Penetration of polar brominated DBPs through the activated carbon columns during total organic bromine analysis

Total organic bromine (TOBr) is a collective parameter representing all the brominated organic disinfection byproducts (DBPs) in water samples. TOBr can be measured using the adsorption-pyrolysis method according to Standard Method 5320B. This method involves that brominated organic DBPs are separated from inorganic halides and concentrated from aqueous solution by adsorption onto the activated carbon (AC). Previous studies have reported that some commonly known brominated DBPs can partially penetrate through the AC during this adsorption step. In this work, the penetration of polar brominated DBPs through AC and ozone-modified AC was explored with two simulated drinking water samples and one chlorinated wastewater effluent sample. Polar brominated DBPs were selectively detected with a novel precursor ion scan method using electrospray ionization-triple quadrupole mass spectrometry. The results show that 3.4% and 10.4% of polar brominated DBPs (in terms of total ion intensity) in the chlorinated Suwannee River fulvic acid and humic acid samples, respectively, penetrated through the AC, and 19.6% of polar brominated DBPs in the chlorinated secondary wastewater effluent sample penetrated through the AC. The ozone-modification of AC minimized the penetration of polar brominated DBPs during the TOBr analysis.     

Monitoring of pharmaceutically active compounds on the Guadalquivir River basin (Spain): occurrence and risk assessment

Guadalquivir River (South of Spain) is among the major freshwater sources of the European Atlantic basin. Until now scientific efforts have been focused on contamination by heavy metals and some priority pollutants in Guadalquivir River. However, the presence of "emerging contaminants", such as pharmaceutically active compounds, has not yet been studied. In this work the occurrence and risk assessment of sixteen pharmaceutically active compounds, belonging to different therapeutic groups, in Guadalquivir River during its course through Seville city are reported. Wastewater effluents from four wastewater treatment plants discharging into Guadalquivir River and river water samples were analyzed. All studied pharmaceutically active compounds, except sulfamethoxazole, trimethoprim, estrone and clofibric acid, were detected in effluent wastewaters at concentration levels up to 28.9 μg L(-1). Among the pharmaceutically active compounds found in effluent wastewater, seven were present in Guadalquivir River samples at concentration levels up to 0.75 μg L(-1), which indicated an important dilution from effluent discharge. Environmental risk assessment reveals that potential ecotoxicological risk cannot be expected on Guadalquivir River at measured concentration levels. Only, the lipid regulator gemfibrozil showed a medium risk for the environment. The risk for acute toxic effects in the environment with the current use of active pharmaceutical ingredients is unlikely. However, the results do not rule out the potential for chronic environmental effects.     

Effectiveness of amendments on re-acidification and heavy metal immobilization in an extremely acidic mine soil

Previous studies have shown that the application of soil amendments is efficient in reducing acidity and heavy metal bioavailability in mine soils. However, it remains a challenge for environmentalists to predict accurately and control economically the re-acidification in re-vegetated mine soils. In this study, net acid generation (NAG) test and bioassay technique were employed to assess the effectiveness of the amendments [including lime, N-P-K (nitrogen, phosphorous and potassium) fertilizer, phosphate and river sediment] on re-acidification and heavy metal immobilization in an extremely acid (pH < 3) mine soil. Our results suggested that NAG test was a rapid and accurate approach to assess the effectiveness of the amendments on re-acidification potential of the mine soil. Interestingly, it was found that phosphate and river sediment played quite specific roles in preventing the re-acidification in the mine soil. In addition, the results also indicated that the addition of 25 t ha(-1) lime combined with river sediment (30%) might be an economical method to successfully control the acidification and re-acidification in the extremely acid mine soil, allowing the re-establishment of the plants. Collectively, our results implied that the combined use of NAG test and bioassay assessment was effective in evaluating a reclamation strategy for extremely acidic mine soils.     

Occurrence and distribution of organophosphorus flame retardants and plasticizers in anthropogenically affected groundwater

Occurrence and distribution of chlorinated and non-chlorinated organophosphates in 72 groundwater samples from Germany under different recharge/infiltration conditions were investigated. Tris(2-chloro-1-methylethyl) phosphate (TCPP) and tris(2-chloroethyl) phosphate (TCEP) were the most frequently detected organophosphates in groundwater samples. Highest individual organophosphate concentrations (>0.1 μg L(-1)) were determined in groundwater polluted by infiltrating leachate and groundwater recharged via riverbank filtration of organophosphate-loaded recipients. In samples from springs and deep groundwater monitoring wells that are not affected by surface waters, organophosphate concentrations were mostly below the limit of detection. The occurrence (3-9 ng L(-1)) of TCPP and TCEP in samples from aquifers with groundwater ages between 20 and 45 years indicates the persistence of both compounds within the aquifer. At urban sites organophosphate-loaded precipitation, surface runoff, and leakage of wastewater influenced groundwater quality. For rural sites, where groundwater recharge is only influenced by precipitation, organophosphates were very rarely detectable in groundwater.     

Presence and partitioning properties of the flame retardants pentabromotoluene, pentabromoethylbenzene and hexabromobenzene near suspected source zones in Norway

The brominated flame retardants (BFRs), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB) and hexabromobenzene (HBB), exhibit physical-chemical properties similar to other persistent organic pollutants, and have been in use as flame retardants for several decades. Data on these BFRs in diverse environmental samples can be found in studies from the 1970s and 1980s, as well as in recent years, though very little in the years in between. Due to a lack of data, the cause for the apparent re-emergence of these BFRs in recent studies is unclear, and could reflect changes in production volumes, accumulation of transformation products from BFR precursors, improved analytical techniques or simply a re-emergence in concern. Very little data are available on their environmentally relevant partitioning properties, which could help to explain the occurrence and fate of these BFRs. In this study we analysed for the presence of HBB, PBT, and PBEB in diverse environmental samples from potential Norwegian BFR source zones. Additionally, environmental partitioning properties of these BFRs as well as brominated benzenes were estimated and validated using experimental data for brominated benzenes. Of the three BFRs, HBB was identified in detectable quantities at most source zones, PBEB only near a metal recycling factory, and PBT only in a few additional locations from where PBEB was detected. Data from this study show that HBB is likely widely distributed, as verified both by chemical analysis and estimated properties. Measured HBB levels in wastewater treatment plants indicate that the treatment practices used in the study locations are not effective at lowering HBB levels, perhaps due to association with low density suspended solids (e.g. microplastics).     

Optical fiber based methodology for assessment of thiocyanate in seawater

A new methodology for the assessment of thiocyanate (SCN(-)) is proposed based on optical fiber (OF) detection coupled to a liquid chromatography system (LC). The developed methodology showed an adequate performance for the analysis of SCN(-) comparable to a high performance liquid chromatography with UV detector (HPLC-UV) methodology: a detection limit of 3 μg L(-1), a linear range from 4 to 400 μg L(-1), and an analytical time of less than 6 min. The OF based methodology was of compact design and easy operation. This simple system has the potential to be used as a sensing approach for SCN(-) in seawater.     

Silver speciation in liver of marine mammals by synchrotron X-ray absorption fine structure and X-ray fluorescence spectroscopies

The chemical form of Ag in the livers of five species of marine mammals was examined using X-ray absorption fine structure (XAFS) and X-ray fluorescence (XRF) spectroscopies. The XAFS analysis suggested that Ag(2)Se was present in the livers of the Franciscana dolphin (Pontoporia blainvillei), Dall's porpoise (Phocoenoides dalli), and Baird's beaked whale (Berardius bairdii), whereas Ag(2)S was present in the livers of the striped dolphin (Stenella coeruleoalba) and pygmy killer whale (Feresa attenuata). XRF spectroscopy results revealed that the distribution patterns of Ag and Se in a thin section of the liver of the Franciscana dolphin were the same; this also implied that Ag was associated with Se in the liver. Thus, the interaction of Ag with Se or S may offer significant protection against the toxicity of Ag in marine mammals. The formation of either Ag(2)Se or Ag(2)S might depend on the Hg levels in the liver. Ag(2)Se was observed in liver samples with relatively high Ag/Hg ratio, whereas liver samples with low Ag/Hg ratio contained Ag(2)S.     

Environmental implications of material leached from coal

Samples of coal were collected from different seams at a South African coal mine and comparative leaching experiments were carried out under various pH conditions and times to investigate the leaching behavior and potential environmental impact of possibly hazardous elements such as As, Cd, Co, Cr, Mn, Ni, Pb, Th and U. The calculated leaching intensities, sequential extraction results and cumulative percentages demonstrate that the leaching behavior of the elements is strongly influenced by the pH, the leaching time and the properties and occurrences of the elements. The leached concentrations of As, Cd, Co, Cr, Mn, Ni and Pb exceeded the maximum concentrations recommended by the Environmental Protection Agency (EPA) for surface water.