Rajab Beigy Mahdieh, Rasekh Behnam, Yazdian Fatemeh, Aminzadeh Behnoush, Shekarriz Marzieh
Department of Life Science Engineering Faculty of New Sciences and Technologies University of Tehran Tehran Iran.
Microbiology and Biotechnology Research Group Research Institute of Petroleum Industry Tehran Iran.
Eng Life Sci. 2017 Dec 27;18(3):187-195. doi: 10.1002/elsc.201700127. eCollection 2018 Mar.
This study was conducted to investigate biodenitrification efficiency with starch-stabilized nano zero valent iron (S-nZVI) as the additional electron donor in the presence of SO in aqueous solutions, under anaerobic conditions. The main challenge for nZVI application is their tendency to agglomeration, thereby resulting in loss of reactivity that necessitates the use of stabilizers to improve their stability. In this study, S-nZVI was synthesized by chemical reduction method with starch as a stabilizer. The synthesized nanoparticles were characterized by TEM, XRD, and FTIR. Transmission electron microscopy (TEM) image shows S-nZVI has a size in the range of 5-27.5 nanometer. Temperature and S-nZVI concentration were the important factors affecting nitrate removal. Biodenitrification increased at 35°C and 500 mg/L of S-nZVI, in these conditions, biodenitrification efficiency increased from 40.45 to 78.84%. Experimental results suggested that biodenitrification increased by decreasing initial nitrate concentration. In the bioreactor biodenitrification rate was 94.07% in the presence of S-nZVI. This study indicated that, Fe could be used as the only electron donor or as the additional electron donor in the presence of SO to increase denitrification efficiency.
本研究旨在探讨在厌氧条件下，以淀粉稳定化纳米零价铁（S-nZVI）作为额外电子供体，在水溶液中存在SO时的生物反硝化效率。nZVI应用面临的主要挑战是其易于团聚的倾向，从而导致反应活性丧失，这就需要使用稳定剂来提高其稳定性。在本研究中，以淀粉为稳定剂，通过化学还原法合成了S-nZVI。采用透射电子显微镜（TEM）、X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）对合成的纳米颗粒进行了表征。透射电子显微镜（TEM）图像显示S-nZVI的尺寸在5-27.5纳米范围内。温度和S-nZVI浓度是影响硝酸盐去除的重要因素。在35°C和500 mg/L的S-nZVI条件下生物反硝化作用增强，在此条件下，生物反硝化效率从40.45%提高到78.84%。实验结果表明，降低初始硝酸盐浓度可提高生物反硝化作用。在生物反应器中，存在S-nZVI时生物反硝化率为94.07%。本研究表明，Fe可作为唯一的电子供体或在存在SO的情况下作为额外的电子供体，以提高反硝化效率。
