海洋科学
海洋科學
해양과학
MARINE SCIENCES
2013年
9期
61-67
,共7页
林勇新%曹西华%宋秀贤%俞志明
林勇新%曹西華%宋秀賢%俞誌明
림용신%조서화%송수현%유지명
氨基酸%改性黏土%动力学%吸附等温线%pH%离子强度
氨基痠%改性黏土%動力學%吸附等溫線%pH%離子彊度
안기산%개성점토%동역학%흡부등온선%pH%리자강도
Amino acid%Modified clays%Adsorption kinetics%Adsorption isotherm%pH%Ionic strength
研究了四种氨基酸(赖氨酸、谷氨酸、甘氨酸、组氨酸)化合物在改性黏土的吸附特征,考察了改性剂PACl添加比例、介质pH及离子强度对吸附过程的影响,并探讨了吸附机制。结果表明,在一定比例的 PACl 改性能促进氨基酸在高岭土上的吸附,最佳改性比例为5%,赖氨酸、谷氨酸、甘氨酸、组氨酸的最大吸附量分别为827、712.56、723.14、732.56μmol/g;氨基酸在改性黏土上的吸附动力学符合伪二阶动力学模型;利用Weber-Morris模型测定四种氨基酸内部粒子扩散常数,5%改性条件下赖氨酸、谷氨酸、甘氨酸、组氨酸的内部粒子扩散常数分别为0.847、0.567、0.780、0.603。热力学研究表明,氨基酸在改性黏土上的吸附等温线是C型等温线,5%改性条件下四种氨基酸(赖氨酸、谷氨酸、甘氨酸、组氨酸)的热力学自由能分别为?1.99、?2.41、?3.16、?2.94 kJ/mol,说明氨基酸在改性黏土上的吸附是一个自发的吸附过程。介质pH及离子强度对吸附过程具有重要影响。
研究瞭四種氨基痠(賴氨痠、穀氨痠、甘氨痠、組氨痠)化閤物在改性黏土的吸附特徵,攷察瞭改性劑PACl添加比例、介質pH及離子彊度對吸附過程的影響,併探討瞭吸附機製。結果錶明,在一定比例的 PACl 改性能促進氨基痠在高嶺土上的吸附,最佳改性比例為5%,賴氨痠、穀氨痠、甘氨痠、組氨痠的最大吸附量分彆為827、712.56、723.14、732.56μmol/g;氨基痠在改性黏土上的吸附動力學符閤偽二階動力學模型;利用Weber-Morris模型測定四種氨基痠內部粒子擴散常數,5%改性條件下賴氨痠、穀氨痠、甘氨痠、組氨痠的內部粒子擴散常數分彆為0.847、0.567、0.780、0.603。熱力學研究錶明,氨基痠在改性黏土上的吸附等溫線是C型等溫線,5%改性條件下四種氨基痠(賴氨痠、穀氨痠、甘氨痠、組氨痠)的熱力學自由能分彆為?1.99、?2.41、?3.16、?2.94 kJ/mol,說明氨基痠在改性黏土上的吸附是一箇自髮的吸附過程。介質pH及離子彊度對吸附過程具有重要影響。
연구료사충안기산(뢰안산、곡안산、감안산、조안산)화합물재개성점토적흡부특정,고찰료개성제PACl첨가비례、개질pH급리자강도대흡부과정적영향,병탐토료흡부궤제。결과표명,재일정비례적 PACl 개성능촉진안기산재고령토상적흡부,최가개성비례위5%,뢰안산、곡안산、감안산、조안산적최대흡부량분별위827、712.56、723.14、732.56μmol/g;안기산재개성점토상적흡부동역학부합위이계동역학모형;이용Weber-Morris모형측정사충안기산내부입자확산상수,5%개성조건하뢰안산、곡안산、감안산、조안산적내부입자확산상수분별위0.847、0.567、0.780、0.603。열역학연구표명,안기산재개성점토상적흡부등온선시C형등온선,5%개성조건하사충안기산(뢰안산、곡안산、감안산、조안산)적열역학자유능분별위?1.99、?2.41、?3.16、?2.94 kJ/mol,설명안기산재개성점토상적흡부시일개자발적흡부과정。개질pH급리자강도대흡부과정구유중요영향。
Algal organic materials (AOMs) has critical influence on the REs. Amino acid is an important ingredient of AOMs, for what is with various function groups and is construction units of proteins and polypeptide. In order to obtain a mechanic understanding of the adsorption of amino acid on modified clays, the adsorption of four amino acids, including lysine, glutamic, glycine and histidine, onto modified clays was studied as a function of modifier dosage, pH and ionic strength through well controlled batch adsorption experiments. The kinetics experiments data is fitted well by a pseudo-second order model. The mechanism of amino acid on modified clays is complicated and both the surface adsorption and intraparticle diffusion contribute to the rate determining step. The adsorbed amount of amino acids is increased with adding appropriate dosage of modifier PACl, and the optimum mass ratio is 5%. The maximum adsorption of Lys., Glu., Gly. and His. are 827, 712.56, 723.14 and 732.56μmol/g, respectively. The equilibrium data is well described by C isotherm curve. The rmodynamic parameters are calculated, e.g. the value of gibbs free energy for Lys., Glu., Gly. and His. are ?1.99, ?2.41, ?3.16 and ?2.94 kJ/mol, respectively. And the results show that the adsorption of amino acid on modified clays is a spontaneous process. The adsorption of amino acid on modified clays is highly dependent on pH, and decreases with increasing ionic strength.