Methodology in Air Pollution Studies Using Irradiation Chambers

Experimentation in large irradiation chambers has been useful in providing insight into the chemistry of the photochemical smog formation problem. Initial efforts to reproduce the atmospheric phenomena artificially at controllable scale were successful in that gross atmospheric smog symptoms were observed in irradiation chambers. However, as the experimentation and evidence produced were becoming more elaborate, the question arose as to how much one could rely on chemical data in understanding and interpreting atmsopheric phenomena. The question becomes highly pertinent in view of the difference in concentration levels between atmosphere and chamber work. This issue was discussed during recent American Chemical Society meetings,^4,8 and the conclusions from presentations and discussions were as follows: (1 ) There is qualitative agreement between chamber data and atmospheric data wherever comparison is feasible. (2) There is need for more precise chamber work at concentration levels more nearly equal to those in the atmosphere. Experimentation in chambers under typical atmospheric conditions presents some special problems associated with the chamber design and chemical analysis. Chamber methodology has been the focus of considerable research effort, and it appears to be an important factor affecting further progress in air pollution research. This paper describes methods and techniques used at the Bartlesville Petroleum Research Center.     

Chemical speciation in natural and brine sea waters

A combined approach consisting of monitoring and thermodynamic modeling was used in order to calculate the concentration of trace element species in water samples of a broad salinity range and to explain their chemical behaviour. The study was performed on water samples (fresh, marine, hyper-saline) taken from the area of Burgas Bay, Bulgaria. The ion association model based on Debye-Hückel theory using the sst2008.dat database and the ion interaction model based on Pitzer theory using a new pit2010.dat database were compared and combined for the purposes of this study. The new pit2010.dat database combines the sst2008.dat database and the pitzer.dat database of the PHREEQCI computer program as well as the thermodynamic data for the elements Fe, Mn, Cu, Zn, Cd and Pb and their Pitzer ion interaction parameters. The results showed that: (1) the predominant species in fresh waters were free ions of Mn(2+) (73.6%), Zn(2+) (58.0%) and Cd(2+) ions (78.3%) as well as carbonate species CuCO?? (81.8%), PbCO?? (77.2%) and hydroxy species Fe(OH) ??(55.2%) and Fe(OH)+?(35.6%); (2) an increase in chloride species MeCl2(n)-(n)(n = 1-4, Me = Mn, Zn, Cu, Pb and Cd) and of the hydroxy species Fe(OH)?? for Fe was calculated for sea and hyper-saline water.     

Chemical speciation in waters influenced by lead–zinc metallurgical industry

The Lead–Zinc Company region, Kardjali city, Bulgaria, is known to be highly polluted with heavy metals from its pyrometallurgical activities. The polluted levels and the chemical speciation in surface natural waters in the region as well as in the wastewaters of the factory were investigated in January 2008 by application of monitoring studies, thermodynamic modeling, and interpretation in terms of the “softness–hardness” factor. It was found that the levels of trace metals pollution of surface waters were lower than the legislation limits for the regions with Pb and Zn production. The wastewater treatment facilities of the company were found to operate properly, and the quality of the cleaned waters in station Kar4 was comparable to the other surface waters studied (e.g., station Kar5). The trace metals were divided into three groups: (1) Fe^3?+? and Al^3?+?, being “hard” acids, existed in all the studied waters as hydroxy species Fe(OH) $_{2}^{+}$ , AlOH^2?+?, and Al(OH) $_{2}^{+}$ , followed by the phosphate species AlPO $_{4}^{0}$ and Al₂(OH)₂PO $_{4}^{+}$ ; (2) Mn^2?+?, Zn^2?+?, and Cd^2?+? being “soft” acids with crystal field stabilization energy (CFSE) = 0 were present in natural waters mainly as free Me^2?+? ions. Small concentrations of their MeSO $_{4}^{0}$ , MeCO $_{3}^{0}$ species, and of MeCl $_{2}^{0}$ (Me = Zn, Cd) species were also calculated. In the wastewaters, two more species [Me(SO $_{4})_{2}^{2-}$ and Me(SO $_{4})_{3}^{4-}$ ] of the softer Zn and Cd metals were also calculated; (3) Cu^2?+? and Pb^2?+?, as “soft” acids with CFSE $\ne $ 0 preferentially coordinated with softer CO $_{3}^{2-}$ ions and in natural waters existed mainly as MeCO $_{3}^{0}$ and PbHCO $_{3}^{+}$ , followed by free Me^2?+?ions and MeOH^?+?. In the wastewaters, MeSO $_{4}^{0}$ and Pb(SO $_{4})_{2}^{2-}$ species increased at the expense of the free Me^2?+? ions. The highest self-cleaning capability of natural waters was found with respect to Al and Fe, followed by Mn and Cd. The lowest corresponded to Pb, Cu, and Zn.     

An Evaluation of the Fuel Factor Through Direct Measurement of Photochemical Reactivity of Emissions

Findings in research at the Bureau of Mines Bartlesville Petroleum Research Center show that photochemical reactivities of vehicular emissions are reliably measured in laboratory experiments in which smog manifestations are observed directly. Results of the direct smog-chamber measurements reveal that the photochemical behavior of emissions may differ significantly from the behavior that is predicted from the exhaust composition using reactivity scales. The concept of direct measurement of reactivity was applied to determine differences in characteristics of emissions from 20 passenger vehicles, each tested using 10 different fuels. The primary objective of the fuel study was to assess the over-all effect on vehicle emissions of fuel modifications designed to reduce the photochemical pollution associated with automotive evaporative losses. A similar, brief, comparative study of leaded and nonleaded fuels was also made. Reducing volatility was found to reduce the over-all smog potential of vehicle emissions but involved some penalty by way of increased exhaust emissions. Replacing light olefin with the corresponding paraffin also reduced over-all smog potential and in this case exhaust reactivity was not affected. In general greater smog potential was found to be associated with prototype nonleaded fuels than with leaded fuels typical of products currently marketed.     

Assessing the Conservation Value of New Zealand's Offshore Islands

New Zealand has over 500 offshore islands. Many consist of relatively pristine wilderness and contain a disproportionately large amount of New Zealand's biological wealth. Increased demand for recreation has increased the pressure to develop these areas. Although the New Zealand public has shown widespread support for the preservation and safeguarding of both wilderness areas and endangered species, economic values attached to the benefits of preservation are not known. Using a telephone survey, we found evidence that the public attaches significant value to the conservation of Little Barrier Island. The results show that these values are influenced by different levels and sources of prior information.     

A Decision Support System Approach for Rivers Monitoring and Sustainable Management

This paper presents a Decision Support System (DSS) approach developed in the context of the Copernicus project entitled System for Water Monitoring and Sustainable Management based on Ground Stations and Satellite Images (WATERMAN). The main objective of WATERMAN is the monitoring and management of the Strymon River in the Southern Balkans. The specific DSS integrates the main components of WATERMAN and helps the decision maker to monitor the Strymon region; to control and forecast the quantity and quality of the river water; as well as to make objective decisions about the state of the water based on data provided by radio computers, earth stations and satellite images processed by mathematical and statistical models and Geographical Information Systems (GIS).     

European Union agricultural policy scenarios' impacts on social sustainability of agricultural holdings

This paper aims to assess the impacts of household behaviour on social sustainability by simulating agricultural policy scenarios of the European Union (EU) Common Agricultural Policy (CAP). For this purpose a multicriteria model was formulated, at farm household level, in order to study the social impacts of the CAPs using different scenarios. The scenarios were chosen on the basis of the main EU policies affecting farm households, such as the alternative crops scenario, the Water Framework Directive scenario and the agrienvironmental schemes scenario. The data for this analysis resulted from the CAP-IRE project, a European FP7-funded project. The model includes a utility function with several conflicting criteria such as maximization of gross margin and risk and labour minimization. The model is further used to simulate the impacts on social sustainability by estimating main social indicators. The model is applied in two different farm types in Greece. The results show that the CAP scenarios have multiple social impacts on agricultural holdings, and particularly on the farm labour structure. These impacts have negative effect on social sustainability.     

Bioconcentration of Cd and Ni in various tissues of two marine bivalves living in different habitats and exposed to heavily polluted seawater

Two marine bivalves, Mytilus galloprovincialis and Callista chione, were exposed to various concentrations of cadmium and nickel (0.5, 1.0, 2.5 and 20 ppm), for 20 days, plus 10 days’ depuration period, in a laboratory experiment. Animals from each experimental condition were dissected and the bioaccumulation and distribution of Cd and Ni were determined in their gills, mantles and remaining bodies. The concentrations of Fe and Zn were also measured. Heavy metal tolerance, bioconcentration and distribution of heavy metals in tissues were considerably different in M. galloprovincialis and C. chione: (i) both animals were tolerant to Ni pollution, even at the highest concentration used; (ii) C. chione was more tolerant to Cd; (iii) M. galloprovincialis was a better Cd and Ni accumulator, with the exception of the highest Cd concentration tested, where C. chione accumulated more Cd; (iv) Fe and Zn levels were much more affected in M. galloprovincialis; (v) in general, accumulation and distribution of Ni and Cd in the tissues were metal-, species- and time of exposure- dependent; (vi) significant amounts of heavy metals remained in the tissues after 10 days’ depuration. Our results support a hypothesis for a two competing processes mechanism for metal accumulation and detoxification.     

Procedures in Sampling and Handling Auto Exhaust

Both the composition and discharge rate of auto exhausts vary widely and rapidly as speed and load demands upon the engine are changed. Moreover, among the combustion products are compounds that are highly reactive under proper conditions and others that are readily bound by receptive surfaces or absorbents. Under these conditions both the sampling procedure and subsequent sample handling must be such that (1) the sample that is recovered contains all or a fixed proportion of each incremental volume of the total to be represented and (2) the products so sampled are not allowed either to react with each other or to be lost or diminished in sample storage or transfer. Experimental research and development relevant to each requirement have been carried out, and results are reported and discussed. Two methods have been used for recovering sample-volume samples representative of the total volume produced during any combination of steady or transient engine modes. One employs a servo-followup system appropriately coupled to both the engine air-intake and to the sampling element; the sampling rate is continuously controlled to bear at all times a fixed ratio to the engine air-intake rate. The second method employs variable dilution, involving addition of diluent gas necessary to maintain a constant total of [exhaust + diluent]. If the mixture is sampled at a constant rate, the sample will contain exhaust appropriately proportioned. Experiments have shown differences in both hydrocarbon and NO_x values determined for comparable samples obtained by the two methods. The seriousness of this problem is discussed in relation to the sampling and sample handling procedures that are used.