Biochar ( IF 13.1 ) Pub Date : 2024-01-10 , DOI: 10.1007/s42773-023-00274-2
Ruofan Wu , Paramsothy Jeyakumar , Nanthi Bolan , Xu Zhai , Hailong Wang , Minghui Pan , Jiapan Lian , Liping Cheng , Jiangzhou Li , Minghei Hou , Yonghe Cui , Xiaoe Yang , Kuai Dai
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Iron-carbon micro-electrolysis system is a promising method for promoting electron transfer in nitrate removal. However, many traditional approaches involving simple physical mixing inevitably suffered from the confined iron-carbon contact area and short validity period, leading to the overuse of iron. Here, a ceramsite-loaded microscale zero-valent iron (mZVI) and acidified carbon (AC) coupled-galvanic cell (CMC) was designed to support chemical, autotrophic and heterotrophic denitrification. Long-term experiments were conducted to monitor the nitrogen removal performance of denitrification reactors filled with CMC and thus optimized the denitrification performance by improving fabrication parameters and various operating conditions. The denitrification contributions test showed that the chemical denitrification pathway contributed most to nitrate removal (57.3%), followed by autotrophic (24.6%) and heterotrophic denitrification pathways (18.1%). The microbial analysis confirmed the significant aggregation of related denitrifying bacteria in the reactors, while AC promoted the expression of relevant nitrogen metabolism genes because of accelerated uptake and utilization of iron complexes. Meanwhile, the electrochemical analysis revealed a significantly improved electron transfer capacity of AC compared to pristine carbon. Overall, our study demonstrated the application of a novel mZVI-AC coupled material for effective nitrate removal and revealed the potential impact of CMC in the multipathway denitrification process.
Graphical Abstract
中文翻译:
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由新型铁碳耦合原电池驱动的增强反硝化:化学和混合营养反硝化
铁碳微电解系统是一种有前景的促进电子转移去除硝酸盐的方法。然而,许多传统的简单物理混合方法不可避免地受到铁碳接触面积有限和有效期短的影响,导致铁的过度使用。在此,设计了负载陶粒的微型零价铁(mZVI)和酸化碳(AC)耦合原电池(CMC)来支持化学、自养和异养反硝化。通过长期实验监测填充CMC的反硝化反应器的脱氮性能,通过改进制造参数和各种操作条件来优化反硝化性能。反硝化贡献测试表明,化学反硝化途径对硝酸盐去除的贡献最大(57.3%),其次是自养反硝化途径(24.6%)和异养反硝化途径(18.1%)。微生物分析证实了反应器中相关反硝化细菌的显着聚集,而AC由于加速了铁络合物的吸收和利用而促进了相关氮代谢基因的表达。同时,电化学分析表明,与原始碳相比,AC 的电子传递能力显着提高。总体而言,我们的研究证明了新型 mZVI-AC 耦合材料在有效去除硝酸盐方面的应用,并揭示了 CMC 在多途径反硝化过程中的潜在影响。