改性麦麸生物吸附剂对废水中苯酚的吸附机理研究

The study of adsorption mechanism of SDMBA-Cl modified Wheat bran biosorbent to phenol wastewater

将麦麸分别用氯化铵(NH4Cl)、十八烷基二甲基苄基氯化铵(SDMBA-Cl)、三乙基苄基氯化铵(TEBAC)进行改性,制得一系列改性麦麸吸附剂。经筛选,确定采用经SDMBA-Cl改性的麦麸作为吸附剂,探讨各种吸附条件对改性麦麸吸附苯酚的影响。当苯酚初始浓度为50 mg·L^(-1),pH=9.0,吸附剂投加量为30 g·L^(-1),吸附时间为240 min时,改性麦麸吸附剂对苯酚的去除率达76.8%,最大理论吸附量为30.12 mg·g^(-1)。吸附动力学研究表明,该吸附过程符合准二级动力学方程,属于化学吸附。改性麦麸对苯酚的吸附符合Langmuir和Freundlich等温吸附模型,R^2均大于0.99。

A series of modified wheat bran were prepared from modification of natural wheat bran by ammonium chloride,octadecyldimethyl benzyl ammonium chloride,and benzyltriethylammonium chloride,respectively. By filtrating,the octadecyldimethyl benzyl ammonium chloride-modified wheat bran was used as adsorbent to study the effect of different conditions of adsorption of SDMBA-Cl modified Wheat bran to phenol. The result showed that when the initial concentration of phenol was 50 mg·L^（-1）,pH = 9. 0,modified wheat bran consumption of 30 g·L^（-1）,adsorption time was 240 min,the adsorption efficiency and the highest theoretical adsorption capacity reached 76. 8% and 30. 12 mg·g^（-1）,respectively. The kinetics study results indicate that the main adsorption process was chemical adsorption according with the pseudo-second-order kinctics equation,The adsorption of modified Wheat bran to phenol fits well to Langmuir equation and Freundlich Equation. The correlation coefficient（ R^2） was higher than 0. 99.