模拟干湿交替环境作用下狗牙根根系分泌物对消落带Pb的影响
|
摘要
为探究狗牙根根系分泌物对消落带Pb迁移能力和生物有效性的作用,通过模拟试验,选取三峡库区消落带优势植物狗牙根根系分泌的低分子量有机酸,研究在干湿交替环境作用下,根系分泌物对污染土壤及上覆水中Pb总量、土壤中Pb赋存形态的影响。结果表明:在干湿交替环境作用下,表层土壤中Pb含量不断减少,底层土壤中Pb含量不断增加;2次落干—淹水结束后,各处理表层土壤中Pb含量为混酸>柠檬酸≈乙酸>丙二酸>对照,底层土壤Pb含量为混酸>柠檬酸≈乙酸>丙二酸>对照。表层土壤中碳酸盐结合态、铁锰氧化态Pb是导致土壤总Pb含量减少的主要原因,最大减少幅度分别为24.89%和19.04%;但添加了低分子量有机酸的处理,表层土壤中铁锰氧化态、有机结合态Pb含量比对照高,可交换态Pb含量比对照低;且有机酸促进了底层土壤中碳酸盐结合态及铁锰氧化态Pb含量的增加。在2次淹水过程中,上覆水Pb含量均呈先增加后降低的趋势,低分子量有机酸抑制了土壤向上覆水释放Pb。总的来说,在干湿交替环境作用下,狗牙根根系分泌物降低了表层土壤中Pb环境风险。
In order to explore the effect of bermuda grass root exudates on migration and bioavailability of Pb in the fluctuation zone,low molecular weight organic acids secreted by bermuda grass roots of the dominant plants in the fluctuating zone of Three Gorges Reservoir area were selected,and the effects of root exudates on the total amount of Pb in contaminated soil and overlying water and the occurrence forms of Pb in soil were investigated in the dry and wet alternate environment through simulation tests.The results showed that in the wet and dry alternate environment,the Pb content in the topsoil decreased,the content of Pb in the bottom soil increased.After two times of wet and dry alternating,the Pb content in topsoil of the different treatments followed the order of mixed acid>citric acid≈acetic acid> malonic acid>control,the Pb content in the bottom soil was sorted as mixed acid>citric acid≈acetic acid> malonic acid>control.Carbonate-bound Pb and iron-manganese oxidized Pb in surface soil were the main reasons for the decrease of total Pb content,maximum reduction rates was 24.89% and 19.04% respectively.However,in the treatments added low molecular weight organic acids,the contents of Fe-Mn oxidized Pb and organic bound Pb in surface soil were higher than those in the control,while the exchangeable Pb content was lower than that of the control.Moreover,organic acids promoted the increase of contents of Pb in the carbonate bound state and FeMn oxidation state in the bottom soil.During the two flooding process,the content of Pb in overlying waterboth increased first and then decreased,low molecular weight organic acids inhibited the release of Pb from soil to overlying water.In general,in the wet and dry alternate environment,the root exudates of bermuda grass reduced the environmental risk of Pb in topsoil.
In order to explore the effect of bermuda grass root exudates on migration and bioavailability of Pb in the fluctuation zone,low molecular weight organic acids secreted by bermuda grass roots of the dominant plants in the fluctuating zone of Three Gorges Reservoir area were selected,and the effects of root exudates on the total amount of Pb in contaminated soil and overlying water and the occurrence forms of Pb in soil were investigated in the dry and wet alternate environment through simulation tests.The results showed that in the wet and dry alternate environment,the Pb content in the topsoil decreased,the content of Pb in the bottom soil increased.After two times of wet and dry alternating,the Pb content in topsoil of the different treatments followed the order of mixed acid>citric acid≈acetic acid> malonic acid>control,the Pb content in the bottom soil was sorted as mixed acid>citric acid≈acetic acid> malonic acid>control.Carbonate-bound Pb and iron-manganese oxidized Pb in surface soil were the main reasons for the decrease of total Pb content,maximum reduction rates was 24.89% and 19.04% respectively.However,in the treatments added low molecular weight organic acids,the contents of Fe-Mn oxidized Pb and organic bound Pb in surface soil were higher than those in the control,while the exchangeable Pb content was lower than that of the control.Moreover,organic acids promoted the increase of contents of Pb in the carbonate bound state and FeMn oxidation state in the bottom soil.During the two flooding process,the content of Pb in overlying waterboth increased first and then decreased,low molecular weight organic acids inhibited the release of Pb from soil to overlying water.In general,in the wet and dry alternate environment,the root exudates of bermuda grass reduced the environmental risk of Pb in topsoil.
引文
[1]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.
[2]王健康,高博,周怀东,等.三峡库区蓄水运用期表层沉积物重金属污染及其潜在生态风险评价[J].环境科学,2012,33(5):1693-1699.
[3] Montiel-Rozas M M,Madejón E,Madejón P.Effect of heavy metals and organic matter on root exudates(low molecular weight organic acids)of herbaceous species:An assessment in sand and soil conditions under different levels of contamination[J].Environmental Pollution,2016,216:273-281.
[4] Wang S,Mulligan C N.Effects of three low-molecularweight organic acids(LMWOAs)and pH on the mobilization of arsenic and heavy metals(Cu,Pb,and Zn)from mine tailings[J].Environmental Geochemistry&Health,2013,35(1):111-118.
[5] Chen H X,Dou J F,Xu H B.The effect of low-molecular-weight organic-acids(LMWOAs)on treatment of chromium-contaminated soils by compost-phytoremediation:Kinetics of the chromium release and fractionation[J].Journal of Envirtomental Sciences,2018,70(8):45-53.
[6] Jiang H,Li T Q,Han X,et al.Effects of pH and low molecular weight organic acids on competitive adsorption and desorption of cadmium and lead in paddy soils[J].Environmental Monitoring and Assessment,2012,184(10):6325-6335.
[7]何沅洁,刘江,江韬,等.模拟三峡库区消落带优势植物根系低分子量有机酸对土壤中铅的解吸动力学[J].环境科学,2017,38(2):600-607.
[8]梁丽,王永敏,李先源,等.三峡水库消落带植物汞的分布特征[J].环境科学,2015,36(11):4103-4111.
[9]乔冬梅,庞鸿宾,齐学斌,等.不同质量浓度铅对黑麦草根系分泌物和铅吸收富集的影响[J].灌溉排水学报,2012,31(2):43-47.
[10]鲍士旦.土壤农化分析[M].3版.北京:中国农业出版社,1999:42-50.
[11] Iwai C B,Oo A N,Topark-Ngarm B.Soil property and microbial activity in natural salt affected soils in an alternating wet-dry tropic climate[J].Geoderma,2012,189/190(6):144-152.
[12]胡雯竹.干湿交替对保护地土壤微团聚体及化学性质的影响[D].吉林延边:延边大学,2016.
[13] Huang P M.Soil mineral-organic matter-microorganism interactions:Fundamentals and impacts[J].Advances in Agronomy,2004,82(2):391-472.
[14]张猛.干湿交替过程中土壤容重、水分特征曲线和热特性的动态变化特征[D].北京:中国农业大学,2017.
[15]钱翌,张玮,冉德超.青岛市土壤Pb的形态分布及其影响因素分析[J].安徽农业科学,2010,38(22):11960-11961.
[16]姜军,徐仁扣,潘经健,等.宜兴乌栅土干湿交替过程中土壤pH与Eh的动态变化及原因初探[J].土壤学报,2012,49(5):1056-1061.
[17]刘霞,刘树庆,王胜爱.河北主要土壤中Cd和Pb的形态分布及其影响因素[J].土壤学报,2003,40(3):393-400.
[18]张雪雯.干湿交替对若尔盖湿地枯落物和土壤有机质分解的影响[D].北京:北京林业大学,2014.
[19]杨晓燕,侯青叶,杨忠芳,等.成都经济区黄壤土壤剖面Pb形态分布特征及其影响因素[J].现代地质,2008,22(6):966-974.
[20] Xu R,Zhao A,Ji G.Effect of low-molecular-weight organic anions on surface charge of variable charge soils[J].Journal of Colloid and Interface Science,2003,264(2):322-326.
[21]张连科,刘心宇,王维大.2种油料作物秸秆生物炭对土壤中铅的钝化修复[J].生态环境学报,2018,27(1):166-173.
[22]钟晓兰,周生路,黄明丽,等.土壤重金属的形态分布特征及其影响因素[J].生态环境学报,2009,18(4):1266-1273.
[23]徐明露,方凤满,林跃胜.湿地土壤重金属污染特征、来源及风险评价研究进展[J].土壤通报,2015,46(3):762-768.
[24]王图锦.三峡库区消落带重金属迁移转化特征研究[D].重庆:重庆大学,2011.
[25]马俊,傅成诚.不同剂量外源重金属注入对土壤重金属形态分布的影响[J].科学技术与工程,2016,16(35):129-135.
[26]韩勇.三峡库区消落带污染特性及水环境影响研究[D].重庆:重庆大学,2007.
[27] Weiner S,Addadi L.Effect of pH,temperature,dissolved oxygen,and flow rate of overlying water on heavy metals release from storm sewer sediments[J].Journal of Chemistry,2013:e434012.
[28] Huang Y,Zhang D,Xu Z,et al.Effect of overlying water pH,dissolved oxygen and temperature on heavy metal release from river sediments under laboratory conditions[J].Archives of Environmental Protection,2017,43(2):28-36.
[29]Godyn B,Chudzińska M,Barakiewicz D,et al.Heavy metal contents in the sediments of astatic ponds:Influence of geomorphology,hydroperiod,water chemistry and vegetation[J].Ecotoxicology&Environmental Safety,2015,118:103-111.
[30]柏建坤,李潮流,康世昌,等.雅鲁藏布江中段表层沉积物重金属形态分布及风险评价[J].环境科学,2014,35(9):3346-3351.
[2]王健康,高博,周怀东,等.三峡库区蓄水运用期表层沉积物重金属污染及其潜在生态风险评价[J].环境科学,2012,33(5):1693-1699.
[3] Montiel-Rozas M M,Madejón E,Madejón P.Effect of heavy metals and organic matter on root exudates(low molecular weight organic acids)of herbaceous species:An assessment in sand and soil conditions under different levels of contamination[J].Environmental Pollution,2016,216:273-281.
[4] Wang S,Mulligan C N.Effects of three low-molecularweight organic acids(LMWOAs)and pH on the mobilization of arsenic and heavy metals(Cu,Pb,and Zn)from mine tailings[J].Environmental Geochemistry&Health,2013,35(1):111-118.
[5] Chen H X,Dou J F,Xu H B.The effect of low-molecular-weight organic-acids(LMWOAs)on treatment of chromium-contaminated soils by compost-phytoremediation:Kinetics of the chromium release and fractionation[J].Journal of Envirtomental Sciences,2018,70(8):45-53.
[6] Jiang H,Li T Q,Han X,et al.Effects of pH and low molecular weight organic acids on competitive adsorption and desorption of cadmium and lead in paddy soils[J].Environmental Monitoring and Assessment,2012,184(10):6325-6335.
[7]何沅洁,刘江,江韬,等.模拟三峡库区消落带优势植物根系低分子量有机酸对土壤中铅的解吸动力学[J].环境科学,2017,38(2):600-607.
[8]梁丽,王永敏,李先源,等.三峡水库消落带植物汞的分布特征[J].环境科学,2015,36(11):4103-4111.
[9]乔冬梅,庞鸿宾,齐学斌,等.不同质量浓度铅对黑麦草根系分泌物和铅吸收富集的影响[J].灌溉排水学报,2012,31(2):43-47.
[10]鲍士旦.土壤农化分析[M].3版.北京:中国农业出版社,1999:42-50.
[11] Iwai C B,Oo A N,Topark-Ngarm B.Soil property and microbial activity in natural salt affected soils in an alternating wet-dry tropic climate[J].Geoderma,2012,189/190(6):144-152.
[12]胡雯竹.干湿交替对保护地土壤微团聚体及化学性质的影响[D].吉林延边:延边大学,2016.
[13] Huang P M.Soil mineral-organic matter-microorganism interactions:Fundamentals and impacts[J].Advances in Agronomy,2004,82(2):391-472.
[14]张猛.干湿交替过程中土壤容重、水分特征曲线和热特性的动态变化特征[D].北京:中国农业大学,2017.
[15]钱翌,张玮,冉德超.青岛市土壤Pb的形态分布及其影响因素分析[J].安徽农业科学,2010,38(22):11960-11961.
[16]姜军,徐仁扣,潘经健,等.宜兴乌栅土干湿交替过程中土壤pH与Eh的动态变化及原因初探[J].土壤学报,2012,49(5):1056-1061.
[17]刘霞,刘树庆,王胜爱.河北主要土壤中Cd和Pb的形态分布及其影响因素[J].土壤学报,2003,40(3):393-400.
[18]张雪雯.干湿交替对若尔盖湿地枯落物和土壤有机质分解的影响[D].北京:北京林业大学,2014.
[19]杨晓燕,侯青叶,杨忠芳,等.成都经济区黄壤土壤剖面Pb形态分布特征及其影响因素[J].现代地质,2008,22(6):966-974.
[20] Xu R,Zhao A,Ji G.Effect of low-molecular-weight organic anions on surface charge of variable charge soils[J].Journal of Colloid and Interface Science,2003,264(2):322-326.
[21]张连科,刘心宇,王维大.2种油料作物秸秆生物炭对土壤中铅的钝化修复[J].生态环境学报,2018,27(1):166-173.
[22]钟晓兰,周生路,黄明丽,等.土壤重金属的形态分布特征及其影响因素[J].生态环境学报,2009,18(4):1266-1273.
[23]徐明露,方凤满,林跃胜.湿地土壤重金属污染特征、来源及风险评价研究进展[J].土壤通报,2015,46(3):762-768.
[24]王图锦.三峡库区消落带重金属迁移转化特征研究[D].重庆:重庆大学,2011.
[25]马俊,傅成诚.不同剂量外源重金属注入对土壤重金属形态分布的影响[J].科学技术与工程,2016,16(35):129-135.
[26]韩勇.三峡库区消落带污染特性及水环境影响研究[D].重庆:重庆大学,2007.
[27] Weiner S,Addadi L.Effect of pH,temperature,dissolved oxygen,and flow rate of overlying water on heavy metals release from storm sewer sediments[J].Journal of Chemistry,2013:e434012.
[28] Huang Y,Zhang D,Xu Z,et al.Effect of overlying water pH,dissolved oxygen and temperature on heavy metal release from river sediments under laboratory conditions[J].Archives of Environmental Protection,2017,43(2):28-36.
[29]Godyn B,Chudzińska M,Barakiewicz D,et al.Heavy metal contents in the sediments of astatic ponds:Influence of geomorphology,hydroperiod,water chemistry and vegetation[J].Ecotoxicology&Environmental Safety,2015,118:103-111.
[30]柏建坤,李潮流,康世昌,等.雅鲁藏布江中段表层沉积物重金属形态分布及风险评价[J].环境科学,2014,35(9):3346-3351.