Effect of triclosan and its photolysis products on marine bacterium V. fischeri and freshwater alga R. subcapitata.

The use of antibacterial agents in consumer products may lead to adverse effects in waters receiving treated wastewater. Triclosan is one of the antibacterial agents used widely in the world and its high usage leads to relatively high concentrations in wastewater effluents. In this study, the probable effect of triclosan in receiving waters was assessed using different organisms. The EC50 values were 668 ±â€¯80 µg/L and 7.8 ±â€¯0.1 µg/L, for Vibrio fischeri and Raphidocelis subcapitata, respectively, indicating the higher sensitivity of the alga. The toxicity of triclosan upon exposure to UV light decreased for both species, as suggested by the increase in EC50 values (1300 ±â€¯50 µg/L and 8.7 ±â€¯0.6 µg/L for V. fischeri and R. subcapitata, respectively). The effect of photolysis on toxicity reduction was higher for V. fischeri and the EC50 values were similar for direct and indirect photolysis. LC-MS/MS analysis of samples with and without UV exposure suggested a decrease in triclosan concentration as well as formation of photolysis byproducts upon photolysis.

Anaerobic Biodegradation of Alternative Fuels and Associated Biocorrosion of Carbon Steel in Marine Environments.

Fuels that biodegrade too easily can exacerbate through-wall pitting corrosion of pipelines and tanks and result in unintentional environmental releases. We tested the biological stability of two emerging naval biofuels (camelina-JP5 and Fischer-Tropsch-F76) and their potential to exacerbate carbon steel corrosion in seawater incubations with and without a hydrocarbon-degrading sulfate-reducing bacterium. The inclusion of sediment or the positive control bacterium in the incubations stimulated a similar pattern of sulfate reduction with different inocula. However, the highest rates of sulfate reduction were found in incubations amended with camelina-JP5 [(57.2 ± 2.2)-(80.8 ± 8.1) µM/day] or its blend with petroleum-JP5 (76.7 ± 2.4 µM/day). The detection of a suite of metabolites only in the fuel-amended incubations confirmed that alkylated benzene hydrocarbons were metabolized via known anaerobic mechanisms. Most importantly, general (r(2) = 0.73) and pitting (r(2) = 0.69) corrosion were positively correlated with sulfate loss in the incubations. Thus, the anaerobic biodegradation of labile fuel components coupled with sulfate respiration greatly contributed to the biocorrosion of carbon steel. While all fuels were susceptible to anaerobic metabolism, special attention should be given to camelina-JP5 biofuel due to its relatively rapid biodegradation. We recommend that this biofuel be used with caution and that whenever possible extended storage periods should be avoided.

Ozonation in advanced treatment of secondary municipal wastewater effluents for the removal of micropollutants.

The objective of this study was the experimental evaluation of ozonation as an additional treatment step for the removal emerging contaminants from secondary effluents of two wastewater treatment plants (WWTPs), one receiving a primarily domestic wastewater (WWTP-A), and the other one domestic sewage together with pretreated tannery wastewater streams (WWTP-B). The experimental runs were conducted at two different pH values (i.e., original pH and adjusted pH of 10) and at six different ozone doses ranging between 0.2 and 1.5 mg O3/mg DOC. A total of 20 compounds, including 12 micropollutants (MPs) and 8 metabolites, were selected as the target analytes for the evaluation of ozonation performance. When the tested MPs and metabolites were considered individually, the maximum elimination level for each compound was reached at different doses; therefore, optimum ozone doses were determined based on the reduction of the total MP content. Ozonation at the original pH with an ozone dose in the range of 0.4-0.6 and 0.8-1.0 mg O3/mg DOC was selected as the optimum operating condition for WWTP-A and WWTP-B, respectively, both resulting in an average overall removal efficiency of 55%. Ozone treatment yielded only poor elimination for o-desmethyl naproxen (15%), which was found to be by far the main contributor accounting alone for approximately 30% of the total MP concentration in the secondary effluents. The systematic approach used in this study could well be adopted as a guide to other domestic and municipal WWTPs, which are thought to have a highly variable composition in terms of the MPs and metabolites.

Respirometric evaluation of a mixture of organic chemicals with different biodegradation kinetics.

The study evaluated the biodegradation characteristics of a mixture of organics with different biodegradation characteristics in an integrated chemical plant effluent. The wastewater had a total chemical oxygen demand (COD) content of 12,800mg/L, mostly soluble and 93% biodegradable. The evaluation was based on respirometry, and mainly consisted on model calibration and interpretation of the oxygen uptake rate data, which exhibited an original and specific profile with a sequence of two peaks and three plateaus. A specific model was defined for this purpose, which identified four different biodegradable COD components with significantly different process kinetics. The major fraction accounting for 57% of the total biodegradable COD in the wastewater had to be hydrolyzed before biodegradation with a low hydrolysis rate of 1.3day(-1). The analysis of the experimental data showed that the oxygen utilization started with a delayed response after substrate addition. The delayed logarithmic phase could be characterized by a Haldane type of inhibition kinetics.

Anaerobic biodegradation of biofuels and their impact on the corrosion of a Cu-Ni alloy in marine environments.

Fuel biodegradation linked to sulfate reduction can lead to corrosion of the metallic infrastructure in a variety of marine environments. However, the biological stability of emerging biofuels and their potential impact on copper-nickel alloys commonly used in marine systems has not been well documented. Two potential naval biofuels (Camelina-JP5 and Fisher-Tropsch-F76) and their petroleum-derived counterparts (JP5 and F76) were critically assessed in seawater/sediment incubations containing a metal coupon (70/30 Cu-Ni alloy). Relative to a fuel-unamended control (1.2 ±â€¯0.4 µM/d), Camelina-JP5 (86.4 ±â€¯1.6 µM/d) and JP5 (77.6 ±â€¯8.3 µM/d) stimulated much higher rates of sulfate reduction than either FT-F76 (11.4 ±â€¯2.7 µM/d) or F76 (38.4 ±â€¯3.7 µM/d). The general corrosion rate (r2 = 0.91) and pitting corrosion (r2 = 0.92) correlated with sulfate loss in these incubations. Despite differences in microbial community structure on the metal or in the aqueous or sediment phases, sulfate reducing bacteria affiliated with Desulfarculaceae and Desulfobacteraceae became predominant upon fuel amendment. The identification of alkylsuccinates and alkylbenzylsuccinates attested to anaerobic metabolism of fuel hydrocarbons. Sequences related to Desulfobulbaceae were highly enriched (34.2-64.8%) on the Cu-Ni metal surface, regardless of whether the incubation received a fuel amendment. These results demonstrate that the anaerobic metabolism of biofuel linked to sulfate reduction can exacerbate the corrosion of Cu-Ni alloys. Given the relative lability of Camelina-JP5, particular precaution should be taken when incorporating this hydroprocessed biofuel into marine environments serviced by a Cu-Ni metallic infrastructure.

Metabolomic and Metagenomic Analysis of Two Crude Oil Production Pipelines Experiencing Differential Rates of Corrosion.

Corrosion processes in two North Sea oil production pipelines were studied by analyzing pig envelope samples via metagenomic and metabolomic techniques. Both production systems have similar physico-chemical properties and injection waters are treated with nitrate, but one pipeline experiences severe corrosion and the other does not. Early and late pigging material was collected to gain insight into the potential causes for differential corrosion rates. Metabolites were extracted and analyzed via ultra-high performance liquid chromatography/high-resolution mass spectrometry with electrospray ionization (ESI) in both positive and negative ion modes. Metabolites were analyzed by comparison with standards indicative of aerobic and anaerobic hydrocarbon metabolism and by comparison to predicted masses for KEGG metabolites. Microbial community structure was analyzed via 16S rRNA gene qPCR, sequencing of 16S PCR products, and MySeq Illumina shotgun sequencing of community DNA. Metagenomic data were used to reconstruct the full length 16S rRNA genes and genomes of dominant microorganisms. Sequence data were also interrogated via KEGG annotation and for the presence of genes related to terminal electron accepting (TEA) processes as well as aerobic and anaerobic hydrocarbon degradation. Significant and distinct differences were observed when comparing the 'high corrosion' (HC) and the 'low corrosion' (LC) pipeline systems, especially with respect to the TEA utilization potential. The HC samples were dominated by sulfate-reducing bacteria (SRB) and archaea known for their ability to utilize simple carbon substrates, whereas LC samples were dominated by pseudomonads with the genetic potential for denitrification and aerobic hydrocarbon degradation. The frequency of aerobic hydrocarbon degradation genes was low in the HC system, and anaerobic hydrocarbon degradation genes were not detected in either pipeline. This is in contrast with metabolite analysis, which demonstrated the presence of several succinic acids in HC samples that are diagnostic of anaerobic hydrocarbon metabolism. Identifiable aerobic metabolites were confined to the LC samples, consistent with the metagenomic data. Overall, these data suggest that corrosion management might benefit from a more refined understanding of microbial community resilience in the face of disturbances such as nitrate treatment or pigging, which frequently prove insufficient to alter community structure toward a stable, less-corrosive assemblage.

Silver nanoparticles: a mechanism of action on moulds.

Silver nanoparticles (AgNPs) are widely used in all branches of industry. However, their mechanisms of action towards moulds have not been studied yet. Thus we conducted this study in which we have used laser desorption/ionization time-of-flight mass spectrometry (LDI-ToF-MS) analysis to determine metabolomic changes, and microscopic analysis (transmission electron microscopy, fluorescent microscopy) to observe changes in mould cells. The AgNP treatment caused the downregulation of 162 (15 ppm) and 284 (62 ppm), and 19 (15 ppm) and 29 (62 ppm) metabolites of Aspergillus niger and Penicillium chrysogenum, respectively. All influenced features were below m/z 600 (mass-to-charge ratio). We have observed silver ions and their clusters (Ag, Ag2, and Ag3) accumulated in the mould mycelium. As well as, mono-silver ion adducts with nucleotide derivatives (Coenzyme A), amino acids (phenylglycine), peptides (LeuSerAlaLeuGlu) and lipids (fatty acids, diacylglycerophosphoglycerols, monoglicerides and glycerophospholipids). The ultrastructure analysis revealed many sever alterations due to the action of AgNPs, such us shortening and condensation of hyphae, ultrastructural reorganisation, cell plasmolysis, increased vacuolisation, numerous membranous structures, collapsed cytoplasm, accumulation of lipid material, condensed mitochondria, disintegration of organelles, nuclear deformation, condensation and fragmentation of chromatin, creation of apoptotic bodies, as well as a new inside cell wall in P. chrysogenum.

A rating system for determination of hazardous wastes.

Although hazardous waste lists and their classification methodologies are nearly the same in most of the countries, there are some gaps and subjectiveness in determining the waste as hazardous waste. A rating system for the determination of waste as a hazardous waste is presented in this study which aims to overcome the problems resulted from the existing methodologies. Overall rating value (ORV) calculates and quantifies the waste as regular, non-regular or hazardous waste in an "hourglass" scale. "ORV" as a cumulative-linear formulation in proposed model consists of components such as ecological effects of the waste (Ee) in terms of four main hazard criteria: ignitability, reactivity, corrosivity and toxicity; combined potential risk (CPR) including carcinogenic effect, toxic, infectious and persistence characteristics; existing lists and their methodology (L) and decision factor (D) to separate regular and non-regular waste. Physical form (f) and quantity (Q) of the waste are considered as factors of these components. Seventeen waste samples from different sources are evaluated to demonstrate the simulation of the proposed model by using "hourglass" scale. The major benefit of the presented rating system is to ease the works of decision makers in managing the wastes.

Acute and chronic responses of denitrifying culture to diclofenac.

Acute and chronic effect as well as biodegradation potential at different sludge retention times (SRTs) of a priority pollutant, diclofenac on denitrification process was assessed. The continuous amendment of the culture for 6months with 1µg/L diclofenac resulted in 30% decrease in gas production. The average diclofenac removal observed in the diclofenac-acclimated culture was less than 15%. Batch tests showed that nitrate was removed in diclofenac free-control reactor at a higher rate compared to diclofenac amended reactor. Although, SRT did not have any progressive effect on diclofenac degradation, the system operated at low SRT was more sensitive to diclofenac and resulted in an increase in N2O emission. Wastewater treatment plants (WWTPs) operated at higher SRTs may tolerate and recover from the adverse effects of such micropollutants. The study can lead to other researchers to understand the fate and effect of other emerging pollutants in the anoxic unit of WWTPs.

Mass spectrometric metabolomic imaging of biofilms on corroding steel surfaces using laser ablation and solvent capture by aspiration.

Ambient laser ablation and solvent capture by aspiration (LASCA) mass spectrometric imaging was combined with metabolomics high-performance liquid chromatography (HPLC) mass spectrometry analysis and light profilometry to investigate the correlation between chemical composition of marine bacterial biofilms on surfaces of 1018 carbon steel and corrosion damage of steel underneath the biofilms. Pure cultures of Marinobacter sp. or a wild population of bacteria present in coastal seawater served as sources of biofilms. Profilometry data of biofilm-free surfaces demonstrated heterogeneous distributions of corrosion damage. LASCA data were correlated with areas on the coupons varying in the level of corrosion attack, to reveal differences in chemical composition within biofilm regions associated with corroding and corrosion-free zones. Putative identification of selected compounds was carried out based on HPLC results and subsequent database searches. This is the first report of successful ambient chemical and metabolomic imaging of marine biofilms on corroding metallic materials. The metabolic analysis of such biofilms is challenging due to the presence in the biofilm of large amounts of corrosion products. However, by using the LASCA imaging interface, images of more than 1000 ions (potential metabolites) are generated, revealing striking heterogeneities within the biofilm. In the two model systems studied here, it is found that some of the patterns observed in selected ion images closely correlate with the occurrence and extent of corrosion in the carbon steel substrate as revealed by profilometry, while others do not. This approach toward the study of microbially influenced corrosion (MIC) holds great promise for approaching a fundamental understanding of the mechanisms involved in MIC.

S2O8(2-)/UV-C and H2O2/UV-C treatment of Bisphenol A: assessment of toxicity, estrogenic activity, degradation products and results in real water.

The performance of S2O8(2-)/UV-C and H2O2/UV-C treatments was investigated for the degradation and detoxification of Bisphenol A (BPA). The acute toxicity of BPA and its degradation products was examined with the Vibrio fischeri bioassay, whereas changes in estrogenic activity were followed with the Yeast Estrogen Screen (YES) assay. LC and LC-MS/MS analyses were conducted to determine degradation products evolving during photochemical treatment. In addition, BPA-spiked real freshwater samples were also subjected to S2O8(2-)/UV-C and H2O2/UV-C treatment to study the effect of a real water matrix on BPA removal and detoxification rates. BPA removal in pure water was very fast (⩽7 min) and complete via both H2O2/UV-C and S2O8(2-)/UV-C treatment, accompanied with rapid and significant mineralization rates ranging between 70% and 85%. V.fischeri bioassay results indicated that degradation products being more toxic than BPA were formed at the initial stages of H2O2/UV-C whereas a rapid and steady reduction in toxicity was observed during S2O8(2-)/UV-C treatment in pure water. UV-C treatment products exhibited a higher estrogenic activity than the original BPA solution while the estrogenicity of BPA was completely removed during H2O2/UV-C and S2O8(2-)/UV-C treatments parallel to its degradation. 3-methylbenzoic and 4-sulfobenzoic acids, as well as the ring opening products fumaric, succinic and oxalic acids could be identified as degradation products. BPA degradation required extended treatment periods (>20 min) and TOC removals were considerably retarded (by 40%) in the raw freshwater matrix most probably due to its natural organic matter content (TOC=5.1 mg L(-1)). H2O2/UV-C and S2O8(2-)/UV-C treatment in raw freshwater did not result in toxic degradation products.

Metabolomic and high-throughput sequencing analysis-modern approach for the assessment of biodeterioration of materials from historic buildings.

Preservation of cultural heritage is of paramount importance worldwide. Microbial colonization of construction materials, such as wood, brick, mortar, and stone in historic buildings can lead to severe deterioration. The aim of the present study was to give modern insight into the phylogenetic diversity and activated metabolic pathways of microbial communities colonized historic objects located in the former Auschwitz II-Birkenau concentration and extermination camp in Oswiecim, Poland. For this purpose we combined molecular, microscopic and chemical methods. Selected specimens were examined using Field Emission Scanning Electron Microscopy (FESEM), metabolomic analysis and high-throughput Illumina sequencing. FESEM imaging revealed the presence of complex microbial communities comprising diatoms, fungi and bacteria, mainly cyanobacteria and actinobacteria, on sample surfaces. Microbial diversity of brick specimens appeared higher than that of the wood and was dominated by algae and cyanobacteria, while wood was mainly colonized by fungi. DNA sequences documented the presence of 15 bacterial phyla representing 99 genera including Halomonas, Halorhodospira, Salinisphaera, Salinibacterium, Rubrobacter, Streptomyces, Arthrobacter and nine fungal classes represented by 113 genera including Cladosporium, Acremonium, Alternaria, Engyodontium, Penicillium, Rhizopus, and Aureobasidium. Most of the identified sequences were characteristic of organisms implicated in deterioration of wood and brick. Metabolomic data indicated the activation of numerous metabolic pathways, including those regulating the production of primary and secondary metabolites, for example, metabolites associated with the production of antibiotics, organic acids and deterioration of organic compounds. The study demonstrated that a combination of electron microscopy imaging with metabolomic and genomic techniques allows to link the phylogenetic information and metabolic profiles of microbial communities and to shed new light on biodeterioration processes.

Optimization of diclofenac quantification from wastewater treatment plant sludge by ultrasonication assisted extraction.

A rapid quantification method of diclofenac from sludge samples through ultrasonication assisted extraction and solid phase extraction (SPE) was developed and used for the quantification of diclofenac concentrations in sludge samples with liquid chromatography/tandem mass spectrometry (LC-MS/MS). Although the concentration of diclofenac in sludge samples taken from different units of wastewater treatment plants in Istanbul was below the limit of quantification (LOQ; 5ng/g), an optimized method for sludge samples along with the total mass balances in a wastewater treatment plant can be used to determine the phase with which diclofenac is mostly associated. Hence, the results will provide information on fate and transport of diclofenac, as well as on the necessity of alternative removal processes. In addition, since the optimization procedure is provided in detail, it is possible for other researchers to use this procedure as a starting point for the determination of other emerging pollutants in wastewater sludge samples.

Seasonal variation of diclofenac concentration and its relation with wastewater characteristics at two municipal wastewater treatment plants in Turkey.

The pharmaceutically active compound diclofenac has been monitored during one year at separate treatment units of two municipal wastewater treatment plants (WWTPs) to evaluate its seasonal variation and the removal efficiency. Conventional wastewater characterization was also performed to assess the possible relationship between conventional parameters and diclofenac. Diclofenac concentrations in the influent and effluent of both WWTPs were detected in the range of 295-1376 and 119-1012ng/L, respectively. Results indicated that the higher diclofenac removal efficiency was observed in summer season in both WWTPs. Although a consistency in diclofenac removal was observed in WWTP_1, significant fluctuation was observed at WWTP_2 based on seasonal evaluation. The main removal mechanism of diclofenac in the WWTPs was most often biological (55%), followed by UV disinfection (27%). When diclofenac removal was evaluated in terms of the treatment units in WWTPs, a significant increase was achieved at the treatment plant including UV disinfection unit. Based on the statistical analysis, higher correlation was observed between diclofenac and suspended solids concentrations among conventional parameters in the influent whereas the removal of diclofenac was highly correlated with nitrogen removal efficiency.

Analysis, occurrence and fate of commonly used pharmaceuticals and hormones in the Buyukcekmece Watershed, Turkey.

The occurrence of 14 mostly used pharmaceuticals from different classes (antibiotics, ß-blockers, non-steroidal anti-inflammatory drugs, and stimulant) and hormones in surface water in Istanbul, Turkey was investigated in this study. An important drinking water source, Buyukcekmece Lake and main rivers flowing into the lake were selected for the monitoring of the compounds. Sampling was conducted five different times in a year in order to observe seasonal changes. A rapid, robust and sensitive method using solid phase extraction and ultra-performance liquid chromatograph coupled with triple quadrupole tandem mass spectrometer was established for quantification of both pharmaceuticals and hormones. Limit of quantifications were between 0.5 and 1.1 ng L(-1). Recoveries were between 72-119% and 61-98% for ultra-pure water and for surface water, respectively. All selected compounds were detected at least once in the samples. Some pharmaceuticals were detected as high as a few of micrograms per liter levels in the rivers. Most frequently detected compounds were caffeine and antibiotics (amoxicillin, ciprofloxacin, erythromycin and sulfamethoxazole). Synthetic hormone (17α-ethynylestradiol) was detected only 4times corresponding least detected compound in whole sampling period. Field data confirms that amoxicillin is more prone to degradation with respect to other antibiotics. Estrone and 17-ß estradiol are converted to estriol by natural processes in surface water.

Occurrence of THM and NDMA precursors in a watershed: Effect of seasons and anthropogenic pollution.

In pristine watersheds, natural organic matter is the main source of disinfection by-product (DBP) precursors. However, the presence of point or non-point pollution sources in watersheds may lead to increased levels of DBP precursors which in turn form DBPs in the drinking water treatment plant upon chlorination or chloramination. In this study, water samples were collected from a lake used to obtain drinking water for Istanbul as well as its tributaries to investigate the presence of the precursors of two disinfection by-products, trihalomethanes (THM) and N-nitrosodimethylamine (NDMA). In addition, the effect of seasons and the possible relationships between these precursors and water quality parameters were evaluated. The concentrations of THM and NDMA precursors measured as total THM formation potential (TTHMFP) and NDMA formation potential (NDMAFP) ranged between 126 and 1523µg/L THM and <2 and 1648ng/L NDMA, respectively. Such wide ranges imply that some of the tributaries are affected by anthropogenic pollution sources, which is also supported by high DOC, Cl(-) and NH(3) concentrations. No significant correlation was found between the water quality parameters and DBP formation potential, except for a weak correlation between NDMAFP and DOC concentrations. The effect of the sampling location was more pronounced than the seasonal variation due to anthropogenic pollution in some tributaries and no significant correlation was obtained between the seasons and water quality parameters.