The key roles of Fe oxyhydroxides and humic substances during the transformation of exogenous arsenic in a redox-alternating acidic paddy soil

IF 11.4 1区环境科学与生态学 Q1 ENGINEERING, ENVIRONMENTAL

Water Research Pub Date : 2023-08-15 DOI:10.1016/j.watres.2023.120286

Zebin Hong , Shiwen Hu , Yang Yang , Ziwei Deng , Xiaomin Li , Tongxu Liu , Fangbai Li

{"title":"The key roles of Fe oxyhydroxides and humic substances during the transformation of exogenous arsenic in a redox-alternating acidic paddy soil","authors":"Zebin Hong , Shiwen Hu , Yang Yang , Ziwei Deng , Xiaomin Li , Tongxu Liu , Fangbai Li","doi":"10.1016/j.watres.2023.120286","DOIUrl":null,"url":null,"abstract":"<div><p>Arsenic (As) from mine wastewater is a significant source for acidic paddy soil pollution, and its mobility can be influenced by alternating redox conditions. However, mechanistic and quantitative insights into the biogeochemical cycles of exogenous As in paddy soil are still lacking. Herein, the variations of As species in paddy soil spiking with As(III) or As(V) were investigated in the process of 40 d of flooding followed 20 d of drainage. During flooding process, available As was immobilized in paddy soil spiking As(III) and the immobilized As was activated in paddy soil spiking As(V) owing to deprotonation. The contributions of Fe oxyhydroxides and humic substances (HS) to As immobilization in paddy soil spiking As(III) were 80.16% and 18.64%, respectively. Whereas the contributions of Fe oxyhydroxides and HS to As activation in paddy soil spiking As(V) were 47.9% and 52.1%, respectively. After entering drainage, available As was mainly immobilized by Fe oxyhydroxides and HS and adsorbed As(III) was oxidized. The contribution of Fe oxyhydroxides to As fixation in paddy soil spiking As(III) and As(V) was 88.82% and 90.26%, respectively, and of HS to As fixation in paddy soil spiking As(III) and As(V) was 11.12% and 8.95%, respectively. Based on the model fitting results, the activation of Fe oxyhydroxides and HS bound As followed with available As(V) reduction were key processes during flooding. This may be because the dispersion of soil particles and release of soil colloids activated the adsorbed As. Immobilization of available As(III) by amorphous Fe oxyhydroxides followed with adsorbed As(III) oxidation were key processes during drainage. This may be ascribe to the occurrence of coprecipitation and As(III) oxidation mediated by reactive oxygen species from Fe(II) oxidation. The results are beneficial for a deeper understanding of As species transformation at the interface of paddy soil-water as well as an estimation pathway for the impacts of key biogeochemical cycles on exogenous As species under a redox-alternating condition.</p></div>","PeriodicalId":443,"journal":{"name":"Water Research","volume":"242 ","pages":"Article 120286"},"PeriodicalIF":11.4000,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Research","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0043135423007224","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}

引用次数: 2

Abstract

Arsenic (As) from mine wastewater is a significant source for acidic paddy soil pollution, and its mobility can be influenced by alternating redox conditions. However, mechanistic and quantitative insights into the biogeochemical cycles of exogenous As in paddy soil are still lacking. Herein, the variations of As species in paddy soil spiking with As(III) or As(V) were investigated in the process of 40 d of flooding followed 20 d of drainage. During flooding process, available As was immobilized in paddy soil spiking As(III) and the immobilized As was activated in paddy soil spiking As(V) owing to deprotonation. The contributions of Fe oxyhydroxides and humic substances (HS) to As immobilization in paddy soil spiking As(III) were 80.16% and 18.64%, respectively. Whereas the contributions of Fe oxyhydroxides and HS to As activation in paddy soil spiking As(V) were 47.9% and 52.1%, respectively. After entering drainage, available As was mainly immobilized by Fe oxyhydroxides and HS and adsorbed As(III) was oxidized. The contribution of Fe oxyhydroxides to As fixation in paddy soil spiking As(III) and As(V) was 88.82% and 90.26%, respectively, and of HS to As fixation in paddy soil spiking As(III) and As(V) was 11.12% and 8.95%, respectively. Based on the model fitting results, the activation of Fe oxyhydroxides and HS bound As followed with available As(V) reduction were key processes during flooding. This may be because the dispersion of soil particles and release of soil colloids activated the adsorbed As. Immobilization of available As(III) by amorphous Fe oxyhydroxides followed with adsorbed As(III) oxidation were key processes during drainage. This may be ascribe to the occurrence of coprecipitation and As(III) oxidation mediated by reactive oxygen species from Fe(II) oxidation. The results are beneficial for a deeper understanding of As species transformation at the interface of paddy soil-water as well as an estimation pathway for the impacts of key biogeochemical cycles on exogenous As species under a redox-alternating condition.

Abstract Image

查看原文本刊更多论文

氧化还原-交替酸性水稻土中铁氧化物和腐殖质在外源砷转化中的关键作用

矿山废水中的砷(As)是酸性水稻土污染的重要来源，其流动性受到交替氧化还原条件的影响。然而，对水稻土中外源砷的生物地球化学循环机制和定量认识仍然缺乏。本文研究了在淹水40 d、排水20 d的过程中，水稻土中As(III)和As(V)穗化过程中As种类的变化。在淹水过程中，有效As被固定在水稻土As(III)中，固定As在水稻土As(V)中被去质子活化。在水稻土中，铁氧化物和腐殖质(HS)对As的固定化贡献分别为80.16%和18.64%。而铁氧氢氧化物和HS对水稻土As(V)活化的贡献分别为47.9%和52.1%。进入排水后，有效As主要被铁氧化物和HS固定，吸附的As(III)被氧化。氧化铁对水稻土As(III)和As(V)固定As的贡献分别为88.82%和90.26%，HS对水稻土As(III)和As(V)固定As的贡献分别为11.12%和8.95%。模型拟合结果表明，铁氢氧化物的活化和HS结合As的活化以及As(V)的还原是水驱过程中的关键过程。这可能是因为土壤颗粒的分散和土壤胶体的释放激活了吸附的砷。无定形铁氢氧化物对有效As(III)的固定化以及吸附As(III)的氧化是排水过程中的关键过程。这可能是由于Fe(II)氧化产生的活性氧介导的共沉淀和As(III)氧化。研究结果有助于深入了解水稻土-水界面As物种的转化过程，并为氧化还原-交替条件下关键生物地球化学循环对外源As物种的影响提供估计途径。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Water Research 环境科学-工程：环境

CiteScore

20.80

自引率

9.40%

发文量

1307

审稿时长

38 days

期刊介绍： Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include: •Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management; •Urban hydrology including sewer systems, stormwater management, and green infrastructure; •Drinking water treatment and distribution; •Potable and non-potable water reuse; •Sanitation, public health, and risk assessment; •Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions; •Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment; •Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution; •Environmental restoration, linked to surface water, groundwater and groundwater remediation; •Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts; •Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle; •Socio-economic, policy, and regulations studies.