The aim of this study was to examine the pollution level of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and selected chloroorganic pesticides (HCH isomers, DDT and its metabolites, aldrin, dieldrin, endrin, heptachlor, endosulfan I and II, and methoxychlor) in surface sediments from selected fjords, tidal plains and lakes from the North Svalbard area. The sediments were collected from 34 sampling stations in July 2005. Only endosulfan I and methoxychlor, among selected chloroorganic pesticides, were measured in concentrations near detection limit (LoD) in fourteen sediment samples. The sum of seven PCB congeners varied from < 0.9 to 5.6 ng g-1 d.w. in sediments from fjords and tidal plains and from < 0.1 to 14.6 ng g-1 d.w. in sediments from lakes. The concentrations of analysed PAH compounds in surface sediments from lakes were over ten times higher (Ʃ16PAHs to 429 ng g-1 d.w.) than in sediments from fjords and tidal plains (Ʃ16PAHs to 36 ng g-1 d.w.).
Polycyclic aromatic hydrocarbons (PAHs) constitute a large group of organic compounds that make constant threat to the environment. Their contents from natural sources are low. The processes of incomplete organic fuel combustion are the main sources of PAHs. In Upper Silesia (Poland), large amounts of PAHs are emitted into the air as a result of coal combustion in home furnaces and liquid fuel burning in combustion engines (low emission). PAHs get into surface water because of the surface runoff and point source wastewater discharges from certain industries. The following study presents PAHs concentrations in raw municipal wastewater. The tests were performed out of the heating season. The samples were collected from the combined sewer system. The analyses of PAHs were carried out with gas chromatography coupled with a mass detector (GC-MS). The concentrations of 16 PAHs sum (EPA list) ranged between 1.025 and 3.056 μg/L. Phenanthrene dominated in nearly all the analysed samples. The contents of PAHs, which are priority hazardous substances according to the directive, were high in the analysed samples. The obtained results and the analysis of diagnostic ratios for the emissions of PAHs into the air helped to reach the conclusion that traffic emissions were the main source of PAHs in the examined wastewater.
Compounds present in oil sludge such as polycyclic aromatic hydrocarbons (PAHs) are known to be cytotoxic, mutagenic and potentially carcinogenic. Microorganisms including bacteria and fungi have been reported to degrade oil sludge components to innocuous compounds such as carbon dioxide, water and salts. In the present study, we isolated different bacteria with PAH-degrading capabilities from compost prepared from oil sludge and animal manures. These bacteria were isolated on a mineral base medium and mineral salt agar plates. A total of 31 morphologically distinct isolates were carefully selected from 5 different compost treatments for identification using polymerase chain reaction (PCR) of the 16S rRNA gene with specific primers (universal forward 16S-P1 PCR and reverse 16S-P2 PCR). The amplicons were sequenced and sequences were compared with the known nucleotides from the GenBank. The phylogenetic analyses of the isolates showed that they belong to 3 different clades; Firmicutes, Proteobacteria and Actinobacteria. These bacteria identified were closely related to the genera Bacillus, Arthrobacter, Staphylococcus, Brevibacterium, Variovorax, Paenibacillus, Ralstonia and Geobacillus. The results showed that Bacillus species were predominant in all composts. Based on the results of the degradation of the PAHs in the composts and results of previous studies on bacterial degradation of hydrocarbons in oil, the characteristics of these bacterial isolates suggests that they may be responsible for the breakdown of PAHs of different molecular weights in the composts. Thus, they may be potentially useful for bioremediation of oil sludge during compost bioremediation.
This study is aimed at measuring the effect of pig, cow, horse and poultry manures on the degradation of selected Polycyclic Aromatics Hydrocarbons present in oil sludge. Four kilograms of soil amended with 1.2 kg of oil sludge was mixed with wood chips in a ratio of 1:2 (w:v) soil mixture: wood chips. The mixture was divided into fi ve parts and four parts were separately mixed with pig, cow, horse or poultry manures in a ratio of 2:1 (w:w) and the fi fth portion was used as the control with no manure added. All experiments were incubated for 10 months at room temperature. Compost piles were turned weekly for aeration and moisture level was maintained by adding deionised water enough to prevent the compost from getting dry. Moisture level, pH, temperature, CO2 evolution and oxygen consumption were measured monthly and the ash content of the compost at the end of experimentation. Highest temperature reached was 27.5°C in all compost heaps, pH ranged from 5.5 to 7.8 and CO2 evolution was highest in poultry manure at 18.78 μg/dwt/day. Microbial growth and activities were enhanced as indicated by increase in temperature, moisture level, pH value and respiration rate in all the compost piles. Bacteria capable of utilizing PAHs were isolated, purifi ed and characterized by molecular techniques using polymerase chain reaction with specifi c universal primers and the amplicons were sequenced. Bacteria identifi ed were Bacillus, Arthrobacter and Staphylococcus species. Percentage reduction in PAHs was measured using automated soxhlet extractor with Dichloromethane and gas chromatography/mass spectrometry. Results from PAH concentration measurements showed reduction of between 77% and 99%. Co- -composting of contaminated soil with animal manures enhanced the reduction in PAHs.
The content of polycyclic aromatic hydrocarbons (PAHs) in water and sediments of the Blachownia reservoir (South Poland) was investigated. Spatial variability of PAH concentrations in the longitudinal profi le of the tank was determined. PAHs in samples were determined by gas chromatography coupled with mass spectrometric detection (GC-MS QP-2010 Plus Shimadzu) using an internal standard. Concentrations ranged from 0.103 μg/L to 2.667 μg/L (Σ16 PAHs) in water samples and from 2.329 mg/kg d.w. to 9.078 mg/kg d.w. (Σ16 PAHs) in sediment samples. A pollution balance was calculated and it was estimated that the infl ow load was 17.70 kg PAHs during the year and the outfl ow load was 9.30 kg PAHs per year. Accumulation of about 50% of the annual PAH loads (8.90 kg) is a threat to the ecological condition of the ecosystem. It was calculated that the PAH loads in bottom sediment were about 80 kg, which limits their economic use. Improvement of the ecological status of this type of reservoir can be achieved by removing the sediment. Analysis of the diagnostic ratios obtained for selected PAHs showed that the potential sources of PAH emissions in small agricultural – forest catchments can be combustion of a coal, wood, plant material (low emission, forest fi res, burning grass, etc.). Transportation is also signifi cant.
In Poland, according to the statistical data, about 40% of sewage sludges originating from wastewater treatment plants are applied in the agriculture. The mentioned way of application of sewage sludges causes the hazard of contamination of environment with carcinogenic compounds due to the presence of some organic micropollutants, such as polycyclic aromatic hydrocarbons (PAHs). The proposal of changing UE Directive obligates control of organic pollutants (PAHs and others) in sewage sludges applied in the agriculture. The aim of the investigations was to estimate the persistence of PAHs under stored conditions by determining half-life of their decomposition. Eight carcinogenic PAHs, among 16 compounds, listed by EPA were determined. In this study, the quantity changes in the concentration of PAHs in stored sewage sludges were investigated. Sewage sludges were stored under aerobic conditions for 16 weeks. At the same time the sewage sludges with sodium azide added, in order to deactivate the microorganisms (abiotic samples), were also stored. Gas chromatography-mass spectrometry was used to qualify and quantify PAHs in 2- and 4-week intervals. Sewage sludges were taken two fold from a municipal wastewater treatment plant. In practice, the sewage sludges are directed to the disposal site. The initial concentration of 16 PAHs in sewage sludge was equal to 582 μg/kg.d.m. The changes in the concentration of PAHs corresponded to exponential function. Values of correlation coefficients indicate a significant dependence of PAHs persistence and concentration on time exposition. Under experimental conditions the half-lives of individual compounds were diversed. In biotic samples half-life of hydrocarbons was in the range of 17 to 126 days. Half-life of PAHs in abiotic sewage sludges was in the range of 32 to 2048 days. The most persistent were benzo(a)pyrene and benzo(b) fluoranthene, respectively. A significant dependence of PAHs' decrease on the presence of microorganisms in sewage sludges after 10 weeks of storage was found.