Harmful evaluation of heavy metals from soil layer to the groundwater: Take the Jilin Hunchun Basin as an example

The continuous enrichment of heavy metals in soils has caused potential harm to groundwater.Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies.Based on the theory of groundwater circulation and solid-liquid equilibrium,a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed.Based on groundwater environmental capacity,an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed,which has been applied in Hunchun Basin,Jilin Province,China.The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn,Cu,As,Pb,Cd,Ni,and Hg in descending order.The content of heavy metals in groundwater(As,Hg,Cu,Pb,Zn,Ni,and Cd)in most areas has not risen to the threshold of environmental capacity within 10 years.The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below.This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly,determine the residual capacity of groundwater to heavy metals,evaluate the harm level of soil heavy metals to groundwater,provide support for relevant departments to carry out environmental protection of soil and groundwater,and provide a reference to carry out similar studies for related scholars.

Effects of Red Mud on the Remediation of Pb, Zn and Cd in Heavy Metal Contaminated Paddy Soil

[Objective] To study the remediation efficiency of red mud on Pb, Zn and Cd in the heavy metal contaminated paddy soil of mine area, to clarify its remediation mechanism and fertilizer efficiency on heavy metal contaminated soil. [Method] The soil incubation experiment was conducted to study the effect of red mud on the pH values and electrical conductivity （EC）, and the remediation efficiency of red mud on lead （Pb）, zinc （Zn） and cadmium （Cd） in heavy metal contaminated soil. [Result] Red mud addition reduced the content of exchangeable Pb, Zn and Cd in the soil significantly. Compared with the control, when incubated for 30, 60 and 90 d with the red mud dosage of 4% （W/W）, the exchangeable Pb content was decreased by 39.25%, 41.38% and 50.19%; exchangeable Zn content was decreased by 49.26%, 57.32% and 47.16%; and exchangeable Cd content was decreased by 19.53%, 24.06% and 25.70%, respectively. The application of red mud had significant impact on the share of Pb, Zn and Cd contents in five forms, and different amounts of red mud application all reduced the proportion of exchangeable Pb, Zn and Cd to the total Pb, Zn and Cd. In addition, the proportion of exchangeable Pb, Zn and Cd to total Pb, Zn and Cd decreased with the increasing amount of red mud addition. [Conclusion] The study provided references for reasonable application of red mud and reduction of heavy metal pollution in paddy soil.

甜玉米自交系重金属Pb、Cd积累差异及分子检测

【目的】筛选获得在重金属Pb、Cd单一污染及复合污染下Pb、Cd低积累的优良甜玉米自交系,以及可用于甜玉米重金属Pb、Cd积累早代鉴定的分子技术。【方法】以10个甜玉米自交系为供试材料,通过盆栽试验研究重金属Pb、Cd单一污染及Pb、Cd复合污染下,玉米根系、茎叶和籽粒中Pb、Cd含量的积累差异;同时对供试材料ZmHMA2 InDel位点进行Pb、Cd积累差异分子检测,综合分子标记检测与重金属Pb、Cd在不同材料间的积累结果,筛选甜玉米重金属低积累自交系。【结果】无论是单一污染还是复合污染,重金属Pb、Cd的积累规律均表现为根系>茎叶>籽粒;在复合污染下,玉米不同组织对重金属Pb、Cd的积累无明显竞争与协同效应,表明玉米Pb、Cd的积累机制存在一定差异。通过鉴定,获得籽粒Pb低积累玉米自交系2份,籽粒Cd低积累玉米自交系3份,仅有一份材料闽甜系X901表现出籽粒Pb、Cd均低积累。利用InDel位点(InDel2307)对供试材料进行分子检测,结果发现供试材料中有4份存在该位点,含有该位点的材料中根系、茎叶和籽粒Cd含量平均值较其他材料平均值分别低1.801、0.64、0.131 mg·kg^(-1)。【结论】InDel2307位点能将不同玉米自交系按Cd累积量进行区分,对甜玉米Cd含量的区分具有特异性标记。综合分子标记检测与Pb、Cd含量积累结果,筛选出自交系闽甜系X901为Pb、Cd低积累材料。

Cd在污泥厌氧消化中的检测及其对产沼气的抑制研究

为了研究重金属Cd对污泥厌氧消化产甲烷的影响,在序批式反应器中,通过控制进料中Cd的浓度,分析了Cd在污泥处理系统内的检出与去除规律,以及Cd对污泥厌氧消化产甲烷的影响。研究结果表明,石墨炉原子吸收光谱法能有效检测污泥中Cd的浓度,且Cd的初始浓度会影响Cd的去除效率;浓度>1.0 mg·L-1的Cd抑制了污泥厌氧消化产甲烷,最低甲烷产量为77.9 mL·g-1;Cd降低了污泥厌氧消化内有机质的水解,5.0 mg·L-1的Cd暴露组中溶解性COD和挥发性脂肪酸(VFA)的最大值分别为1455 mg·L-1和794 mg·L-1,低于对照组。高浓度Cd会降低污泥减量率,至24.5%,增加了污泥后续处理的难度。

洋葱伯克霍尔德菌菌株JLS17对Cd^(2+)胁迫的生长及代谢响应机制

【目的】探究1株植物促生菌洋葱伯克霍尔德菌菌株JLS17对Cd^(2+)的耐受与去除能力以及在Cd^(2+)胁迫下的代谢响应,以期为菌株在土壤镉污染修复的应用提供基础理论依据,并为阐明具有抗镉功能分子与代谢途径的挖掘及微生物Cd^(2+)耐受机制提供数据支撑。【方法】通过测定含不同Cd^(2+)浓度培养液的吸光度(OD600)值评价菌株对Cd^(2+)的耐受性,利用电感耦合等离子体质谱仪(ICP-MS)测定菌株对LB培养基中Cd^(2+)的去除效果,采用非靶向代谢组学技术(LC-MS)分析菌株在Cd^(2+)胁迫下的差异代谢物与代谢途径。【结果】1)不同程度的Cd^(2+)胁迫(50~800 mg·L^(−1))均对菌株JLS17的生长速率及生物量增长(OD600)有明显的抑制作用,且抑制作用随Cd^(2+)浓度的升高而不断加剧。2)菌株JLS17对LB培养基中Cd^(2+)的去除量随Cd^(2+)浓度的提高(10~100 mg·L^(−1))而增加,最高去除量可达55.90 mg·L^(−1),但去除率受Cd^(2+)浓度影响相对较小,维持在41.9%~66.0%。3)LC-MS分析结果表明,菌株JLS17在50 mg·L^(−1)和300 mg·L^(−1)的Cd^(2+)浓度胁迫处理下,共有147种差异代谢物表达趋势一致,其中92种共性上调,55种共性下调,主要涉及氨基酸及其衍生物、核苷酸及其衍生物、脂质、有机酸及其衍生物、萜类、酮类、生物碱等。KEGG富集分析结果表明,菌株JLS17在50 mg·L^(−1)和300 mg·L^(−1)的Cd^(2+)浓度胁迫处理下显著富集的共有代谢通路为嘧啶代谢、氨基苯甲酸酯降解、半胱氨酸和蛋氨酸代谢、色氨酸代谢、β-丙氨酸代谢、叶酸的生物合成与磷酸戊糖途径,其中嘧啶代谢、色氨酸代谢、磷酸戊糖途径共性下调,叶酸的生物合成共性上调。【结论】1)菌株JLS17对Cd^(2+)胁迫具有极强的适应性,并能有效去除LB培养基中的Cd^(2+),在镉污染修复中具有良好的应用潜力。2)菌株JLS17在Cd^(2+)胁迫下可通过氨基酸及其衍生物、核苷酸及其衍生物、脂质等代谢物含量变化影响体内的代谢途径,其中色氨酸代谢、β-丙氨酸代谢、半胱氨酸和蛋氨酸代谢、嘧啶代谢、磷酸戊糖途径、叶酸的生物合成等代谢途径与JLS17的Cd^(2+)耐受性密切相关。

外源脯氨酸降低Cd对喜旱莲子草的迫害

喜旱莲子草(Alternanthera philoxeroides)为苋科多年生草本植物,是重金属镉(Cd)的超富集植物,具有药用价值高、抗逆性强等特点,是一种Cd污染土壤修复的重要候选植物。为探究添加外源脯氨酸条件下,重金属Cd对喜旱莲子草的形态、生理指标、抗氧化系统等的影响,以同一水域的喜旱莲子草为试验材料进行一系列生理生化试验,旨在揭示Cd毒害下,外施脯氨酸对喜旱莲子草的作用机理。结果表明,从形态指标上看,喜旱莲子草受到Cd毒害时,其根、茎、叶的生长明显受到抑制。但在外施脯氨酸的条件下,能够缓解Cd对喜旱莲子草所造成的伤害,降低Cd对喜旱莲子草的毒害作用。从生理指标上看,喜旱莲子草在Cd的毒害作用下,其丙二醛(MDA)、过氧化氢(H_(2)O_(2))、游离脯氨酸(Pro)、可溶性糖(SS)显著提高,可溶性蛋白(SP)处理之间差异并不显著。从抗氧化系统指标上看,喜旱莲子草在Cd的毒害作用下,其谷胱甘肽过氧化物酶(GPX)、过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)含量显著提高,但在茎部处理之间SOD含量差异不显著。总体来看,对喜旱莲子草添加外源脯氨酸,能够缓解Cd对喜旱莲子草的毒害作用。以此,为今后喜旱莲子草在修复Cd污染土壤方面的开发利用提供科学理论基础和参考依据。

Causal Analysis Between Rice Growth and Cadmium Accumulation and Transfer under Arbuscular Mycorrhizal Inoculation

Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The results indicated that AMF significantly increased rice biomass,with an increase of up to 40.0%,particularly in root biomass by up to 68.4%.Notably,the number of prominent rice individuals also increased,and their plasticity was enhanced following AMF inoculation.AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice.In the AMF treatment group,the Cd concentration in the rice roots was significantly higher(19.1%‒68.0%)compared with that in the control group.Conversely,the Cd concentration in the rice seeds was lower in the AMF treatment group,indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds.Path coefficients varied across different treatments,suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds.The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects.Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF.

Comparative expression analysis of heavy metal ATPase subfamily genes between Cd-tolerant and Cd-sensitive turnip landraces

The heavy metal ATPase(HMA)subfamily is mainly involved in heavy metal(HM)tolerance and transport in plants,but an understanding of the definite roles and mechanisms of most HMA members are still limited.In the present study,we identified 14 candidate HMA genes named BrrHMAl—BrrHMA8 from the turnip genome and analyzed the phylogeny,gene structure,chromosome distribution,and conserved domains and motifs of HMAs in turnip(Brassica rapa var.rapa).According to our phylogenetic tree,the BrrHMAs are divided into a Zn/Cd/Co/Pb subclass and Cu/Ag subclass.The BrrHMA members show similar structural characteristics within subclasses.To explore the roles of BrrHMAs in turnip,we compared the gene sequences and expression patterns of the BrrHMA genes between a Cd-tolerant landrace and a Cd-sensitive landrace.Most BrrHMA genes showed similar spatial expression patterns in both Cd-tolerant and Cd-sensitive turnip landraces;some BrrHMA genes,however,were differentially expressed in specific tissue in Cd-tolerant and Cd-sensitive turnip.Specifically,BrrHMA genes in the Zn/Cd/Co/Pb subclass shared the same coding sequence but were differentially expressed in Cd-tolerant and Cd-sensitive turnip landraces under Cd stress.Our findings suggest that the stable expression and up-regulated expression of BrrHMA Zn/Cd/Co/Pb subclass genes under Cd stress may contribute to the higher Cd tolerance of turnip landraces.

Tissue distribution of cadmium and its effect on reproduction in Spodoptera exigua

Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.Under the stress of different concentrations of cadmium(0.2,3.2,and 51.2 mg kg^(-1)),the cadmium content in each tissue of S.exigua increased in a dose-dependent manner.At the larval stage,the highest cadmium accumulation was found in midgut in all three cadmium treatments,but at the adult stage,the highest cadmium content was found in fat body.In addition,the cadmium content in ovaries was much higher than in testes.When F1S.exigua was stressed by cadmium and the F_(2)generation was not fed a cadmium-containing diet,the larval survival,pupation rate,emergence rate and fecundity of the F_(2)generation were significantly reduced in the 51.2 mg kg^(-1)treatment compared to the corresponding F1generation.Even in the F_(2)generation of the 3.2 mg kg^(-1)treatment,the fecundity was significantly lower than in the parental generation.The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg^(-1)cadmium exposure levels.When only mothers were stressed at the larval stage,the fecundity of the F_(2)generation was significantly lower than that of the F1generation in the 51.2 mg kg^(-1)treatment,and it was also significantly lower than in the 3.2 and 0.2 mg kg^(-1)treatments.The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution.

Effects of the heavy metal cadmium on photosynthetic activity and the xanthophyll cycle in Phaeodactylum tricornutum

A bstract Cadmium(Cd) is one of the most common and widespread heavy metals in the environment. Cd has adverse effects on photosynthesis that are countered by photosystem I(PSI) and photosystem II(PSII); however, the protective responses of these photosystems to heavy metal stress remain unclear. Using the model diatom P haeodactylum tricornutum, a biological indicator that is widely used to assess the impact of environmental toxins, we simultaneously measured the effects of Cd on PSI and PSII and examined the levels of pigments in response to high light treatments before and after Cd exposure. Cd significantly reduced the quantum yield and electron transport rates of PSI and PSII. The quantum yield of non-photochemical energy dissipation in PSI due to donor side limitation increased faster than the quantum yield due to acceptor side limitation. The Cd treatment activated the P. tricornutum xanthophyll cycle under artificial light conditions, as indicated by an increased diatoxanthin content. Xanthophyll is important for photoprotection; therefore, the accumulation of diatoxanthin may down-regulate PSII activities to reduce oxidative damage. Together, our results suggest that the rapid reduction in PSII activities following Cd exposure is an adaptive response to heavy metal stress that reflects the variable exposure to external stressors in the native P. tricornutum environment.

江苏南京沿江地区土壤-底泥重金属Cd富集特征及风险评价

镉(Cd)等重金属元素污染是广泛关注的环境问题。为了探究南京沿江地区不同生态系统中重金属Cd富集特征及污染情况,为该区土壤安全利用提供依据,对该区农用地、建设用地、栖霞山矿区、长江底泥、滨江湿地等不同地类共采集了3552个土壤/底泥样品,并测定其pH值和重金属Cd含量,采用累积指数法(ACd)、超标指数法(PCd)、地累积指法(Igeo)和潜在生态危害指数法(Er)对各地类重金属Cd污染风险进行了评价。结果表明:栖霞山矿区、长江底泥和滨江湿地表层土壤/底泥中Cd含量出现高度异常,平均含量分别为1.25 mg/kg、0.82 mg/kg、0.72 mg/kg;与丘陵岗地区相比,长江冲积平原也出现Cd的富集,平均含量为0.35 mg/kg;Cd平均含量依次为栖霞山>长江底泥>滨江湿地>长江冲积平原区>丘陵岗地区>滁河底泥≈南京市背景值;重金属Cd累积指数(ACd)依次为长江底泥>滨江湿地>长江冲积平原>滁河底泥>丘陵岗地区;Cd单项超标指数(PCd)揭示全区95%的区域处于安全状态,约5%的区域出现Cd超标,超标级别为轻微—轻度级,超标区主要分布于东部和八卦洲中南部;地累积指法(Igeo)和潜在生态危害指数法(Er)均揭示,全区约有50%的区域存在生态危害风险,主要分布于长江冲积平原和长江底泥。对于土壤重金属含量超标区建议采用土壤调理剂改善土壤pH值、轮作种植、深耕或添加重金属钝化剂等安全利用措施,同时加强土壤-作物环境监测工作,以防土壤环境进一步恶化。

营养型阻控剂影响菜园土中水稻生长及其Cd吸收

为了探索以钙硅钾等营养元素为主要成分的土壤调理剂(营养型阻控剂)对镉(Cd)超标菜园土旱改水时水稻(Oryza Sativa L.)生长及其Cd吸收的影响,于2014年下半年在Cd超标菜园土中施用营养型阻控剂,对不同用量(分别为0、1.5、3.0、4.5、6.0 g·kg^(-1),分别记作CK、T1、T2、T3、T4)营养型阻控剂的水稻盆栽试验开展研究。结果表明:营养型阻控剂对菜园土中水稻生长没有较好的促进作用,没有提高稻谷产量。供试水稻品种黄超占各部位Cd质量分数大小顺序为根>茎叶>稻米>稻壳,且各部位间达到显著差异水平;所有处理稻米Cd质量分数均低于现行的食品安全国家标准中Cd限量指标;与CK相比,营养型阻控剂显著降低糙米、水稻茎叶、水稻根的Cd质量分数,且呈现随营养型阻控剂用量增加而降低效应更佳的剂量效应;与CK相比,处理T4对稻米、水稻茎叶、水稻根三者Cd质量分数的降低效应最佳,降幅分别为32.8%、39.7%、24.4%;营养型阻控剂显著降低水稻根、茎叶和稻谷中Cd的累积量。施用营养型阻控剂显著提高了土壤pH值,提高的最大值为0.3个单位,但对土壤DTPA-Cd质量分数有提高作用(处理T1的DTPA-Cd质量分数显著大于CK、T3)、对土壤有效态硅质量分数有降低效应(处理T2、T3的有效态硅质量分数显著小于CK)。营养型阻控剂可适用于Cd超标菜园土,通过降低根Cd生物富集系数来显著降低水稻根、茎叶和稻米Cd质量分数,本盆栽试验中营养型阻控剂降低稻米Cd质量分数的最佳用量为6.0 g·kg^(-1)。

银叶树对Pb、Cd、Cu污染模拟湿地的适应性和修复潜力

【目的】探究银叶树(Heritiera littoralis)对重金属污染湿地环境的修复潜力。【方法】以银叶树为研究对象,在盆栽条件下模拟湿地环境,以不添加重金属为对照(CK),探究T_(1)(50 mg·L^(-1)Pb+5 mg·L^(-1)Cd+100 mg·L^(-1)Cu)、T_(2)(100 mg·L^(-1)Pb+10 mg·L^(-1)Cd+200 mg·L^(-1)Cu)、T_(3)(200 mg·L^(-1)Pb+20 mg·L^(-1)Cd+400 mg·L^(-1)Cu)3个复合污染水平(处理)对银叶树幼苗生长、养分吸收及Pb、Cd、Cu累积量的影响。【结果】与CK相比,T_(1)对银叶树根部生物量无显著影响,而T_(2)、T_(3)显著抑制根部生物量生长,3个处理银叶树的株高、地上生物量、总生物量与CK无显著差异;T_(1)处理银叶树的耐性系数为103.96%,T_(2)、T_(3)处理分别降至95.18%、80.80%;3个处理银叶树的N、P、K吸收量无显著变化。随着重金属含量的提高,银叶树对Pb、Cd、Cu的吸收量均不断增加,且大部分储存在根部;3个处理银叶树对Pb、Cu的转运系数较对照均显著下降,对Cd的转运系数则呈现先上升后下降的变化趋势。熵权TOPSIS模型评价结果表明,T_(3)处理银叶树的修复潜力最好,T_(2)、T_(1)次之。【结论】银叶树对复合重金属污染湿地的适应性较高,但高浓度重金属显著抑制根系生长;在ρ(Pb)≤50 mg·L^(-1)、ρ(Cd)≤5 mg·L^(-1)、ρ(Cu)≤100 mg·L^(-1)的重金属污染湿地中,银叶树生长不受影响。

生物炭老化对土壤中Cd^(2+)的吸附性能及机制研究

生物炭老化后会对土壤重金属固定化作用的稳定性和持久性产生影响,导致其钝化性能发生变化。研究了以花生壳(peanutshell,PS)为原料,在温度600℃、缺氧条件下采用热解法制备花生壳生物炭(PSB),并采用模拟田间氧化、浸出、酸化方式对PSB进行老化,制备了氧化生物炭(OPSB)、浸出生物炭(LPSB)、酸化生物炭(APSB)。通过等温吸附模型、动力学模型,以及FT-IR和XRD探讨了3种老化方式对生物炭吸附Cd^(2+)效应和机制的影响。结果表明:氧化老化过程能明显促进含氧官能团(—COOH、—OH等)在生物炭表面的积累,提升OPSB对Cd^(2+)的吸附性能,使Cd^(2+)吸附量提高10.13%;浸出老化后生物炭的官能团含量无明显变化,但大量可溶性矿物流失,使LPSB对Cd^(2+)的吸附性能大幅下降,吸附量降低13.35%;酸化老化会影响生物炭表面对Cd^(2+)的吸附活性,导致APSB对Cd^(2+)的吸附量降低26.52%;4种生物炭对Cd^(2+)的吸附过程均为有效吸附,其中,OPSB对Cd^(2+)的吸附亲和力最优,其次为PSB、LPSB和APSB;在低pH条件下,Langmuir等温吸附模型能更好地拟合4种生物炭对Cd^(2+)的吸附过程;同时,4种生物炭对Cd^(2+)的吸附过程均以物理静电吸附为主导,适合用准一级动力学模型描述。

鼠李糖脂对水中重金属Cd的去除效率研究

此研究在纯水环境下,测定出鼠李糖脂的临界胶束浓度值,并通过正交实验的方法研究了鼠李糖脂对重金属Cd的去除效率以及影响因素。结果表明,在鼠李糖脂的临界胶束浓度下,可得到最佳的去除效率,鼠李糖脂的浓度、反应时间、温度、pH对去除效率均有影响,最优实验方案为:鼠李糖脂浓度为2 g/L,pH为10,温度为50℃时震荡3小时可达到最佳去除效率76.28%,无机盐K^(+)、Ca^(2+)的存在,可在一定程度上促进重金属的解脱附,同时二者存在一定竞争关系,表现为:Ca^(2+)>K^(+)。

虾青素对镉离子(Cd^(2+))诱导下斑马鱼胚胎抗氧化指标的影响

(28.0±0.5)℃下,将100个产后1 h的斑马鱼(Danio rerio)胚胎放在120 mm培养皿中,暴露在<0.02%浓度的二甲基亚砜(DMSO,对照组)、50μg/L Cd^(2+)(低浓度暴露组)、500μg/L Cd^(2+)(高浓度暴露组)和Cd^(2+)+雨生红球藻(Haematococcus pluvialis)虾青素AST联合暴露组(50μg/L Cd^(2+)+100μg/L AST组和500μg/L Cd^(2+)+100μg/L AST组)5个处理组中,120 h后测定斑马鱼幼鱼活性氧(ROS)、丙二醛(MDA)和谷胱甘肽酶(GSH)含量、超氧化物歧化酶(SOD)活性和总抗氧化能力(T-AOC),研究重金属镉离子(Cd^(2+))暴露下斑马鱼胚胎的抗氧化响应,探讨AST对斑马鱼机体氧化损伤的缓解效果。结果表明,斑马鱼胚胎Cd^(2+)暴露120 h后,体内活性氧(ROS)和丙二醛(MDA)含量随着Cd^(2+)浓度的升高而增加;GSH含量、SOD和T-AOC的活性随着Cd^(2+)浓度的增加而降低。说明Cd^(2+)可诱导斑马鱼机体出现氧化应激和氧化损伤。添加AST后,斑马鱼幼鱼体内ROS和MDA含量下降,GSH含量、SOD和T-AOC活性上升,说明添加AST可在一定程度上缓解重金属Cd^(2+)对斑马鱼体内抗氧化指标的负面影响。本研究结果可为AST作为新型鱼类饲料添加剂提供理论依据。

Advances in Research on Effect of Heavy Metals Cd and Pb on Wheat and Mitigation Effect of Conditioners

In this article,the effect of heavy metals Cd and Pb on seed germination,seedling growth and yield of wheat is investigated,and the effect of related conditioners on improving soil and alleviating Cd and Pb stress is explored.

ALA协同PASP强化伴矿景天提取土壤重金属Cd的研究

[目的]探究5-氨基酮戊酸(ALA)协同螯合剂聚天冬氨酸(PASP)增强伴矿景天提取土壤Cd的最佳条件。[方法]通过盆栽试验,伴矿景天种植于Cd污染土壤(总Cd0.68 mg/kg)中,且在移栽45 d后开始浇灌不同添加浓度的PASP(3、6、12 g/kg,分别等分为3次使用,2~3次使用的间隔时间分别为15、30 d);ALA(25 mmol/L)于PASP处理后第3天灌施,按不同的施用次数(0、1、2、3)处理,间隔时间同PASP处理。分析伴矿景茎长、地上部生物量、Cd含量和Cd提取量,建立各指标之间的相关性并拟合生物量和Cd提取量与PASP施用量、ALA使用次数的预测模型。[结果]ALA协同中等剂量(6 g/kg)PASP连续3次的施用能显著提高伴矿景天茎长、地上部生物量、地上部分Cd含量和Cd提取量;线性回归显示PASP施用量和ALA施用次数是地上部分生物量和Cd提取量的关键影响因子;地上部分Cd提取量在PASP施用量为6 g/kg协同ALA 3次连续使用时达到最大,为1.09 g/盆,是CK提取量的2.79倍;地上部分生物量、茎长与ALA施用次数呈显著正相关,而与PASP施用量呈显著负相关。[结论]研究结果揭示了ALA协同PASP在强化伴矿景天提取土壤Cd具有重要意义,且需选择合适的配比和施用次数。

Absorption capacity of major urban afforestation species in north-eastern China to heavy metal pollutants in the atmosphere

Totally 24 arbor tree species and 6 shrub species were measured on their absorption capacities to heavy metal Pb, Cd, Cr, and Hg by collecting and analyzing the leaves of trees along different streets in Harbin city in Sept. to Oct. of 2003. The results showed that all the measured species had certain absorbency to the pollutants (Pb, Cd, Cr and Hg), but there existed significant difference in absorption capacity for different species to different pollutants. The measured tree species were classified into three categories by their absorption quantum of heavy metal pollutants. Among the species measured,Betula platyphylla, Ulmus pumila var.pendula, andPrunus persicaf.rubro-plena had high capacity in absorbing Pb;Populus xiahei, P. nigra var.Italica, P. alba x P. berolinensis andSalix matsudana had had high capacity in absorbing Cd;Phellodendron amurense, Syringa oblata, Salix matsudana, Pinus tabulaeformis var.mukdensis, Picea koraiensis, Prunus persica f.rubro-plena, P. triloba andAcer negundo, etc. had high capacity in absorption of Cr;Prunus triloba, Quercus mongolica, Salix matsudana, Sambucus williamsii, Pyrus ussuuriensis andSpiraea fritschiana were good at absorption of Hg. This study might offer scientific foundation for selection of urban afforestation species in different polluted conditions caused by heavy metals. Keywords Greening tree species - Heavy metal - Pollutants - Plumbum - Cadmium - Chromium - Mercury - Absorptivity CLC number S731.2 - X501 Document code A Foundation item: This study is financially supported by the Special Programme for Agriculture under Ministry of Chinese Science and Technology (No. 2002BA516A15-01).Biography: MU Li-qiang (1966-), female, Associate professor in Northeast Forestry University, Harbin 150040, P. R. China.Responsible editor: Zhu Hong