follows:extracting agent,sodium lauryl sulfate with concentration of 0.025 8 mol/L;ratio of starting material to extracting agent,1∶10 (g∶mL);pre-soaking time,4 h;ultrasonic power,120 W;extraction time,40 min for three times.The extract was further processed for enrichment of the sisal saponin in 100 mL extract under conditions as:temperature,50 ℃;adding 20 mL of 1% aluminum chloride polymer,followed by adding 2 mL of 0.1% cationic polyacrylamide.Under the above mentioned conditions of extraction and flocculation,the flocculated material was hydrolyzed by sulfuric acid.Results show that as comparing with the traditional process,the new approach can increase the product yield for 15.5%,decrease 81.2% of acid consumption and 96.5% of COD discharge per 1 g sisal saponin.

Key words: surfactant, extraction, flocculation, sisal saponin