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Ramos MC 《Journal of environmental management》2006,78(3):209-215
The application of organic wastes to improve soil physical characteristics in mechanized vineyards planted after land levelling is becoming a common practice in Mediterranean areas. It may be useful as an additional source of organic matter and nutrients, but these wastes could also have negative effects due to their metal content. The aim of the study was to evaluate the influence of compost application on soil metal contents in mechanized vineyard soils of the Spanish Mediterranean area, where this practice is repeated every three years. The study was carried out in a ten-year-old vineyard where the main soil type is Typic Calcixerept. Composted cattle manure was applied in alternate rows, at a rate of 40 Mgha(-1) dry-weight. Nine sampling points were located along the slopes of two plots: a levelled plot prepared for mechanization with large soil disturbance movements within the plot, and a plot of undisturbed soil. At each location, soil samples were taken in both treated and untreated soils. Total concentrations (digestion with aqua regia) and the extractable DTPA (Diethylene-triaminepentacetic)-CaCl2-TEA (Triethanolamine) fractions of Cu, Zn and Mn were analyzed in each sample. For Cu and Zn, the initial concentration was higher in the undisturbed plot. In both cases, total Cu and total Zn were positively affected by manure input and the concentration in treated soils was significantly higher than in untreated soil. For Mn, the initial concentration was higher in disturbed soils than in undisturbed ones, and although in both scenarios the concentrations increased with manure, no significant differences were found between treated and untreated soils. The extractable fraction also increased in treated versus untreated soils, although for Cu and Mn the extractable/total metal ratio was similar in treated and untreated soils. After one compost application, total metal contents increased significantly, particularly for Zn. Most of those metals are accumulated in the soil, due to the soil characteristics. 相似文献
214.
An efficient technology to treat heavy metal--lead--contaminated soil by microwave radiation 总被引:1,自引:0,他引:1
Jou CJ 《Journal of environmental management》2006,78(1):1-4
Microwave (MW) technology can be used to vitrify contaminated soil wastes and immobilize heavy metal ions in soils. More than 93% of the Pb(II)-contaminated soil was vitrified to a glass/ceramic formation after 30 min of MW radiation. In a 6-year study, the Pb(II) concentration of the vitrified soil in the leaching test was less than 1.0 mg/l, which is substantially below the USEPA regulatory limit of 5.0 mg/l. 相似文献
215.
大宝山采矿活动对环境的重金属污染调查 总被引:2,自引:0,他引:2
调查了大宝山铁铜多金属矿床固体废弃物-水相互作用对环境的重金属污染,结果表明,矿床固体废弃物导致了水、土壤的重金属污染,污染元素主要有Cd、Cu、Pb、Zn等;重金属元素的水迁移强度由大至小顺序为Cr、Cu、Zn、Ni、Cd、As、Pb、Hg;元素的生物吸收系数由大至小顺序为Cd、Zn、Hg、Ni、Cu、Cr、As、Pb,虽然水稻糙米中的重金属含量未超过国家标准,但Cd、Cr两种元素含量已远远超出了植物中毒量的下限值. 相似文献
216.
UV/TiO2光催化还原Cr(Ⅵ)过程中吸附作用的影响及其消除 总被引:13,自引:1,他引:12
研究了水体中Cr(Ⅵ)离子在UV/TiO2体系中光催化还原过程.结果表明,Cr(Ⅵ)离子UV/TiO2光催化还原过程符合Langmuir-Hinshelwood动力学规律.不存在有机物时,TiO2吸附作用是该反应的前提.pH=1.5~2.5时吸附性能较好,而且pH=1.5~10的初始反应速率同pH值有线性关系.在TiO2表面的竞争吸附能力按PO43->SO42->Cl->NO3-依次减弱.甲酸、甲醛有机物的协同作用可提高Cr(Ⅵ)离子的光催化还原速率和效率,并消除由暗态吸附对反应所起的作用,磷酸根离子极强的竞争吸附能力,使有机物的协同作用减弱. 相似文献
217.
218.
在我国社会经济快速发展的过程中,人们对自然资源需求无度,造成生态环境破坏问题非常严重。通过环境监测可以及时分析空气中有毒有害的物质成分,并且对环境污染问题进行及时有效的解决。但是在监测的过程中所采用大量的空气试剂很容易造成环境二次污染等问题,为此必须要积极加强对环境监测中重金属污染的合理控制,对空气试剂产生的大量废弃物进行及时的回收处理,从而有效避免出现二次污染的情况,充分发挥环境监测的作用。 相似文献
219.
Lei Zheng Xingbao Gao Wei Wang Zifu Li Lingling Zhang Shikun Cheng 《Frontiers of Environmental Science & Engineering》2020,14(1):5
220.
Due to rapid industrialization and urbanization during last two decades, contamination of soils by heavy metals is on an increase globally. Lands under peri-urban agriculture are the worst affected. In NCT, Delhi about 14.4% of land area is chemically degraded. In order to take care of this problem, recently the Supreme Court of India ordered to shift various non-confirming (about 39,000 units) industries to regions outside NCT, Delhi. However in spite of this, there have been several reports and parliamentary debates on the phyto-toxicity and extensive accumulation of heavy metals in the region. Literature review revealed that the basis of these debates is a few studies on some point locations in/around Delhi. It was further observed that information on the distribution and extent of heavy metal pollution problem in the region was completely missing. The present study was thus basically aimed at assessing the spatial distribution/extent and type of heavy metal pollution in the study area, for enabling future designing of appropriate site-specific management measures by the decision makers.For this, detailed spatial information on bio-available heavy metal concentrations in the soils and surface/sub-surface waters of NCT (Delhi) was generated through actual soil/water surveys, standard laboratory methods and GIS techniques. The study showed that concentration of all micronutrients (viz. Zn: 0.05–0.18 ppm; Cu: in traces; Fe: 0–0.5 ppm; and Mn: 0–1.2 ppm) and most heavy metals (viz. Ni: 0–0.7 ppm; Pb: 0–0.15 ppm and Cd: in traces) in the surface/sub-surface irrigation waters were well within permissible limits. However Cr concentrations in irrigation waters of Alipur and Shahdara blocks were far above their maximum permissible limit of 1 ppm. It was further observed that Ni and Cr concentrations in the drinking waters of almost entire test area were far above maximum permissible levels of 0.02 and 0.01 ppm, respectively. Bio-available concentrations of several heavy metals (viz. Pb: 0.1–2 ppm; Cd: traces; Ni: 0.05–2 ppm and Cr: 0–0.4 ppm) in the study area soils were also observed to be well within the maximum permissible limits. However there were point Cu contaminations (5–10 ppm) in the sewage-sludge amended soils of vegetable growing areas near south Shahdara block. This was attributed to increased Cu availability due to oxidized acidic conditions generated by over-irrigation of agricultural lands. Available Mn concentrations in Kanjhawala, western Najafgarh and Alipur soils were also observed to be above maximum permissible limit of 10 ppm. This was observed to be mainly due to the geology (i.e. presence of Mn rich sedimentary rocks) and prevalence of reduced acidic conditions, due to paddy cultivation, in these areas. It was further observed that there is acute zinc (Zn) deficiency (< 0.6 ppm) in paddy growing soils of north Kanjhawala, Alipur and some parts of Najafgarh and Shahdara blocks due to extensive leaching of available Zn fractions to lower soil horizons. Similar available Zn deficiencies in high pH (8.5) soils of areas around Bamnoli village in E-Najafgarh block were also observed. 相似文献