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1.
总氮总磷联合测定方法研究 总被引:2,自引:0,他引:2
介绍总氮、总磷联合测定的一种方法。实验中,调整了消解过程的氧化剂用量和酸度,以含有氮和磷的混合标准溶液配制一系列标准样品,经高温、高压消解后,分别进行比色,测定样品中总氮和总磷。该方法与标准方法相比,大大简化了分别测定总氮、总磷的工作量和时间,测定结果令人满意。 相似文献
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密封消解法测定高氯化物废水的化学需氧量 总被引:5,自引:0,他引:5
开发出测定高氯化物废水COD的密封消解法,该法可排除高浓度氯离子的干扰。通过丁酮氧化率、氯离子干扰、混配水样和实际水样的测定,对密封消解法和重铬酸钾法进行了验证。试验结果表明:在测定高氯离子废水的COD时,密封消解法优于重铬酸钾法,能够真实、准确地测定废水的COD。 相似文献
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用碱性甲醇提取棉籽、棉叶及土壤中残留的盖草能,经溶剂萃取、微型Sea-Pak硅胶柱分离、甲基化反应和酸性氧化铝柱净化后,进行气相色谱(ECD)测定。方法回收率大于80%,最低检出限为0.002ppm。研究了盖草能在棉叶和棉田土壤中残留的消解动态,测定了消解半衰期及棉籽和土壤中的最终残留量。据此,制定了盖草能在棉花上的合理使用准则。 相似文献
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微波消解-流动注射分光光度法测定总氮和总磷 总被引:2,自引:0,他引:2
以碱性过硫酸钾溶液为消解液,采用微波消解-流动注射分光光度法测定水中总氮和总磷。在碱性过硫酸钾溶液中氢氧化钠质量浓度为9.6g/L、微波功率为320W、消解管长度为16m的条件下,总氮和总磷的检出限分别为0.040m g/L和0.020mg/L,线性范围分别为0.040~3.500mg/L和0.020~2.500mg/L,相对标准偏差分别为1.6%和1.0%。微波消解-流动注射分光光度法应用于河水、湖水、化工废水等实际水样中总氮和总磷的测定,加标回收率分别为95.7%~98.1%和97.2%~102.2%。 相似文献
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伴随着我国工业现代化的发展,我国逐步进入塑料废弃物增长的高峰期,而塑料的再生利用成为了当今的热题,由于塑料再生加工过程中产生有毒有害物质,因此对人类和环境构成威胁。以微波消解为前处理方法,对不同批次再生塑料中重金属的含量进行研究,探究出重金属含量最低的可再生塑料。该方法前处理中再生塑料用量少,微波消解完全,适用于再生塑料中有毒有害物质的快速测定。 相似文献
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Lake sediment cores were analyzedto study the history of mercury (Hg) pollution andparticularly to determine whether recent sedimentconcentrations have declined in response todeclining atmospheric deposition of Hg. Sedimentcores from 6 forest lakes distributed fromsouthern to northern Sweden and 3 northernmountain lakes were analyzed for Hg using CVAAS. A400 cm sediment profile from Måkevatten insouthwest Sweden indicates that the onset of Hgpollution occurred in the 18th century. Anindisputable increase in Hg concentrationsoccurred concurrent with the appearance ofspheroidal carbonaceous flyash particles (SCP)derived from fossil-fuel combustion, in themid-19th century. There is a strong correlationbetween Hg and SCP concentrations in the sedimentcores (r=0.67 to 0.91), which suggests a strongrelationship between historical Hg pollution andfossil fuel burning. In contrast to sediment corestaken in 1979, maximum Hg concentrations are nowobserved below the sediment surface and declinetowards the sediment surface. This study confirmsthat reductions in atmospheric deposition of Hgover Sweden have resulted in a decreased transferof total Hg to aquatic environments as reflectedby lake sediments, and that lake sediment profilesof Hg concentrations reflect relative trends inthe atmospheric deposition of Hg rather thanpost-depositional diagenetic processes. 相似文献
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The deposition patterns of Mn, Fe, Cr, Sb, Zn and As wereinterpreted together with enrichment factor calculations. Samples collected around iron-steel plant had very high concentrations and EF values of Mn, Fe, Cr, Sb and Zn implying that these plants are serious pollution sources in the region. High As concentrations around the settlementareas showed that coal combustion is another important anthropogenic source in the region. 相似文献
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The SO4–S and NO3–N concentrations and pH in bulk precipitation, throughfall, stemflow and soil water for the 1994–2004 period were studied
in pine forests in Latvia (Rucava and Taurene Integrated Monitoring stations). The SO4–S and NO3–N concentrations decreased over the study period, simultaneously with a decrease of acidity in precipitation. The changes
were more evident in the western part of Latvia, probably due to declining long-range air pollution from West Europe. The
trend of decreasing sulphate concentrations and increasing pH in precipitation were not followed by respective changes in
soil water. In the upper soil horizon sulphate ion concentrations and acidity increased in soil water. Over the observation
period, nitrate concentrations also showed an increasing trend in soil water at Rucava and Taurene, but these changes were
not statistically significant. 相似文献
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The research concerns the Wielkopolski National Park (West Poland), which suffered a huge human impact in the 1970s and 1980s
owing to the nearby location of an industrial plant. Since then, fundamental technological changes that it introduced into
its production of phosphate fertilizers have radically reduced the amount of pollution emitted. A three-year study (2002–2004)
of fluorides in precipitation in open terrain and under tree crowns showed their concentrations to range from levels below
the detection limit (0.003 mg/l) to 0.560 mg/l. Those registered under tree crowns were several times higher and indicated
substantial dry deposition of fluorides on the trees. The highest values were recorded in 2003, with 43% of samples ranging
from 0.01 to 0.05 mg/l, and with 51% of throughfall ranging from 0.10 to 0.50 mg/l. A strong connection was shown to exist
between fluoride and sulphate concentrations in the precipitation. An analysis was made of the available data on F concentrations
in the air and the dust levels around the factory, but these figures did not show an unequivocal effect on F concentrations
in precipitation. A great similarity was found to occur between the fluoride content in rainwater in the Wielkopolski National
Park and in the centre of the nearby Poznań metropolitan area, which indicates that there are also other F sources besides
the local factory. 相似文献
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Within the European monitoring network (EMEP, ) several different sampling procedures for measuring the main air components have been applied. This has contributed to systematic
concentration differences and a comparability problem. Since 1997 co-located experiments in 15 countries have been carried
out to quantify these differences. In addition, three major measurement campaigns were organized by EMEP between 1985 and
1991. Differences among results depend on the concentration level and methods used. The decrease in SO2 concentrations over the last twenty years has placed greater demands on the methodology. Absorbing solutions methods for
SO2, (H2O2 and tetrachloromercurate (TCM)) typically have higher detection limits than the reference method, which uses KOH impregnated
filters. The TCM method also has problems with negative interference, especially in summertime. UV fluorescence monitors have
in a few cases proven to give good results, but interferences, detection limit and poor maintenance can be problems. For NO2, many countries are using the TGS absorption solution method, which has a higher detection limit than the reference method
using NaI impregnated glass sinters. The Salzmann method gives unreliable results at concentrations below 1 μgN/m3, and even at higher concentrations the uncertainty is rather unsatisfactory. The chemiluminescence monitor with molybdenum
converters tends to systematically overestimate NO2 concentrations, possibly because zero-drift problems and the non-specific response to NO2. Particulate sulphate measurements in general have lower bias and uncertainties than gas and other aerosol measurements. 相似文献
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A wide variety of antibiotics have been detected in natural water samples and this is of potential concern because of the adverse environmental effects of such antibiotic residues. One of the main sources of antibiotics effluence to the surrounding environment is livestock manures which often contain elevated concentrations of veterinary antibiotics (VAs) which survive digestion in the animal stomach following application in animal husbandry practices. In Korea, livestock manures are normally used for compost production indicating that there is potential for antibiotic release to the environment through compost application to agricultural lands. Therefore, reduction of the amount of VAs in composts is crucial. The purpose of this study was to understand the influence of the composting process and the components of the compost on the levels of three common classes of antibiotics (tetracyclines, sulfonamides, and macrolides). Composted materials at different stages of composting were collected from compost manufacturing plants and the variation in antibiotic concentrations was determined. Three different antibiotics, chlortetracycline (CTC), sulfamethazine (SMZ), and tylosin (TYL) at three different concentrations (2, 10, and 20 mg kg−1) were also applied to a mixture of pig manure and sawdust and the mixtures incubated using a laboratory scale composting apparatus to monitor the changes in antibiotic concentrations during composting together with the physicochemical properties of the composts. During composting, in both field and lab-scale investigations, the concentrations of all three different antibiotics declined below the relevant Korean guideline values (0.8 mg kg−1 for tetracyclines, 0.2 mg kg−1 for sulfonamides and 1.0 mg kg−1 for macrolides). The decline of tetracycline and sulfonamide concentrations was highly dependent on the presence of sawdust while there was no influence of sawdust on TYL decline. 相似文献
17.
刘敏清 《再生资源与循环经济》2012,5(6):23-25
广州市作为国家再生资源回收体系建设试点城市,在大力发展循环经济、推进再生资源回收利用网络体系建设方面进行了先行先试探索,取得了明显成效。“广州模式”对推进广东省加快转型升级具有启示借鉴意义。 相似文献
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《Waste management & research》1990,8(5):379-385
This paper develops a quantitative model which attempts to relate volumetric changes in landfill gas emissions to variations in the surface atmospheric pressure. The model considers gas emissions as the sum of two terms, one constant over a period of weeks, and the other able to vary on a scale of hours. Results from computer simulations are given which indicate that the magnitude of the variable factor is proportional to the rate at which surface pressure is changing, rather than the actual value of the surface pressure. 相似文献
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Chung Yong-Seung Kim Hak-Sung Park Kie-Hyon Dulam Jugder Gao Tao 《Water, Air, & Soil Pollution: Focus》2005,5(3-6):15-35
A joint monitoring of dust-storms that occurred in East Asia from March until May 2003 has been carried. Our discussions include
dust-storm observations in the source areas of China and Mongolia, and measurements with satellites and ground monitors in
central Korea. Differences were found in the definition and measurement of dust-storms. Over the source area of Mongolia there
were 6 dusty days in March, 18 days in April, and 10 dusty days in May. In Inner Mongolia of northern China there were 4 dust-storms
with 14 dusty days observed over the three months. In central Korea, a sink area, there were 4 cases of weak dust-storm and
17 dusty days in the spring of 2003. The highest PM10 value was 607 μgm−3 and PM 2.3 was 149 μgm−3, respectively. These observations identify the growing need for further universal observation practices and dust-storm reporting
in future.
Observations indicated that snow covered the central part of the Gobi Desert, near the boundary of China and Mongolia, from
December until mid-March. This is in contrast to other years when the Gobi was relatively wet, producing unfavourable conditions
for the formation of intense dust-storms. In addition, the very strong winds associated with intense cyclones and anticyclones
were not apparent and the systems shifted northward during the spring. As a result, the frequency and intensity of observed
dust-storms in 2003 in this region were very low. This confirms that there is variability in the frequency of dust-storm formation
due to the current process of desertification and climate change. 相似文献
20.
论述了膨润土的吸附机理,介绍了膨润土的物理及化学改性方法及其对有机染料废水,焦化废水,烟草废水,煤泥水,含酚类、石油烃类、抗生素废水及微污染水等的处理效果。针对膨润土作为环保吸附剂存在的问题指出了今后的研究方向:1)将研究成果应用于实际废水;2)研究环境友好且效果好的改性工艺及材料;3)研究新的吸附剂制备形式;4)加大膨润土在废气处理上的研究力度;5)研制吸附效果更佳且能处理复杂成分污水的新型复合吸附剂。 相似文献