硝酸银沉淀－颗粒物返还法去除COD样品中的氯化物

将样品中的颗粒物分离出来后，向样品中加入适量硝酸银，除去生成的氯化银沉淀，再将预先分离的颗粒物合并到水样中，混匀后测定。经过这样处理，既去除了水样中的Ｃｌ－，又保留了水样中原来的组份，保证了ＣＯＤ测定结果的准确性。     

Monitoring and Assessment of Exhaust Emission in Bangkok Street Air

Measurement of the exhaust emission from gasoline-powered motor vehicles in Bangkok were performed on chassis dynamometer. A fleet of 10 vehicles of different model, years and manufacturers were selected to measure the air pollutants in the exhaust effluent. The study revealed that the carbon monoxide and hydrocarbon emissions averaged 32.3–64.2 and 1.82–2.98 g km^–1, respectively, for 1990–1992 cars and decreased to 17.8–40.71 and 0.75–1.88 g km^–1, respectively, for 1994–1995 cars. A monitoring program for air pollutant concentrations in ambient air was also conducted to evaluate the air pollution problems in Bangkok arising from vehicle exhaust emission. Four air sampling stations were strategically established to cover the Bangkok Metropolitan Region (BMR). Composite air samples in this study area were collected during the day/night times and weekday/weekend. The average concentrations of suspended particulate matter, carbon monoxide, and nitrogen dioxide in Bangkok street air were found to be 0.65 mg/m³ (24 hr ave.), 19.02 mg/m³ (8 hr ave.) and 0.021 mg/m³ (1 hr ave.), respectively. The average concentrations of benzene and toluene in the ambient air of the study area were found to be 15.07–50.20 and 25.76–130.95 g/mf³, respectively, for 8 hr average. These results indicated that there was a significant increase in air pollutant emissions with increasing car mileage and model year. Subsequent analysis of data showed that there were only 20% of the test vehicles complied to approved emission standard. The finding also revealed that there was a correlation between the average air pollutant concentrations with average traffic speed in each traffic zone of the Bangkok Metropolitan Region (BMR).     

Interlaboratory variability of amphipod sediment toxicity tests in a cooperative regional monitoring program

Marine sediment toxicity tests are widely applied in monitoring programs, yet relatively little is known about the comparability of data from different laboratories. The need for comparability information is increased in cooperative monitoring programs, where multiple laboratories (often with variable skill levels) perform toxicity tests. An interlaboratory comparison exercise was conducted among seven laboratories in order to document the comparability of sediment toxicity measurements during the Bight'98 regional sediment survey in southern California. Sediments from four stations in Los Angeles and Long Beach Harbors were tested using a 10-day survival test of the amphipod Eohaustorius estuarius. All laboratories successfully performed the sediment test and associated reference toxicant test. Statistically significant differences were found in mean amphipod survival rates among some laboratories for the field-collected sediments, but there was little evidence of a consistent bias among laboratories. Although the reference toxicant test indicated a five-fold variation in test sensitivity among laboratories, these results were not accurate predictors of interlaboratory performance for the sediment tests. The laboratories demonstrated excellent concordance (Kendall's W = 0.91) in ranking the field-collected sediments by toxicity. Agreement on classifying the sediments into categories (nontoxic, moderately toxic, and highly toxic) based upon the percent of survival was best for highly toxic sediments. An analysis of test precision based upon the variance among replicates within a test indicated that the measured survival rate for a sample may vary by up to 12 percentage points from the actual response.     

黄河(喇嘛湾段)沉积物中铜、铅、锌、镉的化学形态研究

建立了黄河 (清水河段 )沉积物中铜、铅、锌、镉的化学形态分析方法 ,系统地研究了它们在其有效态中的聚集能力及在各种粒径沉积物中的分布     

黄河口的水质、底质污染及其变化

分析了2001年在黄河口附近所取的3处水样和3处泥样中污染物的含量,并与历史数据进行了比较.利用<地表水环境质量标准>(GB3838-2002)和美国国家海洋大气管理局(NOAA)水体泥沙质量标准等分别对水体和底泥中的重金属(砷)和氮磷污染进行了评价.认为黄河口的水污染严重,主要污染物为汞和氮;泥沙污染尚不严重,但污染物的增长率高;水体中较高的氮含量和泥沙中氮含量的迅速增高可能会对渤海湾的富营养化情况产生影响.     

Spatial Extent Of Degraded Sediment Quality In Puget Sound (Washington State, U.S.A.) Based Upon Measures Of The Sediment Quality Triad

A survey was designed and conducted to determine the severity, spatial patterns, and spatial extent of degraded sediment quality in Puget Sound (Washington State, USA). A weight of evidence compiled from results of chemical analyses, toxicity tests, and benthic infaunal analyses was used to classify the quality of sediments. Sediment samples were collected from 300 locations within a 2363 km² area extending from the US/Canada border to the inlets of southern Puget Sound and Hood Canal. Degraded conditions, as indicated with a combination of high chemical concentrations, significant toxicity, and adversely altered benthos, occurred in samples that represented about 1% of the total area. These conditions invariably occurred in samples collected within urbanized bays and industrial waterways, especially near the urban centers of Everett, Seattle, Tacoma, and Bremerton. Sediments with high quality (as indicated by no toxicity, no contamination, and the presence of a relatively abundant and diverse infauna) occurred in samples that represented a majority (68%) of the total study area. Sediments in which results of the three kinds of analyses were not in agreement were classified as intermediate in quality and represented about 31% of the total area. Relative to many other estuaries and marine bays of the USA, Puget Sound sediments ranked among those with minimal evidence of toxicant-induced degradation.     

Incidence of stress in benthic communities along the U.S. Atlantic and Gulf of Mexico coasts within different ranges of sediment contamination from chemical mixtures

Synoptic data on concentrations of sediment-associated chemical contaminants and benthic macroinfaunal community structure were collected from 1,389 stations in estuaries along the U.S. Atlantic and Gulf of Mexico coasts as part of the nationwide Environmental Monitoring and Assessment Program (EMAP). These data were used to develop an empirical framework for evaluating risks of benthic community-level effects within different ranges of sediment contamination from mixtures of multiple chemicals present at varying concentrations. Sediment contamination was expressed as the mean ratio of individual chemical concentrations relative to corresponding sediment quality guidelines (SQGs), including Effects Range-Median (ERM) and Probable Effects Level (PEL) values. Benthic condition was assessed using diagnostic, multi-metric indices developed for each of three EMAP provinces (Virginian, Carolinian, and Louisianian). Cumulative percentages of stations with a degraded benthic community were plotted against ascending values of the mean ERM and PEL quotients. Based on the observed relationships, mean SQG quotients were divided into four ranges corresponding to either a low, moderate, high, or very high incidence of degraded benthic condition. Results showed that condition of the ambient benthic community provides a reliable and sensitive indicator for evaluating the biological significance of sediment-associated stressors. Mean SQG quotients marking the beginning of the contaminant range associated with the highest incidence of benthic impacts (73–100% of samples, depending on the province and type of SQG) were well below those linked to high risks of sediment toxicity as determined by short-term toxicity tests with single species. Measures of the ambient benthic community reflect the sensitivities of multiple species and life stages to persistent exposures under actual field conditions. Similar results were obtained with preliminary data from the west coast (Puget Sound).     

Levels and Trend of Suspended Particles around Large Lignite Power Stations

The results of a 16 year long sampling program in a heavily industrialized area of NW Greece are presented and analyzed. Fourlignite power stations are operated in this area, which account forabout 70% of the total electrical energy produced in Greece.Ambient concentrations of Total Suspended Particles (TSP) over much of the period 1983–1998 as well as of particles of less than10 m aerodynamic diameter (PM₁₀) for three years were measured. Emphasis is given on the assessment of the levels of the daily average concentrations for the data period as well asthe determination of the spatial and temporal variation of suspended particle concentrations. Based on the data analysis, useful information is provided about air quality levels after taking into account air quality standards. The interannual concentrations trend is also investigated and an attempt is madeto examine the effectiveness of antipolluting procedures, which have occasionally been implemented in this industrial area. Finally the results are compared to those in the literature.     

Validation of two air quality models for Indian mining conditions

All major mining activity particularly opencast mining contributes to the problem of suspended particulate matter (SPM)directly or indirectly. Therefore, assessment and prediction are required to prevent and minimize the deterioration of SPM due tovarious opencast mining operations. Determination of emission rate of SPM for these activities and validation of air quality models are the first and foremost concern. In view of the above, the study was taken up for determination of emission rate for SPMto calculate emission rate of various opencast mining activitiesand validation of commonly used two air quality models for Indianmining conditions. To achieve the objectives, eight coal and three iron ore mining sites were selected to generate site specific emission data by considering type of mining, method of working, geographical location, accessibility and above all resource availability. The study covers various mining activitiesand locations including drilling, overburden loading and unloading, coal/mineral loading and unloading, coal handling orscreening plant, exposed overburden dump, stock yard, workshop, exposed pit surface, transport road and haul road. Validation of the study was carried out through Fugitive Dust Model (FDM) and Point, Area and Line sources model (PAL2) by assigning the measured emission rate for each mining activity, meteorologicaldata and other details of the respective mine as an input to the models. Both the models were run separately for the same set ofinput data for each mine to get the predicted SPM concentrationat three receptor locations for each mine. The receptor locationswere selected such a way that at the same places the actual filedmeasurement were carried out for SPM concentration. Statisticalanalysis was carried out to assess the performance of the modelsbased on a set measured and predicted SPM concentration data. The value of coefficient of correlation for PAL2 and FDM was calculated to be 0.990-0.994 and 0.966-0.997, respectively, which shows a fairly good agreement between measured and predicted values of SPM concentration. The average index of agreement values for PAL2 and FDM was found to be 0.665 and0.752, respectively, which represents that the prediction by PAL2 and FDM models are accurate by 66.5 and 75.2%, respectively. These indicate that FDM model is more suited for Indian mining conditions.     

典型城市工业区TSP中重金属污染研究

以徐州市北郊工业区作为研究对象,探讨工业型城市大气总悬浮颗粒物中重金属元素的时空分布特征。监测结果表明,该区大气TSP中重金属污染较为严重,单个样品中重金属铅、锌、镉、铬、铜和锰的最高含量分别达350.9、1037.9、5.5、16.3、17.8、238.5mg/kg;元素浓度呈秋冬季偏高,夏秋季偏低的趋势;空间分布充分体现了与污染源地域分布的一致性。