In this study, nitrate removal from aqueous solution was performed using nano zerovalent iron–reduced graphene (nZVI‐rGO) composite. The effect of operational parameters including initial nitrate concentration, composite dosage, solution pH, and contact time on the removal process was examined using design expert software. Our investigation revealed that the nitrate‐contaminated water can be easily treated by applying the synthesized composite within the short contact time of 1 min. In the presence of nZVI‐rGO composite, about 96% of nitrate reduced to nitrogen gas (~64%) and small amounts of ammonium (~32%) and nitrite (~0.3%) were released. The kinetics results confirmed that the adsorption and chemical reduction of nitrate by the composite are well fitted to the pseudo‐second‐order and pseudo‐first‐order kinetic models, respectively. The thermodynamic results showed that the removal of nitrate by the composite is a spontaneous and endothermic process.

中文翻译：

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纳米零价铁还原氧化石墨烯复合物去除水溶液中的硝酸盐：参数优化

在这项研究中，使用纳米零价铁还原石墨烯（nZVI-rGO）复合材料从水溶液中去除硝酸盐。使用设计专家软件检查了操作参数（包括初始硝酸盐浓度，复合剂量，溶液pH值和接触时间）对去除过程的影响。我们的研究表明，可以在1分钟的短时间内应用合成的复合材料轻松处理受硝酸盐污染的水。在nZVI-rGO复合材料的存在下，约96％的硝酸盐还原为氮气（约64％），并释放出少量的铵（约32％）和亚硝酸盐（约0.3％）。动力学结果证实，复合材料对硝酸盐的吸附和化学还原分别与拟二级动力学模型和拟一级动力学模型完全吻合。