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1.
改良剂对土壤Cu形态转化及其生物可给性的影响   总被引:2,自引:0,他引:2  
通过室内土壤培养实验,研究添加9种不同改良剂(沸石、石灰、磷矿粉、油菜秸秆、堆肥、赤泥、生物调理剂、生物炭和骨炭)对污染土壤Cu化学形态和生物可给性的影响。培养2个月,除堆肥处理外,添加5%的其他8种改良剂均显著地提高了土壤的p H值,提高效果为石灰生物炭赤泥生物调理剂油菜秸秆=骨炭磷矿粉沸石。培养2个月后,添加所有改良剂均显著地降低了土壤中酸可提取态Cu的含量,生物调理剂、生物炭和骨炭处理效果最为显著,分别比对照下降28%、18.1%和33.7%。添加不同的改良剂对土壤Cu的生物可给性也有影响。培养1个月,石灰、生物炭和骨炭处理分别导致土壤中生物可给性Cu含量比对照降低9.8%、10.5%和18.3%;培养2个月,赤泥、生物炭和堆肥处理分别导致生物可给性Cu含量比对照降低13.2%、17.6%和18.6%。研究表明,生物炭和骨炭可作为Cu污染土壤的理想改良剂。  相似文献   

2.
改性沸石对土壤铅、锌赋存形态的影响   总被引:2,自引:0,他引:2  
通过室内土壤培养实验,研究改性沸石对污染土壤中Pb、Zn赋存形态的影响。结果表明,土壤中的Pb主要是以Fe-Mn氧化物结合态存在,土壤Zn主要以残渣态存在。添加天然沸石和改性沸石不同程度地降低土壤酸提取态Pb、Zn的含量,提高土壤残渣态Pb、Zn的含量。与CK处理相比,添加4种沸石导致土壤酸提取态Pb含量降低8.7%~40.3%,土壤酸提取态Zn含量降低10.5%~49.8%(培养1个月)。硝酸钾改性沸石比天然沸石更能显著地降低土壤酸提取态Pb、Zn的含量,而氢氧化钠改性沸石和硝酸钾改性沸石比天然沸石更能显著地降低土壤酸提取态的Zn含量。培养1、2和3月后,不同沸石处理导致土壤残渣态Zn比率分别比CK处理提高14.4%~23.5%、19.6%~23.7%和1.9%~11.1%。研究结果表明,天然沸石经过一定方法改性后,是固定污染土壤Pb、Zn的潜在改良剂。  相似文献   

3.
添加堆肥和赤泥对土壤生物有效性Cd和Zn的影响   总被引:7,自引:0,他引:7  
采用土壤培养实验,研究添加堆肥和赤泥对土壤中Zn和Cd生物有效性的影响。结果表明,单独添加堆肥或赤泥以及赤泥和堆肥一起添加到土壤,均可以降低土壤中的交换态Cd和Zn含量以及生物有效态Zn和Cd含量。与对照相比,培养1~3个月后,单独添加堆肥、单独添加赤泥和同时添加赤泥与堆肥导致土壤交换态Cd含量分别降低14%~18%、33.3%~46.1%和44.2%~57.7%;土壤交换态Zn含量分别降低54.4%~59%、100%和100%;土壤生物有效态Cd含量分别降低11.8%~14.7%、25.1%~33.7%和32.6%~43.9%;土壤生物有效态Zn含量分别降低14.1%~15.8%、59.7%~72.2%和43.2%~58.4%。  相似文献   

4.
通过田间种植小麦实验,研究添加不同剂量拜耳赤泥(0%、1%、2%、3%、4%和5%)对重金属污染的石灰性土壤Pb、Cd化学形态和小麦幼苗根系的影响。培养1个月,添加赤泥显著地提高了土壤p H值,提高幅度随赤泥投加量增加而增大。培养3个月,添加不同剂量的赤泥均明显降低土壤中可交换态Pb和Cd的含量,赤泥投加量为5%时效果最为显著,分别比对照下降90%和72%。添加赤泥对所种植小麦幼苗的根系也有影响。种植5个月,小麦根系总根长、总表面积和总体积等随添加赤泥的剂量增加呈现先增大后减小的趋势,赤泥投加量为3%时增幅最大,总根长、总表面积和总体积分别比对照增加88.23%、75%和90.32%。研究表明,赤泥可作为重金属污染的石灰性土壤的理想改良剂,但考虑到小剂量赤泥(即1%~3%)促进重金属污染农田中小麦根系的生长,建议在种植区采用小剂量赤泥(即3%)处理的重金属污染修复方案。  相似文献   

5.
通过室内土壤培养实验,研究改性沸石对污染土壤中Pb、Zn赋存形态的影响。结果表明,土壤中的Pb主要是以Fe—Mn氧化物结合态存在,土壤zn主要以残渣态存在。添加天然沸石和改性沸石不同程度地降低土壤酸提取态Pb、zn的含量,提高土壤残渣态Pb、zn的含量。与CK处理相比,添加4种沸石导致土壤酸提取态Pb含量降低8.7%-40.3%,土壤酸提取态zn含量降低10.5%-49.8%(培养1个月)。硝酸钾改性沸石比天然沸石更能显著地降低土壤酸提取态Pb、zn的含量,而氢氧化钠改性沸石和硝酸钾改性沸石比天然沸石更能显著地降低土壤酸提取态的zn含量。培养1、2和3月后,不同沸石处理导致土壤残渣态zn比率分别比CK处理提高14.4%~23.5%、19.6%~23.7%和1.9%-11.1%。研究结果表明,天然沸石经过一定方法改性后,是固定污染土壤Pb、zn的潜在改良剂。  相似文献   

6.
采用土壤培养实验,研究了海泡石、钙基膨润土、钠基膨润土、汉白玉和石灰5种矿物材料在3个添加量下对Cd污染土壤p H和CEC、Cd植物有效性、浸出毒性和生物可给性以及Cd形态分布的影响。结果表明:几种矿物材料均可显著提高土壤p H和CEC。与对照相比,添加几种矿物材料后土壤p H提高0.46~1.15个单位,CEC增加5.8%~39.3%,其提高幅度随添加量的增加而增大。添加矿物材料显著降低土壤Cd的植物有效性(DTPA-Cd)、浸出毒性(TCLP-Cd)和生物可给性(SBET-Cd),且DTPA-Cd、TCLP-Cd和SBET-Cd含量的降低比例分别为9.4%~27.5%、6.4%~23.8%和7.7%~20.5%。添加几种矿物材料后,土壤中酸提取态Cd含量显著降低,残渣态Cd含量显著增加,可还原态和可氧化态Cd含量无明显变化。与对照相比,土壤酸提取态Cd含量降低6.2%~31.4%,残渣态Cd含量增加2.8%~9.7%。几种矿物材料中,海泡石和汉白玉对土壤Cd钝化效果相当,且优于其他矿物材料。  相似文献   

7.
重金属污染及生态修复是环境和生态领域研究的热点和难点。皇草是重要的纤维素生物燃料和电力植物。选用皇草作为重金属污染土壤的修复植物,探讨皇草对重金属的耐性机理和对重金属污染土壤的修复效果。结果表明:皇草的株高和干重在Ni、As、Zn、Pb处理中显著高于对照处理或者与对照处理没有显著差异,但在Cr处理中显著低于对照处理。皇草在Ni、As、Zn、Pb和低浓度Cr污染土壤均能生产大量的生物质,每季产25.55~28.51 t·hm~(-2)鲜草和8.23~9.12 t·hm~(-2)干草。皇草叶片中MDA和POD的含量随着Cr、Ni、As和Pb浓度的升高有所增加,但CAT和SOD的活性表现出相反的趋势。在Zn的2个浓度梯度下,皇草叶片中的CAT、POD和SOD的活性均随着Zn浓度升高而下降。从重金属在皇草各器官分布来看,Cr、As和Pb的浓度为根叶茎;Ni和Zn为根茎叶。从重金属在植物叶片中的形态来看,Cr、Ni、Zn和Pb的盐酸提取态的含量较高。从重金属在亚细胞分布来看,Cr、As和Pb在皇草叶片亚细胞组分分布为细胞质细胞壁细胞器,Ni和Zn在皇草叶片亚细胞组分分布为细胞器细胞质细胞壁。皇草对重金属的富集系数和转运系数均小于1,对重金属的提取量较低,但其耐性强、生物量大,适合应用于土壤重金属污染的植物稳定技术。  相似文献   

8.
化学固定是重金属污染土壤修复及改良技术之一。通过盆栽实验,研究了水稻秸秆炭及其与石灰、磷酸盐组合改良剂对石漠化土壤-玉米体系中As、Zn和Pb 3种重金属迁移的影响,分析了玉米及土壤重金属含量、形态变化。结果表明,几种改良剂均显著促进了玉米生长,地上部分生物量:水稻秸秆炭石灰+水稻秸秆炭石灰秸秆磷酸盐+水稻秸秆炭磷酸盐对照。水稻秸秆炭、石灰及其组合均能够提高土壤pH值,抑制重金属向玉米地上部分迁移。添加改良剂后土壤中As的弱酸提取态和可还原态含量显著降低,均小于3 mg·kg~(-1)。水稻秸秆炭、秸秆与石灰及其组合均能够降低土壤中重金属提取态和还原态量,能够降低玉米籽粒中重金属的含量,但玉米籽实中Pb依然超标。  相似文献   

9.
为了探究伊利石与种植模式在重金属污染修复中的应用效果,采用室内盆栽试验,测定了植物的生理生化指标和土壤、植物的重金属含量,评价了不同种植模式下植物对重金属的吸收富集能力。结果表明,添加伊利石可以显著提高土壤pH,枸骨(Ilex cornuta var.fortunei)与绿萝(Epipremnum aureum)间作模式有利于提高土壤的有机质含量,提高枸骨抗逆性。添加1%(质量分数)伊利石后,各处理Pb有效态含量显著低于空白对照,而Zn有效态含量无显著性差异。枸骨与绿萝间作模式下,土壤有效态Zn含量显著高于绿萝单种,而与枸骨单种无显著差异。间作模式下,绿萝地上部Pb含量高于单种107.92%,而地下部Pb较单种显著降低19.69%。因此,枸骨与绿萝间作可显著提高绿萝对Pb的转运能力。  相似文献   

10.
通过3种洗脱方式(TE,EDTA-Na2传统洗脱方式;UE-1,超声波先作用于土壤后再加入EDTA-Na2洗脱;UE-2,超声波强化EDTA-Na2洗脱)对湖南典型矿区周边重金属复合污染农田土壤进行洗脱处理,研究了3种洗脱方式对土壤中Pb和Cd的洗脱效果及洗脱前后土壤中Pb和Cd的形态分布。结果表明:3种洗脱方式均对土壤中Pb和Cd有较好的洗脱效果,其中UE-2对土壤中Pb和Cd洗脱率均大于TE和UE-1;在作用时间为5~480 min时,UE-2对郴州土壤中Pb和Cd的洗脱率分别为43.9%~55.9%和63.6%~74.4%,对衡阳土壤中Pb和Cd的洗脱率分别为63.1%~80.9%和74.7%~86.7%,相对于传统萃取方式(TE),UE-2洗脱方式使土壤中Pb和Cd的洗脱率提高了将近25%;与未洗脱土壤相比,UE-2洗脱方式能显著降低土壤中Pb的Fe-Mn氧化物结合态和残渣态含量,显著降低Cd的残渣态、Fe-Mn氧化物结合态和酸可提取态含量;UE-2洗脱方式能显著降低土壤中Cd的TCLP提取态含量,而使Pb的TCLP提取态含量有所增加。  相似文献   

11.
An international inter-laboratory research program investigated the effectiveness of in situ remediation of soils contaminated by cadmium, lead and zinc, measuring changes in soil and soil solution chemistry, plants and soil microbiota. A common soil, from mine wastes in Jasper County MO, was used. The soil was pH 5.9, had low organic matter (1.2 g kg(-1) C) and total Cd, Pb, and Zn concentrations of 92, 5022, and 18 532 mg kg(-1), respectively. Amendments included lime, phosphorus (P), red mud (RM), cyclonic ashes (CA), biosolids (BIO), and water treatment residuals (WTR). Both soil solution and NH4NO3 extractable metals were decreased by all treatments. Phytotoxicity of metals was reduced, with plants grown in P treatments having the highest yields and lowest metal concentration (0.5, 7.2 and 406 mg kg(-1) Cd, Pb, and Zn). Response of soil micro-organisms was similar to plant responses. Phosphorus addition reduced the physiologically based extraction test Pb from 84% of total Pb extracted in the untreated soil to 34.1%.  相似文献   

12.
We evaluated the effectiveness of lime and red mud (by-product of aluminium manufacturing) to reduce metal availability to Festuca rubra and to allow re-vegetation on a highly contaminated brown-field site. Application of both lime and red mud (at 3 or 5%) increased soil pH and decreased metal availability. Festuca rubra failed to establish in the control plots, but grew to a near complete vegetative cover on the amended plots. The most effective treatment in decreasing grass metal concentrations in the first year was 5% red mud, but by year two all amendments were equally effective. In an additional pot experiment, P application in combination with red mud or lime decreased the Pb concentration, but not total uptake of Pb in Festuca rubra compared to red mud alone. The results show that both red mud and lime can be used to remediate a heavily contaminated acid soil to allow re-vegetation.  相似文献   

13.
通过田间实验,研究了过磷酸钙和石灰混施对重金属污染农田上低累积玉米产量以及籽粒、茎叶重金属含量的影响,并分析了施用过磷酸钙和石灰后土壤pH和有效重金属含量的变化。结果表明,与单施过磷酸钙和单施石灰相比,过磷酸钙和石灰混施更能显著提高玉米生物产量,且过磷酸钙和石灰均有一定的后效。单施石灰处理、石灰与过磷酸钙混施处理都均显著降低玉米籽粒Cd、Zn和Cu含量,其中以中量(0.4 kg/m2)、高量石灰(0.6 kg/m2)+中量过磷酸钙(0.2kg/m2)处理效果最佳,其玉米籽粒Cd、Zn和Cu含量降低到了国家食品卫生标准允许的含量水平。石灰处理均不同程度地提高了玉米籽粒Pb含量,配施过磷酸钙也不能明显降低玉米籽粒Pb含量,但仍低于饲料卫生标准允许的含量水平。另外,单施石灰处理和石灰与过磷酸钙混施处理均显著降低了玉米茎叶Cd、Pb、Zn和Cu含量,可以安全用作有机肥。  相似文献   

14.
Lai HY  Chen ZS 《Chemosphere》2005,60(8):1062-1071
Rainbow pink (Dianthus chinensis), a potential phytoextraction plant, can accumulate high concentrations of Cd from metal-contaminated soils. The soils used in this study were artificially added with different metals including (1) CK: original soil, (2) Cd-treated soil: 10 mg Cd kg(-1), (3) Zn-treated soil: 100 mg Zn kg(-1), (4) Pb-treated soil: 1000 mg Pb kg(-1), (5) Cd-Zn-treated soil: 10 mg Cd kg(-1) and 100 mg Zn kg(-1), (6) Cd-Pb-treated soil: 10 mg Cd kg(-1) and 1000 mg Pb kg(-1), (7) Zn-Pb-treated soil: 100 mg Zn kg(-1) and 1000 mg Pb kg(-1), and (8) Cd-Zn-Pb-treated soil: 10 mg Cd kg(-1), 100 mg Zn kg(-1), and 1000 mg Pb kg(-1). Three concentrations of 2Na-EDTA solutions (0 (control), 2, and 5 mmol kg(-1) soil) were added to the different metals-treated soils to study the influence of applied EDTA on single and combined metals-contaminated soils phytoextraction using rainbow pink. The results showed that the Cd, Zn, Pb, Fe, or Mn concentrations in different metals-treated soil solutions significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). The metal concentrations in different metals-treated soils extracted by deionized water also significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). Because of the high extraction capacity of both 0.005 M DTPA (pH 5.3) and 0.05 M EDTA (pH 7.0), applying EDTA did not significantly increase the Cd, Zn, or Pb concentration in both extracts for most of the treatments. Applying EDTA solutions can significantly increase the Cd and Pb concentrations in the shoots of rainbow pink (p<0.05). However, this was not statistically significant for Zn because of the low Zn concentration added into the contaminated soils. The results from this study indicate that applying 5 mmol EDTA kg(-1) can significantly increase the Cd, Zn, or Pb concentrations both in the soil solution or extracted using deionized water in single or combined metals-contaminated soils, thus increasing the accumulated metals concentrations in rainbow pink shoots. The proposed method worked especially well for Pb (p<0.05). The application of 2 mmol EDTA kg(-1) might too low to enhance the phytoextraction effect when used in silty clay soils.  相似文献   

15.
A contaminated soil was collected in a field adjacent to a derelict As((III)) smelter in Reppel (Bocholt, Belgium). A single soil treatment (% by soil weight) based on either iron grit (SS, 1%), beringite (B, 5%), or iron grit (1%) + beringite (5%) (BSS) was applied. Untreated and treated Reppel soils and a control soil were placed in lysimeters inside a greenhouse and cropped annually. The efficiency of soil treatments in decreasing As and metals in exposure sources and restoring soil functions was assessed 6 years after the treatments commenced. Decreases in extractable Cd, Mn, Zn and As occurred in the BSS soil. Only BSS treatment reduced both As and metal concentrations in leachates. BSS treatment produced best growth of lettuce and cabbage, the highest shoot and pod yields for dwarf bean, the lowest As, Cd and Zn concentrations in plant tissues, and partly restored Rhizobium nodulation on bean roots. The epigeic earthworm (Dendrobaena octaedra) could only survive in the BSS soil. Depurated living worms from the BSS soil had Cd concentration similar to those in control worms, but higher As, Ca, Fe, and Zn concentrations. Based on physiologically based extraction test (PBET), As bioaccessibility was reduced from 12% (untreated soil) to 7.4% (BSS) and 3% (SS), but only the SS treatment decreased the bioaccessibility of Cd (-30%) and Pb (-35%). The range of chemical and biological indicators suggested that BSS amendment was the most effective treatment for restoration of normal soil functions 6 years after initial treatment of the Reppel soil.  相似文献   

16.
Accumulation of Zn, Cu, Pb and Cd was studied in snails fed for 120 days on diets contaminated with each metal separately and with all metals mixed together. The concentrations of Zn in food were in the range 39 to 12 200 mg kg(-1), Cu 9-1640 mg kg(-1), Pb 0.4-12 700 mg kg(-1), and Cd 0.16-146 mg kg(-1) on a dry weight basis. At the highest concentrations of all metals the consumption rates decreased significantly. For the remaining concentrations, Zn and Cu were accumulated in soft tissue in proportion to their concentrations in food. The lowest treatments of Pb and Cd did not cause any increase in soft tissue concentrations of these metals but at average treatments, a clear increase was observed. Copper was accumulated especially efficiently, exceeding concentrations in food throughout the whole range of treatments. Except for the lower end of experimental treatments, Zn was accumulated approximately in direct proportion to its concentration in the diet. Lead was the most efficiently regulated metal, with soft tissue concentrations always substantially lower than in food. Approximately 60% of Zn, 90% of Cu, 43% of Pb and 68% of Cd on average was assimilated from food. The assimilation efficiency of food alone was ca 74%. The concentrations of metals in shells increased significantly with exposure, but (with one exception) the concentrations in shells did not exceed 5% of those found in soft tissue. We argue that snails are more important as agents of food-chain transport of Cu and Cd, than of Zn or Pb. Our results indicate also that snails are not able to deposit significant quantities of metals in their shells, at least during the time scale of our laboratory experiment.  相似文献   

17.
Wu LH  Luo YM  Christie P  Wong MH 《Chemosphere》2003,50(6):819-822
A pot experiment was conducted to study the effects of EDTA and low molecular weight organic acids (LMWOA) on the pH, total organic carbon (TOC) and heavy metals in the soil solution in the rhizosphere of Brassica juncea grown in a paddy soil contaminated with Cu, Zn, Pb and Cd. The results show that EDTA and LMWOA have no effect on the soil solution pH. EDTA addition significantly increased the TOC concentrations in the soil solution. The TOC concentrations in treatments with EDTA were significantly higher than those in treatments with LMWOA. Adding 3 mmol kg(-1) EDTA to the soil markedly increased the total concentrations of Cu, Zn, Pb and Cd in the soil solution. Compared to EDTA, LMWOA had a very small effect on the metal concentrations. Total concentrations in the soil solution followed the sequence: EDTA > citric acid (CA) approximately oxalic acid (OA) approximately malic acid (MA) for Cu and Pb; EDTA > MA > CA approximately OA for Zn; and EDTA > MA > CA > OA for Cd. The labile concentrations of Cu, Zn, Pb and Cd showed similar trends to the total concentrations.  相似文献   

18.
The availability of Cd, Cr, Cu, Ni, Mn, Pb and Zn present in the finest size particles of urban soils is studied by comparing the concentrations in the clay fraction with those extracted from the whole soil by either single-extraction or sequential extraction method. Many metals are preferentially present in the finest particles as compared to coarser fractions. This is true for most metals studied, except Mn and, perhaps, Cd. Those metals present in the clay fraction are often in easily bio-accessible forms, especially Cu, Pb and Zn. The results suggest that bio-accessible forms of these three metals are distributed among the three sequential fractions, and even the fraction considered as ‘residual’ is also bio-accessible to a significant extent. The statistical analysis shows some distinctions among metals that are compared to the ‘urban’, ‘natural’, or intermediate behaviour of the various metals as proposed earlier in the literature.  相似文献   

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