Study On Resins Adsorption To Recovery Quebrachitol From Natural Rubber Processing Wastewater

Quebrachitol (2-methoxy-L-(-)-inositol) is a drug and pharmaceutical rawmaterials with sinistral structure, accounting for about0.2%-1.9%of the latex byweight. In the traditional extraction, the rude quebrachitol was obtained from thewaste water produced by coagulating or centrifuging latex using the heating-concentration method, and separated and purified by the traditional chemicaltechnology. Because of the large amount of wastewater generated by coagulating orcentrifuging latex and the huge energy consumption of the traditional extractionmethod, it was difficult to realize industrialization for quebrachitol. So thequebrachitol in the natural rubber was mostly discharged with the wastewater, whichleads to a great waste of resource. Based on this current situation, the novel extractionmethod of quebrachitol and its effect on the wastewater emission targets were studiedin this paper.According to the composition of the natural rubber processing wastewater, weselected five hydrogen bond type adsorption resins include HcR, PcR,PTER,ADS-7and ADS-17ranging from the non-polar to strong polar, adsorption and desorptionexperiment results showed that the strong polarity of the ADS-17, had a better effectin quebrachitol’s adsorption and desorption, And after an equilibrium time of2h, theadsorption capacity could reach5.6mg/g dry resin. Then the rude quebrachitol wasgained by dynamic adsorption experiment. After purification, the analysis of IR, TGA,NMR indicated that the extracted material was quebrachitol and its extraction rate was0.1%, which proved the extraction process was reasonable.The effect of the five adsorption resin to the natural rubber processingwastewater emission targets including COD, total nitrogen and total phosphorus wasalso studied. The result demonstrated the five resins could reduce natural rubber processing wastewater emissions targets at a certain degree, among which theADS-17macroporous resin had the best effect. The fresh latex coagulationwastewater COD, total nitrogen and total phosphorus were reduced from20.0g/L to14.7g/L,7.3mg/L to6.6mg/L and3.3mg/L to1.1mg/L respectively. And theCOD, total nitrogen, total phosphorus of centrifugal wastewater of the concentratedlatex decreased from22.5g/L to11.2g/L,14.8mg/L to8.4mg/L and4.2mg/Lto0.6mg/L respectively.