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701.
考察了在不同运行阶段,间歇式生物脱氮除磷处理系统内活性污泥混合蔽中细菌总数及主要细菌组成的变化特性。试验结果表明:①在稳定运行期,试验装置内活性污泥混合液中细菌总数大大多于启动期(约大26倍);②在启动运行期,活性污泥混合液中的优势菌为气单胞菌属;其次是假单胞菌属;没有发现不动杆菌属。在稳定运行期间,优势菌是假单胞菌属,其次是气单胞菌属和棒杆菌属。  相似文献   
702.
ZE-1号印染废水脱色菌群结构与功能的研究   总被引:2,自引:0,他引:2  
印染废水是水体的主要工业污染源之一。研究表明,利用微生物对印染废水进行脱色处理是一条可行的途径。浙江省环保科研所曾选育得到一组脱色性能较好,具有应用前景的混合菌群。命名为ZE-1号脱色菌群。  相似文献   
703.
通过采用GDX-502富集,GC-MS分析,对城市河流、湖库中的痕量有机污染物进行分析,共检出58种有机污染物,其中含有多种美国EPA公布的重点污染物,从而为痕量有机污染物的研究建立了灵敏度高,分辨率好的测试方法。  相似文献   
704.
腐蚀性气体硫化氢测定方法的探讨   总被引:2,自引:0,他引:2  
腐蚀性气体硫化氢的测定方法最常见的是亚甲基蓝分光光度法和碘量法,这两种测定方法都受到众多因素的影响。对于亚甲基蓝分光光度法而言,采样,标准曲线的绘制,以及样品的分析等过程都会影响硫化氢测定结果的可靠性;同样,对于碘量法,采样,硫代硫酸钠标准溶液的配制,以及样品的分析等过程也都会对测定结果造成影响。  相似文献   
705.
This paper discusses actions aimed at sustainable management of healthcare wastes (HCW) in China, taking into account the current national situation in this field, as well as the requirements deriving from the Stockholm Convention on Persistent Organic Pollutants and the WHO recommendations. By the end of 2005, there were 149 low-standard HCW disposal facilities in operation in China, distributed throughout different areas. According to the National Hazardous Waste and Healthcare Waste Disposal Facility Construction Plan, 331 modern, high-standard, centralized facilities will be built up in China in municipal level cities. Although incineration is still the main technical option for HCW disposal in China, it is expected that, especially for medium and small size facilities, non-incineration technologies will develop quickly and will soon become the main technical option. The basic management needs – both from the point of view of pollution control and final disposal – have been defined, and a system of technical and environmental standards has been formulated and implemented; however, there are still some shortages. This is particularly true when considering the best available techniques and best environmental practices developed under the Stockholm Convention, with which the present technological and managing situations are not completely compliant. In this framework, the lifecycle (from generation to final disposal of wastes) of HCW and holistic approaches (technology verification, facilities operation, environmental supervision, environmental monitoring, training system, financial mechanism, etc.) towards HCW management are the most important criteria for the sustainable and reliable management of HCW in China.  相似文献   
706.
DO对同步硝化反硝化协同除磷的影响   总被引:9,自引:3,他引:6  
采用序批式活性污泥反应器(SBR)处理模拟城市污水,在厌氧--好氧运行方式下,考察了DO对同步硝化反硝化协同除磷效果的影响.结果表明,DO的变化对该系统中有机物的去除影响不显著,当DO为1.5~2.0 mg/L时,TN及TP去除率均能达到90%以上,并可以应用pH曲线拐点来判断系统硝化过程是否完成.  相似文献   
707.
Background, aim, and scope  Pesticides and heavy metals pollution in soil environment has become a serious problem in many countries including China. Repeated applications of bordeaux mixture (a blend of copper sulfate and calcium hydroxide) and pyrethroid (Pys) insecticides have led to elevated copper (Cu) and Pys concentrations in vineyard surface soils. However, few studies focused on the interaction of Pys and heavy metals in the soil environment. Our previous studies had indicated the combined effect of cypermethrin (CPM) and Cu on soil catalase activity. Also, we had suggested that the addition of Cu could catalyze photo-degradation of CPM and lambda-cyhalothrin (λ-CHT) in aqueous solution and restrain their degradation in soil. To better understand the potential influence of Cu on the fate of Pys in the soil environment, the aim of the present work was to examine the effect of Cu on the adsorption of λ-CHT and CPM on two typical Chinese soils with different soil characteristics, which was one of the key processes controlling the fate of Pys, and to provide more information about the potential ecological risk of chemicals on the soil ecosystem. Fourier transform infrared and point charges analysis using the MOPAC program of the Gaussian system were also used to reveal the probable adsorption mechanism of λ-CHT and CPM on soils. Materials and methods  Two vineyard soils with different properties were chosen as experimental samples. They were sampled from 0 to 10 cm, dried, and sieved to 2 mm. Each soil was spiked with copper sulfate solution to obtain the following total soil Cu concentrations: 100, 200, 400, 800, and 1,600 mg·kg−1. The treated soils were incubated for 2 weeks and then dried at 20°C. For each soil sample and at each soil Cu concentration, the adsorption of λ-CHT and CPM was measured using a batch equilibrium method. The concentration of λ-CHT was determined by HPLC, and the amount of λ-CHT and CPM adsorbed by the soil sample at equilibrium was determined by the difference between the initial and equilibrium concentrations in solution corrected by the blank adsorption measurement. Results  Without the addition of Cu, the adsorption of λ-CHT and CPM on Black soil is greater than that on Red soil, while the adsorption of λ-CHT on both soils is significantly stronger than that of CPM. As the soil Cu concentration increased from 19 (or 18; background) to 1,600 mg·kg−1, the adsorption coefficient (K d) of λ-CHT decreased from 12.2 to 5.9 L·kg−1 for Red soil, and from 26.1 to 16.8 L·kg−1 for Black soil, whereas the CPM adsorption coefficient in both soils decreased nearly by 100% (K d decreased from 9.4 to 0.2 L·kg−1 for Red soil and from 16.2 to 0.5 L·kg−1 for Black soil). Discussion  Pys adsorption is a surface phenomenon which depends on the surface area and the organic matter content. Thus, the Black soil, having higher organic matter and greater surface area than that of the Red soil, show greater adsorption affinity to λ-CHT and CPM. In our study, the different adsorption affinity of the two Pys was obtained, which was probably attributed to differences with respect to their physical–chemical properties. Further comparison upon the two Pys was conducted. The point charges of halogen atoms in the λ-CHT and CPM were calculated, the differences of which probably lead to the fact that λ-CHT has a stronger binding capacity to soils than CPM. Also, FTIR spectra show that competitive adsorption occurs between CPM and Cu for the same adsorption sites, which is responsible for the obtained suppression of CPM adsorption affected by Cu. Conclusions  Lambda-cyhalothrin shows a significantly stronger adsorption than cypermethrin on both soils. This phenomenon may be due to several reasons: (1) λ-CHT has lower solubility and a higher octanol–water partition coefficient value than CPM; (2) λ-CHT consists of specific isomers, whereas CPM is mixtures of eight different isomers; (3) the chlorine and fluorine atoms in the λ-CHT have a negative point charge, whereas the chlorine atoms in the CPM have a positive point charge. As the soil Cu concentrations increased from 19 (or 18) mg·kg−1 to 1,600 mg·kg−1, the adsorption coefficient of λ-CHT and CPM decreased on both soils. This is mainly due to a competition between Cu and Pys for occupying the adsorption sites on soils. The information from this study have important implications for vineyard and orchard soils, which often contain elevated levels of Cu and Pys. These results are also useful in assessing the environmental fate and health effect of λ-CHT and CPM. Recommendations and perspectives  It is important for environmental scientists and engineers to get a better understanding of soil–metal–organic contaminant interactions. However, pesticide adsorption involves complex processes, and shortcomings in understanding them still restrict the ability to predict the fate and behavior of pesticide. Therefore, considerable research should be carried out to understand the mechanism of interaction between Pys and heavy metal on soils clearly.  相似文献   
708.
通过对首钢烧结厂的污染结点、污染物特性、污染物控制技术措施和技术规范进行分析,提出了烧结厂PM10控制方案,对烧结厂采用高效除尘设备的PM10削减量及改造费用进行了估算,确定了烧结厂PM10治理技术方案排序,为钢铁企业烧结厂治理颗粒污染物的同时选择最为经济实用的除尘器类型提供理论依据.  相似文献   
709.
通过对首钢烧结厂的污染结点、污染物特性、污染物控制技术措施和技术规范进行分析,提出了烧结厂PM10控制方案,对烧结厂采用高效除尘设备的PM10削减量及改造费用进行了估算,确定了烧结厂PM10治理技术方案排序,为钢铁企业烧结厂治理颗粒污染物的同时选择最为经济实用的除尘器类型提供理论依据。  相似文献   
710.
镉胁迫对向日葵幼苗生长和生理特性的影响   总被引:7,自引:0,他引:7  
采用溶液培养方法,研究了不同浓度镉(0、0.05、0.1、0.5和1 mg/L)处理7 d对向日葵幼苗生长和生理特性的影响。结果表明:随着镉处理浓度的增加,向日葵幼苗对镉的吸收显著增加。1 mg/L镉浓度处理时,叶、茎和根中镉浓度分别为0.05 mg/L镉处理时的16.3、19.2和581倍;根中积累的镉含量明显高于叶和茎, 各浓度根部积累的镉分别为叶和茎的37.8~63倍和29.4~41倍。镉胁迫显著抑制向日葵幼苗生长和叶绿素合成,当镉浓度达1 mg/L时,整株植物生物量和总叶绿素含量分别为对照的55.9%和52.6%。镉胁迫下向日葵幼苗游离脯氨酸和丙二醛(MDA)含量显著增加,1 mg/L镉浓度时,根中含量分别为对照的4和5.8倍。向日葵幼苗可溶性蛋白含量和过氧化物酶(POD)活性变化与镉胁迫浓度呈明显的倒U字型关系,可溶性蛋白含量在0.05 mg/L镉浓度时达到最大值,叶、茎、根中的POD活性分别在0.1、0.1和0.05 mg/L镉浓度时达到最大值。  相似文献   
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