Study On Preparation,Characterization And Application Of Modified Carbon Materials

Removal of heavy metals from marine animal protein hydrolysates has become a major task in ensuring the quality and safety of hydrolysates.Due to the special effects on immune regulation,tumor suppression,enzyme inhibition,antibacterial,antiviral,antioxidant,anti radiation and other similar aspects,Marine protein hydrolysates,which contain large amounts of bioactive peptides and particular physiological activities,have been widely used in food,health care and cosmetics industries.But the quality and safety of active peptides has been restricting the rapid development of the industry group,especially the problem of heavy metals exceeded become more prominent.In this study,a new modified carbon is prepared by using poly-aspartic acid called green food additive as raw material for the removal of heavy metals cadmium and lead in marine hydrolysates.To determinate 0.05mol/L PASP is the best make-up concentration through the preparation of modified bamboo charcoal and modified rice husk and the analysis of impacts of PASP concentration on the ability of modified bamboo charcoal and modified rice husk to adsorb heavy metals.The surface functional groups are determined by the Boehm method,we can find there are some effective functional groups which can absorb heavy metal materials attach on the surface,such as hydroxyl,carboxyl and lactones.Compared the micrographs of bamboo charcoal and rice husk before and after modification,the surface becomes smoother,less ash,lower roughness,the number of pores increased and became more regular and more uniform.The efficiency of the adsorption of heavy metal ions increased,which shows that,the method by modified bamboo charcoal and rice husk is more significant and easier to adsorb heavy metals.The adsorption of the modified bamboo charcoal for Cd2+in the boold clam shell meat enzymolysis liquid is in accordance with the pseudo-second order kinetic equation.The saturated adsorption capacity of the modified bamboo charcoal for Cd2+in the boold clam shell meat enzymolysis liquid is 135.05mg/g,while the modified rice husk for Cd2+in the boold clam shell meat enzymolysis liquid is 126.09mg/g.The response surface analysis method helps the thesis to confirm the optimal conditions that the modified bamboo charcoal and rice husk get rid of Cd2+from the boold clam shell meat enzymolysis liquid are as follows:pH=5.The removal time is 30min.The dosage is 24mg/mL.The removal rate of the modified bamboo charcoal for Cd2+is 94.20%.The optimal conditions that the modified rice husk gets rid of Cd2+from the boold clam shell meat enzymolysis liquid are as follows:pH=4.5.The removal time is 50min.The dosage is 30mg/mL.The removal rate of the modified rice husk for Cd2+is 93.40%.The removal rate of cadmium is 80%when the modified bamboo charcoal is used repeatedly,and the loss rate of the modified bamboo charcoal for nitrogen compounds in the boold clam shell meat enzymolysis liquid is 7.74%.The adsorption of the modified rice husk for Pb2+is in accordance-with the quasi-second order kinetic equation.The saturated adsorption capacity of the modified bamboo charcoal for Pb2+in the squid viscera enzymolysis liquid is 109.05mg/g,while the modified rice husk for Pb2+in the squid viscera enzymolysis liquid is 106.09mg/g.The optimal conditions that the modified bamboo charcoal and rice husk get rid of Pb2+from the squid viscera enzymolysis liquid are as follows:pH=3.5.The removal time is 30 min.The dosage is 8mg/mL,and the removal rate of Pb2+is 94.55%.The best conditions that the modified rice husk removes the Pb2+from squid viscera enzymolysis liquid are as follows:pH=3.5.The removal time is 40min.The dosage is 6mg/mL.The removal rate of Pb2+is 95.36%.The removal rate of lead is 85.05%when the modified rice husk is used repeatedly,and the loss rate of the modified rice husk for nitrogen compounds in the squid viscera enzymolysis liquid is 6.44%.The research shows that the modified bamboo charcoal and rice husk have lots of advantages,such as:high removal rate of heavy metals,less loss of nutrients,repeated usage,green,safe,simple operation,economical,practical and so on.So the modified bamboo charcoal and rice husk can be used for the removal of heavy metals from the enzymatic hydrolysate.