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1.
畜禽粪便中的重金属含量及其生物有效性是限制其农业利用的重要因素。采用好气模拟培养方法对6种畜禽粪便好氧堆肥过程中Pb、Cd、Cu、Zn的总量以及生物有效性动态变化进行研究探讨,并分析了影响重金属生物有效性的因素。结果表明,根据现有的国际以及我国农用污泥农用标准,某些粪便中存在着Cd、Cu、Zn含量超标,由于饲料受重金属污染的不同,造成不同畜禽粪便中不同的重金属含量差异性较大。堆肥过程中,由于挥发性物质的挥发作用,4种重金属含量均呈现增加现象,尤其是在0~14 d的堆肥中增加量最高;而生物有效性重金属占其全量重金属的比例呈现先增加而后下降的趋势,除仔猪粪外,堆肥均能降低重金属生物有效性部分的比例,这将有利于降低其农业利用的风险。温度和水溶性碳对堆肥过程中4种重金属的生物有效性部分重金属相对含量的变化有着显著的影响。  相似文献   

2.
Spinach grown in cadmium (Cd)-contaminated soils accumulates Cd compounds in toxic concentration contaminating the food chain leading to the chronic toxic effects on human and animal health. A study was conducted in a Cd-contaminated soil to examine the ameliorative effect of lime and organic manure on the mobility of Cd and its uptake in spinach. Application of lime or organic manure or both decreased the Cd concentration in soil and shoots and increased chlorophyll content of leaves. As compared to the control treatment, combined application of lime and organic manure decreased the level of Cd in soil by 54.7%, in spinach shoot by 61.3%, and the transfer factor of Cd by 35.0% and increased in leaf chlorophyll content by 29.4%. Combined application of lime and organic manure emerged as a viable option in reducing the mobility of Cd in contaminated soil for growing spinach.  相似文献   

3.
对长期电池废水灌溉的新乡市寺庄顶污灌区和对照区土壤重金属进行取样分析,结果表明,对照区土壤中Cd,Ni,Zn,Cu和Cr含量都能达标,污灌区土壤中Cr含量能达标,Cd,Ni,Zn和Cu的含量超标,其平均含量分别为65.31,1 196.64,2 799.25,145.78 mg/kg,是国家土壤环境质量二级标准的108.85,19.94,9.33和1.46倍。形态分析结果表明,污灌区污染最严重的Cd主要以铁-锰氧化物结合态存在,所占比例平均为56.84%;Ni主要以铁-锰氧化物结合态和残余态存在,所占比例平均为37.44%和39.55%;Zn主要以残余态存在,所占比例平均为78.24%;Cu主要以有机结合态存在,所占比例平均为57.70%;Cr主要以有机结合态和残余态存在,所占比例平均为45.55%和34.18%。与对照相比,污灌降低了Cd,Ni,Zn,Cu和Cr残余态所占比例,提高了重金属迁移能力和生物有效性。在4种超标重金属中Cd可交换态所占比例最高,平均为24.54%,由于其生物有效性最高,Cd迁移能力和植物毒性最值得关注。  相似文献   

4.
粪肥添加明矾对降低农田磷和重金属流失的作用   总被引:1,自引:0,他引:1  
施用粪肥引起农田氮、磷流失的增加已引起人们广泛的关注。为了解粪肥中添加明矾可否降低农田污染物的流失,采用化学分析与田间试验相结合的方法研究了添加明矾对粪肥中水溶性养分和重金属浓度及施粪肥后农田养分、重金属流失的影响。结果表明,粪肥中添加明矾可大大降低其中的水溶性P和重金属浓度,其中水溶性P的下降幅度达79.3%。添加明矾后,粪肥施入农田形成的径流中P和重金属浓度明显低于不添加明矾的处理。但添加明矾对农田可溶性总N、NO3-N和NH4-N流失的影响不大。粪肥中添加明矾不会引起地表径流中铝浓度明显增加,对蔬菜产量影响不明显。  相似文献   

5.
畜禽固废沼肥中重金属来源及其生物有效性研究进展   总被引:6,自引:2,他引:6  
陈苗  崔岩山 《土壤通报》2012,(1):249-256
畜禽养殖业的规模化快速发展给环境带来大量的畜禽固废,通过沼气工程,不仅可以得到沼气这一能源,其发酵产物-沼肥还可以作为有机肥施用于农田,这一模式,被我国众多的规模畜禽养殖场采用。然而,由于畜禽粪便中重金属含量的不断增加,沼渣、沼液中的重金属含量及其施入土壤中的生物有效性逐渐受到人们的关注。本文将从畜禽固废沼渣、沼液中重金属的主要来源、含量、生物有效性及其可能的风险等方面进行论述,以期为深入研究沼肥的使用安全提供借鉴,并为合理利用沼肥,采取相关措施降低生态危险提供依据。  相似文献   

6.
A hydroponic culture was used to study different nitrogen and calcium supply patterns on biomass, nutritive, and safety quality of spinach seven days before harvesting. The results showed that the complete or partial withdrawal of nitrogen (N) and calcium (Ca) nutrient decreased spinach biomass compared to control (CK). At the same time, the withdrawal of N and Ca supply before harvesting increased vitamin C contents and decreased nitrate and oxalate content in edible parts of spinach. The decrease in spinach biomass could be partially compensated by the increase of the nutritive and safety quality of spinach and the reduced use of N and Ca nutrients.  相似文献   

7.
巢湖表层沉积物重金属的分布特征及生物有效性   总被引:2,自引:0,他引:2  
为分析沉积物中重金属的分布特征、相互关系及其可能来源,以安徽巢湖表层沉积物为研究对象,利用原子吸收分光光度法(AAS)测定5种重金属(铅、铜、镍、锌、镉)总量和同步浸提重金属(SEM)含量,同时测定酸可挥发性硫化物、总氮、总磷、总有机碳等多种指标,利用低影响程度(ER-L)和中影响程度(ER-M)基准值,[∑SEM]/[AVS]模型和[∑SEM]-[AVS]模型,判断预测表层沉积物中重金属的生物有效性。结果显示:重金属总量在全湖的空间分布不均匀,具有入湖口大于湖心的特征,共8个指标超过ER-L基准值,西湖区各金属总量大于东湖区,两者之间具有显著性差异(P<0.05),全湖[∑SEM]/[AVS]的值在1.097~2.076之间,但[∑SEM]-[AVS]的变化范围为0.127~0.996μmol/g;表明重金属Cu、Cd污染较严重,人为输入影响大,AVS对重金属的束缚作用有重要影响,大部分表层沉积物中的重金属生物有效性低。  相似文献   

8.
采用BCR(community bureau of reference)连续提取法对大宝山矿山槽对坑尾矿库尾砂和周边农田土壤重金属Cd、Pb、Cu和Zn的形态分布及其生物有效性进行了分析。结果表明,尾砂中Cd、Pb、Cu和Zn残渣态占绝对优势,占其总量的百分数均在85%以上。农田土壤中Cd、Cu和Zn都以残渣态为主,分别占其总量的60%、60%和90%以上,Pb以残渣态和可还原态为主,占其总量的93.44%。农田土壤重金属有效性较尾砂大,尾砂和农田土壤重金属生物有效性均以Pb为最高。  相似文献   

9.
ABSTRACT

Investigating available nutrients and non-essential elements in manures is important for safe management of animal and plant waste. Therefore, this study was carried out to chemically characterize cow manure (CM) and poultry manure (PM) after co-composting with privet and cypress residues. Results showed that heavy metals concentrations in manures varied as Fe > Zn > Mn > Cu > Ni > Pb > Cd. Addition of privet and cypress residues to both manures altered the extractability of heavy metals after composting. Higher concentrations of heavy metals were observed in manures at 1:0 ratio while lowest was noted in both CM and PM composted with plant residues at 1:2 ratio. Total K, Ca, and Mg significantly increased when CM and PM were co-composted with privet and cypress residues. There was an increase in the P content in co-composted CM with privet residual application whereas a reduction in total P was noticed with the addition of cypress plant residues in both manures. Manures amended with plant waste reduced N content. Both CM and PM retained higher NO3 content without plant residues.  相似文献   

10.
以猪粪和秸秆为主要试验材料,添加不同浓度重金属Zn,采取发酵罐处理方法,在好氧高温条件下研究了重金属Zn对猪粪堆肥过程中多酚氧化酶、脱氢酶活性的变化,以及堆腐过程堆体温度、堆料pH值、胡敏酸E4/E6值的变化。结果表明:(1)低量重金属Zn处理(L)较不添加重金属Zn(CK)和添加高量重金属Zn(H)堆料升温快、温度高、高温持续时间长。(2)重金属Zn的加入对堆料的pH值影响不大,不是影响堆肥进程的直接原因。(3)H处理在整个堆肥过程中E4/E6值均高于L和CK,表明高浓度Zn处理抑制腐殖质的缩合和芳构化。(4)L处理的多酚氧化酶活性大多数时间高于H处理的活性,说明低量重金属Zn更好地促进了木质素的降解及其产物的转化。(5)从整个堆肥过程来看,3个不同处理的脱氢酶活性表现出一定的不稳定性,可能是重金属对脱氢酶活性有抑制作用的同时发生"抗性酶活性"现象。  相似文献   

11.
Effects of conventional and optimized water and nitrogen managements on spinach (Spinacia oleracea L.)growth and soil mineral N (Nmin) residues were compared in an open field experiment in which water balance method and N recommendation with the KNS-system were included. It was shown that the conventional water treatment (seasonal irrigated amount: 175 mm) reduced spinach growth compared to the water balance treatments (seasonal irrigated amount: 80 and 85 mm) at the same N supply level due to N loss through leaching caused by excessive water supply. Although 309 kg N ha-1 was applied in the conventional N treatment, compared to 82 and 66 kg N ha-1 in the optimum N treatments, no significant difference in crop yield was investigated between the N treatments with the same irrigation practice. N uptake in spinach and soil residual Nmin contents were also significantly affected by the irrigation practices. The conventional water supply not only decreased water use efficiency, but also resulted in excessive NO-3-N being leached below the root zone. In order to meet the same target value of N requirement for the next crop, cauliflower, based on the KNS-system, at least extra 50 kg N ha-1 was needed in the conventional water treatments in comparison to the water balance treatment.  相似文献   

12.
[目的]了解北京市五环内绿地表层(0—20cm)土壤重金属(Cu,Cd,Pb和Zn)的形态特征及其生物有效性,为北京市绿地土壤重金属污染防治提供比较可靠的参考依据。[方法]在建成时间为2~400a的绿化区内共采集表层土壤样品151个,运用改进BCR提取法分析样品中重金属的赋存形态,而后通过风险评价编码法(RAC)和次生相与原生相分布比值法(RSP)对重金属生物有效性进行评估。[结果]样品中重金属Cu,Cd,Pb和Zn的含量分别为31.42,0.29,29.89,76.78 mg/kg,Cu,Zn在中部和东北部含量较高,Pb在中部地区含量较高,Cd在西北部、东北部和南部存在少量高值区。Cu,Cd,Pb和Zn形态分布的总体规律均为:残渣态可氧化态弱酸溶态可还原态,稳定态含量均远高于有效态,有效态含量比例表明重金属生物有效性大小顺序为:CdZnCuPb风险评价编码法(RAC)表明,Cd和Zn环境风险程度为低风险,Cu和Pb无环境风险。次生相与原生相分布比值法(RSP)显示,Cu,Cd,Pb和Zn元素RSP值分别为0.06,0.49,0.18,0.13,土壤整体上未受到重金属污染,但是有少部分地区存在被污染现象。[结论]北京市五环内绿地土壤总体上不存在重金属Cu,Cd,Pb和Zn污染,环境风险较低,但应对重金属赋存形态保持关注。  相似文献   

13.
皖南茶园土壤重金属化学形态及其生物有效性   总被引:4,自引:0,他引:4  
以皖南茶园为研究对象,通过Tessier连续提取分级法对茶园土壤重金属(Zn,Cu,Pb,Ni)全量及其化学形态进行了分析,利用活性态重金属占全量之比来评价其生物有效性。结果表明,皖南茶园土壤中Zn,Cu,Pb,Ni含量均未超过国家标准;除Zn外,其他元素均高出背景值,存在较明显的富集现象;土壤中4种重金属在5种形态上表现出不同的分布规律,Zn,Cu,Ni以残渣态为主,分别占总量的72.55%,90.00%和81.79%,而Pb以铁锰氧化物结合态为主,占总量的70.09%;Zn,Cu,Pb,Ni的活性态部分占全量比例分别为5.04%,1.51%,0.97%和0.23%,土壤重金属活性态部分与茶叶中重金属含量之间呈现正相关关系,且皖南茶区的茶叶重金属含量在限量值的安全范围内。  相似文献   

14.
It has been previously indicated that arbuscular mycorrhizal (AM) fungi can enhance the bioremediation abilities of their host plant. Barley (Hordeum vulgare L.) is a crop plant with some unique physiological properties, such as tolerance to salinity. However, its tolerance to other stresses such as heavy metals must be tested. Accordingly, it was hypothesized that barley can be efficiently used to treat heavy metals in symbiotic and non-symbiotic association with AM fungi. In a greenhouse experiment barley plants were inoculated with the AM species Glomus mosseae and grown in a soil polluted with cadmium (Cd), cobalt (Co), and lead (Pb). Relative to Cd and Co, mycorrhizal barley absorbed significantly higher amounts of Pb. AM species also significantly decreased Cd and Co uptake by barley indicating the alleviating effects of G. mosseae on the stress of such heavy metals.  相似文献   

15.
对猪粪有机肥中胶体态重金属的分布进行了定量分析。结果表明,水提取态Cu、Zn、Fe、Mn主要以胶体态存在,Ni、Cr、Cd、As几乎都以可溶态存在。胶体态Cu在0.02~0.2μm胶体中的含量最高,胶体态Zn、Fe、Mn在粒径为1~10μm的大粒径胶体中含量最高。在长期连续施用有机肥引起重金属积累的土壤中,高Cu负荷的小粒径胶体可能会引起深层土壤中重金属积累问题,胶体态有机碳与可溶态有机碳对重金属结合能力的不同可能是导致重金属分布存在差异的重要原因。重金属在不同粒径的分布特征可以为讨论猪粪有机肥中的重金属在环境中的化学行为提供论据。  相似文献   

16.
A hydroponic experiment was conducted to study the effects of fertilization with different nitrate/glycine (Gly) ratios on spinach growth and composition of amino acids. Results showed partly replacing nitrate (NO3?) by Gly supplied both nitrogen and carbon nutrition for spinach. Spinach accumulated the equal biomass. Total nitrogen (N) in plant had a positive relationship with nitrate/Gly ratios in nutrition. There was more than 2-fold increase in N uptake from all glycine to nitrate, and plant nitrate contents increased from 0.97 to 3.13 mg g?1. All of 17 proteogenic amino acids in mature leaves exhibited a similar trend, the content in leaf tissue increased with an increasing ratio of nitrate/Gly, whereas relative change rate differed for each individual amino acid. In principal component analysis (PCA), the first component accounted for 80.5% of the total variance, and the N treatment appeared to be separated by this factor. In self-organizing map (SOM), 17 amino acids were divided into three clusters according to responds to nitrate/Gly ratios.  相似文献   

17.
Abstract

Laboratory experiments were conducted to determine the influence of three types of decomposing fresh organic materials [pig manure (PM), Astagalus sinicus (AS), and Alternanthera philoxeroides (AP)] on dissolution of Fe2O3 and ZnO and also the use of a loamy calcareous soil as an alternative source of iron (Fe) and zinc (Zn). Levels of Fe and Zn concentrations in composting solutions changed with composting time. The maximum levels of solution Fe resulting from the decomposition of the three organic materials were 20, 612, and 348 mg L?1 for PM, AS, and AP, respectively, when the soil was supplied as the Fe source, and 17, 32, and 16 mg L?1 when Fe2O3 was supplied as the Fe source. Corresponding maximum levels of solution Zn were 0.9, 0.7, and 1.3 mg L?1 and 35, 171, and 103 mg L?1 when the soil and ZnO was supplied as the Zn source respectively for the same three organic materials.  相似文献   

18.
Chemical fractionation patterns and plant tissue concentrations were used to assess nickel, copper, zinc, cadmium, and lead phytoavailability to maize in a soil amended with metal salts or poultry manure. A sandy loam was treated with 80–400 mg kg?1 doses of a quinternary mixture of the metal nitrates either directly or as spiked poultry manure. The European Communities Bureau of Reference sequential extraction procedure partitioned the metals among three operationally defined pools in the soil. Metal mobilities were lower in the poultry manure–amended than the metal salt–treated soil, indicating the manure's ability to fix the metals in soil. Pot experiments revealed high metal transferabilities with no apparent phytotoxic symptoms in maize at the doses applied, suggesting some degree of tolerance to the metals. Heavy-metal concentrations in maize increased linearly with metal doses in metal salt–treated soil, but were less phytoavailable in soil amended with poultry manure. Heavy-metal concentrations in maize were reasonably predicted from soil parameters using stepwise multivariate regression models. The findings are useful in the assessment and remediation of heavy metal–contaminated soils.  相似文献   

19.
以北京市大兴区庞各庄镇污水处理厂的堆肥污泥、生污泥和通州区的熟土为对象,探讨污泥混配土淋溶液中相关指标的动态变化.结果表明,生污泥、堆肥污泥和熟土混配后可降低土壤pH值,增加土壤全氮、全磷含量,同时也增加了土壤中重金属As、Cd、Ni、Cu、Ph的含量,生污泥系列淋滤液中Pb对地下水造成污染的可能性最大;堆肥污泥系列淋滤液中给地下水带来污染可能性最大的因子是As.但各处理中重金属的污染程度都很低,基本符合国家第II类地下水水质标准,因此淋滤液中的重金属基本不会对地下水造成污染.  相似文献   

20.
In this study, complexation extractants ammonium bicarbonate diethylene triamine pentaacetic acid (AB-DTPA), diethylene triamine pentaacetic acid (DTPA), and ethylene diamine tetraacetic acid (EDTA) and mild cation-exchange extractants calcium chloride (CaCl2) and ammonium nitrate (NH4NO3) were used to evaluate the bioavailability of soil cadmium (Cd) to cacao in the field. Among the five extractants, the extractable Cd generally followed the order EDTA > DTPA > AB-DTPA > CaCl2 > NH4NO3. Correlation analysis was done between the extractable Cd in soil and total Cd content of cacao tissues (nibs, shells, leaves, and pods). The Cd extracted by CaCl2 and NH4NO3 was significantly (P < 0.05) correlated with some of the tissues but their Pearson correlation coefficients were weak. In contrast, extractants AB-DTPA, DTPA, and EDTA showed stronger, significant correlations to the Cd concentration in all four tissues. Overall, regression analysis demonstrated that AB-DTPA, DTPA, or EDTA can be used to predict bioavailable Cd in soils for cacao. Of these, AB-DTPA and DTPA both showed the strongest correlations compared to EDTA. However, the ease of preparation and the superior shelf-life of DTPA over AB-DPTA make it the preferred reagent for Cd bioavailability extractions from cacao soils and is currently being used to develop cost-effective soil treatments to reduce bioavailable Cd to cacao plants.  相似文献   

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