Xi Beidou, Tang Zhurui, Jiang Jie, Tan Wenbing, Huang Caihong, Yuan Wenchao, Xia Xiangqin
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences Beijing 100012 China
Innovation Base of Ground Water & Environmental System Engineering, Chinese Research Academy of Environmental Sciences Beijing 100012 China.
RSC Adv. 2018 Sep 20;8(57):32588-32596. doi: 10.1039/c8ra04278k. eCollection 2018 Sep 18.
Humic substances (HS) are redox-active organic compounds that constitute a major fraction of natural organic matter in soils. The electron transfer capacity (ETC) of soil HS is mainly dependent on the type and abundance of redox-active functional groups in their structure. It is unclear whether or not agricultural land-use types can affect the ETC of HS in soils. In the present study, we evaluate the responses of ETCs of soil humic acids (HA) and fulvic acids (FA) to different agricultural land-use types. Our results show that both HA and FA of paddy soil showed the highest ETCs, followed by tomato soil, celery cabbage soil, grapevine soil, and myrica rubra soil, respectively. Agricultural land-use types could affect the transformation and decomposition of HS in soils, and thus further change the intrinsic chemical structures associated with ETC. Consequently, the ETC of soil HS exerts a significant difference among different agricultural land-use types. The results of this study could give insight into the roles of HS redox properties on the transport, fate, and redox conversion of organic and inorganic pollutants in different agricultural soils.
腐殖质（HS）是具有氧化还原活性的有机化合物，是土壤中天然有机质的主要组成部分。土壤HS的电子转移能力（ETC）主要取决于其结构中氧化还原活性官能团的类型和丰度。尚不清楚农业土地利用类型是否会影响土壤中HS的ETC。在本研究中，我们评估了土壤腐殖酸（HA）和富里酸（FA）的ETC对不同农业土地利用类型的响应。我们的结果表明，水稻土的HA和FA的ETC均最高，其次分别是番茄土、芹菜土、葡萄土和杨梅土。农业土地利用类型会影响土壤中HS的转化和分解，进而进一步改变与ETC相关的内在化学结构。因此，土壤HS的ETC在不同农业土地利用类型之间存在显著差异。本研究结果有助于深入了解HS氧化还原特性在不同农业土壤中有机和无机污染物的迁移、归宿及氧化还原转化中的作用。
