Spatial sampling and the environment: some issues and directions

In this paper we summarize research issues for spatial environmental sampling stemming from a NISS/USEPA workshop held on 21-22 September 1994 at Chapel Hill, NC.     

前处理残余铝对曝气池活性污泥的影响规律研究

从活性污泥的絮凝特点、有机物与 NH 4-N 的微生物代谢过程等方面探讨前处理残余铝对曝气池活性污泥的影响规律.结果显示,随着进水Al3 浓度的不断增加,污泥瞬时沉降速度明显增加,而对污泥沉降比影响不大.Al3 对COD去除率基本上没有影响,而对废水中 NH 4-N 氧化过程的影响却非常明显,随着活性污泥中Al3 的逐渐增加, NH 4-N 去除率出现了先升后降的变化趋势. NH 4-N 去除率下降的趋势与Al3 对微生物细胞膜电解质透性的影响规律呈负相关关系,说明Al3 对氨氧化微生物种群的干扰作用最强.     

高效原油降解菌处理油田采出水

利用油田采用废水中原有微生物种群分离驯化出的高效原油降解菌，通过单一菌种高效原油降解菌降解性能实验，高效混合菌正交实验，最佳组合菌株的连续生物处理油田采出水实验，都取得了处理低浓度含油废水的良好效果。这表明在常规物理，化学法处理油田采出水的基础上，利用生物再空度处理是可行的。     

Residual dynamics of thiacloprid in medical herbs marjoram, thyme, and camomile and in soil

Thiacloprid is a new insecticide of the chloronicotinyl family. To assess its risk after application, residual characteristics of thiacloprid in marjoram, thyme, and camomile and in soil were studied under field conditions. The active ingredient was extracted from the plant material using a mixture of acetone-water. After filtration, the extract was concentrated to the aqueous phase, diluted with water, and portioned against ethyl acetate on a matrix solid phase dispersion column. Thiacloprid was extracted from soil using a mixture of methanol-water, filtered, and re.extracted （clean up） with dichloromethane. The residues were quantified using HPLC-MS-MS. The methods were validated by recovery experiments. Thiacloprid residues in marjoram, thyme, and camomile and in soil persisted beyond 10, 14, 14, and 21 d but no residues were detected after 14, 21, 21, and 28 d, respectively. The data obtained in this study indicated that the biexponential model is more suitable than the first-order function to describe the decline of thiacloprid in fresh marjoram, fresh thyme, and dried camomile flowers with half-life （t1/2） of 1.1, 0.7, and 1.2 d, respectively. However, both the first-order function and biexponential model were found to be applicable for dissipation of thiacloprid in soil with almost the same t1/2 values of 3.5 and 3.6 d. The results indicated that thiacloprid dissipates rapidly and does not accumulate in the tested herbs and in soil.     

水中余氯测定方法进展

综述了水体中余氯的分析方法研究进展,对每种分析方法的原理、测定条件、干扰因素及其消除方法、检测限、线性范围及应用对象做了较为详细的论述。     

A conceptual approach to selection of a control measure for residual chlorine discharge in Kuwait bay

It is estimated that some 17 metric tons of residual oxidants (chlorine) are discharged into the enclosed coastal seawater of Kuwait on a daily basis from power-desalination plants alone. Alarmed by the unlimited number of reported cases of damage to marine aquatic systems due to chlorine discharge around the world, several alternatives were proposed to control such a massive discharge of residual oxidant into seawaters. Most of the proposed alternatives lacked the basic criteria necessary for their evaluation, justification, and then selection. The objective of this article is to provide a conceptual approach that can be used to select a control measure for residual oxidant discharge in Kuwait coastal seawaters. This approach is based on state-of-the-art knowledge and the unique operational and environmental factors involved. A matrix system was designed whereby the cost of residual chlorine control alternative, its effectiveness, and environmental and public health impact, performance, and reliability in Kuwait can be compared and evaluated. The selection approach considered currently operating power plants in terms of their engineering design and material (cast iron or steel condensers), current operational conditions, operator's perception, acceptability, and projected problems associated with the environmental management of proposed modifications. The proposed approach revealed that in Kuwait, conventinal chlorination was marginally superseded only by chlorination/dechlorination using SO₂ and operation alteration using process optimization. The overall cost-effective assessment matrix classified other alternatives as worse than chlorination by various degrees. Ozone and UV were found to be the worst and the least desirable alternatives for biofouling control of seawater in Kuwait. In light of the available information on the consequences of the Gulf War on the marine environment, and the potential formation of additional halogenated organic compounds through the reaction of residual chlorine with the released petroleum hydrocarbons, it is essential to control residual chlorine discharged into the nearshore environment of Kuwait.     

A GIS-based approach to spatio-temporal analysis of environmental pollution in urban areas: A case study of Prague's environment extended by LIDAR data

Environmental pollution of urban areas is one of key factors that state authorities and local agencies have to consider in the decision-making process. To find a compromise among many criteria, spatial analysis extended by geostatistical methods and dynamic models has to be carried out. In this case, spatial analysis includes processing of a wide range of air, water and soil pollution data and possibly noise assessment and waste management data. Other spatial inputs consist of data from remote sensing and GPS field measurements. Integration and spatial data management are carried out within the framework of a geographic information system (GIS). From a modeling point of view, GIS is used mainly for the preprocessing and postprocessing of data to be displayed in digital map layers and visualized in 3D scenes. Moreover, for preprocessing and postprocessing, deterministic and geostatistical methods (IDW, ordinary kriging) are used for spatial interpolation; geoprocessing and raster algebra are used in multi-criteria evaluation and risk assessment methods. GIS is also used as a platform for spatio-temporal analyses or for building relationships between the GIS database and stand-alone modeling tools. A case study is presented illustrating the application of spatial analysis to the urban areas of Prague. This involved incorporating environmental data from monitoring networks and field measurements into digital map layers. Extra data inputs were used to represent the 3D concentration fields of air pollutants (ozone, NO₂) measured by differential absorption LIDAR. ArcGIS was used to provide spatial data management and analysis, extended by modeling tools developed internally in the ArcObjects environment and external modules developed with MapObjects. Ordinary kriging methods were employed to predict ozone concentrations in selected 3D locations together with estimates of variability. Higher ozone concentrations were found above crossroads with their heavy traffic than above the surrounding areas. Ozone concentrations also varied with height above the digital elevation model. Processed data, spatial analysis and models are integrated within the framework of the GIS project, providing an approach that state and local authorities can use to address environmental protection issues.     

Assessing the risk of soil contamination in the Swiss Jura using indicator geostatistics

The probability that the concentrations of toxic substances in soil or other medium exceed tolerablemaxima at any unsampled place can be estimated by indicator geostatistics. The method is developed and used to estimate and map the risk of contamination by cadmium, copper and lead in the topsoil of a 14.5 km 2 region in the Swiss Jura. It combines both direct measurements of metal concentrations and thecalibration of a geological map, and it shows that the risk of toxicity is least on Argovian rocks. Two approaches are proposed to divide a region into safe' and 'hazardous' zones on the basis of probability maps. The first declares as contaminated all places where the risk of contamination exceeds a given threshold. The second approach first evaluates the financial costs that might result from a wrongdeclaration, after which the site is allocated to a class so as to minimize that cost. The risk of exposure for humans and animals is generally greater for contaminated agricultural land than for forest soil, and so land use is taken into account in both procedures.     

Determinants of parental effort: a behavioural study in the Eurasian kestrel,Falco tinnunculus

We recorded behaviour of kestrels (Falco tinnunculus) in western Finland during the courtship (1988–1992), incubation (1989–1991), early nestling (age of young 1–2 weeks, 1989–1992) and late nestling stages (3–4 weeks, 1989–1991) to examine determinants of their parental effort (PE). In males, PE was estimated as the hunting effort (the proportion of budget time spent in flight-hunting) and in females as the food provisioning rate (number of prey items delivered to the nest per hour). The following predictions derived from the parental investment theory were examined. (1) Parents rearing large clutches and broods should invest more in breeding than do parents rearing small clutches and broods. The hunting effort of parents did not increase with clutch or brood size, but males tending large broods had a higher prey delivery rate than males tending small broods (Figs 1–2). (2) PE of parents should increase in the course of the breeding season. In males, this was true only between the incubation and early nestling phases (Fig. 3). (3) The early pairs should invest more in breeding than late ones. This tended to be true during the early (for males) and late nestling phases (for females) (Fig. 4). (4) There should be a negative correlation between PE of mates within pairs, but no evidence for such adjustment was found (Fig. 5). (5) Females mated with bright-coloured attractive males should show higher PE than females mated with dull-coloured males but our results were inconsistent with this prediction. We conclude that PE decisions of kestrels are mainly based on cost-benefit estimates of residual reproductive value, rather than on current investment indicators, like clutch or brood size. This might be beneficial in environments with highly variable survival prospects of offspring caused by pronounced among-year variation in abundance of the main food (microtine rodents). The results also show that hypotheses explaining variation in PE in the short term are not necessarily valid for long-term PE, e.g. tending clutches or broods, which also reflects the demands of female and young.     

Study on the effects of organic matter characteristics on the residual aluminum and flocs in coagulation processes

Characteristics of organic matter may affect the residual aluminum after the coagulation process. This study reported the results of a survey for one drinking water treatment plant and measured the concentration of residual aluminum species with different molecular weights.Survey results indicated that humic acid or organic matter whose molecular weight was smaller than 1500 Da had significant effects on residual aluminum. All the treatment processes were ineffective in removing dissolved organic matter whose molecular weight was smaller than1500 Da. These results also indicated that the addition of sand or polyacrylamide in the coagulation process could greatly decrease the concentration of humic acid, and the concentration of residual aluminum also decreased. These results revealed that for all water samples after filtration, the majority of total residual aluminum existed in the form of total dissolved aluminum, accounting for 70%–90%. The concentration of residual aluminum produced in bovine serum albumin solutions indicated that when the DOC was larger than4.0 mg/L, there were still significant differences when the solution p H value varied from 4.0 to 9.0.