Biosorption of Cd(II) from synthetic wastewater using dry biofilms from biotrickling filters
Biosorption of Cd(II) from synthetic wastewater using dry biofilms from biotrickling filters
复制标题
使用生物滴滤器的干生物膜生物吸附合成废水中的 Cd(II)
DOI：
10.1007/s13762-017-1507-8
复制
发表时间：
2018-07-01
影响因子：
3.1
通讯作者：
Yang, C. P.
中科院分区：
文献类型：
--
作者：
He, H. J.;Xiang, Z. H.;Yang, C. P.
生物膜废弃物从生物滴滤塔干燥，并用作生物吸附剂从水溶液中去除镉（II）。研究了吸附条件、吸附效果、吸附等温线和动力学，并考察了竞争金属离子对Cd（II）去除的影响。结果表明，当Cd（II）初始浓度为50 mg/L，pH值为6.0时，在25 °C下反应120 min，生物膜对Cd（II）的最大吸附量为42 mg/g.在此条件下，当生物吸附剂投加量为2.0 g/L时，Cd（II）的去除率可达89.3%。Langmuir等温线模型比Freundlich等温线模型更好地与等温线数据相关，伪二级模型比伪一级模型更好地拟合动力学数据。结果表明，吸附为单分子层吸附，并伴有化学吸附。当Cd（II）浓度为50 mg/L、吸附剂投加量为0.5 g/L、pH值为6.0时，二价金属离子Ca和Zn对Cd（II）的吸附有显著的抑制作用，而Na（I）、K（I）和Fe（III）对Cd（II）的吸附影响较小，而Na（I）、K（I）和Fe（III）的价态高于或低于Ca（II）。扫描电子显微镜和傅里叶变换红外光谱分析表明，生物吸附剂具有多孔结构，酰胺基是吸附Cd（II）的主要基团。干生物膜是一种有效去除Cd（II）的新型吸附剂，可重复利用。
Biofilms wasted from biotrickling filters was dried and used as biosorbent for Cd(II) removal from aqueous solutions. The adsorption condition and effect, adsorption isotherms and kinetics of Cd(II) removal were investigated, and the effects of competitive metal ions on Cd(II) removal were also examined. Results showed that the dry waste biofilms reached the maximum adsorption capacity of 42 mg/g of Cd(II) at 25 °C for 120 min when the initial concentration of Cd(II) and their pH were 50 mg/L and 6.0, respectively. Under these conditions, the removal efficiency of Cd(II) reached to 89.3% when the biosorbent dosage was 2.0 g/L. The Langmuir isotherm model correlated with the isotherm data better than the Freundlich isotherm model, and the pseudo-second-order model fitted the kinetic data better than the pseudo-first-order model. These results indicated that the adsorption was monolayer accompanied with chemical adsorption. In the presence of other metal ions, divalent metal ions of Ca and Zn inhibited the performance of Cd(II) biosorption significantly, while Na(I), K(I) and Fe(III) which had a higher or lower valence than Ca(II) affected slightly when containing 50 mg/L Cd(II), 0.5 g/L adsorbent dosage and pH 6.0. The analyses of scanning electron microscopy and Fourier transform infrared spectroscopy illuminated that the biosorbent had porous structures and the amide group was the majorly responsible for Cd(II) removal. Dry biofilms were novel sorbents for effective removal Cd(II), and it could be reused and recycled if necessary.