Determination of Ni^(2+) in Waters with Sodium Polyacrylate as a Binding Phase in Diffusive Gradients in Thin-films

An aqueous solution containing sodium polyacrylate（PAAS） was used in diffusive gradient in thin-films technique（DGT） to measure DGT-labile Ni2＋ concentrations.The DGT devices（PAAS DGT） were validated in four types of solutions,including synthetic river water containing metal ions with complexing EDTA or that without complexing EDTA,natural river water（Ling River,Jinzhou,China） spiked with Ni2＋,and an industrial wastewater （Jinzhou,China）.Results show that only free metal ions were measured by PAAS DGT,recovery=97.36% in the solutions containing only free metal ions,recovery=49.62% in a solution with metal/EDTA molar ratio of 2：1 and recovery=0 in the solutions with metal/EDTA molar ratios of 1：1 and 1：2.These indicated that the complexes of Ni-EDTA were DGT-inert.The DGT performance in spiked river water（recovery=18.24%） and in industrial wastewater（recovery=12.25%） were investigated,which indicated that the measurement of metals by this DGT device did not include the humic substances complexed fractions of metals.The binding properties of PAAS DGT for Ni2＋ were investigated under different conditions of pH value and ionic strength.Conditional stability constants（lgK） of PAAS-Ni complexes were also evaluated.

Evaluation of the Bioavailability of Metals in Sediment from the Southern Coastal Wetland of the Qiantang Estuary by Using Diffusive Gradients in Thin Films Technique

Metal pollution has become an major issue governing the wetland ecosystem health.The southern coastal wetland of the Qiangtang Estuary are facing unusual perturbation due to rapid development along the embayment in recent decades.This study evaluated the bioavailability of metals(Cu,Pb,Cd,Cr and Zn)in the sediment of the southern coastal wetland of the Qiangtang Es-tuary using diffusive gradients in thin films(DGT)techniques and compared with several methods based on total metal content.The results showed that the contents of Cr,Pb,Cd and Cu in sediment,as detected using DGT,were considerably correlated with the exchangeable fraction and the content in Phragmites australis roots,while a weak correlation was observed for Zn.Therefore,DGT analysis could be used to evaluate the bioavailability and potential risk of Cr,Cd,Pb and Cu for P.australis.Quantitative indices,such as DGT concentration,bioaccumulation in P.australis,geoaccumulation index(Igeo)and potential ecological risk index(RI),revealed that Cd was a major potential ecological risk factor along the southern coast wetland of the Qiantang Estuary,especially in the upstream region,which is potentially more vulnerable to the anthropogenic pollution.

Evaluation of Cadmium Bioavailability in Soils Using Diffusive Gradients in Thin Film Technique and Traditional Methods

The developed technique of diffusive gradients in thin film( DGT) has been suggested as a promising tool for evaluation of cadmium( Cd) availability in soils,but there exists considerable debate on its suitability. In this study,Cd bioavailability in soils was systemically investigated by comparing this technique with seven traditional methods, including soil solution concentration and six commonly used extraction methods( HAc,EDTA,Na c,NH4Ac,CaCl2 and MgCl2). Two typical plants( wheat and maize) were examined for Cd uptake. Maize was more sensitive to increasing exposure to Cd in soils than wheat when the added amounts of Cd ranged from 3. 5 to 5. 0 mg · kg-1,accompanied by the significant decreases of shoot and root biomasses. Cd concentrations in shoots and roots of two plants increased continuously with increasing levels of Cd in soils. Cd uptake was higher in wheat than that in maize. The bioavailable concentrations of Cd measured by all methods increased nearly linearly with increasing addition of Cd in soils. Positive correlations were observed between various bioavailable indicators of Cd in soils and Cd concentrations in two plants. The extractable Cd by six chemical extractants was considerably higher for maize than for wheat,while the DGT-measured and soil solution concentrations of Cd were lower for maize than for wheat,following the same trend as plant Cd uptake. The results imply that DGT measurement can effectively predict the bioavailable levels of Cd in soil solutions and that it is an ideal tool for prediction of Cd bioavailability in soils.

基于梯度扩散薄膜(DGT)技术评估玉米农田土壤中铅的生物有效性及动力学过程

为验证梯度扩散薄膜(DGT)技术在准确评估自然环境下玉米农田土壤中铅(Pb)的生物有效性的可行性,并基于该技术探究土壤中Pb的动力学过程,本研究使用DGT技术、土壤溶液法和单独提取法测定了湖南省凤凰县内种植玉米的农田土壤中Pb的可提取态含量,并与玉米不同部位中Pb的含量进行了线性拟合分析;利用DGT技术结合DGT诱导土壤/沉积物通量(DIFS)模型模拟了土壤内部Pb的动力学过程。结果表明:35%的土壤点位中Pb的含量超过湖南省Pb背景值,但不存在玉米粒中Pb超标的情况(GB 2762—2022)。Pb在玉米不同部位迁移富集能力较低,且主要富集在根部,难以向地上部位迁移。不同方法测定的土壤中Pb的生物有效态含量分别为DGT技术(1.32±2.49)µg·L^(-1)、土壤溶液(2.23±3.75)µg·L^(-1)、二乙基三胺五乙酸(DTPA)单独提取法(5.79±2.51)mg·kg^(-1)、醋酸(HAc)单独提取法(0.81±0.49)mg·kg^(-1)和氯化钙(CaCl_(2))单独提取法(0.05±0.13)mg·kg^(-1)。DGT技术对玉米不同部位Pb含量的预测效果优于其他方法,且对叶中Pb含量的预测效果最佳。研究区大部分土壤固相Pb补给液相的能力较低,但固相上Pb的释放量较为稳定,仍可能会对当地造成潜在的生态风险。整体而言,DGT技术是评估玉米农田土壤中Pb生物有效性的最佳方法,其测定的Pb含量对玉米叶部Pb含量预测效果最佳,但对粒中Pb含量预测效果较差。此外,DGT技术可以结合DIFS模型深入分析土壤内部Pb的动力学的过程,为土壤污染的精准防控提供科学依据。

Diffusive gradients in thin films(DGT) probe for effectively sampling of per-and polyfluoroalkyl substances in waters and sediments

The passive sampling technique, diffusive gradients in thin films(DGT) has attracted increasing interests as an in-situ sampler for organic contaminants including per-and polyfluoroalkyl substances(PFAS). However, its effectiveness has been questioned because of the small effective sampling area(3.1 cm^(2)). In this study, we developed a DGT probe for rapid sampling of eight PFAS in waters and applied it to a water-sediment system. It has a much larger sampling area(27 cm^(2)) and as a result lower method quantification limits(0.15 –0.21 ng/L for one-day deployment and 0.02 – 0.03 ng/L for one-week deployment) and much higher(by > 10 factors) sampling rate(100 m L/day) compared to the standard DGT(piston configuration). The sampler could linearly accumulate PFAS from wastewater, was sensitive enough even for a 24 hr deployment with performance comparable to grab sampling(500m L). The DGT probe provided homogeneous sampling performance along the large exposure area. The use of the probe to investigate distributions of dissolved PFAS around the sediment-water interface was demonstrated. This work, for the first time, demonstrated that the DGT probe is a promising monitoring tool for trace levels of PFAS and a research tool for studying their distribution, migration, and fate in aquatic environments including the sediment-water interface.

基于DGT和化学提取法研究浙西北地质高背景区土壤镉生物有效性

地质高背景区相较于人类活动引起的土壤镉污染影响范围更广,在区域尺度上对生态系统和人类健康构成危害。土壤镉生物有效性是决定其生物可利用性、生物毒性的关键因素,因此探寻可行的土壤镉生物有效性评价方法对污染农用地安全利用和风险管控具有重要的理论和实际意义。DGT技术、单一提取法、连续提取法和土壤溶液法常用于测定土壤有效镉,但已有研究成果主要基于同种土地利用类型土壤的室内盆栽实验,难以代表自然污染土壤中的复杂情况。为探明各土壤重金属有效态提取技术对地质高背景区不同土地利用类型土壤Cd生物有效性评估效果,本文以浙江西北部土壤Cd高地质背景区水田土壤-水稻籽实和旱地土壤-小白菜样品为研究对象,实验应用DGT技术、单一提取法(0.01mol/L氯化钙提取)、连续提取法(七步连续提取)和土壤溶液法评价土壤中镉生物有效性。结果显示:①研究区水田和旱地土壤Cd平均含量分别为1.07mg/kg和0.73mg/kg,显著高于浙江和全国土壤平均水平,Cd的异常富集主要与浙西北地区广泛分布的黑色岩系有关。②相较于碳酸盐岩区,黑色岩系区土壤中Cd的生物有效组分占比较高,水田和旱地土壤Cd的活动系数(MF)高达59.9%和51.8%,Cd易在土壤-作物系统中发生迁移富集;③植物体内镉含量Cd-P与不同方法测定的有效镉含量均呈显著正相关,但Cd-P与DGT技术测定的有效镉含量相关性优于其他三种方法,水田土壤测得的有效Cd与水稻籽实相关关系:C_(soln)>C_(DGT)>C_(Cacl_(2))>C_(F_(1)+F_(2)+F_(3)),旱地土壤测得的有效Cd与小白菜相关关系:CDGT>C_(Cacl_(2))>C_(F_(1)+F_(2)+F_(3))>C_(soln)。综合比较不同土壤有效Cd测定方法的优缺点,DGT技术可以模拟植物体对Cd的动态吸收过程,更能准确地反映土壤Cd生物有效性,预测作物Cd含量水平,这与已有研究成果一致。此外,本文研究成果表明DGT技术评价土壤Cd生物有效性,不仅适用于人为污染区,也可应用于地质高背景区。

Diffusive gradients in thin films using molecularly imprinted polymer binding gels for in situ measurements of antibiotics in urban wastewaters

Urban wastewater is one of main sources for the introduction of antibiotics into the environment.Monitoring the concentrations of antibiotics in wastewater is necessary for estimating the amount of antibiotics discharged into the environment through urban wastewater treatment systems.In this study,we report a novel diffusive gradient in thin films(DGT)method based on molecularly imprinted polymers(MIPs)for in situ measurement of two typical antibiotics,fluoroquinolones(FQs)and sulfonamides(SAs)in urban wastewater.MIPs show specific adsorption toward their templates and their structural analogs,resulting in the selective uptake of the two target antibiotics during MIP-DGT deployment.The uptake performance of the MIP-DGTs was evaluated in the laboratory and was relatively independent of solution pH(4.0-9.0),ionic strength(1-750 mmol/L),and dissolved organic matter(DOM,0-20 mg/L).MIP-DGT samplers were tested in the effluent of an urban wastewater treatment plant for field trials,where three SA(sulfamethoxazole,sulfapyridine,and trimethoprim)and one FQ(ofloxacin)antibiotics were detected,with concentrations ranging from 25.50 to 117.58 ng/L,which are consistent with the results measured by grab sampling.The total removal efficiency of the antibiotics was 80.1%by the treatment plant.This study demonstrates that MIP-DGT is an effective tool for in situ monitoring of trace antibiotics in complex urban wastewaters.

Determining cadmium bioavailability in sediment profiles using diffusive gradients in thin films

Cadmium(Cd)uptake by plants or benthic organisms largely depends on its bioavailability in sediments,so it is necessary to understand Cd bio availability for determining its ecological risks in riverine sediments.Pore water is easily disturbed during sample collection,indicating that there was a shortage of traditional methods for investigating Cd bio availability.Here,sediment cores were collected from rivers,after which sequential extraction and diffusive gradients in thin films(DGT)method were employed to determine Cd potential bio availability in the sediments and pore water.We found that Cd concentrations measured by DGT were lower than that in pore water profiles,and Cd distribution in various fractions changed remarkably.Pearson correlation analysis showed significant positive correlations between Cd concentrations measured by DGT and total Cd concentrations(r^2=0.76),exchangeable and weak acid soluble fraction(r^2=0.68),ferromanganese fraction(r^2=0.72)and bound organic matter or oxidizable fraction(r^2=0.54).However,the correlation was relatively low between Cd concentrations measured by DGT and that in pore water profiles(r^2=0.26).These results demonstrated that DGT method could provide more accurate information of Cd bio availability in sediment profiles than traditional methods.

纳米LDHs-DGT用于土壤环境无机砷提取检测技术研究

为有效测量土壤环境中的砷污染,本研究开发了一种基于纳米层状双金属氢氧化物(LDHs)为结合膜的梯度扩散薄膜设备(LDHs-DGT)。对设备的基本性能以及适用条件进行了探究,对不同水分管理下土壤As(Ⅲ)和As(Ⅴ)的动态变化进行监测,探究了不同水分管理下的不同深度砷的形态变化情况,实验结果表明,该技术能够在较宽的pH(4~8)和离子强度(CNaNO_(3)<0.7 mol·L^(-1))范围内对As(Ⅲ)和As(Ⅴ)进行有效的提取和检测,其中,LDHs结合膜对As(Ⅲ)和As(Ⅴ)的吸附容量分别为30μg·cm^(-2)和85μg·cm^(-2),结合膜在6 h内实现全解离;且LDHs-DGT具有较好的抗干扰特性,As(Ⅲ)和As(Ⅴ)在结合膜上没有明显的竞争吸附效应,对实际样品测定结果也能较好地反映DGT设备的实用性。综上所述,LDHs-DGT具有制备简单、适用范围广、检测效果好等特点,可为环境监测和评估提供新的解决方案。

基于LDHs-DGT的环境中活性态Cr原位提取检测方法研究

为原位监测土壤Cr的形态变化,本研究开发了一种以纳米Mg/Al双层氢氧化物(Mg/Al-LDHs)作为结合膜的梯度扩散薄膜(LDHs-DGT)装置,并通过ICP-MS和超痕量六价铬分析仪联用,实现对环境中活性态Cr含量及Cr(Ⅲ)、Cr(Ⅵ)的原位提取、测定。实验结果表明,该装置中LDHs结合膜对Cr(Ⅲ)和Cr(Ⅵ)均有较快的吸附速率,其最大吸附量分别是181.27μg·cm^(-2)和176.29μg·cm^(-2),该装置可在pH为5~8、离子强度小于50 mmol·L^(-1)的环境中对Cr(Ⅲ)和Cr(Ⅵ)实现准确提取,能够有效避免干扰离子对装置的影响,空白背景值为4.9 ng,方法检出限为0.22 ng·mL^(-1),Cr(Ⅲ)和Cr(Ⅵ)在扩散膜中的扩散系数分别为(3.58±0.02)×10^(-6)cm^(2)·s^(-1)和(7.03±0.09)×10^(-6)cm^(2)·s^(-1)。LDHs-DGT可以高效侦测土壤活性态Cr的时空变化态势,并能对Cr(Ⅲ)和Cr(Ⅵ)的价态变化进行动态监测。

梯度薄膜扩散技术(DGT)与传统化学方法评估黑麦草吸收Cd的对比

为研究不同方法评估黑麦草吸收Cd的效果,采集了16个不同理化性质实际Cd污染土壤,盆栽试验种植黑麦草,采用梯度薄膜扩散技术(DGT)测定黑麦草根际土Cd的生物有效性,并与离心法采集土壤溶液、乙酸(HAc)和乙二胺四乙酸二钠(EDTANa2)3种传统提取方法所提取土壤有效态Cd含量进行比较,研究其与黑麦草地上部和地下部Cd含量的相关关系.结果表明,DGT提取的土壤有效态Cd含量与黑麦草中Cd含量的相关性显著高于化学提取法.运用多元统计分析研究土壤pH、阳离子交换量(CEC)、有机质(OM)和土壤颗粒组成等理化指标的影响,提取出两种主成分因子,建立了多元回归模型.第一主成分与OM和黏粒(clay)之间呈显著相关,定义为土壤中影响重金属生物有效性的"有机指标",第二主成分则与土壤pH和CEC相关程度较高,定义为土壤中影响重金属生物有效性的"无机指标".研究表明,第二主成分显著影响了3种化学方法构建的预测模型,而DGT技术综合了两种主成分对土壤有效态Cd含量的影响,所构建的模型几乎不受土壤基本理化性质的影响,说明DGT分析法是一种预测黑麦草吸收Cd的较好方法.

利用DGT高分辨率研究沉积物孔隙水中重金属的浓度和释放通量

2006年5月采集了大辽河河段3个忙状沉积物，测定了沉积物的理化性质和重金属元素的含量，并利用常规离心方法和DGT方法测定了柱状沉积物孔隙水中重金属元素的含量．研究发现沉积物中cd、co、cr和cu元素含量高低的顺序依次是Cr〉Cu〉Co〉Cd．用DGT方法测定的孔隙水中cd、co、cr和cu的浓度比用离心方法测定的浓度要低．DGT测定的孔隙水中cd、co、cr和cu的浓度Cdgt与离心方法测定的孔隙水浓度c的平均比值JR分别为0．389、0．328、0．863和0．403，这说明沉积物中这几种金属从固相到液相的再补给速率大小遵循如下规律：Cr〉Cu〉Cd〉Co．沉积物中cd、co、cr和cu元素的释放通量分别为1．12×10^-7～3．28×10^-7mmol／（cm^2·s）、2．48×10^-7～10．40×10^-7mmol／（cm^2·s）、8．80×10^-6～12．65×10^-6mmol／（cm^2·s）和6．14×10^～6-13．93×10^-6mmol／（cm^2·s）．相关分析结果表明，cd和cu元素的迁移转化主要受有机质影响；而cr元素的迁移转化除了受有机质影响外，还受铁锰氧化物影响比较显著；而co元素可能受氧化还原电位影响较大．

梯度扩散薄膜技术(DGT)的理论及其在环境中的应用I:工作原理、特性与在土壤中的应用

根据文献资料,详细阐述了梯度扩散薄膜技术(DGT)的原理、影响DGT技术测量的因素和它的应用特性,同时回顾了DGT技术问世以来在土壤中的应用实例,并认为DGT技术为研究土壤重金属的生物可利用性提供了可行可靠而又有效的方法。

梯度扩散薄膜技术(DGT)的理论及其在环境中的应用Ⅲ——植物有效性评价的理论基础与应用潜力

梯度扩散薄膜技术(DGT)是一种测定环境介质中多元素植物有效性的原位分析方法。由于其能模拟植物根系,综合考虑环境多介质的动态平衡,因此近年来被广泛应用于多元素植物有效性的评价。本文简要阐述了DGT技术基于动力学过程进行有效性测定的原理;深入剖析了DGT技术涉及的动力学过程与植物吸收机制的相似性与差异性;详细评估DGT技术预测多元素植物有效性的评价效果;并基于以上内容,对DGT技术在植物有效性方面的应用进行总结和展望。

DGT法原位测量水体中金属有效态组分及动力学研究

根据不同厚度扩散膜DGT(梯度扩散薄膜)对金属络合易解离态解离能力差异性这一原理,提出了一套计算金属解离动力学及有效态组分方法,并将其应用于水体Zn、Ni、Cu、Fe、Mn、Cd、Pb等金属形态及运移动力学特征差异性计算中。结果表明,研究提出的计算方法,克服了原有方法过拟合的缺点,可以不借助第三方金属形态分析软件一次性计算出金属有效态含量、组分构成及K-1值,且计算结果更好地体现出有效态中络合易解离部分的贡献,计算公式假设参数少,避免了金属价态、有机质组分构成差异性等因素对有效态含量计算的影响。

DGT和传统化学法比较研究复合污染土壤中Cd的生物有效性

以小麦和玉米2种陆生植物为金属吸收材料,利用盆栽试验比较研究了新型DGT(diffusive gradients in thin films,薄膜扩散梯度技术)法与5种传统化学法评价土壤中Zn复合存在下Cd的生物有效性.结果显示:1土壤中w(Cd)为4 mgkg时明显抑制了2种植物的生长,与对照组相比,小麦的地上部和根系生物量分别降低了26.2%和23.4%,玉米的分别降低了23.5%和30.9%.2Zn的添加能够减轻Cd对植物的毒害,并促进植物生长;Cd污染土壤中Zn的复合存在会抑制2种植物对Cd的吸收,并随w(Zn)的增加其抑制作用更加明显;DGT法、土壤溶液法测定的土壤溶液中ρ(Cd)和4种化学提取法(HAc、EDTA、CaCl2和NaAc)测定的土壤中w(有效态Cd)均随w(Zn)的增加而明显降低.3Pearson相关分析显示,2种植物体内w(Cd)与6种方法表征的土壤中w(有效态Cd)均呈显著正相关(R>0.900,P<0.01),但植物体内w(Cd)与DGT和土壤溶液法测定的土壤溶液中ρ(Cd)的R(>0.940)大于其他4种化学提取法.可见,对于评价Cd-Zn复合污染土壤中Cd的生物有效性而言,DGT与土壤溶液法均优于传统的化学提取法.

原位覆盖控制沉积物磷释放效果的验证评估

文章通过覆盖材料(方解石、湖沙或方解石+湖沙)对底泥磷释放的阻控实验以及利用梯度扩散薄膜(DGT)的底泥原位测试,验证评估覆盖剂对呼伦湖沉积物磷的生态修复效果。结果发现:(1)方解石、方解石+湖沙或湖沙能有效降低表层沉积物的DGT-P浓度(CDGT(PO_(4)^(3-)-P)),沉积物/水界面扩散通量和上覆水溶解反应性磷;方解石、方解石+湖沙覆盖的表层沉积物的CDGT(PO_(4)^(3-)-P)峰值或平均值明显低于对照样;方解石、方解石+湖沙的上覆水DRP的去除率分别超过78%和81%;方解石+湖沙可以将沉积物/水界面无机磷扩散通量降低至负值;(2)方解石和方解石+湖沙能明显地降低表层沉积物总磷(TP)、活性磷(NH_(4)Cl-P和BD-P)含量及其占TP的百分比,沉积物反应性磷再补给系数r减少而惰性成份(NaOH_(85)-P和Ca-P)及其占TP的百分比增加;(3)方解石+湖沙覆盖的表层沉积物TP变化范围:-45~-30 mg/kg;磷提取相(NH_(4)Cl-P、BD-P、Ca-P和NaOH_(85)-P)含量变化值,磷提取相变化量占对照沉积物对应提取成份的百分比分别为-17~-10 mg/kg (-38.46%~-29.31%);-23~-16 mg/kg (-46.15%~-32.86%);10~15 mg/kg (2.41%~3.63%)和8~14 mg/kg(3.20%~3.99%);r降低范围:0.02~0.19。综上,方解石的吸附或阻隔作用能降低沉积物总磷和活性磷,降低沉积物磷再补给能力;NH_(4)Cl-P和BD-P被转化为情性成份(NaOH_(85)-P和Ca-P),磷迁移性降低。覆盖剂对沉积物磷内源负荷控制效果为方解石+湖沙>方解石>湖沙。方解石+湖沙的磷阻控机制是方解石对磷的吸附,磷和方解石的共沉淀以及湖沙的物理阻隔;方解石+湖沙的多层覆盖是一种应用价值较高的沉积物原位修复技术。

利用CDM-PSS-DGT装置累积测量水中的Ni^(2+)和Co^(2+)

研究了CDM-PSS-DGT装置对Ni^(2+)和Co^(2+)的累积和测量.测定了Ni^(2+)和Co^(2+)与聚乙烯苯磺酸(PSS)的条件配位稳定常数以及Ni^(2+)和Co^(2+)在扩散层中的扩散系数.考察了酸度、离子强度以及碱金属和碱土金属对CDM-PSS-DGT装置累积水中Ni^(2+)和Co^(2+)的影响.在pH 4-9范围内,酸度对Ni^(2+)和Co^(2+)的累积容量影响不大;离子强度对Ni^(2+)和Co^(2+)的累积容量有较强的影响,随着离子强度的不断增大,CDM-PSS- DGT装置对Ni^(2+)和Co^(2+)的累积容量逐渐下降;碱金属、碱土金属与Ni^(2+)和Co^(2+)共存时,CDM-PSS-DGT装置对Ni^(2+)和Co^(2+)优先累积.经测定Ni^(2+)和Co^(2+)与结合相PSS的条件配位稳定常数(lg K)分别为8.04和8.07.配制水中CDM-PSS-DGT装置能准确地对Ni^(2+)和Co^(2+)进行测量,Ni^(2+)和Co^(2+)的测量回收率分别为:93.84%和91.82%,RSD%分别为:3.53%和4.89%.

春夏季巢湖湖滨沉积物-水界面磷动态与内源释放潜力

采用传统采样和薄膜扩散梯度技术(DGT),分析了春夏季巢湖西北部湖滨上覆水、间隙水及沉积物中磷形态和DGT有效态磷铁(DGT-P、DGT-Fe)的动态变化及扩散通量.结果表明,初夏季(6月)湖滨上覆水磷含量显著降低,可能源于藻类生长吸收营养盐;而间隙水磷形态含量季节差异显著.巢湖西北部湖滨沉积物无机磷主要为自生磷(Auth-P),占无机磷(IP)比例为19.7%~61.3%.湖滨带消落区(S1、S2)沉积物磷含量明显低于堤坝隔离区(S3),但受有机质水平、水动力扰动等因素影响,具有更高的磷释放潜力;夏季沉积物内源磷释放潜力高于春季.DGT-P和DGT-Fe的相关分析结果表明,湖滨带消落区沉积物内源磷释放主要受控于铁结合态磷还原过程,而堤坝隔离区沉积物受铁磷循环调控作用较弱.

利用梯度扩散薄膜技术(DGT)研究沉积物中重金属生物有效性的应用展望

梯度扩散薄膜技术(Dffusive grdients in thin-films,DGT)是一种新的原位被动采样技术,可以高分辨地测定水体、土壤和沉积物中重金属的生物有效态,近年来在水环境领域中得到了广泛应用。本文根据文献、资料分析,介绍了DGT装置、基本原理,扩散相和结合相的发展,展望了DGT技术的发展前景。重点综述DGT技术在评价沉积物环境中重金属生物有效性的研究进展,并认为DGT技术为研究沉积物重金属生物有效性提供了快速高效的方法,为水环境中沉积物-水界面重金属迁移转化研究提供了强有力的技术支撑。