Sulfur dioxide (SO2) emissions from chemical process plants are increasing at an alarming rate. It is necessary to implement the best methodology to reduce the SO2 emissions. This paper presents physical modeling, computational fluid dynamics (CFD) analysis, and experimental analysis of a packed column used for flue gas desulfurization (FGD) process to reduce SO2 emission at a greater extent. The packed column parameters such as liquid/gas (L/G) ratio, diameter, packed height and total height were determined using physical modeling with two–film gas–liquid absorption theory. Simulation model of the packed column is developed by GAMBIT 2.2.30 and analysis is carried out by FLUENT 6.2.16. In CFD analysis, hydrogen peroxide (H2O2) (with different concentrations) was used as an absorbent. CFD simulation result ensures that when H2O2 is used as a reactant, better removal efficiency is obtained. Based on the physical modeling and CFD analysis, a lab scale packed column was developed. Experimental result showed that 95% SO2 removal efficiency is achieved for 0.1M H2O2 as a reactant. Experimental results agreed excellently with the developed CFD model and can be used for designing industrial packed columns.

Critical habitats of at-risk populations of northeast Pacific “resident” killer whales can be heavily trafficked by large ships, with transits occurring on average once every hour in busy shipping lanes. We modeled behavioral responses of killer whales to ship transits during 35 “natural experiments” as a dose–response function of estimated received noise levels in both broadband and audiogram-weighted terms. Interpreting effects is contingent on a subjective and seemingly arbitrary decision about severity threshold indicating a response. Subtle responses were observed around broadband received levels of 130dB re 1μPa (rms); more severe responses are hypothesized to occur at received levels beyond 150dB re 1μPa, where our study lacked data. Avoidance responses are expected to carry minor energetic costs in terms of increased energy expenditure, but future research must assess the potential for reduced prey acquisition, and potential population consequences, under these noise levels.

The effects of several aquatic environmental factors on the photochemical transformation of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) have been investigated. Ferric ion (Fe(III)) has been found to promote the phototransformation of BDE-47, and this process is further enhanced with the added chloride ion (Cl−), while it is suppressed with increasing pH. Electron spin resonance results show that the formation of hydroxyl radical, and the added Cl− could influence the generation of hydroxyl radical in Fe(III) solution. Hence, Cl− enhances the phototransformation of BDE-47 most probably because of the reaction with Fe(III) species under irradiation, yielding hydroxyl and chloride radicals. These radicals can not only decompose PBDEs, but also lead to their photodebromination and photochlorination. These results indicate that the aquatic environmental factors and Cl− in particular played an important role in the photochemical transformation process of PBDEs, providing insight into the likely fate of PBDEs in the marine environment.

The southern Baltic countries have been identified as significant sources of Hg into the sea. Are anthropogenic activities the sole source? How do meteorological parameters influence the deposition? Studies on input of Hg to the Baltic were conducted in 2008–2012 in the Polish coastal stations. The riverine load was found to depend directly or indirectly on the amount of precipitation and catchment type. Input of atmospheric Hg increased along with the number of precipitation episodes from remote maritime air masses, as well as with the number of days when continental air masses from regional (when domestic heating prevailed) and remote sources moved over the Baltic, during the heating season. During the non-heating season metal input was found to be proportional to episodes of rain from continental regional air masses and to the number of days under influence of continental and maritime air masses from regional sources.

Biosurfactants are surface active materials that are produced by some microorganisms. These molecules increase biodegradation of insoluble pollutants. In this study sediments and seawater samples were collected from the coastline of Bushehr provenance in the Persian Gulf and their biosurfactant producing bacteria were isolated. Biosurfactant producing bacteria were isolated by using an enrichment method in Bushnell-Hass medium with diesel oil as the sole carbon source. Five screening tests were used for selection of Biosurfactant producing bacteria: hemolysis in blood agar, oil spreading, drop collapse, emulsification activity and Bacterial Adhesion to Hydrocarbon test (BATH). These bacteria were identified using biochemical and molecular methods. Eighty different colonies were isolated from the collected samples. The most biosurfactant producing isolates related to petrochemical plants of Khark Island. Fourteen biosurfactant producing bacteria were selected between these isolates and 7 isolates were screened as these were predominant producers that belong to Shewanella alga, Shewanella upenei, Vibrio furnissii, Gallaecimonas pentaromativorans, Brevibacterium epidermidis, Psychrobacter namhaensis and Pseudomonas fluorescens. The largest clear zone diameters in oil spreading were observed for G. pentaromativorans strain O15. Also, this strain has the best emulsification activity and reduction of surface tension, suggesting it is the best of thee isolated strains. The results of this study confirmed that there is high diversity of biosurfactant producing bacteria in marine ecosystem of Iran and by application of these bacteria in petrochemical waste water environmental problems can be assisted.

In a review of the literature on impacts of spilled oil on marshes, 32 oil spills and field experiments were identified with sufficient data to generate recovery curves and identify influencing factors controlling the rate of recovery. For many spills, recovery occurred within 1–2 growing seasons, even in the absence of any treatment. Recovery was longest for spills with the following conditions: Cold climate; sheltered settings; thick oil on the marsh surface; light refined products with heavy loading; oils that formed persistent thick residues; and intensive treatment. Recovery was shortest for spills with the following conditions: Warm climate; light to heavy oiling of the vegetation only; medium crude oils; and less-intensive treatment. Recommendations are made for treatment based on the following oiling conditions: Free-floating oil on the water in the marsh; thicker oil (>0.5cm) on marsh surface; thinner oil (<0.5cm) on marsh surface; heavy oil loading on vegetation; and light to moderate oil loading on vegetation.

In this study, the influence of sediments deposited on the leaves of different mangrove species due to tidal movements on photosynthetic characteristics and chlorophyll fluorescence of the species was explored. The degree of accelerated degradation among different mangrove species was also obtained. Results show that the leaves of mangrove species have varying degrees of sediment deposition. Sediment deposition leads to photosynthetic reduction and physiological stress among Kandelia candel, Aegiceras corniculatum, and Avicennia marina in the Quanzhou Bay. Thus, the deposition of suspended sediments from tidal currents is an important environmental factor that accelerates the degradation of some mangrove species.

Unplanned urban and industrial growth and rise in population are the main factors that had led to air pollution problems. Surface ozone causes human health problems and environmental degradation and acts as a greenhouse gas. Surface ozone is the most significant key substance of photochemical smog. Dependence of air pollutants on meteorology is described with the objective of understanding the prevailing processes pollutants phase interaction. Rigorous measurements of gaseous materials (surface O3, NO2, CO, and SO2) and particulate matter (PM2.5) were carried out regularly during the summer season of 2012 at kerbsite of Agra to assess the characteristics of air pollutants. The air mass trajectories have been calculated using the HYSPLIT 4 and FLEXTRA model. The maximum hourly levels of these pollutants exceeded 116.5 ppb for O3, 96.2 ppb for NO2, 16 ppb for SO2, 4.60ppm for CO and 188µg/m3 for PM2.5. There is obvious diurnal variation in the concentration of surface ozone which clearly follows the diurnal variation of atmospheric temperature. The joint application of principal component analysis and clustering techniques to data collected has led to the recognition of inherent relationships between variables that have been associated with governing processes related to surface O3 formation. The effect of wind on pollutants appears to be noteworthy. We also found that, the maximum average concentrations of SO2 and O3 occurred at humidity ≤30% pinpointing for strong vertical mixing. For CO, NO2 and PM2.5 the maximum average concentrations occurred at humidity below 40%.

This paper summarizes the national inventory of mercury release into all media (air, water, land, impurity in products, general wastes and sector specific disposal) from South Korea, using UNEP mercury Toolkit. Total mercury input and release, distribution into different media, major contributors by source categories are discussed. The total quantified mercury release into different phase media was 284.0 t/y and 281.3 t/y in Level 1 and 2 estimation, respectively. Mercury release from primary metal production, waste incineration, extraction and use of fuels/energy sources were dominant. The replacement of output distribution factors in the Toolkit by real data from mass balance study in the anthropogenic sources resulted decrease in the share of mercury emission into air from 20.6% to 9.6%. Comparison of mercury releases into the atmosphere estimated by the Toolkit Level 2 with real distribution factors data and our earlier estimation with measurements in the selected industries showed only a little discrepancy, with reasonable variation. These differences are due to the use of efficient process technology and air pollution control devices. Since most mercury is released in waste and byproducts, recovery and safe storage issues are to be emphasized in the future studies.

By measuring a battery of cytological and biochemical biomarkers in adult female perch (Perca fluviatilis), the city of Stockholm (Sweden) was investigated as a point source of anthropogenic aquatic pollution. The investigation included both an upstream gradient, 46km westwards through Lake Mälaren, and a downstream gradient, 84km eastwards through the Stockholm archipelago. Indeed, there was a graded response for most of the biomarkers and for the muscle concentrations of ΣPBDE, four organotin compounds and PFOS in the perch. The results indicated severe pollution in central Stockholm, with poor health of the perch, characterised by increased frequency of micronucleated erythrocytes, altered liver apoptosis, increased liver catalase activity, decreased brain aromatase activity, and decreased liver lysosomal membrane stability. Some biomarker responses were lowest in the middle archipelago and increased again eastwards, indicating a second, partly overlapping, gradient of toxic effects from the Baltic Sea.