Spectroscopic characterization of soil dissolved organic matter during dielectric barrier discharge (DBD) plasma treatment: Effects of discharge power, atmosphere and soil moisture content.
Spectroscopic characterization of soil dissolved organic matter during dielectric barrier discharge (DBD) plasma treatment: Effects of discharge power, atmosphere and soil moisture content.
复制标题
DOI：
10.1016/j.chemosphere.2022.134145
复制
发表时间：
2022-02
期刊：
影响因子：
8.8
通讯作者：
Yanan Liu;S. Deng;Lulu Chen;Ai Zhang;S. Suttiruengwong;Zhuyu Sun
中科院分区：
文献类型：
--
作者：
Yanan Liu;S. Deng;Lulu Chen;Ai Zhang;S. Suttiruengwong;Zhuyu Sun
非热等离子体（NTP）技术是一种新兴的高级氧化工艺，在土壤有机污染修复中表现出了优异的性能。溶解有机质（DOM）是土壤中最重要的成分之一，然而，对NTP过程中DOM结构和组成变化的研究还缺乏。因此，在本研究中，我们系统地研究了不同放电电压、大气或不同含水量土壤下土壤DOM的变化。结果表明，NTP处理后，大量土壤有机质被释放并溶解在水中。例如，在80 V放电电压下放电120 min后，DOM的DOC值从21.1急剧增加到197.3 mg L−1。UV-Vis表征结果表明，在放电初期，土壤DOM的亲水性显着增加，芳香性和分子量下降。然而，长时间放电导致芳香性和疏水性略有恢复，这可能是由于小分子的脱水和再缩合所致。 EEM-FRI结果表明，DOM的总荧光强度明显下降，表明荧光溶解有机物（FDOM）被破坏。而腐殖酸类和微生物副产品类物质的比例增加，表明与黄腐酸类和芳香蛋白类物质相比，这些物质在 NTP 处理下更顽固。 PARAFAC鉴定出四种荧光成分，与其他腐殖酸类物质和黄腐酸类物质相比，微生物和陆地腐殖酸类物质更难降解。此外，放电电压和大气对DOM变化影响较大，而土壤含水量影响不显着。总体而言，本研究提供了对NTP过程中DOM变化的深入了解，这对于更全面地评估NTP技术在实际土壤修复中的应用具有重要价值。
Non-thermal plasma (NTP) technology is an emerging advanced oxidation process, which has shown excellent performances in soil organic pollution remediation. Dissolved organic matter (DOM) is one of the most important components in soil, however, investigations on the structural and compositional changes of DOM during NTP process are lacking. Therefore, in the present study, we systematically investigated the soil DOM changes under different discharge voltages, atmospheres or soils with different moisture contents. The results indicated that after NTP treatment, substantial soil organic matters were released and dissolved in water. For instance, the DOC value of DOM increased dramatically from 21.1 to 197.3 mg L−1after being discharged for 120 min under the discharge voltage of 80 V. The UV–Vis characterization results indicated the significant increase of hydrophilicity, and decreases of aromaticity and molecular weight for soil DOM during the initial discharge period. However, long time discharge resulted in slight recovery of aromaticity and hydrophobicity, possibly due to the dehydration and re-condensation of small molecules. EEM-FRI results indicated that the total fluorescence intensity of DOM decreased obviously, indicating the destruction of fluorescent dissolved organic matter (FDOM). While the proportions of humic-like and microbial byproduct-like substances increased, indicating that those substances were more recalcitrant under NTP treatment compared with fulvic acid-like and aromatic protein-like substances. Four fluorescence components were identified by PARAFAC, and microbial and terrestrial humic-like substances were more difficult to degrade compared to other humic-like substances and fulvic acid-like substances. Additionally, discharge voltage and atmosphere had great influences on DOM changes, while the impact of soil moisture content was not significant. Overall, this study provided insights into the DOM changes during NTP process, which is valuable for more comprehensive evaluation of the NTP technique application in practical soil remediation.