Bleaching with the Mixed Adsorbents of Activated Earth and Activated Alumina to Reduce Color and Oxidation Products of Anchovy Oil

Fish oil is a rich source of polyunsaturated fatty acids,and its refinement has drawn attention for years.An appropriate adsorbent can effectively remove the pigment impurities in the fish oil.This study evaluated the impact of different absorbents on the reduction of oxidation products and color of anchovy oil during the decolorization under high vacuum.Using the single factor design,four process parameters including adsorbents type,adsorbent amount,temperature and time were tested to determine the optimum decolorization parameter.The results showed the optimum decolorization conditions were that the fish oil was treated with 8%acti-vated alumina at 80℃for 40 min.In the central group experiment,the addition amounts of mixed absorbents(activated earth and activated alumina),including the mass ratio of adsorbent in oil(5%-11%,w/w)and the mass ratio of activated earth in total absor-bent(20%-80%,w/w)were optimized to remove the oxidation products.Under the optimum condition at 10.18%of adsorbent and 70%of activated earth,the total oxidation value(TOTOX value)showed the minimum with the 44.4%of removal rate.Eight metal elements were analyzed in decolorized oil using inductively coupled plasma mass spectrometry(ICP-MS).The removal rates of Zn and Pb were 94.12%and 55.35%,respectively.The decolorization process using mixed absorbents under appropriate condition can significantly reduce the oxidation products and pigments in fish oil,which will benefit the industrial production of fish oil.

Aluminum and Activated Alumina Powder Additions on Microwave Synthesis of Al_(4)SiC_(4)

Aiming at improving the properties of magnesia carbon materials,silicon aluminum carbide(Al_(4)SiC_(4))containing materials were prepared using industrial aluminum powder,silicon carbide powder,and graphite as raw materials,and activated alumina powder as an additive,mixing thoroughly,pressing into cylinders and then firing at 1200℃for 30 min in a carbon embedded atmosphere by the microwave method.The effects of the aluminum powder addition(20%and 24%,by mass)and activated alumina powder addition(0,3%,5%and 7%,by mass)on the microwave synthesis of Al_(4)SiC_(4) as well as the effect of the obtained Al_(4)SiC_(4) containing material on the properties of magnesia carbon bricks were studied.The results show that:compared with the samples with 20%aluminum powder,those with 24%aluminum powder generate more Al_(4)SiC_(4).With the activated alumina powder addition increasing from 0 to 7%,the amount of Al_(4)SiC_(4) generated increases first and then decreases.Compared with the sample without activated alumina powder,the samples with activated alumina powder show lower bulk density and higher apparent porosity.With the activated alumina powder addition increasing from 3%to 7%,the bulk density of the samples increases first and then decreases,while the apparent porosity of the samples shows an opposite trend.The optimal additions are 24%aluminum powder and 5%activated alumina powder,and Al_(4)SiC_(4) synthesized in this sample has a hexagonal plate structure.With the synthesized Al_(4)SiC_(4) containing material added,the magnesia carbon brick has slightly increased cold modulus of rupture,basically the same modulus of elasticity and improved oxidation resistance.

Preparation of Benzene Adsorption Materials Using Waste Activated Alumina

A new type of benzene adsorption material was prepared by using the airtight heat treatment method.This method can directly transform the organic impurities of the activated alumina waste into carbon with adsorption capability.The microstructure and carbon content of materials were characterized by scanning electron microscope(SEM),X-ray diffraction(XRD),BET(Brunauer Emmett Teller) surface area analysis and elemental analysis.The influences of heat treatment temperature on the properties of the composite materials were discussed.The benzene adsorption capability of the material was investigated.The experimental results show that the optimal heat treatment process condition is airtight heating at 400 ℃ for 2 h.The resulting sample has carbon mass fraction of 3.57%,specific surface area of 234.70 m 2 /g,pore volume of 0.41 m 3 /g,and average pore size of 6.59 nm.The samples show excellent benzene adsorption capability with an adsorption rate of 21.80%.