In-situ electrochemical method for detecting freely dissolved polycyclic aromatic hydrocarbons in water

2014 ◽  
Vol 11 (2) ◽  
pp. 173 ◽  
Author(s):  
Abra Penezić ◽  
Blaženka Gašparović ◽  
Draženka Stipaničev ◽  
Andrew Nelson

Environmental context Polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic compounds found in the atmosphere, soil, sediments and water. They can bioaccumulate in marine organisms where they pose a threat to the health of the organisms. We are developing a low-cost and simple electrochemical method to monitor the concentrations of these compounds in the aquatic environment. Abstract A new sensing system for polycyclic aromatic hydrocarbons (PAHs) in waters is being developed. The system consists of a wafer-based device with a chip-based mercury on platinum microelectrode as a working electrode and a platinum auxiliary electrode, incorporated into a flow cell system with an external reference electrode. The Hg microelectrode was coated with a phospholipid–triglyceride mixed layer and interactions between anthracene, phenanthrene, pyrene and fluoranthene and the layer were monitored using rapid cyclic voltammetry. The layer proved sensitive to interactions with PAHs in ‘organic matter free’ seawater, with respective detection limits of 0.33, 0.35, 0.15 and 0.32μgL–1 for phenanthrene, pyrene, anthracene and fluoranthene. Tested interferences, such as sodium humate, dextran T-500 and bovine serum albumin, representing humic substances, polysaccharides and proteins, did not have an influence on the layer response. The system was also tested with a river water sample where concentrations of PAHs were determined using the standard addition method and compared with the results obtained by using gas chromatography–mass spectrometry (GC-MS). The concentration of total PAHs obtained by the standard addition method is ~80% lower compared with the results obtained by GC-MS analysis. The difference is explained by the fact that the electrochemical method measures water-soluble and free PAHs whereas the chromatographic method measures both dissolved and particulate–organic PAHs.

2020 ◽  
Vol 10 (9) ◽  
pp. 867
Author(s):  
Mikhail V. Milyukin ◽  
Maksym V. Gorban ◽  
Maksym V. Gorban

<div><p>This article presents the monitoring results of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in surface water of the Dnieper River for the period 2011–2019. Total levels of OCPs, PCBs and PAHs consist of 1,4–17,1; 2,8–57,2; and 7,5–378,6 ng/L, respectively. A significant increase in pollution levels was not identified. Research results of the disperse-phase distribution of these substances in water were also provided. Less than half of the total contents of pollutants were in the water phase. Average water-soluble parts of OCPs, PCBs, and PAHs accounted for 32, 42, and 44 %, respectively. It was shown that water-soluble parts of individual pollutants decrease with the increase in <span style="text-decoration: line-through;">the</span> coefficients of hydrophobicity of compounds. The clearest reliable, relevant correlation between water-soluble parts of individual congeners and coefficients of hydrophobicity was obtained for PCBs.</p></div><p align="center"><strong><br /></strong></p>


1995 ◽  
Vol 41 (6) ◽  
pp. 470-476 ◽  
Author(s):  
D. Trzesicka-Mlynarz ◽  
O. P. Ward

A mixed culture, isolated from soil contaminated with polycyclic aromatic hydrocarbons (PAHs), grew on and degraded fluoranthene in aqueous media supplemented with glucose, yeast extract, and peptone. Increased complex nitrogen levels in the medium promoted bacterial growth and a greater extent of fluoranthene degradation. Amendment of the media with high glucose levels also diminished specific fluoranthene degradation. The mixed culture was capable of degrading a range of other PAHs, including benzo[a]pyrene, anthracene, phenanthrene, acenaphthene, and fluorene. The mixed culture contained four predominant isolates, all of which were Gram-negative rods, three of which were identified as Pseudomonas putida, Flavobacterium sp., and Pseudomonas aeruginosa. Better degradation of a defined PAH mixture was observed with the mixed culture than with individual isolates. A reconstituted culture, prepared by combining the four individual isolates, manifested a similar PAH biodegradation performance to the original mixed culture. When compared with the mixed culture, individual isolates exhibited a relatively good capacity to remove more water-soluble PAHs (acenaphthene, fluorene, phenanthrene, fluoranthene). In contrast, removal of less water-soluble PAHs (anthracene and pyrene) was low or negligible with isolated cultures compared with the mixed culture.Key words: polycyclic aromatic hydrocarbons, mixed culture, fluoranthene, Pseudomonas, Flavobacterium.


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