摘要
为得到一种高效去除土壤中总石油烃(TPH)的原氧化技术,利用富里酸(FA)在土壤中原位制备富集铁并进行石油污染土壤修复研究,探究了富集铁组和非富集铁组对不同质地和有机质(SOM)含量的石油污染土壤(S1、S2)氧化效果的影响,以及富集铁组高效原位氧化TPH的机制.结果表明:(1)在S1、S2石油污染土壤(土壤S1、S2中TPH的初始含量分别为16074.33、14528.17 mg/kg)中,富集铁组中TPH的氧化量分别高达7550.32、8747.78 mg/kg,均高于非富集铁组Ⅰ中的相应值(分别为6364.43、5730.73 mg/kg),说明富集铁组可以高效氧化土壤中的TPH.(2)在土壤S1、S2中,富集铁组对中链(C_(19)~C_(24))烷烃的氧化率分别为20%、22%,对长链(C_(25)~C_(30))烷烃的氧化率分别为23%、20%,分别高于土壤S1中非富集铁组Ⅰ(17%、18%)和土壤S2中非富集铁组Ⅰ(19%、12%)的相应值.(3)电子顺磁共振波谱仪(EPR)测定结果表明,富集铁组中羟基自由基(·OH)强度(S1,36.61 a.u.;S2,16.06 a.u)高于非富集铁组Ⅰ中相应指标(S1,27.78 a.u.;S2,7.11 a.u.),并且羟基自由基持续时间(S1,50 h;S2,55 h)也高于非富集铁组Ⅰ中相应指标(S1,45 h;S2,40 h).(4)XPS测定结果显示,富集铁组中峰面积较高的FeOOH(S1,503.52;S2,850.01)和α-FeOOH(S1,399.40;S2,769.62)提高了·OH的瞬时强度,增加了·OH产量.而3D-EEM测定结果显示,富集铁组中类富里酸荧光区域标准体积(S1,1554047.24 au·nm^(2);S2,1110373.00 au·nm^(2))明显高于非富集铁组Ⅰ中相应值(S1,1100706.21au·nm^(2);S2,716069.98 au·nm^(2)),表明高含量的FA有利于FeOOH和α-FeOOH在土壤中的富集.研究显示,富集铁组实现了高效催化H_(2)O_(2)氧化土壤中TPH,为原位化学氧化修复石油污染土壤提供了一个经济有效的方法.
In order to obtain an in-situ Fenton technique for effective oxidation of total petroleum hydrocarbons(TPH)in soils,the remediation of oil-contaminated soil by in-situ preparation of aggregated iron using fulvic acid(FA)was studied.The study focused on the effects of the aggregated iron groups and non-aggregated iron groups on the oxidation of the two types of oil-contaminated soils(S1,S2)with different textures and soil organic matter(SOM),as well as the mechanism of efficient in-situ oxidation of TPH in the aggregated iron groups.The results showed that:(1)In oil-contaminated S1 and S2 soils(the initial concent of TPH was 16,074.33 mg/kg and 14,528.17 mg/kg in S1 and S2 soils,respectively),the TPH oxidation level was as high as 7,550.32 mg/kg(S1)and 8,747.78 mg/kg(S2)in the aggregated iron group,which were higher than the corresponding values in the non-aggregated iron groupⅠ(6,364.43 mg/kg,5,730.73 mg/kg).It indicated that the aggregated iron group could remove TPH efficiently from soils.(2)In the S1 and S2 soils,the oxidation rates of medium-chain alkanes(C19-C24)were up to 20%and 22%,and long-chain(C25-C30)alkanes were 23%and 20%in the aggregated iron group,which were higher than the oxidation rates of non-aggregated iron groupⅠin S1 soil(17%,18%)and S2 soil(19%,12%),respectively.(3)Electron paramagnetic resonance(EPR)technology showed that the intensity of hydroxyl radicals(·OH)in the aggregated iron group(S1,36.61 a.u;S2,16.06 a.u.)was higher than the corresponding indicators in the non-aggregated iron groupⅠ(S1,27.78 a.u.;S2,7.11 a.u.),and the hydroxyl radical durations(S1,50 h;S2,55 h)were also higher than the corresponding indexes in the non-aggregated iron groupⅠ(S1,45 h;S2,40 h).(4)The high contents of FeOOH(S1,503.52;S2,850.01)andα-FeOOH(S1,399.40;S2,769.62)measured by XPS increased the instantaneous strength and yield of·OH in the aggregated iron group.The 3DEEM results confirmed that the standard volume of the fluorescence region of fulvic acid in the aggregated iron group(S1,1,554,047.24 au·nm2;S2,1,110,373.00 au·nm2)was significantly higher than the corresponding values in the non-aggregated iron group(S1,1,100,706.21 au·nm2;S2,716,069.98 au·nm2),indicating that high FA content is beneficial for the aggregation of FeOOH andα-FeOOH in soils.Our study indicated that the aggregated iron group effectively catalyzed the removal of TPH from soils by H2O2,providing an economical and effective method for in-situ chemical oxidation remediation of oil-contaminated soil.
作者
徐金兰
李峰森
曹泽壮
许开慧
赵炎
白文广
刘璐
代佳楠
XU Jinlan;LI Fengsen;CAO Zezhuang;XU Kaihui;ZHAO Yan;BAI Wenguang;LIU Lu;DAI Jianan(School of Environmental and Municipal Engineering,Xi′an University of Architecture and Technology,Xi′an 710055,China;Shaanxi Key Laboratory of Environmental Engineering,Xi′an 710055,China)
出处
《环境科学研究》
CAS
CSCD
北大核心
2023年第12期2407-2416,共10页
Research of Environmental Sciences
基金
国家自然科学基金项目(No.51778524)。
关键词
高效氧化
中长链烷烃
富集铁组
羟基自由基(·OH)
石油污染土壤
efficient oxidation
medium-chain and long-chain alkanes
aggregated iron group
hydroxyl radicals
oil-contaminated soil
作者简介
徐金兰(1973-),女,陕西西安人,教授,博士,博导,主要从事石油污染土壤修复研究,xujinlan@xauat.edu.cn.
