Study On Preparation And Properties Of Camellia Oleifera Shell Fiber Adsorption Material

With the rapid development of agriculture,a large number of agricultural wastes are discarded ad libitum,causing serious environmental pollution.The efficient development and utilization of agricultural wastes can achieve the sustainable use of agricultural resources and can also reduce the environmental pollution problems caused by treatment at will.Camellia shell is a major agricultural waste.In the process of processing tea oil from Camellia oleifera fruit,a large amount of Camellia shell is burned or discarded at will.Camellia shell ingredients are rich in cellulose,lignin,hemicellulose,etc.which have a variety of active functional groups,and have good adsorption for metal ions and drugs,and can be developed for wastewater treatment,and the drug loading.To expand the market application of Camellia shell can avoid the environmental pollution.In this study,Camellia shell as raw materials were pre-treated first to remove excess substances such as lipids,etc.,Then,the insoluble fiber adsorption material of Camellia shell was prepared by chemical modification and enzyme modification.Last,this material was used to adsorb Zn²⁺and quercetin,and the influence of p H,temperature,amount of Camellia shell adsorbent,initial solution concentration on the adsorption were discussed.The results show that the adsorbent has good adsorption properties for Zn²⁺and quercetin.The research content and results are as follows:1. The composition analysis and structural characterization of the Camellia shell.The experimental results show that the Camellia shell contains nearly 70%insoluble fiber,which mainly include cellulose and lignin.Both of them are rich in active groups such as hydroxyl groups,which can combine with heavy metal ion so as to treat wastewater.It can also form hydrogen bonds with drugs,which can be used in drug loading and sustained release.Therefore,it is necessary to extract fiber from Camellia shell to play its value.2. Preparation of insoluble fiber material of Camellia shell by pretreatment and modification.Camellia shell were pretreated with deionized water to clean impurities,petroleum ether degreasing,ethanol extraction and other operations to remove water soluble substances and alcohol soluble substance and lipid substance;The modified Camellia shell IDF1 and IDF2 were prepared by two different modification methods.?1?Acid and alkali treatment:the pre-treated Camellia shell were dealt with 20%Na OH,10%H₂SO₄,The solutions were mixed with Camellia shell material for water bath heating.After the reaction completed,the filter residue was washed with water to p H neutral andfreeze-dried to obtain IDF1.?2?Enzyme treatment:cellulase and xylanase were mixed with the pre-treated Camellia shell in proportion with deionized water at p H=5,temperature 60?for 8 h.Thereafter the temperature was raised to 100?for 2 h reaction,the enzymes were inactivated.After the reaction completed,the filter residue was washed to p H neutral,and then freeze-dried to obtain IDF2.Infrared spectroscopy,SEM,BET and other characterization techniques were used for structural analysis.The results show that the modification treatment causes holes in the originally tightly-bonded tissue,increasement of hole number and the specific surface area.The color of the sample fades,and the IDF2 specific surface area reaches 18.5133 m²/g.IDF2 has abundant-OH active groups,which makes it possible to adsorb heavy metal ions and drugs.3. The enzyme-modified material IDF2 was used to adsorb Zn²⁺and quercetin,the effects of p H,temperature,adsorbent dosage,initial solution concentration and other factors on the adsorption process were discussed to explore the adsorption mechanism.The results show that in the adsorption experiment of Zn²⁺,the maximum adsorption capacity was 6.49 mg/g under the conditions of p H=6,reaction temperature of 25?,adsorbent mass of 0.1 g,and initial concentration of Zn²⁺of 20 mg/L.The adsorption process was fitted by the fitting coefficients of pseudo-first-order kinetic equation,pseudo-second-order kinetic equation,and diffusion model,and it is concluded that the adsorption process of Zn²⁺by Camellia shell material IDF2 after enzyme treatment conforms to the pseudo-second-order kinetic equation model.In the adsorption experiment of quercetin,under the conditions of p H=7,reaction temperature of 25?,adsorbent mass of 0.2 g,and initial concentration of quercetin of 4 mg/m L,the maximum adsorption capacity was 447.62 mg/g.The adsorption process was fitted by the fitting coefficients of pseudo-first-order kinetic equation,pseudo-second-order kinetic equation,and diffusion mode,it is shown that the adsorption process of quercetin by IDF2 conforms to the pseudo-second-order kinetic equation,and the process is controlled by chemical adsorption.