The effect of low temperatures on abiotic and biotic nitrate (NO₃^-) reduction by zero-valent iron (ZVI) were examined at temperatures below 25 °C. The extent and rate of nitrate removal in batch ZVI reactors were determined in the presence and absence of microorganisms at 3.5, 10, 17, and 25 °C. Under anoxic conditions, NO₃^- reduction rates in both ZVI-only and ZVI-cell reactors declined as temperature decreased. In ZVI-only reactor, 62% and 17% of initial nitrate concentration were reduced in 6 days at 25 and 3.5 °C, respectively. The reduced nitrate was completely recovered as ammonium ions (NH₄⁺) at both temperatures. The temperature-dependent abiotic reduction rates enabled us to calculate the activation energy (E_a) using the Arrhenius relationship, which was 50 kJ/mol. Nitrate in ZVI-cell reactors was completely removed within 1 – 2 days at 25 and 10 °C, and 67% of reduction was achieved at 3.5 °C. Only 18 – 25% of the reduced nitrate was recovered as NH₄⁺ in the ZVI-cell reactors. Soluble iron concentrations (Fe²⁺ and Fe³⁺) in the ZVI reactors were also measured as the indicators of anaerobic corrosion. In the ZVI-cell reactors, soluble iron concentrations were 1.7 times higher than that in ZVI-only reactors at 25 °C, suggesting that the enhanced nitrate reduction in the ZVI-cell reactors may be partly due to increased redox activity (i.e., corrosion) on iron surfaces. Anaerobic corrosion of ZVI was also temperature-dependent as substantially lower concentrations of corrosion product were detected at lower incubation temperatures; however, microbially induced corrosion (MIC) of ZVI was much less impacted at lower temperatures than abiotic ZVI corrosion. This study demonstrated that ZVI-supported microbial denitrification is not only more sustainable at lower temperatures, but it becomes more dominant reaction for nitrate removal in microbial-ZVI systems at low temperatures.

上非生物和生物硝酸盐低温的效果（NO ₃ ^- ）的零价铁（ZVI）还原在温度低于25℃下进行了研究。在存在，不存在微生物的情况下，分别在3.5、10、17和25°C下确定ZVI分批反应器中硝酸盐去除的程度和速率。下缺氧条件，NO ₃ ^-在这两个ZVI-仅和ZVI细胞反应器还原率下降，因为温度下降。在仅ZVI的反应器中，分别在25和3.5°C下的6天之内硝酸盐初始浓度分别降低了62％和17％。在两个温度下，还原的硝酸盐均被完全还原为铵离子（NH ₄ ⁺）。与温度有关的非生物还原速率使我们能够计算活化能（E_a）使用阿累尼乌斯关系，为50 kJ / mol。ZVI电池反应器中的硝酸盐在25和10°C的1-2天之内被完全去除，在3.5°C的还原率达到67％。在ZVI电池反应器中，还原的硝酸盐中只有18-25％作为NH ₄ ⁺被回收。可溶性铁浓度（Fe ²⁺和Fe ³⁺还测量了ZVI反应器中的）作为厌氧腐蚀的指标。在ZVI电池反应器中，在25°C时，可溶性铁的浓度比仅ZVI的反应器高1.7倍，这表明ZVI电池反应器中硝酸盐还原的增加可能部分归因于氧化还原活性（即腐蚀）的增加。 ）在铁表面上。ZVI的厌氧腐蚀也是温度依赖性的，因为在较低的培养温度下检测到的腐蚀产物的浓度大大降低。然而，在较低的温度下，微生物引起的ZVI腐蚀（MIC）比非生物ZVI腐蚀要小得多。这项研究表明，ZVI支持的微生物反硝化不仅在较低温度下更可持续，