外源砷在不同土壤类型形态分布及其影响因素  

Distribution of exogenous arsenic in different soil types and its influencing factors

作　　者：韦美溜 黄凤艳 刘智博 宋波[1,2] WEI Meiliu;HUANG Fengyan;LIU Zhibo;SONG Bo(College of Environment Science and Engineering,Guilin University of Technology,Guilin 541004;Collaborative Innovation Center for Water Pollution Control and Water Safety Guarantee in Karst Area,Guilin 541004)

机构地区：[1]桂林理工大学环境科学与工程学院,桂林541004 [2]桂林理工大学岩溶地区水污染控制与用水安全保障协同创新中心,桂林541004

出　　处：《环境科学学报》2025年第1期324-333,共10页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金(No.52230006);广西科技重大专项(No.桂科AA17204047)。

摘　　要：为探讨砷(As)在不同土壤类型的形态含量特征及其关键影响因素,选择未受污染的石灰(岩)土、红壤、黄壤、黄褐土、黄绵土和棕壤,采用BCR分级提取方法,研究了外源As(100 mg·kg^(-1))老化的第3、7、15、30、120和300 d土壤As的赋存形态特征.结果表明:(1)外源As进入土壤后有效态含量降低,发生形态再分配,黄壤与土壤的结合强度最大,黄绵土最小;(2)As在6种土壤的6个老化时间下形态差异显著,赋存形态与土壤类型密切相关,黄绵土的弱酸提取态占比最大,在第120 d时黄褐土中可还原态含量最高(29.43 mg·kg^(-1)),可氧化态含量呈上升趋势,残渣态含量规律为:黄壤>石灰(岩)土>红壤>棕壤>黄绵土>黄褐土;(3)土壤稳定化由多个反应机制共同控制,土壤理化性质与As形态相关性显著,石灰(岩)土、黄壤和黄褐土的低pH值促进了土壤对As的吸附,可通过调控理化性质对土壤安全利用.To explore the speciation of exogenous arsenic(As)in different soil types and key factors influencing speciation,using BCR grading extraction method,the species characteristics of exogenous As(100 mg·kg^(-1))in unpolluted limestone soil,red soil,yellow soil,yellow cinnamon soil,loessal soil and brown soil were investigated on the 3rd,7th,15th,30th,120th,and 300th days of ageing,the results showed that:(1)the effective state content of exogenous As decreased after entering the soil,and the morphological redistribution occurred,the binding strength of yellow soil and soil was the largest,and the loessal soil was the smallest;(2)The morphological differences of As in the six soil ageing time were significant,and the occurrence of As was related to the soil types,and the weak acid-extractable As of loessal soil accounted for the largest proportion,at 120 d,residual As content in yellow cinnamon soil was the highest(29.43 mg·kg^(-1)),and As in the oxidizable form showed an upward trend.The rule of residual As content was:yellow soil>limestone soil>red soil>brown soil>yellow cinnamon soil;(3)Soil stabilization is controlled by multiple reaction mechanisms,and the correlation between soil physical and chemical properties and morphology is significant,the low pH value of limestone soil,yellow soil and yellow cinnamon soil can promote the adsorption of As in the soil,and can be used safely by regulating the physical and chemical properties of the soil.

关 键 词：土壤类型 外源砷(As) BCR分级提取 形态分布 

分 类 号：X131.3[环境科学与工程—环境科学]