【作者】 唐明灯；

【导师】 胡锋； 骆永明；

【作者基本信息】 南京农业大学 ， 土壤学， 2008， 博士

【摘要】 中国原生的铜耐性植物—海州香薷（Elsholtzia splendens）在重金属尤其是铜污染土壤的植物修复中得到广泛关注,经十年研究发现,海州香薷地上部Cu、Zn含量较高,在土壤Cu、Zn污染的修复中具有应用前景,但其地下部Cu、Zn含量远大于地上部,Cu、Zn难以向地上部迁移。为提高海州香薷修复Cu、Zn污染的效率,施加微生物、化学试剂（尤其是低分子量有机酸,如乙二胺二琥珀酸EDDS）以及微生物-化学试剂等多种措施对海州香薷植物修复进行诱导,促进Cu、Zn向地上部迁移,使海州香薷达到诱导富集甚至达到诱导超富集。海州香薷在修复Cu、Zn污染过程中富集了一定量的Cu、Zn等重金属元素,如何合理处理植物修复后的海州香薷植物并实现其资源化利用是环境友好的重金属植物修复技术系统需要加强的内容。本文设置了一系列培养试验、盆栽试验和田间试验,主要研究:（1）产酸菌对海州香薷重金属提取吸收的影响;（2）丛枝菌根真菌与乙二胺二琥珀酸对海州香薷提取重金属的影响;（3）硫粉对复合污染土壤中重金属的活化作用;（4）硫粉与乙二胺二琥珀酸对海州香薷去除土壤Cu、Zn的影响;（5）修复植物香薷堆肥对缺铜土壤上冬小麦（Triticum aestivum L.）生长和铜吸收的初步研究;（6）富铜香薷堆肥对缺铜土壤上冬小麦（T.aestivum L.）产量和Cu、Zn吸收的影响。以期从杭州郊区铜冶炼厂周边长期污染土壤的土壤溶液Cu、Zn浓度变化与土壤Cu、Zn浸提态浓度变化阐述诱导剂显著提高海州香薷地上部重金属浓度,显著提高海州香薷去除土壤Cu、Zn的根际过程;探索海州香薷植物修复后资源化并应用到缺铜土壤的可行性和前景,使海州香薷植物修复成为一个较为完整的技术体系。结果表明:1.无色菌（Achromatium sp.）代谢过程产生大量有机酸,在培养试验中显著降低溶液pH,显著降低溶液可溶性Cu浓度,但同时该菌株使溶液可溶性Zn浓度显著增加。在盆栽试验中,接种菌株10 d显著降低土壤溶液pH,该产酸菌对土壤溶液中Cu、Zn浓度的影响与培养试验的趋势一致;接种无色菌菌株可促进海州香薷生长及其地上部对Cu的吸收,从而显著提高海州香薷对污染土壤Cu的提取吸收量,同时该产酸菌也提高海州香薷对污染土壤Zn的去除量。2.丛枝菌根真菌（AMF）可提高海州香薷地上部重金属浓度,显著提高海州香薷吸收去除污染土壤Cu量;同时,丛枝菌根真菌可提高海州香薷地上部Zn浓度。3.硫粉使土壤pH和土壤溶液pH显著下降,显著提高土壤硝酸铵浸提态重金属浓度与土壤溶液重金属浓度。与对照相比,施用400 mmol kg^-1硫粉使硝酸铵浸提态Cu浓度提高49倍,Zn提高75倍,Cd为11倍,Pb为93倍,使活化的Cu、Zn、Cd、Pb分别达全量的57%、87%、91%、20%。4.施用80 mmol kg^-1或120 mmol kg^-1硫粉也显著降低了土壤pH及土壤溶液pH,提高了土壤溶液中重金属浓度;与此同时,硫粉显著提高海州香薷地上部Zn浓度和硫浓度,且地上部Zn浓度与硫浓度间显著正相关,硫粉显著提高海州香薷去除土壤Zn的量。该土壤施用80 mmol kg^-1硫粉促进海州香薷生长,但120 mmol kg^-1硫粉对海州香薷有显著的抑制作用。5.EDDS可促进土壤Cu、Zn进入土壤溶液,显著增加土壤溶液Cu、Zn浓度;同时EDDS促进Cu、Zn向海州香薷地上部运输、显著提高海州香薷地上部Cu浓度,因而施用EDDS显著提高土壤Cu去除量。高温季节施用EDDS,土壤溶液中高浓度的Cu、Zn迅速下降;低温季节施用EDDS,土壤溶液中高Cu、Zn浓度持续较长时间。EDDS显著抑制生长前期海州香薷的生长并显著降低海州香薷生物量。6.EDDS与丛枝菌根真菌对海州香薷地上部重金属浓度的影响未出现协同作用,另一方面,EDDS与硫粉对海州香薷地上部重金属浓度的影响也未出现协同作用。EDDS对海州香薷去除土壤Cu的效果较Zn佳,而硫粉对海州香薷去除Zn的影响更佳。化学诱导措施对土壤溶液重金属浓度影响效果比生物制剂明显;与硫粉相比较,施用EDDS迅速提高土壤溶液重金属浓度,并促进Cu向海州香薷地上部转运。同时,由于EDDS容易降解,是较好的化学诱导措施。7.两组盆栽试验和一个田间试验显示,富铜海州香薷经堆制后应用到缺铜土壤上能显著改善冬小麦（T.aestivum L.）的生物性状,提高冬小麦的生物量、株高、小麦籽粒产量和千粒重,而对小麦籽粒中Cu、Zn浓度没有显著影响;因而海州香薷在植物修复后以堆肥的形式进行资源化应用是可行的。富铜海州香薷堆肥的肥效是多种营养元素的共同作用;在缺铜土壤上施用富铜海州香薷堆肥需适当配施无机化肥。更多还原

【Abstract】 Elsholtzia splendens,a Chinese native Cu-tolerant plant,has been paying widely attention to in the phytoremediation of heavy metal（in particular Cu） contaminated soils. Investigations for about a decade show that E.splendens can be applied to the rehabilitation of Cu,Zn pollutants of in a soil due to high Cu,Zn concentrations in the shoot.Compared with the shoot,the root has further higher Cu,Zn concentrations because both Cu and Zn are difficult to be transported to the shoot of E.splendens.Addition of microbia chemical reagents[especially low molecular weight organic acids,for example[s, s]-ethylenediamine disuccinic acid（EDDS）],microbia in conjunction with chemical reagents,and so on,to the soil have enhanced Cu,Zn transportation from root to the shoot and increased the phytoremediation potential of Cu,Zn by E.splendens.But there has few successful examples of Cu,Zn concentrations in E.splendens shoot up to 1000,10000 mg kg^-1 DW（Cu,Zn hyperaccumulation levels in plant,respectively） by these inducements. Furthermore,E.splendens has accumulated a certain concentration of Cu,Zn in the shoot after a phytoremedying process of Cu,Zn pollutants in the soil.Batch disposal of E. splendens biomass after phytoremediation and its resourceful utilization are two of the sticking points that environmentally friendly phytoremediation justify itself.We have designed a series of incubation,pot,and field experiments,and mainly focused on:（1） Effect of acid production of Achromatium sp.on heavy metal uptake by Elsholtzia splendens;（2） Influences of arbuscular mycorrhizal fungus（AMF） and[s, s]-ethylenediamine disuccinic acid（EDDS） on the uptake of heavy metals by Elsholtzia splendens;（3） Influence of sulfur powder on solubility of Cu,Pb,Cd,and Zn in the soils contaminated by heavy metals;（4） Effects of sulfur powder and[s,s]-ethylenediamine disuccinic acid （EDDS） on s the uptake of soil Cu/Zn by Elsholtzia splendens; （5） Preliminary study on effect of Elsholtzia Splendens compost on plant growth in a Cu-deficient upland aoil and Cu uptake by winter wheat;（6） Effects of copper-enriched composts applied to copper-deficient soil on the yield and copper and zinc uptake of wheat;We had groped for Cu,Zn fractions in the soil pore water,the reasons of difficult Cu,Zn hyperaccumulation in E.splendens shoot by induced reagents and the application of the Cu-enriched compost made from E.splendens in a Cu-deficient soil, and the main results are shown as the following:①The strain（Achromatium sp.） had produced more acid in the incubation experiment than in the pot one;The soluble Cu concentration in the soil solution was significantly positively related to its pH while the soluble Zn concentration significantly negatively to pH;The bacterium increased E.splendens shoot biomass and shoot Cu content,and increased significantly Cu cleaning-up by E.splendens from the soil polluted by heavy metals.②EDDS decreased significantly the shoot or root biomass of young E.splendens. Addition of EDDS remarkably increased shoot Cu,Zn content and Cu,Zn elimination from soil due to increasing of soluble Cu,Zn concentration in pore water.AMF inoculation affected insignificantly soil Cu,Zn fractions,shoot and root biomass of E.splendens,but increased Cu,Zn concentration in shoot,and AMF increased significantly Cu cleaning-up from the soil.Application of EDDS would increase the Cu elimination from soil contaminated by Cu,Zn in comparison with the inoculation of AMF.③The treatments of 200,300,400 mmol kg^-1 sulfur powder decreased significantly pH of soil pore water and soil pH,simultaneously increased markedly soil heavy metals’ concentrations of pore water and NH₄NO₃ extractable.After 223 d of sulfur treatment,soil NH₄NO₃ extractable Cu,Pb,Cd,Zn concentrations in SH treatment were 57%,20%,91%, and 87%of their soil total concentrations,respectively.④Application of 80 mmol kg^-1 or 120 mmol kg^-1 sulfur powder to the soil decreased significantly pH of soil pore water,and increased its heavy metals concentration,and increased markedly Zn and S concentration in the E.splendens shoot where there was a positively relationship at 0.01 level in the stem.Amendment of EDDS increased significantly Cu transportation from soil to E.splendens leaves.Application of sulfur powder influenced mostly Zn behavior,while EDDS affected mostly Cu,and there was no interaction between sulfur powder and EDDS.The sulfur powder in conjugation with EDDS enhanced the rehabilitation of soil contaminated by Cu,Zn.The degradation of EDDS would be affected by temperature and its half life was not a constant.80 mmol kg^-1 sulfur increased the biomass of E.splendens,while 120 mmol kg^-1 sulfur decreased notably the biomass of E.splendens.⑤Application of E.splendens tissue composts significantly increased plant height, biomass and 1000-grain weight of winter wheat（Triticum aestivum L.）.The effect of ’root-stem’ compost was not as good as that of ’leave’ compost.The leave compost increased 1000-grain weight by 58.9%and the grain yield by one fold compared to CK. Amendment of chemical fertiliser only to the Cu-deficient soil decreased wheat 1000-grain weight,biomass and grain yield.⑥Application of the Cu-rich compost significantly increased plant height,biomass, grain yield,and 1000-grain weight of winter wheat（T.aestivum L.）.In the pot experiment, plant height and shoot biomass in the 2%Cu-rich compost treatment increased 0.8 and 5.2 fold compared with the chemical fertiliser treatment at mature stage.Compared to chemical fertiliser CK,the 2%Cu-rich compost addition increased grain yield per pot by about 9.5 fold and 1000-grain weight by about 50%.In the field study the compost also showed stimulatory effects on plant growth and grain yield.Composting E.splendens plants grown in a Cu-contaminated soil and then applying the compost to a Cu-deficient soil may be an effective technique for the remediation of contaminated soils and re-distribution of the copper as a plant nutrient for copper deficient soils.更多还原