不同强化剂对绿洲一号菌草提取土壤重金属的影响

Effects of Different Enhancing Agents on Extraction of Soil Heavy Metals by JUNCAO Lvzhou No.1

【目的】探明不同强化剂对绿洲一号菌草提取土壤重金属的影响,为绿洲一号菌草修复重金属污染土壤及其安全利用提供参考。【方法】以绿洲一号菌草为研究对象,采用盆栽试验,以不施强化剂为对照(CK),测定添加7种强化剂[鼠李糖脂(RHA)、柠檬酸(CA)、乙二胺二琥珀酸(EDDS)、聚丙烯酸(PAA)、聚丙烯酸接枝腐植酸(PAA-HA)、增产胺(DCPTA)和增产胺接枝氯化胆碱(DCPTA-ChCl)]种植绿洲一号收获后植株地上部的Pb、Cd、As含量,并分析绿洲一号不同生长阶段茎、叶对Pb、Cd、As的富集特征。【结果】DCPTA-ChCl和RHA对绿洲一号植物营养的合成表现为促进作用,叶绿素相对含量分别较CK增加3.32和3.07,氮含量分别增加1.15 mg/g和1.05 mg/g。PAA表现为抑制作用,叶绿素相对含量较CK显著减少5.98,氮含量显著减少1.65 mg/g。DCPTA、RHA和CA的绿洲一号地上部Pb、Cd、As的含量分别较CK提高25.7%~37.7%、54.3%~55.6%、35.0%~56.4%,与CK比,DCPTA-ChCl促进绿洲一号富集Cd和As;DCPTA显著促进富集Pb和Cd;PAA显著促进富集As,而对富集Pb的促进作用不显著,对Cd的富集表现为抑制作用;PAA-HA显著促进富集Pb和As,而对富集Cd的促进作用不明显;EDDS对富集Pb、Cd、As的影响作用均不明显。5—9月,绿洲一号茎、叶的Pb、Cd和As含量随时间增加均呈升高趋势,增幅较大;9—12月随时间的增幅较小。整个生长阶段,叶的Pb、Cd和As含量均较茎高,叶表现为Pb>As>Cd,茎的Pb和Cd含量在5月、6月、7月较相近,且均大于As含量;8—12月茎表现为Pb>Cd>As。【结论】添加DCPTA 0.5mg/株、RHA 2 mmol/kg、CA 2 mmol/kg均可有效促进绿洲一号对Pb、Cd、As的富集,提高绿洲一号修复Pb、Cd、As复合污染土壤能力。在6月底前收割绿洲一号的茎和叶Pb含量分别为0.445 mg/kg和4.57 mg/kg、Cd含量分别为0.405 mg/kg和0.537 mg/kg、As含量分别为0.128 mg/kg和1.329 mg/kg,均小于《饲料卫生标准》(GB13078—2017)规定的限值,适用于畜牧养殖用饲草;7月后收割的绿洲一号叶片Cd含量大于1 mg/kg,超过饲料卫生标准,不适宜用作饲草,可探索其在复合材料、生物质能源等领域中的应用。

【Objective】The effects of different enhancers on the extraction of heavy metals from soil by the JUNCAO Lvzhou No.1 were studied to provide a reference for the remediation of heavy metal-contaminated soil and the safe utilization of the JUNCAO Lvzhou No.1.【Method】Taking the JUNCAO Lvzhou No.1 as the study object,the content of lead(Pb),cadmium(Cd)and arsenic(As)contaminated soil treated with seven different enhancing agents were investigated in pot experiments with no enhancer application as the control(CK).The seven enhancing agents were as follows:rhamnolipid(RHA),citric acid(CA),ethylenediamine disuccinic acid(EDDS),polyacrylic acid(PAA),polyacrylic acid grafted with humic acid(PAA-HA),2-diethylaminoethyl-3,4-dichlorophrylether(DCPTA),diethylaminoethyl-3,4-dichlorophrylether grafted with choline chloride(DCPTA-ChCl).The enrichment characteristics of Lvzhou No.1 to Pb,Cd,and As at different growth stages were also analyzed.【Result】DCPTA-ChCl and RHA showed promoting effects on the synthesis of plant nutrients of Lvzhou No.1,with a significant increase in the relative content of chlorophyll by 3.32 and 3.07,respectively,compared to CK,and an increase in nitrogen content by 1.15 mg/g and 1.05 mg/g,respectively.PAA showed an inhibitory effect,with a significant decrease in the relative content of chlorophyll by 5.98,and a significant decrease in nitrogen content by 1.65 mg/g compared to CK.The content of Pb,Cd,and As in the above-ground parts of Lvzhou No.1 treated with DCPTA,RHA,and CA increased by 25.7%to 37.7%,54.3%to 55.6%,and 35.0%to 56.4%,respectively,compared to CK.Compared with CK,DCPTA-ChCl promoted the enrichment of Cd and As in Lvzhou No.1;DCPTA significantly promoted the enrichment of Pb and Cd;PAA significantly promoted the enrichment of As,but not Pb,and showed an inhibitory effect on the enrichment of Cd;PAA-HA significantly promoted the enrichment of Pb and As,but not Cd;EDDS had no significant effect on the enrichment of Pb,Cd,and As in Lvzhou No.1.From May to September,the content of Pb,Cd,and As in the stems and leaves of Lvzhou No.1 showed an increasing trend with time and with a larger increase;From September to December,the increase was smaller.Throughout the entire growth stage,the content of Pb,Cd,and As in the leaves was higher than in the stems,with Pb>As>Cd in the leaves,and the content of Pb and Cd in the stems was similar in May,June,and July,which were all greater than As,with Pb>Cd>As from August to December.【Conclusion】Adding DCPTA at 0.5 mg per plant,RHA at 2 mmol/kg,and CA at 2 mmol/kg can effectively promote the enrichment of Pb,Cd,and As in Lvzhou No.1,thereby enhancing its ability to remediate Pb,Cd,and As contaminated soil.At the end of June,the content of Pb in the stems and leaves of harvesting Lvzhou No.1 is 0.445 mg/kg and 4.57 mg/kg,Cd is 0.405 mg/kg and 0.537 mg/kg,and As is 0.128 mg/kg and 1.329 mg/kg,respectively,all of which are less than the limits set by Hygienical Standard for Feeds(GB 13078-2017),indicating that it is suitable for forage in animal husbandry.After July,the content of Cd in the leaves of harvesting Lvzhou No.1 exceeded 1 mg/kg,which is above the hygienical standard for feeds and not suitable for forage.Its application in fields such as composite materials and biomass energy can be explored.