In this paper a novel methodology for estimating the parameters for an extended biokinetic model (Peev, Schönerklee, and De Wever, Water Science and Technology, 2004) of micropollutant removal in wastewater treatment is presented. In particular, the work concentrates on parameter estimation of the micropollutant degradation sub-model by specialised microorganisms in the case when only substrate measurement data are available. We have proven the structural identifiability of the model and have developed a new approach allowing practical identifiability on the basis of multiple substrate degradation curves with different initial concentrations. Experimental and related numerical methods for unambiguous parameter estimation have been developed. Finally, by means of simulated pseudo-experiments we have found convincing indications that the proposed algorithm is stable and yields appropriate parameter estimates even in unfavourable regimes.

Sulfur dioxide (SO₂) is basically resulted from emission of fossil fuel. The ammonia washing is of methods used to remove SO₂ from fuel gas. Several wastewaters contain high ammonia concentrations causing the various problems at wastewater treatment or receiving environment. The synthetic wastewater containing NH₃ was sprayed down as flue gas moved up in the scrubber so that it could be a reaction between SO₂ and NH₃. The effect of NH₃ concentration and pH on SO₂ removal was determined. SO₂ was decreased from about 1,000 to 0, 36, 49 and 66 ppm at NH₃ concentrations of 328, 88, 32 and 9 mg l⁻¹, respectively. While SO₂ of 1,000 ppm was completely treated at 328 mg NH₃ l⁻¹, pH was around 7.16 at the end of process. Consequently, it was recognized that this process could be used for both the SO₂ removal and the wastewater neutralization.

In coastal marshy lands, halogen bromide concentration is reported to be generally higher than in the inland soils where, annual halophytic species naturally grow. The effect of bromide on plant responses is relatively less known. The objectives of this study were to assess the effect of sodium bromide (NaBr) on growth, photosynthetic pigments, tissue ions content and changes in enzymes activity in Salicornia brachiata, a salt marsh halophyte. Presence of NaBr in the root medium induced 200 percent increase in fresh mass and 30% increase in dry mass, compared to untreated control. Relative water content also increased significantly with NaBr treatment. Increase in fresh and dry mass was not associated with high photosynthetic efficiency as evidenced by decrease in photosynthetic pigments accumulation. However, inorganic ion analysis revealed that S. brachiata accumulated Na⁺ as a primary osmotica. The concentration of Na⁺ in NaBr treated plants was ~4 fold higher than that measured in untreated controls and this was associated with significant reduction in K⁺, Ca²⁺, Mg²⁺ contents. Bromide content also increased significantly and accounted for 20 to 50 percent of dry weight. In addition, significant differences in the activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT) and ATPase were observed in bromide treated plants. For the first time bromide tolerance in coastal halophyte was reported and the results suggest that bromide was not toxic to S. brachiata for growth and metabolism even at 600 mM. concentration and suggest that the species can be used in phytoremediation of bromide contaminated soils.

A commercial strain of the fungus Pleurotus ostreatus was used to mediate the degradation of lindane, by landfarming technology during a 4 weeks statistical experiment. The Multilevel Factorial Design was used with two design factors, namely, straw content X ₁ (%) and lindane content X ₂ (ppm). The optimization parameters (responses) investigated were: biodegradation rate Y ₁ (μg d⁻¹), biomass growth rate Y ₂ (mg d⁻¹), biodegradation/biomass Y ₃ (μg mg⁻¹), total organic carbon Y ₄ (%), total organic nitrogen Y ₅ (%) and total organic carbon/total organic nitrogen Y ₆. The optima of the adequate models obtained for the period of 2 and 4-weeks were found. An overall kinetic study, conducted in this work with the aid of experimental design, determined the optimum (maximum) specific lindane degradation rate to be 0.16 g kg⁻¹ month⁻¹.

The objective of this investigation is to analyse the variations of xenobiotic concentrations and the fluxes of dissolved xenobiotics during runoff events in the small rural Mess catchment (35 km²) in the Southwestern part of Luxembourg. Sulfonamides, tetracyclines, analgesics and hormones, dissolved nutrients, sulphate and chloride were measured to gather information about runoff generation. Typically, the highest values can be found during the first flush mainly in the rising limb of the flood hydrographs. The highest concentrations in eleven flood events are measured for ibuprofen (2,383 ng l⁻¹), estrone (27 ng l⁻¹) and diclofenac (20 ng l⁻¹). From the tetracycline group tetracycline (9 ng l⁻¹) itself is of relevance, while the sulfonamides are mainly represented by sulfamethoxazole (5 ng l⁻¹). The variable patterns of chemographs are attributed to the heterogeneous runoff generation characterised by different reactions of storm overflows from the combined sewer systems. During single flood events, the fluxes of ibuprofen (maximum 24,000 mg), 17α-ethinylestradiol (122 mg), 17β-estradiol (32 mg) or estrone (274 mg) are rather low.

Water and sediment were studied to assess the impact of wastes from an area used for a disposal area of treated petrochemical effluents in Rio Grande do Sul, Brazil. The study was performed using the Daphnia magna (Straus 1820) for chronical evaluations, mutagenesis in Salmonella/microsome assays, and micronuclei induction in cultures of V79 cell to assess genotoxicity. Six sites were defined for chronic and genotoxic tests by micronuclei induction with liquid and sediment samples. Long-term tests were planned in semi-static flow, with microcrustaceans 2 to 26 h old in the beginning of assays. The minimum level of reproduction required to maintain the species was not reached. There are delays for the beginning of the reproductive process. Survival was also affected in some samples. The reproductive responses were more sensitive on identifying environmental quality than the survival rate. The study of mutagenicity by Salmonella/microsome assay made it possible to define the seasonality of the components showing greater frequency in winter. The predominant event was the frameshift mutation in assays with the presence of metabolism. However, the cytotoxic activity, although present in all seasons, was less frequent in winter. The genotoxicity analysis in V79 cells exposed to liquid samples from the area also showed that cytotoxicity was the most frequent event. This may have interfered in the detection of a potential micronuclei induction. The results showed that, even after treatment, effluents disposed on the soil continue with active pollutants interfering in cladoceran's quality of life, cellular physiology, and DNA integrity.

Atmospheric mercury deposition by wet and dry processes contributes mercury to terrestrial and aquatic systems. Factors influencing the amount of mercury deposited to boreal forests were identified in this study. Throughfall and open canopy precipitation samples were collected in 2005 and 2006 using passive precipitation collectors from pristine sites located across the Superior National Forest in northern Minnesota, USA. Samples were collected approximately every 2 weeks and analyzed for total (THg) and methyl mercury (MeHg). Forest canopy type and density were the primary influences on THg and MeHg deposition. Highest THg and MeHg concentrations were measured beneath conifer canopies (THg mean = 19.02 ng L⁻¹; MeHg mean = 0.28 ng L⁻¹) followed by deciduous throughfall (THg mean = 12.53 ng L⁻¹; MeHg mean = 0.19 ng L⁻¹) then open precipitation (THg mean = 8.19 ng L⁻¹; MeHg mean = 0.12 ng L⁻¹). The greater efficiency of conifers at scavenging THg and MeHg from the atmosphere may increase the risk of mercury related water quality issues in conifer-dominated systems.

This work is concerned with analysis of the transport trajectories and identification of the probable emission sources of a set of chemical elements monitored in samples of atmospheric precipitation collected in the area of Central Bohemia, Czech Republic. This is based on evaluation of the significance of transport trajectories obtained using the HYSPLIT model for specific periods of duration of the sampled precipitation episodes in dependence on the values of the corrected concentrations of the monitored elements in the individual samples. The proposed method of correction of the measured concentrations of the elements is concerned with elimination of meteorological effects that are unspecific from with respect to the direction of the transport trajectories. The results for the group of elements with higher concentration levels in the sampled precipitation agree with the assumptions on their probable most important sources. The common main source of Na, Mg and Ca is marine aerosol, while K, P and Mn are probably of biogenic origin. The common main sources of Al and Fe--probably terrigenic dust--also correspond to the assumptions. Sulfur does not exhibit a significant predominant direction to the sampling site. Zinc, Cd, Cu and also Si are transported to the greatest degree from the north-westerly direction, indicating the probable effect of large energy-production sources in the area under the Krušné Mountains in the CR or the effect of traffic in the Capital City of Prague. The predominant direction of dispersion of Pb and As is a north-easterly to easterly direction of transport.

Compost enriched with inorganic amendments has been evaluated in laboratory-based experiments for its effectiveness to immobilise heavy metals in contaminated soils. This paper reports the results pertaining to copper (Cu) and cadmium (Cd) only. The inorganic amendments used were naturally occurring zeolite-Clinoptilolite and synthetic iron oxide (Fe₂O₃). A series of experiments have been performed on the amended soils and the results demonstrated that a combination of compost/iron oxide was effective in reducing the uptake of Cu in rye grass (Lolium perenne L.) whereas compost/iron oxide as well as compost/zeolite mixture was effective for reducing Cd uptake. The amended compost performed better in re-vegetating contaminated soil compared to compost or amendments alone. The sequential extraction of the control sample showed that major fraction of both Cu and Cd were associated with organic fraction indicating that the metals might be available to plants under oxidising conditions of soil. The percentage of Cu in the control sample associated with different fractions was in the following order: Organic > Residual > Reducible > Exchangeable fraction whereas for Cd it was: Organic > Reducible > Residual > Exchangeable. The sequential extraction of amended soils showed that exchangeable Cu decreased by 50% to 92% compared to the control. An increase in residual fraction of Cd (up to 40%) was observed in the amended soils. It was concluded that zeolite and/or iron oxide enriched compost can be used effectively for immobilising Cu and Cd in contaminated soils. The effect of amended compost on other metals should be taken into consideration for real field applicaitons.

All commercial gasoline fuels build up deposits on the spark plugs, injectors, oxygen sensors, catalytic converter, and inside the combustion chamber, which will lower the engine's performance and increase air pollution. As a result, fuel-based detergents have been developed to prevent and remove unwanted deposits. Unfortunately, many of the detergents use high amounts of aromatic solvents, which result in a greater risk of exposure to aromatic compounds like benzene. In this study, car exhaust was analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as formaldehyde and acetaldehyde during engine cleaning service using different chemical cleaners. A special device was designed for sampling from car exhaust using solid phase microextraction. The extracted compounds were analyzed using a gas chromatograph with flame ionization detector. The cleaning products were rated with regard to the amount of pollutants produced during the cleaning service.