【作者】 黄建祥；

【导师】 李志刚；

【作者基本信息】 广西大学 ， 作物栽培学与耕作学， 2012， 硕士

【摘要】 构建桶栽的薏米人工湿地(YMW)模拟垂直流人工湿地系统,以无薏米植物(NPW)作对照,采用1/2霍格兰氏营养液为营养源,添加K2Cr2O7配置而成的含不同浓度六价铬(Cr6+)(0、5、20、40、60mg/L)的营养液至人工湿地中,以研究Cr6+对薏米生长发育变化动态、生理响应以及薏米对Fe、Mn、Cr等微量元素的吸收,同时研究Cr6+胁迫下以上两种人工湿地对Cr6+的去除效果、微生物群落等指标的影响。研究结果如下：1、YMW对培养液中NH3-N、TN、Cr6+的吸收净化能力高于NPW系统,在较低浓度(5mg/L) Cr6+处理下,YMW和NPW对NH3-N去除率促进、而高浓度(40、60mg/L) Cr6+胁迫下,随处理时间的延长,两种湿地对NH3-N去除率均呈降低趋势。YMW对TN去除率随处理时间的延长而呈先升高后降低的趋势,Cr6+对NPW的TN去除效果有显著地抑制效应。两种人工湿地对TP的去除效果差异不大,除了6月份NPW对TP的去除效果下降外,其他处理时期对TP的去除率维持在90%。YMW对低中浓度(5、20ml/L)mg/L Cr6+有较好的净化效果,去除率达到99%,但高浓度(40mg/L)Cr6+处理对人工湿地吸收去除Cr6+有抑制作用。2、薏米叶片SOD活性随着处理时期的延长而升高,薏米生长前期5mg/L Cr6+处理促进SOD活性升高,中后期40mg/L Cr6+处理对薏米SOD有促进作用。不同浓度Cr6+处理对薏米叶片POD活性、MDA含量均有促进作用,前中时期POD活性随着Cr6+浓度的提高而提高,整个时期MDA含量随着Cr6+处理浓度的提高而提高。低中浓度(5、20mg/L) Cr6+处理对薏米叶片SP含量有促进作用,SP随着处理时间的延长而不断提高,但后期高浓度(40mg/L) Cr6+处理有抑制作用。3、低浓度(5mg/L) Cr6+处理有利于薏米叶片Pn、Gs、Tr的提高,其他浓度Cr6+处理有抑制作用。薏米叶片Ci随Cr6+处理时间的延长而下降,中高浓度(20、40、60mg/L) Cr6+处理显著促进Ci值增大,并随Cr6+处理浓度的升高而增大。4、微生物群落数量YMW系统多于NPW系统,真菌、细菌、放线菌的数量也表现为类似的处理效应。真菌数量变化趋势随着处理时间的延长而增多,YMW细菌数量随处理时间的延长而增多,NPW细菌数量随着处理时间的延长而降低,放线菌数量随着处理时间的延长表现为先升高后降低。不同浓度Cr6+处理对人工湿地的细菌数量和放线菌数量、NPW真菌数量均有促进作用；低中浓度(5、20mg/L) Cr6+处理对YMW真菌数量有促进作用,高浓度(40、60mg/L) Cr6+处理有抑制作用,NPW细菌数量和YMW放线菌数量均随Cr6+处理浓度的提高而增多。5、人工湿地基质的脲酶和CAT活性均表现为NPW系统高于YMW系统,两种人工湿地的脲酶活性随着处理时间的延长而不断降低。低浓度C5mg/L) Cr6+处理对YMW脲酶活性和NPW的CAT活性均有促进提高的作用,而对于NPW脲酶活性在5、7月份表现为促进作用,随着处理时间的延长表现为中高浓度(20、40、60mg/L)Cr6+处理对两种人工湿地的脲酶活性有抑制作用,NPW的CAT活性也有相同规律,但7月份不同浓度Cr6+处理对NPW脲酶活性有促进作用。低中浓度(5、20mg/L)Cr6+处理对YMW的CAT活性有抑制作用,抑制效果随Cr6+处理浓度的提高而提高,但高浓度(40mg/L)Cr6+处理有显著促进作用。6、薏米植株Fe、Zn、Cu含量在薏米中分布规律为根>叶>茎,Mn、Cr在薏米中分布规律为根>茎>叶。生长前期的Cr6+抑制薏米根系对Fe、Zn、Cu的吸收,低浓度Cr6+促进薏米根系对Mn、Cr的吸收、高浓度Cr6+产生抑制效应,之后时期Fe、Mn、Cu、Cr含量随着Cr6+增加而降低,但中高浓度的Cr6+促进Zn的吸收。薏米茎对Fe、Zn、Cu吸收在不同浓度Cr6+处理下有着不同程度的抑制作用,低浓度(5mg/L)Cr6+促进对Mn的吸收,之后时期Mn含量随Cr6+增加而降低；在前中时期,薏米茎的Cr随Cr6+增加而增加,9月份20mg/LCr6+显著促进对Cr的吸收。薏米叶片的Fe、 Mn、Cu含量在有些时期随Cr6+增加而降低的规律,在薏米的初期或中期Cr6+对Zn、 Cr有促进吸收作用。7、低浓度(5mg/L) Cr6+促进薏米株高伸长、20mg/L以上浓度Cr6+均有抑制效应,并随Cr6+浓度的增加而抑制作用显著增强；Cr6+对薏米的基部直径影响差异不显著；薏米分蘖数在5月份至7月份随Cr6+浓度增加而减少,高浓度(40mg/L) Cr6+处理下显著抑制薏米的分蘖。低浓度(5mg/L) Cr6+对薏米根系的根总长有促进、高浓度(40mg/L) Cr6+有抑制的作用,根系总表面积、总体积、干物质量在Cr6+处理下均有类似效应。8、YMW真菌数量与TN、TP的去除率呈负相关,YMW细菌数量与NH3-N的去除率呈负相关；NPW脲酶活性与TN的去除率相关,YMW NH3-N的去除率与TN的去除率、Cr6+去除率均相关,YMW TN去除率与Cr6+去除率相关。薏米根系中的铁、锰、锌、铜四种元素之间的相互均相关,薏米茎的铁、锰、锌、铜这四种微量元素之间的运输无拮抗作用,但铬对以上四种元素的影响不一,薏米叶片中的铁与铜相关,锌与铜相关,铬与铜相关,但锌与锰之间呈负相关。薏米叶片SOD和POD活性与铁含量相关,POD活性与锰、铬含量相关,SP含量与锌含量相关。更多还原

【Abstract】 This simulation experiments in order to study the effect of artificial additive different concentrations of hexavalent chromium(0,5,20,40,60mg/L)on wastewater of and vertical flow Coix aquatica Roxb constructed wetlands(YMW) and no Coix aquatica Roxb constructed wetlands(NPW), nutrientsource by1/2hoagland’s nutrient solution. Study the effects of Coix aquatica Roxb growth and development trends、respond of physiology and uptake microelement such as Fe、Mn、Cr and so on, and meanwhile study the effects of two types constructed wetlands purification hexavalent chromium effects、microbiologic community population and so on. The results showed:1The effect of purification of Ammoniacal Nitrogen(NH3-N), total Nitrogen (TN),Hexavalent chromium(Cr6+)in YMW better than NPW, the lower Cr6+concent-ration(5mg/L) would enhance uptake NH3-N,higher Cr6+(40,60mg/L)treating show inhibition effects following treating times extend in YMW and NPW. As treating time extend showed rise then reduce effects purification of TN in YMW, Cr6+treating showed purification TN significance inhibition effects in NPW.There is no different effect purification TP in two types of constructed wetlands,other treating stages removal rate hold90%except NPW purification TP showed reduce effects.The lower and middle Cr6+concentrations(5,20mg/L) treating showed better effects purification Cr6+in YMW, the removal rate reach99%,but higher Cr6+concentrations(40mg/L) treating showed inhibition effects.2The effects of SOD activity of Coix aquatica Roxb leaf rise with constant extend growth stages,5mg/LCr6+concentration treating showed enhelped SOD activity in earlier growth stage of Coix aquatica Roxb,40mg/LCr6+concentration treating showed promoting enhance SOD activity in varying degrees as treating time extend.The different Cr6+concentration treating showed enhance POD activity,MDA content of Coix aquatica Roxb leaf, POD activity rise with Cr6+concentration treating at earlier and middle growth stage of Coix aquatica Roxb,and MDA content rise with Cr6+concentration treating at whole stages.The lower and middle Cr6+concent-ration(5,20mg/L) treating showed enhanced SP content of Coix aquatica Roxb leaf,and SP content rise with treating times extend,but higher Cr6+concentration (40mg/L) treating showed inhibition effects at later stages.3Lower Cr6+concentration(5mg/L) treating showed enhance Pn,Gs,Tr of Coix aquatica Roxb leaf,other Cr6+concentration treating showed inhibition effects. Ci of Coix aquatica Roxb leaf appear reduce with Cr6+treating times, middle and higher Cr6+concentration(20,40,60mg/L) treating showed significance promoting enhance Ci,and rise with Cr6+concentration treating rise.4Microorganism communities population showed YMW more than NPW, the effect of fungi,bacteria,actinomycetes communities population showed similar as treating effect.The fungi population variation trend appear constant increase with treating times extend, the bacteria population in YMW showed constant increase with treating times,but the actinomycetes population appear increase then reduce effects with treating times extend.The different Cr6+concentration treating showed enhanced bacteria,actinomycetes communities population,and also enhanced fungi population of NPW; the lower and middle Cr6+concentration(5,20mg/L) treating showed enhanced fungi population of YMW, higher Cr6+concentration(40,60mg/L) treating showed inhibition effects, bacteria population of NPW and actinomycetes population of YMW showed all increase with Cr6+concentration treating increase.5The urease activit and catalase activit of constructed wetlands matrix showed NPW more than YMW, urease activit in the two types of constructed wetlands matrix showed constant decreased along with treating times extend. The lower Cr6+concentration(5mg/L) treating appear enhance effects for urease activit of YMW and catalase activit of NPW, meanwhile also enhance effects for urease activit of NPW in May and July,middle and higher Cr6+concentration(40,60mg/L) treating showed inhibition effects of urease activit for two types of constructed wetlands, catalase activit appeared similar as effects,but different Cr6+concentrations showed enhanced urease activit of NPW in Juiy. The lower and middle Cr6+concentrations(5,20mg/L) treating showed inhibition effects for catalase activit of YMW,and inhibition effects appeared increase with Cr6+concentrations treating increase,but higher Cr6+concent-rations (40mg/L) treating showed significance promoting effects.6The contents of Mn,Zn,Cu in Coix aquatica Roxb plant were as follows:root> leaf> stem; The contents of Fe and Cr were as follows:root>stem> leave. At the early growth stage Cr6+inhibited the absorption of Fe,Zn,Cu in roots, low concentrations of Cr6+helped to the absorption of Mn and Cr, but higher concentrations inhibited in root; afterward time Fe, Mn, Cu, Cr contents decreased along with concentrations increase, but middle and higher concentrations of chromium promoted the Zn absorption.The absorptions of Fe, Zn, Cu in stems have the varying degree inhibitory action under the Cr6+treatment processing, the Mn absorption promoted under the treatment of5mg/L Cr6+concentration and decreased gradually with the increase of Cr6+concentrations; at the early and middle growth stage,the content of Cr6+in stems gradually increased along with the enhancement of Cr6+concentration, and it was significantly promoted under the treatment of20mg/LCr6+in September. Cr6+helped to the absorption of Zn and Cr in leaves at the early and middle growth times,the contents of Fe,Mn,Cu in leaves decreased with the increase of Cr6+concentrations at some times.7The lower Cr6+concentration (5mg/L)treating showed would be enhance Coix aquatica Roxb height elongation,but higher Cr6+concentrations (20mg/L and above)treating showed inhibition effects, the with inhibition effects showed significance enhance with the increase of Cr6+concentrations;There is no significantly differents that diameter of Coix aquatica Roxb stem base under Cr6+stress. Tillers showed Cr6+concentrations rise then reduce effects from May to July, the lower Cr6+concentration (5mg/L)treating showed would be enhance total length of root, the higher Cr6+concentrations(40mg/L) showed inhibition effects;the surfarea, root volume, dry matter weight showed effects similar as total length of root.8Correlation coefficients between fungi population in YMW and purification of TN、TP have negative contrast, Correlation coefficients between bacteria population in YMW and purification of NH3-N have negative contrast; Correlation coefficients between urease activit in NPW and purification of TN have positive contrast, Correlation coefficients between purification of NH3-N and purification of TN> Cr6+all havepositive contrast, Correlation coefficients between purification of TN in YMW and purification of Cr6+have positive contrast. Correlation coefficients between Fe,Mn,Cu and Zn of Coix aquatica Roxb roots all have positive contrast, There is not antagonism effects between Fe,Mn,Cu and Zn of Coix aquatica Roxb stems,but Correlation Cr and four microelement showed different effects, Correlation coefficients between Fe and Cu of Coix aquatica Roxb leavies have positive contrast, Correlation coefficients between Zn and Cu of Coix aquatica Roxb leavies have positive contrast, Correlation coefficients between Cr and Cu of Coix aquatica Roxb leavies have positive contrast, but Correlation coefficients between Zn and Mn of Coix aquatica Roxb leavies have negative contrast. Correlation, coefficients between SOD、POD and Fe content of Coix aquatica Roxb leavies have positive contrast, Correlation coefficients between POD and Mn,Cr content of Coix aquatica Roxb leavies have positive contrast, Correlation coefficients between SP content and Zn have positive contrast.更多还原