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Particulate samples taken from both the indoor (working) and outdoor (community) environments contain a wide range of metallic trace elements most of which are mutagenic in at least one of the short term tests for genotoxicity currently in use. Because of the demonstrated presence of a short lived biologically active species (Cr(VI)), and the uncertainty with which the results of the screening of metallic compounds in short term tests can be interpreted in terms of human risk, great care must be taken to assure the appropriate collection, storage, and chemical and biological assay of such material. The sensitivity of the results for fly ash and welding fumes to variations in these protocols is demonstrated and discussed. 相似文献
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An oil spill polluted site at Ogbodo-Isiokpo in Ikwere Local Government Area of Rivers State in southern Nigeria, was identified
for study following three successive reconnaissance surveys of oil fields in the Agbada west plain of Eastern Niger Delta.
A sampling area of 200 m × 200 m was delimited at the oil spill impacted site using the grid technique and soils were collected
at surface (0–15 cm) and subsurface (15–30 cm) depths from three replicate quadrats. A geographically similar, unaffected
area, located 50 m adjacent to the polluted site, was chosen as a control (reference) site. Total extractable hydrocarbon
contents of the polluted soils ranged from 3.02–4.54 and 1.60–4.20 mg/kg (no overlap in standard errors) at surface and subsurface
depths respectively. The concentrations of two “diagnostic” trace heavy metals, nickel (Ni) and vanadium (V), which are normal
constituents of crude oil, were also determined in the soils by atomic absorption spectrophotometric method after pre-extraction
of cations with dithionite–citrate carbonate. Ni varied from 0.15 to 1.65 mg/kg in the polluted plots and from 0.18 to 0.82
mg/kg in the unpolluted plots; vanadium varied from 0.19 to 0.70 mg/kg in the polluted plots and from 0.14 to 0.38 mg/kg in
the unpolluted plots. Ni and V were more enhanced (p < 0.05) in the oil-polluted soils, especially at subsurface depth. Whilst the oil spillage could be said to be indirectly
responsible for the enhanced concentrations of nickel and vanadium via the injection and availability of the petroleum hydrocarbons
that might have increased the activities of biodegradation on site, the physico-chemical properties of the soils and inherent
mobility of metals, as well as the intense rainfall and flooding that characterized the period of study, may have also contributed,
at least in part, to these enhanced concentrations. Such levels of Ni and V may result to enhanced absorption by plants, which
may bring about possible bioaccumulation in such plants and the animals that depend on them for survival and all of these
may lead to toxic reactions along the food chain. 相似文献
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悬浮液进样石墨炉原子吸收法直接测定土壤、底泥中的铅、镓、钴、镍 总被引:1,自引:0,他引:1
介绍一种悬浮液进样直接测定土壤、底泥中多种微量金属元素的快速分析方法。基体改进剂的使用,适宜的原子化温度的选择,使用水相标准溶液作校准曲线成为可能.对标准作品的测定证明了此方法的精密度和准确度较好,适合于常规环境样品分析. 相似文献
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将丁二酮肟分光光度法应用于硝酸镍生产废水中镍的测定,以过硫酸铵作氧化剂,丁二酮肟为显色剂,在波长465nm处测定硝酸镍生产废水中的镍. 相似文献
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We quantified the contents of four toxic metals in cosmetic products that are commercially available in Jordan; 112 cosmetics, representing 10 product types, were tested in triplicate after acid digestion using inductively coupled plasma optical emission spectrometry and a mercury analyzer. Ni was most abundant, detected in 104/112 (92.8%) products (average, 2.32 ppm; and median, 1.47 ppm); 66/112 (59%) contained >1 ppm and 13/112 (11.6%), >5 ppm Ni. Cd was second-most abundant, detected in 86/112 (76.7%) products (mean, 1.71 ppm; range from< detection limit [DL] to 18.07 ppm); 16 products (14.3%) exceeded the 3 ppm suggested limit. Pb was detected in 82/112 (73.2%) products (mean, 7.8 ppm; range, < detection limit to 190.43 ppm); 20/112 (17.8%) contained more than the suggested 10 ppm limit. Hg was least-frequently detected, present in 29/112 (25.9%) and at >3 ppm in 15/112 (13.4%) products. The highest content of Hg was observed in skin lightening creams (mean concentration, 1,008 ppm). Hg was detected in 20 (62.5%) of the 32 skin lightening creams tested, of which 11/32 (34.4%) contained > 3 ppm Hg. Of the 112 cosmetics tested, 17 (15.1%) products contained Ni, Pb, Cd, and Hg; 19/112 (16.9%) contained Cd, Pb, and Hg –no product exceeded the maximum acceptable limits for all three elements, and 9/112 (8%) products exceed the maximum recommended levels for at least two elements (Hg, Cd, and Pb). 相似文献
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采用二次酸浸出的方法回收镍钴湿法冶金工业污泥中的有价金属。先采用水和硫酸作为浸出剂浸出Mg和Na,最佳工艺条件为浸出液的pH 7.5、浸出时间5 min、浸出剂体积与干污泥质量的比(ω)为10 mL/g。再采用硫酸作为浸出剂、焦亚硫酸钠作为还原剂进行二次酸浸,在硫酸与污泥质量比为1.3、焦亚硫酸钠与污泥质量比为0.3、ω为5 mL/g、浸出温度85℃、浸出时间20 min的最佳工艺条件下,Co、Ni、Cu、Mn和Zn的浸出率分别达92.45%、93.48%、89.52%、97.78%和94.79%。经XRD表征,浸出后污泥中未见原污泥中的矿物相,说明原污泥中的矿物几乎全部被溶解。 相似文献