Effects of Flooding and Dry-Wet Alternation on the Stability of Chromium(Cr) in Soil after Solidification/Stabilization Remediation
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摘要: 采用固化/稳定化技术修复后的场地和土壤因其污染物未彻底清除而备受关注，外界环境胁迫下重金属存在再活化的风险，但再活化的速率和形式尚不明确. 我国华南地区高温多雨，水热交换频繁剧烈，固化/稳定化后修复场地的安全利用面临更大的潜在风险. 以珠三角地区2个典型固化/稳定化修复后场地土壤为研究对象，开展淹水和干湿交替对土壤重金属铬(Cr)的释放、形态转化及其影响机制研究. 结果表明：①淹水和干湿交替可提高已固化/稳定化土壤中Cr的浸出浓度. 场地A和B土壤Cr的浸出浓度较淹水前分别上升了1.32和8.72倍，干湿交替后场地A土壤Cr的浸出浓度略有下降，场地B土壤Cr的浸出浓度则增加了4.32倍. ②淹水和干湿交替促使已固化/稳定化的Cr从酸可提取态向相对稳定的可氧化态等转化. 场地A和B土壤中酸可提取态Cr含量较淹水前的变化率分别为−60.17%和−14.34%，可氧化态Cr含量的变化率分别为2.71%和13.30%；干湿交替后土壤可提取态Cr含量的变化率分别为−28.78%和−2.13%，可氧化态Cr含量的变化率分别为5.48%和10.22%. ③淹水通过降低土壤氧化还原点位(Eh)、pH和无定形氧化铁等影响Cr的稳定性，促使Mn4+、Fe3+的还原和Cr的重新释放；干湿交替较淹水处理对固化/稳定化体系的影响相对较小. 研究显示，水分胁迫可提高固化/稳定化修复后土壤Cr的浸出浓度、改变赋存形态，但其浸出浓度远低于GB 5085.3—2007《危险废物鉴别标准 浸出毒性鉴别》和HJ/T 301—2007《铬渣污染治理环境保护技术规范(暂行)》规定的浸出液浓度限值；鉴于外界环境胁迫的长期性和复杂性，以及当前“一评定终身”的效果评估管理模式对未彻底清除污染物场地后期监管的无力性，持续关注和系统管控是实现固化/稳定化修复后场地可持续安全利用的必要途径.Abstract: Sites and soils treated with solidification/stabilization remediation have received much attention due to the residual pollutants in the soil. The solidified/stabilized heavy metals may be reactivated under environmental stress, and the rate and form of reactivation are unknown. It is hot and rainy in South China, with frequent and intense heat and humidity exchanges. Therefore, the use of solidified/stabilized sites are at greater risk. Typical solidified/stabilized soil samples were collected from two sites in the Pearl River Delta region to study the effect of flooding and dry-wet alternation on the release and transformation of chromium (Cr) in soil. The results showed that: (1) Flooding and dry-wet alternation increased the Cr leaching concentration. Compared with pre-flooding, the Cr leaching concentration of soil from Sites A and B increased by 1.32 and 8.72 times, respectively. After dry-wet alternation, the Cr leaching concentration of soil from Site A decreased slightly, while the Cr leaching concentration from Site B increased by 4.32 times. (2) Flooding and dry-wet alternation promoted the Cr conversion from the acid extractable state to the relatively stable oxidizable state. Compared with pre-flooding, the acid extractable Cr content of soils from Sites A and B decreased by 60.17% and 14.34%, respectively, and the oxidizable Cr content increased by 2.71% and 13.30%, respectively. After dry-wet alternation, acid extractable Cr content of soils from Sites A and B decreased by 28.78% and 2.13%, respectively, while the oxidizable Cr content increased by 5.48% and 10.22%, respectively. (3) Flooding affected Cr stability by reducing soil oxidation-reduction potential (Eh), pH, and amorphous iron oxides, promoting the Mn4+ reduction, Fe3+ reduction, and Cr re-release. Dry-wet alternation had less influence on the solidified/stabilized system than flooding. This study also showed that water stress increased the Cr leaching concentration of solidified/stabilized soils and changed the Cr occurrence forms, but the leaching concentration was much lower than the Toxic Leaching-Related Limit Specified in the Identification Standards for Hazardous Wastes: Identification for Extraction Toxicity (GB 5085.3—2007) and Environmental Protection Technical Specifications for Pollution Treatment of the Chromium Residue (on trial) (HJ/T 301—2007). In consideration of the long-term and complex environmental stress and the inadequate subsequent supervision of solidified/stabilized sites caused by the current ‘determined by one assessment’ effect evaluation management mode, continuous attention and systematic management are necessary for sustainable and safe utilization of the solidified/stabilized sites.
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Key words:
- flooding /
- dry-wet alternation /
- solidification/stabilization /
- soil heavy metals /
- stability
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图 1 修复后土壤Cr的浸出浓度、铁氧化物含量、pH、Eh等特征指标随淹水时间的变化
Figure 1. Typical characteristics (Cr leaching and iron oxides concentration, pH, Eh) of the remediated soils vs. flooding times
图 2 修复后土壤中Cr的浸出浓度和pH随干湿交替次数的变化
Figure 2. The Cr leaching concentration and pH of the remediated soils vs. rotation cycles
图 3 淹水时间和干湿交替对修复后土壤中Cr形态分布的影响
Figure 3. Effects of flooding time and alternation cycles on the distribution of Cr in the remediated soils
图 4 修复后土壤在淹水处理前后的X射线衍射图
Figure 4. XRD pattern comparisons of the remediated soil samples after flooding treatment
表 1 修复后场地土壤特征参数
Table 1. Characteristics of the remediated soil samples
场地 场地固化/稳定
化修复药剂修复后土壤Cr6+
含量/(mg/kg)修复后土壤总
Cr含量/(mg/kg)修复后土壤Cr初
始浸出浓度/(μg/L)pH CEC/
(cmol/kg)有机质含量/
(g/kg)地块规划
用地类型A FeSO4(6%)，生石灰(1%) 未检出 178.5 2.71 5.4 3.09 5.04 商业金融用地 B 铁基类还原稳定化药
剂(5%)，生石灰(1%)未检出 445.0 0.98 6.2 6.13 14.5 中小学用地 
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表 2 检测项目及分析测试方法
Table 2. The items and analysis methods
测试指标 测试方法 测试方法依据 土壤pH 电位法 《土壤农业化学分析方法》(2000年) 土壤Eh 电位法 《土壤农业化学分析方法》(2000年) 游离态氧化铁(Fed)含量 DCB法 《土壤农业化学分析方法》(2000年) 无定形态氧化铁(Feox)含量 酸性草酸铵提取法 《土壤农业化学分析方法》(2000年) 晶体态氧化铁(FeP)含量 碱性焦磷酸钠浸提法 《土壤农业化学分析方法》(2000年) 土壤总Cr的含量 电感耦合等离子体质谱法 《固体废物 金属元素的测定 电感耦合等离子体质谱法》(HJ 766—2015) 土壤不同形态Cr的含量 顺序提取法 《土壤和沉积物13个微量元素形态顺序提取程序》(GB/T 25282—2010) 土壤Cr的浸出浓度 硝酸硫酸法 《固体废物 浸出毒性浸出方法 硫酸硝酸法》(HJ/T 299—2007) 土壤残渣态Cr的含量 王水提取-电感耦合等离子体质谱法 《土壤和沉积物12种金属元素的测定 王水提取-电感耦合等离子体质谱法》(HJ 803—2016)
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表 3 修复后土壤中Cr的浸出浓度与土壤理化特征指标的相关性
Table 3. Correlation analysis results between Cr leaching concentration and physicochemical characteristics of the soil samples
指标 淹水时间 Cr浸出浓度 Fed含量 Feox含量 FeP含量 Eh pH DOM含量 淹水时间 1 Cr浸出浓度 0.562** 1 Fed含量 −0.011 −0.228 1 Feox含量 −0.025 −0.322** 0.978** 1 FeP含量 0.089 0.504** −0.575** −0.732** 1 Eh −0.451** 0.004 −0.768** −0.741** 0.380** 1 pH −0.501** 0.095 −0.743** −0.773** 0.574** 0.898** 1 DOM含量 −0.461** 0.209 −0.723** −0.784** 0.686** 0.762** 0.923** 1 注：**表示在0.01水平(双侧)上显著相关.
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[1] CHEN Q Y,TYRER M,HILLS C D,et al.Immobilisation of heavy metal in cement-based solidification/stabilisation:a review[J].Waste Management,2009,29(1):390-403. doi: 10.1016/j.wasman.2008.01.019 [2] 闫淑兰,赵秀红,罗启仕.基于文献计量的重金属固化稳定化修复技术发展动态研究[J].农业环境科学学报,2020,39(2):229-238. doi: 10.11654/jaes.2019-0757YAN S L,ZHAO X H,LUO Q S.Bibliometrics-based development trends of solidification/stabilization technology for the remediation of sites contaminated by heavy metals[J].Journal of Agro-Environment Science,2020,39(2):229-238. doi: 10.11654/jaes.2019-0757 [3] CANGIALOSI F,INTINI G,LIBERTI L,et al.Environmental exposure and health:health risk analysis for a contaminated industrial site:pre and post remediation scenarios[J].WIT Transactions on Ecology and the Environment,2005,85:309-318. [4] WANG F,WANG H L,AL-TABBAA A.Leachability and heavy metal speciation of 17-year old stabilised/solidified contaminated site soils[J].Journal of Hazardous Materials,2014,278:144-151. doi: 10.1016/j.jhazmat.2014.05.102 [5] 常春英,曹浩轩,陶亮,等.固化/稳定化修复后土壤重金属稳定性及再活化研究进展[J].土壤,2021,53(4):682-691.CHANG C Y,CAO H X,TAO L,et al.Advances on heavy metal stability and reactivation for soil after solidification/stabilization remediation[J].Soils,2021,53(4):682-691. [6] 张琢,李发生,王梅,等.基于用途和风险的重金属污染土壤稳定化修复后评估体系探讨[J].环境工程技术学报,2015,5(6):509-518. doi: 10.3969/j.issn.1674-991X.2015.06.080ZHANG Z,LI F S,WANG M,et al.Thinking on assessment framework of stabilization effect for heavy metals contaminated soil based on disposal scenarios and risks[J].Journal of Environmental Engineering Technology,2015,5(6):509-518. doi: 10.3969/j.issn.1674-991X.2015.06.080 [7] 谭海剑,黄祖照,宋清梅,等.粤港澳大湾区典型城市遗留地块土壤污染特征研究[J].环境科学研究,2021,34(4):976-986.TAN H J,HUANG Z Z,SONG Q M,et al.Characterization of soil contaminations in brownfield sites in a typical city in Guangdong-Hong Kong-Macao Greater Bay Area[J].Research of Environmental Sciences,2021,34(4):976-986. [8] 杨宾,罗会龙,刘士清,等.淹水对土壤重金属浸出行为的影响及机制[J].环境工程学报,2019,13(4):936-943. doi: 10.12030/j.cjee.201811056YANG B,LUO H L,LIU S Q,et al.Effect and mechanism of water inundation on the leaching behavior of heavy metals in contaminated soils[J].Chinese Journal of Environmental Engineering,2019,13(4):936-943. doi: 10.12030/j.cjee.201811056 [9] ZHANG L W,SHANG Z B,GUO K X,et al.Speciation analysis and speciation transformation of heavy metal ions in passivation process with thiol-functionalized nano-silica[J].Chemical Engineering Journal,2019,369:979-987. doi: 10.1016/j.cej.2019.03.077 [10] ZHENG S N,ZHANG M K.Effect of moisture regime on the redistribution of heavy metals in paddy soil[J].Journal of Environmental Sciences,2011,23(3):434-443. doi: 10.1016/S1001-0742(10)60428-7 [11] SHAHID M,SHAMSHAD S,RAFIQ M,et al.Chromium speciation,bioavailability,uptake,toxicity and detoxification in soil-plant system:a review[J].Chemosphere,2017,178:513-533. doi: 10.1016/j.chemosphere.2017.03.074 [12] FONSECA B,TEIXEIRA A,FIGUEIREDO H,et al.Modelling of the Cr(Ⅵ) transport in typical soils of the North of Portugal[J].Journal of Hazardous Materials,2009,167(1/2/3):756-762. [13] ANTEMIR A,HILLS C D,CAREY P J,et al.Long-term performance of aged waste forms treated by stabilization/solidification[J].Journal of Hazardous Materials,2010,181(1/2/3):65-73. [14] 史开宇,王兴润,范琴,等.不同还原药剂修复Cr(Ⅵ)污染土壤的稳定性评估[J].环境工程学报,2020,14(2):473-479. doi: 10.12030/j.cjee.201904129SHI K Y,WANG X R,FAN Q,et al.Stability evaluation of Cr(Ⅵ)-contaminated soils restoration with different reducing agents[J].Chinese Journal of Environmental Engineering,2020,14(2):473-479. doi: 10.12030/j.cjee.201904129 [15] LYU H H,ZHAO H,TANG J C,et al.Immobilization of hexavalent chromium in contaminated soils using biochar supported nanoscale iron sulfide composite[J].Chemosphere,2018,194:360-369. doi: 10.1016/j.chemosphere.2017.11.182 [16] 毛凌晨,叶华.氧化还原电位对土壤中重金属环境行为的影响研究进展[J].环境科学研究,2018,31(10):1669-1676.MAO L C,YE H.Influence of redox potential on heavy metal behavior in soils:a review[J].Research of Environmental Sciences,2018,31(10):1669-1676. [17] FROHNE T,RINKLEBE J,DIAZ-BONE R A,et al.Controlled variation of redox conditions in a floodplain soil:impact on metal mobilization and biomethylation of arsenic and antimony[J].Geoderma,2011,160(3/4):414-424. [18] CAPPUYNS V,SWENNEN R.The application of pHstat leaching tests to assess the pH-dependent release of trace metals from soils,sediments and waste materials[J].Journal of Hazardous Materials,2008,158(1):185-195. doi: 10.1016/j.jhazmat.2008.01.058 [19] MANCEAU A,CHARLET L,BOISSET M C,et al.Sorption and speciation of heavy metals on hydrous Fe and Mn oxides:from microscopic to macroscopic[J].Applied Clay Science,1992,7(1/2/3):201-223. [20] WANG R H,ZHU X F,QIAN W,et al.Pectin adsorption on amorphous Fe/Al hydroxides and its effect on surface charge properties and Cu(Ⅱ) adsorption[J].Journal of Soils and Sediments,2017,17(10):2481-2489. doi: 10.1007/s11368-017-1702-8 [21] 刘美丽,牛其建,俞洋洋,等.碳基材料负载纳米零价铁去除六价铬的研究进展[J].环境科学研究,2021.doi: 10.13198/j.issn.1001-6929.2021.07.13.LIU M L,NIU Q J,YU Y Y,et al.Progress in removal of hexavalent chromium by carbon-based materials loaded with nano zero-valent iron[J].Research of Environmental Sciences,2021.doi: 10.13198/j.issn.1001-6929.2021.07.13. [22] YAN M Q,MA J,ZHANG C Y,et al.Optical property of dissolved organic matters (DOMs) and its link to the presence of metal ions in surface freshwaters in China[J].Chemosphere,2017,188:502-509. doi: 10.1016/j.chemosphere.2017.09.001 [23] 卢鑫.硫化物对电镀厂铬污染土壤稳定化处理及其长期稳定性研究[D].上海:华东理工大学,2017:55-59. [24] 张雪芹.干湿循环作用下碱渣固化重金属污染土的稳定性研究[D].合肥:合肥工业大学,2017:33-42. [25] SANCHEZ F,GARRABRANTS A C,KOSSON D S.Effects of intermittent wetting on concentration profiles and release from a cement-based waste matrix[J].Environmental Engineering Science,2003,20(2):135-153. doi: 10.1089/109287503763336575 [26] ZHENG S A,ZHENG X Q,CHEN C.Transformation of metal speciation in purple soil as affected by waterlogging[J].International Journal of Environmental Science and Technology,2013,10(2):351-358. doi: 10.1007/s13762-012-0146-3 [27] 陈英旭,何增耀,吴建平,等.外源铬在土壤中的形态转化[J].农业环境保护,1995,14(3):105-110.CHEN Y X,HE Z Y,WU J P,et al.Transformations of fortified Cr in soils[J].Agro-Environmental Protection,1995,14(3):105-110. [28] ALLOWAY B J.Heavy metals in soils[M].2nd edition.London:Blackie Academic & Professional:1995. [29] KALBITZ K,SOLINGER S,PARK J H,et al.Controls on the dynamics of dissolved organic matter in soils:a review[J].Soil Science,2000,165(4):277-304. doi: 10.1097/00010694-200004000-00001 [30] 张素,熊东红,校亮,等.干湿交替对土壤性质影响的研究[J].土壤通报,2017,48(3):762-768.ZHANG S,XIONG D H,XIAO L,et al.Influence of dry-wet cycling on soil properties[J].Chinese Journal of Soil Science,2017,48(3):762-768. [31] DENEF K,SIX J,BOSSUYT H,et al.Influence of dry-wet cycles on the interrelationship between aggregate,particulate organic matter,and microbial community dynamics[J].Soil Biology and Biochemistry,2001,33(12):1599-1611. [32] KAHLE M,KLEBER M,JAHN R.Review of XRD-based quantitative analyses of clay minerals in soils:the suitability of mineral intensity factors[J].Geoderma,2002,109(3):191-205. [33] ZHAO W,TAN W F.Quantitative and structural analysis of minerals in soil clay fractions developed under different climate zones in China by XRD with Rietveld method,and its implications for pedogenesis[J].Applied Clay Science,2018,162:351-361. doi: 10.1016/j.clay.2018.05.019 [34] 张浩,于先坤,徐修平,等.基于XRD与SEM研究风淬渣微粉用于重金属污染土壤的修复机理[J].光谱学与光谱分析,2021,41(1):278-284.ZHANG H,YU X K,XU X P,et al.Study on repairing mechanism of wind quenching slag powder in heavy metal contaminated soil by XRD and SEM[J].Spectroscopy and Spectral Analysis,2021,41(1):278-284. -
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