Effluents from petroleum refineries contain a diverse range of pollutants including heavy metals. They also contain oil and grease, phenols, sulphides, dissolved solids, suspended solids and BOD-bearing materials. An overview of heavy metal removal from industrial effluents with emphasis on biological methods is given. Results of studies to remove heavy metals in effluents from a petroleum refinery by water hyacinth were presented. Limited success has been demonstrated for the case of iron and zinc, but further work needs to be done. There is a need to strike the right balance between the possible amount of uptake of heavy metal ions and the tendency to suffocate the ecosystem through the depletion and reduction of light and dissolved oxygen. Similarly there is a need for better understanding of the process of enhancement of the capability the water hyacinth to uptake heavy metal ions before the on-set of toxic accumulation.

Air pollution associated with particulate matters is a serious problem in the mineral products industrial area (MPIA) in Saraburi, central Thailand. PM₁₀ concentrations monitored at Nah Phra Laan station located in the MPIA show that PM₁₀ levels exhibit strong seasonal variations; the number of days in 2005 that PM₁₀ concentrations exceeded the daily National Ambient Air Quality Standard of 120 μg/m³ were 58%, 29%, and 12% in the winter, rainy, and summer seasons, respectively. In this paper, the Hybrid Particle And Concentration Transport (HYPACT) model with meteorological fields from the Regional Atmospheric Modeling System (RAMS) was applied to Saraburi to investigate the impacts of meteorological parameters upon seasonal variations in PM₁₀ concentration. Analysis of model results shows that daily average PM₁₀ concentrations exceeding 200 μg/m³ are found in the downwind direction of emission sources and their horizontal gradients are strong. Hourly PM₁₀ concentrations exhibit obvious diurnal variation with maximum values in wintertime at around 2000-2100 local standard time in association with low ventilation with light wind speed and weak vertical mixing, while in the rainy season, they are generally higher in the daytime than in the nighttime, as that mixing height in cloudy days is low in daytime whereas emission rates are high during working time.

The purpose of this study was to gather information on the spatial and temporal variation of stream water total mercury concentrations ([THg]) and to test the hypothesis that stream water [THg] increases as stream pH decreases in the Shenandoah National Park (SNP). We based our hypothesis on studies in lakes that found mercury methylation increases with decreasing pH, and studies in streams that found total mercury and other trace metal concentrations increase with decreasing pH. Stream water was collected at baseflow in SNP in April, July, and October 2005 and February 2006. Contrary to our hypothesis, stream water [THg] decreased with decreasing pH and acid neutralizing capacity. In SNP, stream pH and acid neutralizing capacity are strongly influenced by bedrock geology. We found that bedrock also influences stream water [THg]. Streams on basaltic bedrock had higher [THg] (0.648 ng L⁻¹ ± 0.39) than streams on siliciclastic bedrock (0.301 ng L⁻¹ ± 0.10) and streams on granitic bedrock (0.522 ng L⁻¹ ± 0.06). The higher pH streams on basaltic bedrock had the highest [THg]. The variation in stream water [THg] occurred despite no known variation in wet deposition of mercury across the SNP. The findings of this study indicate that the SNP can be an important area for mercury research with significant variations in mercury concentrations across the park.

The contents of ten elements [Cd, Pb, W, Zn, Mn, As, Se, Cr, Cu, and organic carbon (Corg)] have been determined in the surficial sediments of Keratsini harbor, Saronikos Gulf, Greece. The contamination of the sediments was assessed on the basis of geoaccumulation index and to corresponding sediment quality guidelines (SQGs) effects range low/effects range median. The results revealed highly elevated Cd, Pb, W, Zn, As, Se, Cr, Cu, and Corg values (Cd, 190-1,763 mg kg⁻¹; Pb, 521-1,263 mg kg⁻¹; W, 38-100 mg kg⁻¹; Zn, 409-6,725 mg kg⁻¹; Mn, 95-1,101 mg kg⁻¹; As, not detectable-1,813 mg kg⁻¹; Se, not detectable-58 mg kg⁻¹; Cr, 264-860 mg kg⁻¹; Cu, 195-518 mg kg⁻¹; and Corg, 0.69-4.41%). The enrichment of metals in the sediments results from the contribution of the central Athens sewage outfall through which the waste of the Attica basin ends up in Keratsini harbor as well as from industrial and ship contaminants.

Hydrophobic modified vermiculite mixed with soil was investigated in biodegradation experiments of naphthalene and anthracene. The experiments had been carried out on mixtures of soil and vermiculite at a proportion of 2%, 10%, and 15% and also in the absence of clay used for control. Biodegradation of the pollutants was followed by the decline of naphthalene and anthracene concentration, measured by CG. Compound mineralization was also proved by the evolution of CO₂. The results showed that in the mixture with a higher proportion of vermiculite biodegradation is enhanced compared to that performed in the absence of vermiculite. In general, when vermiculite proportions are increased, the rate of degradation increases, which may account for the bioavailability of compounds. Bioavailability is an important factor for the degradation of compounds with low solubility. Comparison of biodegradation rates shows that naphthalene is degraded faster than anthracene. The chemical structure could be responsible for this observation. However, although we did not identify the microorganism that was in the soil, we can conclude that vermiculite could be an alternative for the bioavailability of such compounds. Vermiculite in the modified form could also be very useful as a barrier to retain organic pollutants in accidental spills.

The chemical characteristics of the Urauchi River water in Iriomote Island National park, Okinawa, Japan have been studied. Concentrations of PO₄ ³⁻, NO₂ ⁻, and NH₄ ⁺ were barely detectable. We compared the concentration ratios of Mg²⁺/Na⁺, HCO₃ ⁻/Na⁺, and Ca²⁺/Na⁺ in the Urauchi River to those of 60 large rivers in the world and indicated that the chemical composition of the river is most likely formed by the binary mixing of sea salt components and silicate rock weathering components. Although rock weathering in the catchments area is driven by both H₂CO₃ and H₂SO₄, the role of H₂CO₃ is dominant. The percentages of the concentration of each cation in the river water are almost the same as those of other rivers with drainage areas consisting of silicate rock and sandstone. Thus, the Urauchi River shows the typical chemical characteristics of a river in a silicate rock area that includes sandstone.

The effect of exogenously added sodium dodecylbenzenesulphonate (SDBS) surfactant on biodegradation of a mixture of straight-chain aliphatic hydrocarbons (dodecane and hexadecane) and resulting cell surface hydrophobicity changes of Candida maltosa EH 15 were investigated. Results indicated that up to 75 mg/L SDBS improves the biodegradation potential of examined yeast. A decrease in hydrophobicity was observed when SDBS was supplemented in higher concentrations, having strong impact on biodegradation rates. Phase distribution of surfactant molecules was investigated using methylene blue active substances method (MBAS), accompanied by surface and interfacial tension measurements. Studies showed that portion of SDBS molecules adsorbed on cell surface may play significant role in interaction between anionic surfactant and yeast cells, having influence on biodegradation rates.

The extent of pollution with organotin compounds was investigated in water, sediment and bivalve mussels (Mytilus galloprovincialis) from the Northern Adriatic Sea. Butyl-, phenyl- and octyltin species were quantified after extraction and derivatisation by gas chromatography-mass spectrometry in a total of 99 samples from the period from 2000 to 2006. The accuracies of the analytical procedures were checked by spiking of unpolluted water samples and by the analysis of standard reference materials (harbour sediment PACS-2 and mussel tissue ERM-CE 477). Among organotin species analysed in samples butyltins were the predominant. Tributyltin was found to be present in the highest concentrations, suggesting its recent input into the marine environment. Butyltins were detected at all sites surveyed (sum of butyltins was up to 718 ng Sn L⁻¹, 3,552 ng Sn g⁻¹ d.w. and 9,991 ng Sn g⁻¹ d.w. in water, sediment and mussel samples, respectively), phenytins in much lower concentrations (up to 31 ng Sn L⁻¹, 326 ng Sn g⁻¹ d.w. and 442 ng Sn g⁻¹ d.w. in water, sediment and mussel samples) and to a much smaller extent, while octyltins were not detected at any location. The spatial distribution of tributyltin was closely related to boating, with the highest concentrations found in marinas (up to 586 ng Sn L⁻¹ for water samples, 1,995 ng Sn g⁻¹ d.w. for sediment and 6,434 ng Sn g⁻¹ d.w. for mussel samples). The temporal distribution clearly indicates a decrease of organotin pollution at all sites.

Bivalve mussels can concentrate pollutants which, in high amounts, can cause cellular, physiological and behavioral changes. The gill mucus is essential for many metabolic and behavioral procedures on marine mussels including the response to environmental pollution. The present work analyzed the mucous cell number in Mytella falcata gill filaments from three sites of Santos estuary (Brazil) with different levels of sediment contamination named as sites A, B, and C. Site A is located at a low impacted region of the estuary, and sites B and C are under influence of port activities, domestic sewage, and industries like a still mill located in front of site C (the most contaminated area with high amounts of polycyclic aromatic hydrocarbons). An increase in mucous cell number was detected in animals from sites B and C, when compared to site A; this increase occurred preferentially in the frontal zone and was related to sediment contamination. Mucous cell analysis can be used as an efficient biomarker. It is suggested that mucus produced in lateral and abfrontal zones is responsible for eliminating pollutants previously absorbed and mucus produced in frontal zone is responsible for pollutant arrest and elimination as pseudofeces.

The effects of poor indoor air quality and mould growth in working environment are major problems in built environment, and there is a need to look for improvement of the health, comfort and productivity of the building occupants. Airborne mould sampling studies were conducted in a reference building located in Rockhampton, Central Queensland, Australia. Both indoor culturable and mould spore levels were observed. It was found through the indoor-outdoor ratios of the species that indoor concentrations are mostly related to the outdoor mould levels. The moulds differ in their relative humidity and temperature requirements to support surface growth. Indoor humidity has a significant effect on occupants comfort, perceived air quality, occupants' health, building durability, emissions and energy efficiency. Practical hygrothermal simulation models are employed to analyse the combined heat and moisture behaviour within the built environment. A review of the current modelling options available to predict building performance based on energy and mass transport simulation is presented, and then a case study is presented with the assessment of indoor built environment to avoid mould problem.