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1.
污水快速渗滤土地处理研究进展   总被引:14,自引:0,他引:14  
针对RI系统的污染物去除机制、运行方式、系统恢复以及实践应用等方面的研究进展作一综述。RI技术的应用有着广阔的前景,必将促进我国环境保护与生态建设的发展。  相似文献   

2.
人工快速渗滤系统对污染物的去除机制   总被引:9,自引:0,他引:9  
人工快速渗滤系统(CRI)是在传统的污水快速渗滤处理系统(RI)的基础上发展起来的一种新型的污水土地处理技术.通过对CRI的模拟,揭示了非生物机制与生物机制对有机物、营养元素的降解机制.结果表明,CRI对污水中污染物的去除是在非生物机制与生物机制协同作用下完成的.对污水中的有机物和氮的降解以生物机制为主、非生物机制为辅;对磷的降解则以非生物机制为主、生物机制为辅.生物机制对有机物、氮的去除占70%以上,非生物机制对磷的去除占61.9%.系统中氮转化以硝化效果为主,反硝化效果较弱.  相似文献   

3.
为了解海州湾南部海域表层沉积物重金属空间分布特征、污染程度和生态风险水平,采集11个站位表层沉积物,测定有机碳、铜、铅、锌、镉、铬、汞和砷的含量。利用背景值计算污染负荷指数(PLI)、地累积指数(Igeo)和潜在生态风险指数(RI)。结果表明:重金属总体呈现由岸向海、由南向北减小的趋势;PLI和Igeo表明研究区总体为中等污染,主要污染因子为镉;RI表明研究区处于低风险,主要风险因子为镉。  相似文献   

4.
矿业活动对土壤系统良性运转带来较大的环境负荷,矿区周边土壤重金属污染风险评估是土壤污染防治和资源可持续开发的关键。在应用单因子污染指数法、潜在生态风险指数法、风险评价编码法(RAC),并结合空间分析和冗余分析手段的基础上,对新疆某矿冶区周边土壤重金属生物有效性和生态风险进行了系统研究。结果表明:研究区土壤As、Cu、Mn和Cd超标率分别为88%、38%、49%和24%;土壤Mn、Zn、As和Cd弱酸可溶态高值区主要集中在尾砂库和收砷房的附近区域。单因子污染指数评价揭示As和Cu污染累积较为严重。潜在生态风险评价显示,As、Cd和Cu生态风险较高,Mn为低生态风险。风险编码法(RAC)评价结果进一步揭示Mn和Cd具有显著的土壤迁移风险。冗余分析结果显示,空间异质性是影响土壤重金属弱酸可溶态含量变异的主要因素。土壤pH和重金属弱酸可溶态是影响潜在生态风险指数(RI)的2个重要因素。综合风险评价手段与多尺度分析方法的联合应用有助于提高区域风险评价的准确性。  相似文献   

5.
深圳市河流沉积物重金属污染特征及评价   总被引:16,自引:0,他引:16  
分析了深圳市的深圳河、布吉河、龙岗河和茅洲河等4条河流沉积物中重金属的含量和富集状况,并对重金属污染的潜在生态危害进行了评价。结果表明:(1)1996-2003年,深圳河、布吉河、龙岗河和茅洲河沉积物中重金属的含量都有上升的趋势;布吉河和龙岗河沉积物中的重金属含量较高,特别是Cu、Zn和Cr的含量比其他两条河流高出较多,深圳河居中,茅洲河较小;这4条河流都以Cd、Cu、Cr和Zn的富集为主。(2)在研究时段内,这4条河流沉积物重金属污染的潜在生态危害指数(RI)都有上升的趋势;其中深圳河,布吉河和龙岗河的RI在多数年份都达到强或很强的程度,Cd、Hg、Cu为主要贡献元素;4条河流中,茅洲河受重金属污染最小,其RI为轻微或中等,只有Cd和Hg的生态危害系数为中等或强。针对深圳市河流沉积物中重金属的累积机理,建议通过改善区域水文条件、控制污染物的排放等措施加以控制和治理。  相似文献   

6.
一、前言 医院使用多量的药品,例如、洗液、消毒液、RI等,对这些药品如不加处理就排放,会给环境造成很大影响,所以有必要采用符合医院实际情况的处理方式来进行处理。  相似文献   

7.
胶州湾表层沉积物重金属污染分布特征及其生态风险评价   总被引:2,自引:0,他引:2  
根据2009年对胶州湾东岸表层沉积物中重金属调查结果,对重金属含量分布及富集特征进行分析,并采用潜在生态危害指数(RI)法对其生态危害程度进行评价。结果表明,胶州湾东岸表层沉积物中的重金属含量,除7月的Cu、Cr平均含量略低于12月外,其他重金属(Cd、Zn、Pb、As)平均含量7月均高于12月。在表层沉积物中Cd的污染程度最高,7月平均污染指数达1.68。单个重金属潜在生态危害系数(Eir)表明,Cd的Eir大于其他重金属的Eir,其他重金属的Eir均小于轻微危害程度的划分标准,表明对胶州湾东岸生态环境具有潜在影响的重金属主要是Cd,从多个重金属的RI均值看,均小于150,属于轻微生态危害。  相似文献   

8.
分析了洛阳市3个污水处理厂脱水污泥中Cu、Zn、Ni、Cr和Pb的含量,采用BCR法研究了污泥中重金属的形态分布特征,并利用地累积指数法(Igeo)和潜在生态危害指数法(RI)评价污泥在农用过程中重金属的潜在生态风险。结果表明,涧西污泥中Cu、Zn和Ni含量超过了农用泥质A级标准的限值(CJ/T309-2009),而新区污泥和瀍东污泥显示出良好的农用性质。污泥中Cu和Cr主要以可氧化态存在,Zn主要以酸溶态和可还原态存在,迁移性强,Ni含量分布相对比较均匀,Pb主要以残渣态存在。Igeo表明,污泥中Cu、Zn是潜在的污染元素。RI表明,Cu表现出高潜在生态风险;Zn的总含量虽高,但Zn的生物毒性响应因子低,对污泥的潜在风险贡献较低。  相似文献   

9.
焦化废水处理过程所排放污泥中重金属的含量及化学形态是否构成环境风险将直接影响污泥处置方法的选择,为此,实验采用BCR顺序提取法分析了焦化废水处理站外排污泥中重金属(Cd、Hg、Pb、Cr、As、Ni、Zn、Cu和Mn)的形态特征,并采用地累积指数(Igeo)和潜在生态危害指数(RI)评价了重金属对土壤的潜在环境风险。研究结果表明:除Ni主要以可氧化态存在外,焦化废水外排污泥中其他几种重金属元素主要存在于残渣态,重金属元素的含量低于《城镇污水处理厂污染物排放标准(GB18918—2002)》中的控制限值;与城市污泥相比,焦化废水外排污泥具有低Pb、Cr、Zn、Cu含量,而高Cd、Hg、Mn含量的特点;基于Igeo和RI的评价结果,Cd和Hg是外排污泥中具有一定环境风险的元素,需要考虑其下游去向。焦化废水处理外排污泥中主要存在残渣态重金属成分,不表现为很高的环境风险,其处置应重点考虑其中有机污染物特别是POPs。  相似文献   

10.
对将激光通信技术在环境监控中的应用进行了研究,探讨了大气环境下数据传输的信号调制方式以及提高通信距离和减少系统噪声的方法,设计了可用于环境监控数据传输的激光传输系统实用电路.经安装、调试、运行,结果表明,该妹系统在视距通信条件下应用,具有电路制作简单、设备架设灵活方便、数据传输性能稳定和传输系统成本低廉等优点.  相似文献   

11.
The Management Systems Review is an important component of EPA’s quality assurance program. MSRs enable managers to assess the effectiveness of environmental data operations and the quality assurance/ quality control activities designed to ensure that the results are of the expected quality. These reviews inform managers about aspects of the environmental data operation that are working well and those which may warrant some improvement. A recent review of the Superfund remedial investigation/feasibility study (RI/FS) has shown that the MSR is an excellent tool for providing a systematic definition of complex environmental data operations and for enabling a thorough analysis of these operations. The MSR utilized information gathered from interviews of Regional staff and management and from case studies of recently completed RI/FSs. The findings indicated that environmental data play an important role in most RI/FS decisions and that thorough and structured scoping is critical to the effectiveness of the RI/ FS. Analysis of the RI/FS process using a comprehensive flow model identified several opportunities for changes that may increase efficiency in data collection and the reliability of RI/FS decisions. These changes provide for more effective scoping activities, a streamlined feasibility study, and increased use of treatability studies during the RI. A pilot demonstration of these process changes is being planned for a Regional RI/FS.  相似文献   

12.
The multilayer perceptron (MLP) model is frequently used to assess the relative importance (RI) of surface ozone influential variables when they are used to investigate ozone variation mechanisms. Previous studies, however, suffer from two limitations: 1) indentifying or searching the optimal MLP topology to avoid a biased RI assessment inevitably incurs a heavy computational burden, and 2) the model is suitable only for local-scale analysis of ozone variation mechanisms. To tackle both problems, we selected three typical air-quality monitoring sites in Hong Kong as our study targets, as the ozone variations at these sites are inhomogeneously affected by regional and local factors. An MLP model trained by automatic relevance determination (referred to as MLP-ARD), a Bayesian MLP approach, was employed to assess the RI for both regional and local ozone influential variables. The results indicated the following remarks: 1) The MLP-ARD model, due to its high degree of resistance to both the over-fitting and the under-fitting problems, is exempt from identifying or searching the optimal MLP topology when used to obtain an unbiased RI assessment and thus avoid the heavy computational burden. Furthermore, the RI assessment results obtained with the MLP-ARD method are comparable to those of the best assessment method in the literature. Based on these findings, decision-makers can scientifically promulgate a site-specific air pollution control strategy site; 2) Regional-scale analysis of ozone variation is indispensable, as taking the key regional ozone influential variables into account significantly improves the prediction accuracy of the MLP-ARD model, especially on peak ozone days.  相似文献   

13.
F Haus  J German  G A Junter 《Chemosphere》2001,45(6-7):983-990
The primary biodegradability of 32 mineral base (i.e., unformulated) oils of paraffinic nature was evaluated using the CEC L-33-A-93 test. These oils were refinery products obtained by varying manufacturing processes. Biodegradation percentages ranged between 15% and 75%, i.e., below the commonly accepted standards for environmentally-compatible lubricants. Biodegradability values were compared to the overall chemical composition and main physical properties of base oils. Biodegradability decreased with increasing levels of aromatic and/or polar compounds in the tested oils. For most oils, the biodegradation percentage increased with the viscosity index, but was a decreasing function of the kinematic viscosity (KV), the pour point, the flash point (FP) and the refractive index (RI). Linear relationships between biodegradability and FP or RI values were observed. These results show that, beside chemical features such as the contents in polar and aromatic compounds, simple physical magnitudes such as KV and RI, commonly used to characterize lubricant properties, may be useful parameters for predicting the biodegradability of mineral base oils.  相似文献   

14.
Zheng W  Lichwa J  Yan T 《Chemosphere》2011,84(4):376-382
PAHs are ubiquitous environmental pollutants that can cause adverse health and ecological effects. In the present study, we examined the impact of land use on the concentration and composition of PAHs in 28 coastal stream sediments on the Island of Oahu, Hawaii. In densely populated urban areas, the concentration range of total PAHs in the stream sediments affected by mixed residential and industrial activities (RI) are 0.40-9.05 ppm, which is significantly higher than the 0.36-4.21 ppm detected in the stream sediments affected predominantly by urban residential land uses (UR). The stream sediments affected by agricultural activities (AG) reported a concentration range of 0.09-2.14 ppm, which is lower than those of the RI and UR stream sediments. The molecular weight of PAH is a factor, as only high molecular weight (HMW) PAHs were significantly affected by land uses (ANOVA P = 0.009). Correlation analysis showed that only in the UR stream sediments were significant correlations observed between PAH concentration and two anthropogenic indicators: population density (r = 0.57, P = 0.027) and vehicle density (r = 0.55, P = 0.034). The fractional concentrations of PAHs were analyzed by using PCA analysis, which led to the separate clustering of the RI and AG stream sediments and suggest distinct PAH sources between the two land uses. Two PAH source indicators, including Ant/(Ant + Phe) and Fl/(Fl + Py), indicates that PAHs sources in the RI stream sediments are most likely of petroleum origin, while PAHs in the UR and AG stream sediments most likely came from combustion activities. In addition, the concentration and relative potency of carcinogenic PAHs in the coastal stream sediments exhibited similar patterns as the total PAH concentration with respect to land uses.  相似文献   

15.
煤矿复垦区土壤重金属分布特征与质量评价   总被引:2,自引:0,他引:2  
为保证煤矿复垦区种植农作物的充填复垦土壤的生态安全,以淮南矿区煤矸石充填复垦地为研究对象,通过对研究区内Cd、Cr、Ni、Pb、Cu、Zn和Hg 7种重金属不同深度含量分析,总结其纵向分布特征,并将研究区土壤重金属含量与淮南市土壤背景值、《土壤环境质量标准》(GB 15618-1995)作比较,分析这7种重金属的污染程度.结果表明,这7种重金属都有不同程度的污染,其中土壤受Cd污染最严重,土壤中重金属垂直方向上无确定分布规律.总体而言,土壤重金属潜在生态风险属于强生态危害.从垂直方向来看,重金属潜在生态风险指数(RD随着深度的增加出现先下降后升高的趋势,其中40~60 cm深度的RI最大.重金属生态危害程度依次为Cd> Hg> Ni> Cu> Cr> Pb> Zn,其中Cd为矿区土壤中最主要的重金属污染生态风险因子.  相似文献   

16.
Pesticides are often used in agriculture, especially in floriculture. They are frequently applied in binary or ternary mixtures. Nevertheless, their impact on the genetic material has been scarcely explored. In this study, the mutagenic and cytostatic effect of three widely used pesticides, alone and combined, were analyzed. Briefly, lymphocytes cultures were obtained from peripheral blood samples of five healthy donors to determine the sister chromatid exchange and the replicative index (RI). Then, lymphocytes were exposed to Tamaron (100 ppm), Lannate (200 ppm) and Manzate (300 ppm) alone and combined. For the binary mixtures, the concentrations used were 50 ppm of Tamaron, 100 ppm of Lannate and 150 ppm of Manzate. For the ternary mixtures the following concentrations were used: Tamaron (33 ppm), Lannate (70 ppm) and Manzate (100 ppm). Finally, differential staining was performed. It was found that the frequency of SCE/cell showed a significant difference (P ≤ 0.05) between the control (2.66) and the individual treatments of Tamaron (4.87), Lannate: (5.12) and Manzate (4.23). Also, the values of the SCE in the binary mixture of Tamaron+Lannate (5.57), Tamaron+Manzate (6.06) and Lannate+Manzate (6.22) and the ternary mixture (6.63) were statistically different compared to the control. In the RI there was a significant difference between the control (1.98) and the Manzate (1.87). RI differences were also statistically significant (P ≤ 0.05) in mixtures of Tamaron+Lannate (1.64), Tamaron+Manzate (1.63), Lannate+Manzate (1.69) and total mixture (1.53). Therefore, it is suggested that these pesticides alone and in mixtures have both mutagenic and cytostatic synergistic effect in human lymphocytes in vitro.  相似文献   

17.
In this study, soil samples were collected at 22 sites in Liberty State Park, New Jersey, in 2005, for metal enrichment and potential ecological risk assessment. The geoaccumulation index (I geo) showed that enrichment levels of trace metals followed an order of Cu > Pb > Zn > As > Cr > Hg while the potential ecological risk factor (\( {E}_r^i \)) indicated that the potential ecological risk of the metals was in the order of Cu > Pb > As > Hg > Zn > Cr. Among these 22 sites, this investigation identified 9 sites at moderate ecological risk, 3 sites at considerable ecological risk, and 4 sites at high ecological risk according to the potential ecological risk index (RI). Hierarchical cluster analysis (CA) of soil metal concentrations separated the study sites into four groups, which are supported by the significant difference in RI values. Geographically, three regions in the Liberty State Park brownfield site were determined based on the CA results and RI values. Subarea 1 had low ecological risk while subareas 2 and 3 had a greater potential for ecological risk. Significant correlations of Pb with Cr and Zn were observed in subareas 2 and 3, respectively. This study shows that statistical approaches coupled with a risk assessment index provide a more comprehensive interpretation of land contamination than a single approach in support of planning land redevelopment.  相似文献   

18.
天津市典型河网区沉积物中重金属分布及生态风险评价   总被引:3,自引:0,他引:3  
选择天津市典型河网区为研究对象,分析了沉积物中6种重金属(Cr、Cu、Mn、Ni、Pb和Zn)的分布特征,并采用富集系数法和潜在生态危害指数法分析了重金属的来源,进而评价了其生态风险。结果表明,表层沉积物中Cr、Cu、Mn、Ni、Pb和Zn的平均含量分别是58.18、23.52、524.60、22.93、25.24和49.51 mg/kg,其中Cr、Mn和Ni含量均低于天津市土壤背景值,而Cu、Pb和Zn含量在部分样点高于背景值;在垂直分布上,沉积物中Cr和Ni的含量相对稳定,而Cu、Mn、Pb和Zn的含量从底层到表层均先增加后降低。重金属富集系数(EF)分析显示,河网区表层沉积物中Cu和Zn在个别样点以及Pb在近一半样点存在人为输入过程(EF1.5),与接纳上游及区域的生活污水、农田退水有关,而Cr、Mn和Ni均来自自然源。重金属综合潜在生态危害指数(RI)评价表明,整个河网区表层沉积物为轻微生态危害水平,对区域的水环境质量不构成威胁。  相似文献   

19.
We assess the bioaccumulation of metals (Pb, Hg, Cd, Fe, Mg, Zn, Cu, Mn, Mo, Cr) and effects of landfill leachates on morphological (RI, relative weights), plasma (GPT, GOT, creatinine), and genotoxic (MNT) parameters in wood mice, Apodemus sylvaticus, inhabiting close the Garraf landfill site (NE Spain). Due to the high age- and sex-dependent variation in wild populations, we also studied the effect of these biotic factors on the parameters studied. Wood mice from the landfill site, sited in a partially protected area, showed more Cd, Fe, Zn, Cu, Mn, Mo, and Cr than specimens from the reference site. Moreover, mice near the landfill registered low RI and high relative renal weight, GPT, and MN frequency, which indicate that the landfill affects the health of wild mice. In contrast to sympatric shrews from a previous study, wood mice showed lower bioaccumulation of metals and lower variation caused by biotic factors. Moreover, the morphological and physiological alterations demonstrated that they were also more sensitive at environmental pollution. Given the contribution of small mammals to ecosystem function and the scarce ecotoxicological data on the effects of landfill pollution on wild terrestrial mammals, we consider that our study can be used to improve the management of this protected area.  相似文献   

20.
This paper describes a study of the products of the Cl-atom-initiated oxidation of three alkyl iodides, RI=CH3I, C2H5I, and 2-C3H7I, carried out in synthetic air at atmospheric pressure and at room temperature. Fourier-transform infrared spectroscopy was used to follow the decay of reactants and subsequent formation of products. The primary step proceeds via two channels, one of which yields HCl and an iodinated alkyl radical, and the other I atoms and an alkyl chloride. Quantitative analysis of the product yields, together with an assessment of the formation of HCl in secondary processes, allowed the fractional branching into the two channels to be calculated. The channel yielding HCl from RI constitutes a fraction 0.59, 0.93, and 0.68 for R=CH3, C2H5, and 2-C3H7. The iodinated alkyl radical forms first a peroxy, and then an alkoxy, radical in the presence of air. The final products CH2O, CH3CHO, and CH3COCH3 were observed as expected for the decomposition of these radicals with RI=CH3I, C2H5I, and 2-C3H7I, and the fractions of the alkoxy radicals fragmenting to the carbonyl compounds were 0.88, 0.57, and 0.86, respectively. Atomic iodine is formed concomitantly with the carbonyl species, so that these fractions also indicate the yield of I atoms in the secondary process. Alternative reaction pathways for the iodinated alkoxy radicals, in particular reaction with O2, are evaluated and discussed. The yields of I atoms in the primary and secondary steps, taken in combination with kinetic data, make it possible to estimate the contribution of the Cl-initiated oxidation of the alkyl halides to I-atom production in the atmosphere (and, making certain assumptions, the analogous contribution from OH-initiated oxidation). Radical-initiated processes might augment the photolytic yield of I atoms from simple alkyl iodides: the maximum enhancements lie between 5% (CH3I) and more than 30% (2-C3H7I).  相似文献   

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