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91.
The ion chromatography combined solid phase extraction (SPE) method was developed for the analysis of low concentration haloacetic acids(HAAs),a calss of disinfection by-products formed as a result of chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples' turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and were found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 μg/L and 1.30 μg/L respectively, and the other three are ranging from 0.48 to 0.82 μg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid is the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively.  相似文献   
92.
战略环境评价中公众参与程序和方法研究   总被引:9,自引:0,他引:9  
公众参与贯穿于战略环境评价(SEA)的主要过程,是提高SEA质量的一个重要手段.简要介绍了公众参与SEA的内涵和理论依据;解析了公众参与在SEA整个过程中所处的位置和参与内容;对公众参与SEA的具体工作程序和方法及参与方式进行了探讨.将为公众成功的参与SEA提供有效途径和方法,同时也是提高政府决策效率和公众环境意识的重要途径.  相似文献   
93.
比较传统的压边方式,提出并实现了曲面压边技术,该技术能有效缩小毛坯,节省工序。  相似文献   
94.
松花江污染事故发生后,国家更加重视对已有石化工业园区的风险排查以及事故预防,风险识别是风险评价与管理的基础。通过查阅相关资料以及类比分析,分析了已有区域风险识别与普通风险识别的不同,探讨了识别的原则和重点,指出了识别的程序和相应的方法,并给出了实例论证,为区域环境风险识别研究提供借鉴。  相似文献   
95.
图文化操作规程在海上气田生产作业中的应用   总被引:4,自引:0,他引:4  
为了避免因人的误操作造成的安全事故,东方1-1气田创新推行图文化操作规程。本文介绍了图文化操作规程制订的步骤与方法,论述了图文化操作规程的主要内容,并概括了图文化操作规程的优势和在东方气田生产作业中的实施效果。实施效果表明:通过在东方气田实施图文化操作规程,不仅解决了传统的操作规程均采用纯文字陈述形式,存在不直观、不利于记忆、不易自学等问题,而且气田没有发生一起因人的误操作而造成的安全事件和事故,有效地控制了风险,可见图文化操作规程可有效地规避海上气田生产作业中的风险。  相似文献   
96.
In Québec, workers intervening in hazardous zones of machines, equipment and processes during maintenance, repairs and unjamming activities have to apply lockout procedures. Lockout procedures involve shutting down the equipment, isolating it, applying individual locks, releasing residual energies and verifying the absence of energies. Lockout has mostly been linked to industrial sectors. However, the municipal sector also faces challenges when it comes to controlling hazardous energies. The objectives of this research are to study serious accidents linked to our subject, study the application of lockout in different municipalities in Québec, identify the specificities for the municipal sector and propose some means to support the application of lockout. We will show that lockout procedures are required in different locations in municipalities and that they are currently being implemented in the municipal sector in Québec. Moreover, we propose a model which aims at facilitating the implementation of lockout procedures in the municipal sector.  相似文献   
97.
不同有机物料中的磷形态特征研究   总被引:6,自引:2,他引:4  
采用DOU的磷形态分级方法,研究了猪粪沼渣(ZZ)、牛粪沼渣(NZ)、牛粪秸秆堆肥(NJD)、污泥堆肥(WD)、农村生活垃圾堆肥(NSLD)等7种有机物料中的磷形态及其比例.结果表明,有机物料中全磷及各形态总磷存在较大差异,以猪粪沼渣全磷含量最高,为23.59 g·kg-1,以牛粪沼渣全磷含量最低,仅3.61 g·kg-1.猪粪沼渣、牛粪沼渣、牛粪秸秆堆肥、污泥堆肥中各形态总磷(Pt)大小顺序为HCl-P残留态-PNa HCO3-PNa OH-PH2O-P,而3种农村生活垃圾堆肥中各形态磷含量则为HCl-P残留态-PH2O-PNa HCO3-PNa OH-P.7种有机物料中HCl提取态磷占回收全磷(Ptt)比例达47.75%~84.96%,表明有机物料中的大部分磷更容易被如HCl等强浸提剂提取,而这部分磷不易被植物吸收利用.各有机物料中磷以无机态磷为主,无机磷占全磷比例在53.18%~87.33%之间.各形态中的无机磷以Na HCO3-Pi占形态总磷比例最高(79.72%~94.76%),且在回收全磷中主要分布于HCl提取态,各形态中的有机磷则主要分布于HCl-P和残留态-P.经堆腐后的牛粪秸秆堆肥各形态无机磷占全磷比例较牛粪沼渣均有所增加,表明好氧堆肥有助于有机物料中磷的矿化,提高有机物料中磷的有效性.  相似文献   
98.
Statistical methods are widely used in environmental studies to evaluate natural hazards. Within groundwater vulnerability in particular, statistical methods are used to support decisions about environmental planning and management. The production of vulnerability maps obtained by statistical methods can greatly help decision making. One of the key points in all of these studies is the validation of the model outputs, which is performed through the application of various techniques to analyze the quality and reliability of the final results and to evaluate the model having the best performance. In this study, a groundwater vulnerability assessment to nitrate contamination was performed for the shallow aquifer located in the Province of Milan (Italy). The Weights of Evidence modeling technique was used to generate six model outputs, each one with a different number of input predictive factors. Considering that a vulnerability map is meaningful and useful only if it represents the study area through a limited number of classes with different degrees of vulnerability, the spatial agreement of different reclassified maps has been evaluated through the kappa statistics and a series of validation procedures has been proposed and applied to evaluate the reliability of the reclassified maps. Results show that performance is not directly related to the number of input predictor factors and that is possible to identify, among apparently similar maps, those best representing groundwater vulnerability in the study area. Thus, vulnerability maps generated using statistical modeling techniques have to be carefully handled before they are disseminated. Indeed, the results may appear to be excellent and final maps may perform quite well when, in fact, the depicted spatial distribution of vulnerability is greatly different from the actual one. For this reason, it is necessary to carefully evaluate the obtained results using multiple statistical techniques that are capable of providing quantitative insight into the analysis of the results. This evaluation should be done at least to reduce the questionability of the results and so to limit the number of potential choices.  相似文献   
99.
ABSTRACT

Seven volcanic rocks samples were collected from Southern Qinghai to analyze chemical speciation and migration behavior of heavy metals by sequential chemical extraction procedure and column leaching test. The geo-accumulation index, ecological risk index and the risk assessment code were applied to assess the heavy metal pollution and potential environmental effects in this area. Results revealed that the total concentrations of heavy metals did not exceed the background values in soil of this area. Most of the samples produced acid rock drainage. The order of heavy metal migration and transformation sequence in the volcanic rocks of Zhiduo region was Cd?>?Pb?>?As?=?Cu?=?Zn?=?Mn based on the geo-accumulation index and Cd caused heavy pollution, which was also confirmed by the leaching test. Moderate potential ecological risk posed by heavy metals occurred in the study area based on the potential ecological risk index. Cd contributed to most of ecological risk while the remaining heavy metals (except As) exerted medium to high risks to the environment according to the risk assessment code evaluation results. In summary, volcanic rocks possessed potential risks to the surroundings due to potential release of heavy metals. Cd that caused the pollution should be paid special attention.  相似文献   
100.
固体吸附剂控制燃煤重金属排放的实验研究   总被引:8,自引:0,他引:8  
在滴管炉上进行了烟煤添加固体吸附剂的燃烧实验研究了硫酸钙、石灰石、铝土矿3种吸附剂对重金属元素Pb、Cd、Cu、Co、Ni排放的控制,并采用形态逐级提取法,将排放颗粒物中重金属分为吸附态、离子可交换态、碳酸盐结合态、硫酸盐结合态和残渣态从粗粒灰渣及细微粒子中重金属元素含量的分布和细微粒子中残渣态稳定形态含量增加2个方面说明添加吸附剂对煤中重金属的排放具有一定的捕获力.对不同的重金属,由于吸附剂本身物理化学特性的差异,所表现出的吸附能力也各不相同.硫酸钙对Pb、Cd、Cu的排放有控制作用;石灰石对Pb、Cd、Cu、Nj的排放有控制作用;铝土矿对5种重金属元素的排放都有控制作用吸附剂粒径越小,对重金属的吸附效果越好.  相似文献   
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