Research Of Adsorption Ability And Mechanism Of Freshwater Fish Scales Biological Adsorbent

This thes is researched application of le ftover of aquatic processing in sewagetreatment as renewable and e ffic ie nt bio logica l adsorbent, whic h was consideredfro m waste resource utilization. In this research, adsorption properties, influenc ingfactors and mechanis m of grass carp scale to dyes, meta l ions and pheno ls wereinvestigated, means of improving adsorption effic ienc y and application range ofscale b iolo gical adsorbent was exp lored. All above provided scientific basis anddeve lopment idea for exp loitation of scale as renewable, effic ient b iolo gicaladsorbent.Copper ion（Cu）, Congo red and hydroquino ne were chose as research objectafter adsorptio n effect of grass carp sca le b iologica l adsorbent to different targetmaterials. Used grass carp scale as materia l, whic h was one of ma in freshwater fis hin china, optimum adsorptio n conditio ns of grass carp scale bio logica l adsorbent tothe above three kind of materia ls was determined by static test. Adsorption capacityof grass carp scale bio logica l adsorbent to Copper io n could reach80.74mg/g incond ition as follow: W hile temperature was25℃, the potentia l o f hydrogen was4,adsorbent dosage was1.25g/L, initial concentration o f copper io n was200μg/mL.While the te mperature was25℃, the absorbent dosages was0.2g/L, the potentia l ofhydrogen was7, the concentrate of Congo red was14μg/mL, the adsorptioncapac ity of grass carp scale bio logica l adsorbent to Congo red could reach74.68mg/g. While temperature was25℃, the potentia l of hydrogen was7, theabsorbent dosages was0.5g/L, initia l concentration o f hydroquinone was100mg/L,the adsorption capac ity o f grass carp scale bio logica l adsorbent to hydroquinonecan reach76.71mg/g.Dyna mic model and thermodyna mic model were used to fitting ana lys isexperimenta l data on basis of real-time monitoring concentrate of target materia ls,which was changed with time. Result showed that adsorption of grass carp scalebiolo gical adsorbent to copper io n was a mono layer adsorption process, in whichchemisorptio n was do minated, adsorption effect could be improved by increasingtemperature, the dynamics adsorption behavior could be reflected by Quasisecondary dynamic mode l. Adsorptio n of grass carp scale b iologica l adsorbent toCongo red was a endothermic process that spontaneous and irrevers ib le, whichcould be reflected by Quas i secondary dyna mic model. Further, kinetic andthermodyna mic analyses indicated that the adsorptio n of hydroquinone by grasscarp scales was mostly a phys ical adsorption process, whic h was a multilayeradsorptio n and fitted well with a pseudo-second order k inetic mode l. Moreover, theFreund lic h isotherm model could well describe the isothermal adsorption of hydroquino ne onto grass carp scales. The above three adsorption dyna mic processcould be described by quasi second-order kinetics model.The infrared analys is showed that the functio nal groups which partic ipated inadsorptio n of grass carp scale bio logica l adsorbent to copper ion a nd Congo redwere composed of amino, carboxyl in protein and phosphate, carbonate ion inhydroxyapatite, the former were ma in adsorption compositio n in adsorptio n toCongo red; the latter were ma in adsorption composition in adsorption to copper ion.Fish scales adsorbent was pretreated by d ifferent physica l and chemistrymethod, and adsorptio n ability of fis h sca les adsorbent before and afterpretreatment was compared. Result showed that adsorption ability of fis h sca lesadsorbent to Cu2+and Congo red both raised by different degree, whic h was aga instthe result o f pretreated by HCl and acetic comb ined with enzyme. The resultindicated that adsorption ability could be raised by heat treatment.On the basis of the research, we probe the regeneratio n method of fish scalesabsorbent. Compare the regeneratio n effect of acid and alkali washing regeneration.Optimize acid washing regeneration technica l conditio ns of fis h scales absorbentadsorbed with Cu2+. Result showed that regeneratio n effect of acid washingregeneration is better than the alka li washing regeneration. While the density andvolumetric of the hydrochloric acid solutio n is0.2mol/L and8ml res pective ly,recyc ling time is40min,recyc ling te mperature is20℃is better for restorationratio of0.4g fish scales absorbent.