摘要
本文以废花生壳为原料制备了花生壳纤维素并将其用于去除水中亚甲基蓝染料。系统考察了溶液的p H值,亚甲基蓝的初始浓度,吸附时间,吸附温度以及溶液离子强度对亚甲基蓝吸附性能的影响。结果表明:pH=9时,花生壳纤维素对亚甲基蓝的吸附效果最佳,饱和吸附容量q_m为156.2 mg·g^(-1);吸附热力学研究表明,吸附过程符合Langmuir等温吸附模型。吸附过程焓变ΔH为-44.74 k J·mol^(-1),ΔS为-137.9 J·mol^(-1)·K^(-1),ΔG<0,表明花生壳纤维素对亚甲基蓝的吸附过程是自发的放热过程;吸附过程可在20 min内达到平衡,符合准二级动力学模型;其吸附过程的活化能Ea=82.6 k J·mol^(-1)。吸附容量随着溶液离子强度的增大而减小,说明其吸附是以静电作用为主的吸附过程。10次循环使用后花生壳纤维素对亚甲基蓝的吸附效率仍能保持88%以上,表明该材料可以多次循环使用。
In this paper, a facile method for the preparation of cellulose from waste peanut shell was reported. The obtained cellulose was used as adsorbent for the removal of methylene blue in water. The effects of pH value, the initial concentration of methylene blue （MB） ,contacting time,contacting temperature and coexisted ions were intensively investigated. Results indicated that the adsorptive properties of the obtained cellulose were highly pH dependent and reached optimum at pH 9. 0. Adsorption processes reached 90% of the equilibrium within 10 min. The adsorption data of the obtained cellulose were well fitted with the Langmuir isotherm. The maximum adsorption capacity calculated from Langmuir isotherm was 156. 2 mg＊g Thermodynamic studies suggested that the ad-sorption process of MBwasexothermic （ △H〈0） , entropy disfavored （ △S〈 0 ） , and spontaneous （ △G〈0） in nature. The adsorption process of MB was highly affected by the ionic strength of the solutions, indicating the adsorption mechanism of MB could be mainly related with electrostatic attraction. The recycle of the obtained cellulose has beeninvestigatedand showed that the adsorption effi-ciency remained above 88% after 10 cycles. It should be expected to be very promising material for the removal of MB in wastewater.
出处
《化学研究与应用》
CAS
CSCD
北大核心
2016年第10期1396-1404,共9页
Chemical Research and Application
基金
浙江省自然科学基金项目(LY14B04003)资助
国家级大学生创新创业训练计划项目(201513022009)资助
关键词
花生壳纤维素
亚甲基蓝
吸附
静电作用
peanut shell cellulose
methylene blue
adsorption
electrostatic interaction
