A model of natural degradation of 17-α-ethinylestradiol in surface water and identification of degradation products by GC-MS

Groundwater pollution with pesticides is a problem that occurs all over the world as well as in Slovenia. Considering the past high loads of groundwater with pesticides, the purpose of the presented research was to determine the presence of pesticides in the groundwater of Krško-Brežiško polje in the period 2018-2019 and to check the applicability of the passive sampling method. A total of 21 groundwater samples were taken at 11 locations and 2 samples each in the Sava and Krka rivers. We identified 15 pesticides and their degradation products. Atrazine and its degradation product desethylatrazine were most frequently determined in groundwater samples. They are followed by desethylterbutylazine, terbutylazine, metolachlor and simazine. Atrazine, desethylatrazine, chlortoluron, metolachlor and terbuthylazine were detected in surface water. A total of 24 samples were taken in groundwater and surface water using the qualitative passive sampling method. We singled out 8 pesticides that appear in two campaigns. The frequency and occurrence of individual pesticides by both methods are comparable. Passive sampling has proven to be an appropriate method of identifying the presence of pesticides. The highest loads in the Krško-Brežiško field arise from the agricultural land areas. Groundwater is more contaminated with pesticides in the central part of the field in the direction of groundwater flow from west to east. In the groundwater of the Krško-Brežice field, atrazine and desethylatrazine are still the most frequently detected pesticides with higher concentrations, despite a 20 years long ban on the use of atrazine-based plant protection products.

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Evidence for the Formation of Difluoroacetic Acid in Chlorofluorocarbon-Contaminated Ground Water

Molecules ◽

10.3390/molecules24061039 ◽

2019 ◽

Vol 24 (6) ◽

pp. 1039 ◽

Cited By ~ 1

Author(s):

Ute Dorgerloh ◽

Roland Becker ◽

Melanie Kaiser

Keyword(s):

Surface Water ◽

Ground Water ◽

Microbial Degradation ◽

Trifluoroacetic Acid ◽

Metabolic Pathways ◽

Urban Areas ◽

Degradation Products ◽

Microbial Transformation ◽

Environmental Media ◽

Difluoroacetic Acid

The concentrations of difluoroacetic acid (DFA) and trifluoroacetic acid (TFA) in rainwater and surface water from Berlin, Germany resembled those reported for similar urban areas, and the TFA/DFA ratio in rainwater of 10:1 was in accordance with the literature. In contrast, nearby ground water historically contaminated with 1,1,2-trichloro-1,2,2-trifluoroethane (R113) displayed a TFA/DFA ratio of 1:3. This observation is discussed versus the inventory of microbial degradation products present in this ground water along with the parent R113 itself. A microbial transformation of chlorotrifluoroethylene (R1113) to DFA so far has not been reported for environmental media, and is suggested based on well-established mammalian metabolic pathways.

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Persulfate-mediated Photocatalytic Degradation of Ciprofloxacin in Water Using Ultraviolet Light and Zero-valent Aluminum

Journal of Photocatalysis ◽

10.2174/2665976x01999200430012009 ◽

2020 ◽

Vol 1 (1) ◽

pp. 67-76

Author(s):

Tugba Olmez-Hanci ◽

Idil Arslan-Alaton

Keyword(s):

Surface Water ◽

Acute Toxicity ◽

Vibrio Fischeri ◽

Degradation Products ◽

Pure Water ◽

Inorganic Ions ◽

Toxicity Tests ◽

Resistant Bacteria ◽

Distilled Water ◽

Uv C

Aims: The study aimed at assessing the effectiveness of the PS/UV-C, PS/ZVA and PS/ZVA/UV-C processes in terms of ciprofloxacin, a fluoroquinolone type commercially important antibiotic, and toxicity abatements in raw surface water (RSW) and distilled water (DW). Background: The occurrence of ciprofloxacin (CIP), the most widely prescribed second-generation fluoroquinolone antibiotic, even at trace level (ng/L) gives rise to antibiotic resistant bacteria and resistance genes, which can further impair the selection of genetic variants of microorganisms and impose adverse effect on human health. Objective: The degradation and detoxification of ciprofloxacin with UV-C (PS/UV-C) and ZVA (PS/ZVA) activated PS oxidation systems were investigated in distilled water (DW) and raw (untreated) surface water (RSW) samples. Moreover, CIP degradation with the PS/ZVA/UV-C heterogeneous photochemical treatment combination was also studied. Methods: The process performances of the investigated treatment systems were evaluated in terms of CIP abatement and PS consumption rates as well as dissolved organic carbon (DOC) removal efficiencies. The influence of common inorganic ions and natural organic matter (NOM) on CIP degradation was evaluated. Radical quenching experiments were conducted using probe compounds in order to elucidate the dominant reaction mechanism. In addition, acute toxicity of the original CIP and its degradation products were questioned by employing Vibrio fischeri (V. fischeri), the marine photobacterium, under optimized treatment conditions. Results: CIP was completely degraded in distilled water (DW) and raw (untreated) surface water (RSW) samples after 15 min of treatment with the PS/UV-C process (PS=0.25mM; pH=3; UVC= 2.7W/m2). PS/UV-C experiments conducted with RSW at its natural pH (=8.5) resulted in 98% CIP and practically no DOC removal whereas 56% DOC was removed at pH 3 after 120 min. Radical quenching studies revealed that sulfate radicals prevailed over hydroxyl radicals. CIP degradation was significantly inhibited by the presence of humic acid due to the effect of UV absorption and free radical quenching. Acute toxicity tests with V. fischeri exhibited fluctuating trends throughout the investigated processes and did not change appreciably after 120 min of oxidation. Conclusion: The results of this study demonstrated that PS/UV-C is superior to the PS/ZVA and PS/ZVA/UV-C treatment systems for both DW and RSW samples in terms of CIP removal rates. No additional positive effect was evident for simultaneous catalytic and photochemical PS activation (PS/ZVA/UV-C treatment system). It could be also demonstrated that the selected oxidation processes conducted in pure water might give an idea about the advanced treatment systems but realistic conditions with actual water/wastewater matrices still need to be further investigated to verify their feasibility and ecotoxicological safety.

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A polarographic investigation on interactions between cu(ii) ions and natural degradation products of a herbicide atrazine

Electroanalysis ◽

10.1002/elan.1140061017 ◽

1994 ◽

Vol 6 (10) ◽

pp. 908-913 ◽

Cited By ~ 5

Author(s):

Irena Grabec ◽

Božidar Ogorevc ◽

Vida Hudnik

Keyword(s):

Degradation Products ◽

Polarographic Investigation ◽

Herbicide Atrazine ◽

Natural Degradation

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Enhanced degradation of micropollutants by zero-valent aluminum activated persulfate: assessment of toxicity and genotoxic activity

Water Science & Technology ◽

10.2166/wst.2017.489 ◽

2017 ◽

Vol 76 (12) ◽

pp. 3195-3204 ◽

Cited By ~ 2

Author(s):

T. Olmez-Hanci ◽

I. Arslan-Alaton ◽

M. Doğan ◽

S. Khoei ◽

H. Fakhri ◽

...

Keyword(s):

Surface Water ◽

Bisphenol A ◽

Vibrio Fischeri ◽

Degradation Products ◽

Distilled Water ◽

Genotoxic Effects ◽

Removal Efficiencies ◽

Relative Inhibition ◽

Activated Persulfate ◽

Enhanced Degradation

Abstract Advanced oxidation of the aqueous Triton™ X-45 (TX-45), iopamidol (IOPA), ciprofloxacin (CIP) and bisphenol A (BPA) solutions via activation of persulfate (PS) with zero-valent aluminum (ZVA) was investigated. The study aimed at assessing the effectiveness of the PS/ZVA process in terms of target micropollutants (MPs) and toxicity abatements in raw surface water (RSW) and distilled water (DW). TX-45, CIP and BPA were completely degraded after 90-minute, 120-minute and 40-minute treatment, respectively, with PS/ZVA in DW, whereas 95% IOPA removal was achieved after 120-minute (MPs = 2 mg/L; ZVA = 1 g/L; PS = 0.25 mM for CIP and BPA; PS = 0.50 mM for TX-45 and IOPA; pH = 3). TX-45 (59%), IOPA (29%), CIP (73%) and BPA (46%) removal efficiencies decreased after 120-minute PS/ZVA treatment in RSW. In DW, Vibrio fischeri toxicities of original (untreated) MPs were found as: CIP (51%) > BPA (40%) > TX-45 (15%) > IOPA (1%), and as BPA (100%) > CIP (66%) > IOPA (62%) > TX-45 (35%) in RSW. Acute toxicities of MPs and their degradation products fluctuated during PS/ZVA treatment both in DW and RSW samples and resulted in different relative inhibition values after 120-minute. The original and PS/ZVA-treated TX-45, IOPA and BPA in DW exhibited neither cytotoxic nor genotoxic effects, whereas CIP oxidation ended up in degradation products with genotoxic effects.

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