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1.
在室内培养条件下,应用4因素5水平二次正交回归旋转组合设计方案,对重金属复合污染红壤的微生物活性及群落功能多样性进行了研究。结果表明,在Cu、Zn、Pb、Cd复合污染生境中重金属的微生物毒性效应发挥主要由Cd、Cu两元素决定,其生物毒性顺序表现为:Cd>Cu>Zn>Ph,红砂泥中表现较为突出。与单一镉、单一铅污染处理相比,重金属复合污染对供试红壤微生物生物活性及其群落功能多样性的影响并非仅仅表现出简单的加和作用,同时还存在协同作用和拮抗作用。典型相关分析显示,红壤微生物活性与重金属含量之间关系密切,第一对典型变量的相关系数r达0.885 8、0.932 8,均达极显著水平(p<0.001), 说明重金属复合污染与红壤微生物间存在较为稳定的数量反馈机制,红壤总体微生物活性指标能较好地反映供试红壤重金属复合污染状况,可作为重金属污染红壤环境质量评价及量化分类的有效指标。  相似文献   

2.
This study was conducted to characterize the heavy metal contamination in the soils of peach orchards irrigated with water from Nilüfer creek, which is heavily polluted by industrial and municipal wastes. Twenty-one peach orchards with 3 different cultivars in 7 orchards each located along Nilüfer creek were monitored in the experiment. To determine levels of pollution, soils and aboveground parts of the trees were sampled and analyzed for iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cobalt (Co), nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd). Total amounts of Ni and Cr were found to be at the excessive levels in soils. Extractable Ni concentration decreased with increasing pH and CaCO3 content in soils. Leaf metal contents were generally at tolerable levels, but Ni and Pb accumulated to toxic levels in different parts of the fruit (flesh and peel). Except for Fe and Ni, plant concentrations of the metals did not correlate with their total and DTPA-extractable concentrations in the soils. There was no significant difference among the cultivars in accumulation of heavy metals.  相似文献   

3.
赫章土法炼锌区水-沉积物重金属污染的时空变化特征   总被引:1,自引:0,他引:1  
对赫章土法炼锌区河流水体和沉积物重金属污染状况及时空变化特征进行了研究。结果表明,水体和沉积物受到多种重金属污染:地表水体中Pb、Zn、Cd的均值分别为137.19×10-3、1 919.38×10-3、14.21×10-3 mg.L-1,分别是地表水环境质量标准Ⅲ类水质标准的2.74、1.91、2.84倍;沉积物中Cu、Pb、Zn和Cd的均值分别为702.79、3 242.8、5 427.6、32.19 mg.kg-1,分别是土壤环境质量标准三级标准的1.76、6.49、10.86、32倍。水体和沉积物中Cu、Pb、Zn和Cd沿河流总体呈无规律性的变化,受炼锌废渣堆和铅锌选矿厂影响的地点,水体和沉积物重金属含量均较高,污染严重。近10年来,炼锌区河流水体和沉积物重金属污染仍然很严重,水体重金属污染呈加重特征,沉积物中Pb、Zn污染呈减轻趋势,Cd和Cu污染则加重。  相似文献   

4.
Human exposure to toxic heavy metals via dietary intake is of increasing concern. Heavy-metal pollution of a rice production system can pose a threat to human health. Thus, it was necessary to develop a suitable extraction procedure that would represent the content of metal available to rice plants (Oryza sativa L.). The aim of this study was to predict, on the basis of single extraction procedures of soil heavy metals, the accumulation of heavy metals (cadium, lead, copper, and zinc) in rice plants. Six extracting agents [Mehlich 1, Mehlich 3, EDTA (ethylenediaminetetraacetic acid), DTPA–TEA (diethylenetriaminepentaacetic acid–triethanolamine), ammonium acetate (NH4OAc), and calcium chloride (CaCl2)] were tested to evaluate the bioavailability of heavy metals from paddy soils contaminated with lead–zinc mine tailings to rice. The extraction capacity of the metals was found to be of the order EDTA > Mehlich 3 > Mehlich 1 > DTPA–TEA > NH4OAc > CaCl2. The correlation analysis between metals extracted with different extractants and concentrations of the metals in the grain and stalk of the plant showed positive correlations with all metals. The greatest values of correlation coefficients were determined between the NH4OAc- and CaCl2-soluble fractions of soil and contents in plants in all four metals studied. Therefore, NH4OAc and CaCl2 were the most suitable extractants for predicting bioavailability of heavy metals in the polluted soils to rice. The results suggested that uptake of heavy metals by rice was mostly from exchangeable and water-soluble fractions of the metals in the soils. Soil-extractable metals were more significantly correlated with metal accumulation in the stalk than in the grain. The pH had more significant influence on availability of heavy metals in the soils than total content of metals and other soil properties. The bioavailability of metals for rice plants would be high in acidic soils.  相似文献   

5.
通过向供试土壤中添加CuSO4、ZnSO4、Pb(Ac)2、HgCl2以模拟受污土壤,研究接种于其中的微小双胸蚯蚓对重金属的富集作用。以不加重金属盐类为对照,分别研究了不同培养时间和不同重金属浓度对富集量的影响。结果表明,蚯蚓对各种重金属的富集量随着培养时间的增加而变化,且对不同重金属最大富集量的出现时间也不相同。在第2周时蚯蚓对Cu、Pb富集量达到最大,而对Zn的富集量在第4周时达到最大。与Cu、Zn、Pb的富集量相比,蚯蚓对Hg没有明显的富集作用,且对Hg的最大富集量时间不明显。在其耐受浓度范围内,蚯蚓对重金属的富集量随着重金属浓度的增加而增加,且蚯蚓对重金属的吸收顺序为:Zn〉Cu〉Pb〉Hg,说明了微小双胸蚯蚓对Cu、Zn、Pb、Hg4种元素有一定的忍耐和富集能力,但其对重金属的忍耐和富集能力是有选择性的,说明不同重金属表现出的毒性是不一样的。研究结果初步推断,影响蚯蚓对重金属富集作用的主要原因可能是体内酶的作用,不同重金属可以从多方面干扰了动物机体内的生理生化功能。  相似文献   

6.
Luo  Youfa  Wu  Yonggui  Qiu  Jing  Wang  Hu  Yang  Lian 《Journal of Soils and Sediments》2019,19(2):702-715
Purpose

Zinc smelting activity generates large volumes of highly toxic waste slags and poses a potential extreme environmental risk for the surrounding areas. The establishment of a vegetation cap for the phytostabilization of abandoned mine tailing heaps using plants is usually considered a beneficial approach. This study aimed to evaluate the suitability of phytostabilization of zinc smelting slag using four woody plants combined with organic amendments, to investigate the distribution of heavy metals in the slag–plant system, and to better understand how the direct revegetation of a zinc smelting slag site can influence the mobility and geochemical fraction of heavy metals.

Materials and methods

Slags were collected from the areas planted with vegetation (Arundo donax, Broussonetia papyrifera, Robinia pseudoacacia, and Cryptomeria fortunei) and a bare area in a zinc smelting waste slag site using an indigenous method. Physicochemical properties were determined with the usual procedures. The geochemical fraction and bioavailability of heavy metals was determined using the three-step modified European Community Bureau of Reference (BCR) sequential extraction and diethylene triamine pentaacetic acid (DTPA) sequential extraction schemes. Heavy metal concentrations (Cu, Pb, Zn, and Cd) in the slag and plant samples were also measured.

Results and discussion

Vegetation planted directly in the zinc smelting waste slag significantly enhanced the nutrient accumulation and reduced the bioavailability of heavy metals (Cu, Zn, and Cd) with the exception of A. donax for Zn and Cd. The presence of four woody plants increased the bioavailability of Pb. Sequential extraction revealed that revegetation reduced the acid-soluble extractable fraction and increased the fraction of heavy metals associated with the Fe/Mn oxy(hydr)oxides or organic matter. This is attributed to the establishment of plant-enhanced weathering of minerals in the waste slag that resulted in the formation of an amount of dissolved metals, and the amount of dissolved metals was partly redistributed into the soluble extractable fraction of the zinc smelting waste slag. The final concentration of metals (Cu, Pb, Zn, and Cd) in the soluble extractable fraction is dependent on the dynamics of metals induced by root activity in the rhizosphere. Much lower levels of heavy metals with lower translocation factors accumulated in the four woody plants than in the associated slags.

Conclusions

We conclude that the studied four woody plants showed a beneficial vegetation cover and phytostabilization potential within 5 years of revegetation. These woody plants have the potential for high heavy metal tolerance and low heavy metal accumulation. Therefore, these woody plants could be used for revegetation and phytostabilization of zinc smelting slag sites under field conditions.

  相似文献   

7.
Advances in fungal-assisted phytoremediation of heavy metals: A review   总被引:1,自引:0,他引:1  
Trace metals such as manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) are essential for many biological processes in plant life cycles. However, in excess, they can be toxic and disrupt plant growth processes, which is economically undesirable for crop production. For this reason, processes such as homeostasis and transport control of these trace metals are of constant interest to scientists studying heavily contaminated habitats. Phytoremediation is a promising cleanup technology for soils polluted with heavy metals. However, this technique has some disadvantages, such as the slow growth rate of metal-accumulating plant species, low bioavailability of heavy metals, and long duration of remediation. Microbial-assisted phytoremediation is a promising strategy for hyperaccumulating, detoxifying, or remediating soil contaminants. Arbuscular mycorrhizal fungi (AMF) are found in association with almost all plants, contributing to their healthy performance and providing resistance against environmental stresses. They colonize plant roots and extend their hyphae to the rhizosphere region, assisting in mineral nutrient uptake and regulation of heavy metal acquisition. Endophytic fungi exist in every healthy plant tissue and provide enormous services to their host plants, including growth enhancement by nutrient acquisition, detoxification of heavy metals, secondary metabolite regulation, and enhancement of abiotic/biotic stress tolerance. The aim of the present work is to review the recent literature regarding the role of AMF and endophytic fungi in plant heavy metal tolerance in terms of its regulation in highly contaminated conditions.  相似文献   

8.
The transformation of technogenic compounds of nickel, copper, zinc, and lead entering the soil as nitrates and oxides has been studied in a model experiment. It has been shown that the results of the determination of the fractional composition of the heavy metals strongly depend on the fractionating method used. The fractional composition of heavy metals that entered the soil as the readily soluble compounds mainly depends on the affinity of ions with the reaction centers of the soil components. When soils are polluted by such weakly soluble compounds of heavy metals as oxides, their transformation and, consequently, the fractional composition formed are determined, in the first place, by the solubility of these compounds and only afterwards by the interaction of the products of the dissolution with the soil. The transformation of the technogenictechnogenic zinc and lead oxides in the soils is more complete than that of copper and nickel oxides. This leads to a strong increase in the portion of the residual fraction of these elements under fractionating. The 1 N nitric acid almost does not extract copper and nickel oxides from the soil. This can be a reason for the erroneous estimation of the extent of soil pollution.  相似文献   

9.
Four types of tree leaves were investigated (olive, fig, oak, and carob). The tree leaf samples, washed and unwashed, were analyzed for lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) by atomic absorption spectrophotometry. Variable levels were found in these plants. In addition, all heavy‐metal concentrations of the samples were significantly higher than their counterparts of the control, indicating heavy‐metal pollution was taking place. Very high correlations were found between heavy metals in the same plant, between different plants, and between plants and soil, indicating common sources of heavy metals, possibly soil and soil pollution sources such as traffic. The accuracy of the analytical method used for heavy metals was checked by analysis of standard reference materials, rye grass (CRM 281) and spinach leaf (SRM 1570a). The percentages of recovery of both reference materials for Cd, Cu, Pb, and Zn were better than 93%.  相似文献   

10.
Abstract

Distribution and availability of heavy metals to plants is important when assessing the environmental quality of an area. The objectives of this study, conducted in 1992–1993, were: a) to determine the levels of the heavy metals, cadmium (Cd), chromium (Cr), copper(Cu), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn), in the soils of the Axios Delta (a Ramsar wetland site in Northern Greece) so that the degree of pollution could be ascertained, b) to identify the various heavy metal forms present in soils using a fractionation scheme based on sequential extraction, and c) to find possible dependence on soil physicochemical properties. Total heavy metal content of the soils studied was generally higher than the levels reported in the literature for similar soils, suggesting some degree of pollution with heavy metals. The exchangeable forms of the heavy metals, however, were very low indicating that under present conditions, the availability of the heavy metals to plants is at a minimum. Most of the heavy metals occurred in forms that are considered immobile constituents of inorganic minerals or carbonate compounds. Only Cu and Zn were present in appreciable quantities as organically‐based forms that can become potentially available under certain conditions. Spatial distribution of Zn and Cu was related to the organic matter distribution, and there were indications suggesting that the immobile fraction of the heavy metals was adsorbed on to Mn‐oxides.  相似文献   

11.
Abstract

The purpose of this study was to examine the long‐term effect of compost application on the heavy metal content in soil, leaves, and fruit of grape (Vitis vinifera). Two types of compost were tested in a vineyard. One was compost with a low heavy metal content, which was derived from sewage sludge and bark (SB compost). The other type was compost with a higher concentration of metals, which was derived from municipal solid waste (MSW compost). For 6 years, the levels of zinc (Zn), copper (Cu), nickel (Ni), lead (Pb), cadmium (Cd), and chromium (Cr) in their total (aqua regia digestion), EDTA‐extractable, and DTPA‐extractable forms were monitored in soil, leaves, musts, and wines. The resulting data clearly demonstrate that SB compost did not cause any significant increase in heavy metal levels in the soil and the plants. Thus, this type of compost can be used for soil fertilization with no danger either to the environment or to crops. In contrast, the use of MSW compost caused a significant accumulation of Ni, Pb, Cd, and Cr in the soil, in vegetation, and in musts. Skin‐contact fermentation dramatically decreased the heavy metal content of the wines. The concentration of heavy metals in plant tissues was found to be positively correlated with the DTPA‐extractable form of the metals in the soil, but not correlated with the total or the EDTA‐extractable forms.  相似文献   

12.
香薷植物修复铜污染土壤的研究进展   总被引:11,自引:0,他引:11  
土壤铜污染有自然来源和人为来源。铜污染土壤中有机质、Fe/Al氧化物对铜的专性吸附,是影响土壤中铜生物有效性的主要因素。近年来,我国原生植物修复材料如海州香薷、鸭跖草、酸模、紫花香薷在国内铜污染土壤的研究中得到广泛应用。其中.采用海州香薷开展铜污染土壤植物修复机理和修复技术的研究,已从实验室水培、盆栽试验的生长反应特性、耐及解铜毒的生理生化反应,进展到室外大田修复的示范工程及技术推广阶段。紫花香薷在重金属复合污染土壤上,也有修复前景。开展植物修复材料的产后处置研究,综合利用和深加工,增大植物修复材料价值,对加强植物修复工程的示范和推广步伐,有重要意义。  相似文献   

13.
Soil development and heavy metal contents of a street sweepings dump Soils from an unsealed street sweepings dump of the city of Kiel are inhomogeneous in their properties and in their distribution pattern. The deposited material is contaminated with copper, zinc, lead, and at lower concentrations with cadmium. The high pH-values lead to predominating immobility of heavy metals. However, heavy metals bonded in organic complexes are liable to be leached into the underground because of a high portion of large pores in these soils. Since there are only few other possible bonding mechanisms than organics, after the leaching of lime, pH decline, and mineralization of organic matter mobilization of heavy metals may be predicted. Thus, in the unsealed dump a danger of groundwater pollution with heavy metals remains. The site should be treated accordingly permanently after closing.  相似文献   

14.
长期集约化耕作导致中国设施土壤重金属累积和面源污染风险增加的状况已引起广泛关注。该研究总结了中国设施土壤重金属累积状况及其来源,发现长期盲目投入肥料及农药是引发设施菜田土壤重金属累积问题的主要原因。目前,设施土壤重金属累积呈现出广泛性和中轻度污染特征,其中镉是主要的污染元素。遵循面源污染治理中“源头预控-过程阻断-末端修复”原则,基于国内外文献综述,该文总结归纳出适用于设施土壤重金属累积特征与污染的联合阻控技术及作用机制。首先在灌溉和肥药投入等源头环节减少重金属输入;其次在作物种植过程中,通过选用重金属低积累特性的蔬菜种类或品种,结合水肥一体化施用大分子有机水溶性肥料或叶面喷施具有阻控重金属作用的营养型阻控剂,抑制作物吸收重金属;最后在末端修复环节,利用具有多元功能的土壤改良剂或微生物菌剂进行土壤钝化修复,或采用具有超重金属富集能力且能提高设施土壤生物多样性的植物作为填闲作物,实现生物修复的目标。该联合阻控技术的原则在于协同考虑污染防治、土壤改良、减肥增效等农学和环境目标,集成土壤修复与改良、水肥一体化、填闲作物栽培等技术,并兼顾设施土壤重金属污染修复工程所面临的投入品成本较高、经济效益不明显、缺失可持续改良导致效果不稳定等问题,优推能够钝化重金属并改良土壤的多功能土壤改良剂以及具有阻控重金属吸收、提高作物抗逆性的多功能有机水溶性肥料。上述措施能解决设施土壤普遍存在的重金属累积问题,提升土壤的安全生产能力,可为设施农业可持续发展提供更有效的技术支撑。  相似文献   

15.
秸秆还田是我国培肥地力和增加农田土壤碳固定的重要措施,但进入农田的秸秆存在着活化土壤重金属的风险。为了解不同来源的秸秆对污染水平不同农田土壤重金属活性的影响,采取相应措施防止因秸秆还田对农田土壤重金属的激活,开展了盆栽和田间小区试验研究秸秆还田配施石灰对水田土壤铜、锌、镉、铅活性的影响。盆栽和田间试验在轻度和重度污染2种土壤上同时进行。盆栽试验中施用秸秆包括重污染水稻秸秆、轻污染水稻秸秆和轻污染油菜秸秆3种,石灰用量设对照(0 kg·hm-2)和石灰处理(750 kg·hm-2)2个处理;田间小区试验设对照(不施秸秆和石灰)、秸秆还田及秸秆还田+石灰3个处理。动态观察了试验过程中土壤有效态重金属、重金属形态及水稻籽粒中重金属积累情况。结果表明,试验初期(前20 d)秸秆还田显著增加了水田土壤中水溶性有机碳与水溶性重金属的含量;与对照处理比较,水溶性重金属含量以重度污染土壤增幅较为明显。试验后期(60 d后)秸秆还田对土壤重金属的活性的影响逐渐变得不明显。油菜秸秆还田土壤中水溶性重金属含量低于水稻秸秆还田,重污染水稻秸秆还田土壤中水溶性重金属含量高于低污染水稻秸秆还田。盆栽试验和田间试验的结果都表明,重污染水稻秸秆还田可轻微增加水稻籽粒中镉的积累,但轻度污染水稻秸秆还田与油菜秸秆还田对水稻籽粒镉积累的影响较小;3种秸秆还田对水稻籽粒铅、铜、锌积累的影响不明显。配施石灰可显著降低土壤中水溶性重金属的含量,降低水稻籽粒中重金属的积累。研究认为,在污染农田管理上应控制重污染水稻秸秆还田,在秸秆还田的同时适量配施石灰。  相似文献   

16.
The accumulation of heavy metals in soils and crops by practical sewage sludge application An accumulation of cadmium, lead, zinc and copper was found in some soils and crops after sewage sludge application as compared with same soils and plants not fertilized with sewage sludge. In the soils the heavy metals mainly were accumulated in the Ap-horizons. The displacement into subsoils was small, in spite of the good permeability of the sandy soils investigated. Relatively the mobility of zinc and cadmium in soils was most distinct. Within the plants the accumulation of the heavy metals was strongest in the roots, however also evident in the shoots of rye, barley and oats. Zinc and copper was concentrated in the grains, too. On the meadow-land an accumulation of the elements investigated was found in the blades of rye grass (Lolium perenne L.).  相似文献   

17.

Purpose

This work studies the implications of different traffic patterns for heavy metal and solid pollution generation processes following rainfall events with contrasting antecedent meteorological conditions, at a periurban catchment. The aim is to provide information on the pollution processes and their potential environmental impacts for urban areas.

Materials and methods

Seven campaigns were performed covering winter, spring, and summer conditions, for rainfall events with different antecedent conditions. Four types of roads were monitored: low traffic, average traffic, heavy traffic with demanding driving situations (break and turning), and heavy traffic with high vehicle speed (motorway profile). Samples were taken at the beginning, middle and end of the events to measure within event variation in concentration. Analytical standard procedures were used to quantify pH, conductivity, turbidity, total solids, volatile solids, suspended solids, volatile suspended solids and heavy metals (Cd, Cu, Pb and Zn) in the total and dissolved forms (as to infer the particulate fraction), namely copper, zinc, cadmium and lead.

Results and discussion

The collected data show a direct relation among the number of vehicles and/or the driving manoeuvres performed by them and the amount of solids and heavy metals present in the wash out overland flow collected. An important fraction of the heavy metals is washed off in the particulate form, which represents an increased problem since the road overland flow is directed to green/brown areas and for the local aquatic ecosystems. Maximum copper values recorded exceed 0.6 mh L?1, zinc exceeds 5 mg L?1, lead 0.1 mg L?1 and cadmium 0.01 mg L?1. Values are higher after long dry spells and reduce concentration throughout the rainfall events.

Conclusions

An important part of the heavy metals (with relevance for zinc and lead) are washed off in the particulate form, pollutants are typically related to the amount of traffic, and especially to the existence of driving manoeuvres. The summer events show the highest values, due to the accumulation of pollutants during the long dry spells.
  相似文献   

18.
重金属铜和锌胁迫下的小麦冠层反射光谱特征   总被引:2,自引:0,他引:2  
目前关于土壤重金属污染对作物的光谱影响仍然处于探索阶段,受植物种类和环境等因素的影响,植物重金属胁迫机理的诊断仍存在不明确的问题,作物不同生长阶段对不同重金属的耐受程度存在差异。为了探究快速监测作物受重金属污染胁迫状况,采用田间小区试验,利用光谱分析方法研究了土壤重金属不同质量分数铜(0、100、300、600、900 mg/kg)和锌(0、250、500、750、1 000 mg/kg)处理下小麦分蘖期、拔节期和抽穗期冠层光谱特征。结果表明,小麦在分蘖期和拔节期冠层光谱在可见光(350~760 nm)波段内反射率总体随着铜、锌污染浓度的增加而升高,而在近红外(760~900 nm)波段内反射率随铜、锌处理浓度的增加而降低;分蘖期不同浓度铜、锌处理下,小麦冠层光谱出现红边蓝移和红谷蓝移现象;分蘖期铜处理在600、900 mg/kg和拔节期铜处理在900 mg/kg下小麦红边归一化指数值(NDVI705)均低于0.2;分蘖期锌处理在750和1 000 mg/kg下小麦红边归一化指数值(NDVI705)均低于0.2;该试验中引起小麦受到胁迫作用冠层光谱响应的铜临界浓度介于300与600 mg/kg之间,而锌临界浓度介于500与700 mg/kg之间。  相似文献   

19.
哈尔滨市城市土壤重金属生态风险评价   总被引:9,自引:0,他引:9  
孟昭虹  周嘉  郑元福 《水土保持研究》2009,16(2):152-155,159
研究哈尔滨城市土壤中Cd、Pb、Cr、Cu和Zn含量与分布特征,采用Hakanson潜在生态危害指数法对土壤重金属污染环境质量和潜在生态风险进行评价.结果表明:哈尔滨城市土壤5种重金属含量与松辽平原土壤背景值相比有较大积累,污染源的空间差异性引起不同功能区土壤重金属含量不同.土壤表层5种重金属污染程度:工业区>交通区>郊区耕地区>植物园区,潜在生态风险系数在工业区和交通区为中度危害,在郊区耕地区和植物园区为低度危害.最后,对土壤重金属污染来源进行综合分析,提出相应的管理防治对策.  相似文献   

20.
Levels of heavy metals (chromium, copper, lead and cadmium) in water and sediments of the lower Salado River (Argentina) are presented and compared to Canadian and Argentinian environmental standards. Measurement of metal levels was performed using atomic absorption spectroscopy. In order to interpret analytical results, one way ANOVA, hierarchical cluster analysis and correlations were used. Geoaccumulation Index was used as a measure of metal pollution in sediments. There were differences between the accumulation of metals in sediments and water and the control sampling site. Heavy metals, especially chromium, copper and lead, appear to be an important problem to these freshwater environments.  相似文献   

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