Study On Adsorption Of Cadmium In Glycosaminoglycan From Two Seashells By Attapulgite-chitosan Adsorbent

Polysaccharide is one of the important macromolecules in organismand,andhas important physiological functions, such as the regulation of immune,anti-tumor,anti-virus and so on, which indicates its promising application in the field of medicineand health care products. Pinctada martensii and Crassostrea rivularis are the largernumber of China’s seashells, and the glycosaminoglycan extracted from them areimportant active substances. However, due to serious pollution of sea water aboutheavy metals in recent years, the two kinds of seashells are with a strong enrichmentability of heavy metals, therefore, the glycosaminoglycan security is affected seriously.To reduce heavy metal content of glycosaminoglycan from the two kinds of seashells,improving their safety and value, the paper studied on the reduction of the heavymetal cadmium content in glycosaminoglycan from two seashells.The main researchconclusions are as follows:Modified natural attapulgite by use of chitosan, preparaing attapulgite-chitosancomplex was studied in the paper. The preparation condition of the complex wereoptimized, and the optimum combination conditions was the heat treatmenttemperature is700℃, the concentration of chitosan is3%,the ratio of chitosan geland attapulgite is3:1, the maximum chitosan loading rate was33.3%; The resultsshowed that the cluster structure of attapulgite-chitosan had great difference withnatural attapulgite clay, which changed from needle-like structure into a layeredmaterial, and the chitosan load on it, developing a kind of greater surface area ofporous material.Absorting the cadmium of hydrolyzate of Pinctada Martensii whole organ byattapulgite-chitosan complex was study in our research. The effeets of pH, time，thedosage of chitosan and speed on cadmium removal rate and GAG yield wereinvestigated by single faetor experiments. It edueed the ranges in quadraturere action.By CCD and Response Surfaee Methodology analysis showed that the optimizeconditions were: pH7.0, shaking time32min, attapulgite-chitosan13.5mg/mL andshaking speed133r/min, cadmium removal rate was75.4%, GAG yield was43.0%. Absorting the cadmium of hydrolyzate of Crassostrea Rivularis whole organ byattapulgite-chitosan complex was study in our research. The effeets of pH, time，thedosageof chitosan and speed on cadmium removal rate and GAG yield wereinvestigated by single faetor experiments. It edueed the ranges in quadraturere action.By CCD and Response Surfaee Methodology analysis showed that the optimizeconditions were: pH7.5, shaking time33min, attapulgite-chitosan7.0mg/mL andshaking speed146r/min, cadmium removal rate was73.5%, GAG yield was44.1%.Through the removal of cadmium in glycosaminoglycan from the two seashellsfound that, the attapulgite-chitosan complexes can effectively reduce the cadmiumcontent of the glycosaminoglycan, indicating that the composite adsorbent has acertain value.