Tavker Neha, Yadav Virendra Kumar, Yadav Krishna Kumar, Cabral-Pinto Marina Ms, Alam Javed, Shukla Arun Kumar, Ali Fekri Abdulraqeb Ahmed, Alhoshan Mansour
School of Nano Sciences, Central University of Gujarat, Gandhinagar 382030, India.
School of Lifesciences, Jaipur National University, Jaipur 302017, India.
Polymers (Basel). 2021 Jan 12;13(2):234. doi: 10.3390/polym13020234.
Nano-fibrillated cellulose (NFC) was extracted by a chemical method involving alkali and acid hydrolysis. The characterisation of the citrus sinensis fruit peel bran and nano-fibrillated cellulose was performed by XRD, FTIR, TEM, and FESEM. XRD confirmed the phase of NFC which showed monoclinic crystal with spherical to rod shape morphology with a size of 44-50 nm. The crystallinity index of treated NFC increased from 39% to 75%. FTIR showed the removal of lignin and hemicellulose from waste peels due to the alkaline treatment. Silver nanoparticles were also synthesised by utilizing extract of citrus sinensis skins as a reducing agent. Pharmaceutical effluent samples from an industrial area were tested by Atomic Absorption Spectrometry. Out of the four metals obtained, cadmium and chromium were remediated by silver nanoparticles with nano-fibrillated cellulose via simulated method in 100 mg/L metal-salt concentrations over a time period of 160 min. The highest removal efficiency was found for cadmium, i.e., 83%, by using silver and NFC together as adsorbents. The second highest was for chromium, i.e., 47%, but by using only NFC. The Langmuir and Freundlich isotherms were well fitted for the sorption of Cd (II) and Cr (II) with suitable high R values during kinetic simulation. Thus, the isolation of NFC and synthesis of silver nanoparticles proved efficient for heavy metal sorption by the reuse of waste skins.
通过碱解和酸解的化学方法提取了纳米纤丝化纤维素（NFC）。采用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、透射电子显微镜（TEM）和场发射扫描电子显微镜（FESEM）对脐橙果皮麸皮和纳米纤丝化纤维素进行了表征。XRD证实了NFC的晶相，其呈现单斜晶体，形态为球形至棒状，尺寸为44 - 50纳米。处理后的NFC结晶度指数从39%提高到了75%。FTIR表明由于碱处理，废果皮中的木质素和半纤维素被去除。还利用脐橙皮提取物作为还原剂合成了银纳米颗粒。采用原子吸收光谱法对工业区的制药废水样品进行了检测。在100 mg/L金属盐浓度下，经过160分钟的模拟实验，通过银纳米颗粒与纳米纤丝化纤维素，从获得的四种金属中去除了镉和铬。以银和NFC作为吸附剂一起使用时，镉的去除效率最高，即83%。其次是铬，去除效率为4７%，但仅使用NFC。在动力学模拟过程中，Langmuir和Freundlich等温线对Cd（II）和Cr（II）的吸附拟合良好，R值较高。因此，NFC的分离和银纳米颗粒的合成证明了利用废果皮再利用对重金属吸附是有效的。
