樱花生物质炭的制备及对废水中六价铬的吸附  

Preparation of cherry blossom biomass charcoal and adsorption of hexavalent chromium in wastewater

作　　者：丁绍兰 严赛宁 谢林花 孙月 刘佳林 马飞 李晨 DING Shao-lan;YAN Sai-ning;XIE Lin-hua;SUN Yue;LIU Jia-lin;MA Fei;LI Chen(College of Environmental Science and Engineering,Shaanxi University of Science & Technology,Xi’an 710021,China;Xi’an Fifth Water Reclamation Plant,Xi’an 721021,China)

机构地区：[1]陕西科技大学环境科学与工程学院,陕西西安710021 [2]西安市第五再生水厂,陕西西安721021

出　　处：《应用化工》2021年第12期3309-3314,3319,共7页Applied Chemical Industry

基　　金：国家自然科学基金(21677092);温州市科技计划项目(G20180035)。

摘　　要：选用樱花为原料制备新型生物质炭,应用其吸附含Cr(Ⅵ)的模拟废水,用单因素静态实验对影响吸附的5个主要因素(吸附剂投加量、pH值、Cr(Ⅵ)初始浓度、反应温度和吸附时间)进行分析,并结合吸附过程的动力学特征以及特性表征,对吸附机理进行了初步探究。结果表明,樱花生物炭含有较多中孔,表面官能团如酮基、羧基和C=C能作为电子供体将Cr(Ⅵ)还原为Cr(Ⅲ);樱花生物炭的最佳吸附条件为樱花炭投加量为1 g/L,pH=2,Cr(Ⅵ)浓度为50 mg/L,吸附时间为4 h,反应温度为25℃,在此条件下,吸附量为49.52 mg/g;拟合系数表明准二级动力学方程能更好地反映樱花炭的吸附过程,说明以化学吸附为主;樱花炭的吸附过程更符合Langmuir等温线方程,说明其是单层吸附,最大吸附量为49.78 mg/g;可见,樱花炭在吸附Cr(Ⅵ)方面有一定的发展前景。A new type of biomass carbon was prepared from cherry blossom,and the simulated wastewatercontaining Cr(Ⅵ) was adsorbed with it. The five main factors affecting the adsorption(dosage of adsor-bent,pH value,initial concentration of Cr(Ⅵ),reaction temperature and time) were analyzed by single-factor static experiment. Combined with the kinetic characteristics and characterization of the adsorptionprocess,the mechanism of adsorption was studied. The results showed that the pore diameter of sakura bio-char was mainly mesopore,and the surface functional groups of sakura biomass charcoal,such as ketonegroup,carboxyl group and C =C,could be used as electron donors to reduce Cr(Ⅵ) to Cr(Ⅲ). Theoptimum adsorption conditions of cherry blossom biochar were as follows:the dosage of cherry blossomcharcoal was 1 g/L,pH = 2,the concentration of Cr(Ⅵ) was 50 mg/L,the adsorption time was 4 h,thereaction temperature was 25 ℃,and the adsorption capacity is 49. 52 mg/g under this condition. The fit-ting coefficient indicated that the quasi-second-order kinetic equations could better reflect the adsorptionprocess of sakura charcoal,indicating that the adsorption process was dominated by chemical adsorption.The adsorption process of cherry blossom charcoal is more in line with the Langmuir isotherm equation,which indicates that it is monolayer adsorption,and the maximum adsorption capacity is 49. 78 mg/g.Thus,sakura charcoal has a good prospect in Cr(Ⅵ) adsorption.

关 键 词：六价铬 吸附 樱花 生物质炭 含铬废水 

分 类 号：X712[环境科学与工程—环境工程] X523