In view of the global concern about the occurrence of taste and odor (T&O) compounds in waters for drinking water supply and the necessity for the development of more innovative and efficient ...technologies for water treatment and depuration, the focus of this study is to provide a state of the art overview on current knowledge for the application of advanced oxidation technologies for the treatment of T&O compounds in aquatic media. The most representative and newly emerging compounds belonging to the major groups of T&O compounds, such as geosmin, methylisoborneol, benzothiazoles, mercaptans and sulfides as well as aromatic and other miscellaneous T&O compounds, are included in the systematic overview. The current data has been compiled and extensively discussed in terms of the degree of degradation, reaction kinetics, effect of operational parameters and water quality, identity of intermediate and final products and possible transformation pathways.
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•The applications of AOPs for the treatment of T&O compounds in water are reviewed.•AOPs exhibited fast kinetics and great degrees of mineralization of T&O compounds.•The main effects of operational parameters and water constituents are discussed.•An overview of the transformation products and reaction mechanisms is provided.•Data gaps and future research needs of AOPs for T&O removal have been assessed.
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•Photocatalytic degradation and mineralization kinetics of DEET were studied.•Degradation products were elucidated using HR-LC–MS and GC–MS techniques.•Hydroxy-methylcyclohexadienyl ...radicals were detected as initial DPs by EPR.•The acute toxicity of DEET and its TPs was assessed along photocatalytic treatment.
Analytical and electron paramagnetic resonance (EPR) spectroscopic methods were systematically used for the kinetic and mechanistic investigation of the photocatalytic degradation of N,N-diethyl-m-toluamide (DEET), in aqueous TiO2 suspensions under simulated solar light. The degradation of DEET followed first-order kinetics while enhanced reduction (>85%) of total organic carbon (TOC) and stoichiometric transformation of nitrogen to nitrate and ammonium ions took place after 240min of irradiation. Numerous different structures of transformation products (TPs), with at least one isomer for the majority of them, were identified with high resolution accurate mass liquid chromatography (HR-LC–MS) and gas chromatography mass spectrometry (GC–MS). Low temperature EPR spectroscopy was used to study the photoinduced radicals created during the initial events of the photocatalytic oxidation. Two kinds of aromatic ring carbon-centered radicals i.e. hydroxy-methylcyclohexadienyl radicals have been resolved at 77K. The second-transient conformation of the radicals is maximized after 5min. of irradiation and then slowly decays. On the basis of identified products and radicals, a proposed pathway of photocatalytic degradation of DEET is presented, involving mono- and polyhydroxylation and/or oxidation, dealkylation and continuously the opening of the aromatic ring. Scavenging experiments indicated the contribution of OH as the main species in the DEET oxidation while O2- contributes also to the degradation in a lesser extend after the initial steps of the reaction. Finally, toxicity studies based on luminescence of Vibrio fischeri bacteria before and after the photocatalytic treatment were also performed.
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•N,S-doped TiO2 photocatalysts have been prepared by sol–gel.•N,S-TiO2 catalysts showed low crystallite sizes and visible-light response.•Photocatalytic activity was evaluated towards ...TCPP degradation in aqueous solutions.•N-doped TiO2 was found the most photoactive catalyst under UV–vis light.•N,S-TiO2 with equimolar Ti:N,S ratio showed the higher activity under visible light.
N and N,S co-doped TiO2 catalysts were prepared by a simple sol–gel method and were characterized by various techniques such as X-ray diffraction, scanning electron microscopy, UV–vis spectroscopy, porosimetry and particle size distribution. The photocatalytic efficiency of the prepared catalysts was evaluated for the degradation of organophosphorus flame retardant TCPP in aqueous solutions at environmental relevant concentrations under UV–vis and visible light irradiation. All the prepared N and N,S doped catalysts showed lowered crystallite size and higher visible-light response compared to the undoped TiO2 catalyst. An increased surface acidity was observed for N,S co-doped catalysts as a result of surface sulfate species which play a crucial role in the photocatalytic performance. N-doped TiO2 was found to be the most photoactive catalyst for the removal of TCPP, under UV–vis irradiation. Among N,S co-doped TiO2 catalysts, the one prepared with equimolar Ti:N,S ratio showed the higher performance for the removal of TCPP under both UV–vis and visible irradiation. Its higher activity was attributed to the higher surface area, larger pore volume, well-crystallized anatase and red shift in light absorption. Under visible light irradiation the degradation kinetics of TCPP were slower than under UV–vis irradiation due probably to reduced production of hydroxyl radicals.
•The photocatalytic degradation of IPMP in aqueous solution was investigated in detail.•Eleven intermediates identified using HR-LC–MS and GC–MS techniques.•Photogenerated •OH radicals were ...principally responsible for the degradation of IPMP.•Almost total detoxification of the irradiated solution after 300min.
In recognition of the growing demand regarding the control of undesired taste and odor (T&O) problems in natural water resources, the photocatalytic degradation of 2-isopropyl-3 methoxy pyrazine (IPMP), a common metabolite of soil actinomycetes which contributes a rotten vegetable odor to water, was investigated under simulated solar irradiation. Under the studied conditions (C=10mgL−1, CTiO2=100 mg L−1 and I=600Wm−2), 95% of IPMP was removed within 20min of irradiation. The reaction intermediates were completely mineralized to CO2 and the nitrogen was predominantly released as NH4+ ions after 240min irradiation. The major transformation products of TiO2 photocatalysis of IPMP have been determined by the use of high resolution accurate liquid chromatography–orbitrap mass spectrometry as well as gas chromatography–mass spectrometry (GC–MS) techniques. Hydroxylation of the isopropyl and methoxy groups has been identified as the main reaction pathway. Scavenging experiments indicated the important role of HO•, h+ and O2•− in the photocatalytic process. Toxicity assessment revealed the efficiency of the photocatalytic treatment to achieve almost complete detoxification of the irradiated solution.
•Successful application of heterogeneous photocatalysis for tebuconazole degradation.•Nine transformation products were identified using HR-LC–MS and GC–MS techniques.•Main reaction pathways included ...loss of tert-butyl chain, hydroxylation, dechlorination and oxidation.•Degradation mechanism of TEB by TiO2 was mainly driven by HO• and h+.
The photocatalytic degradation of tebuconazole (TEB), a common fungicide with numerous agricultural and urban uses, has been investigated under simulated solar irradiation. Response surface methodology (RSM) was employed to assess individual and interactive effects of the three main independent parameters (initial TEB concentration, irradiation intensity and catalyst concentration) on the efficiency of the process. Optimization results showed that maximum TEB degradation and TOC removal was achieved at the optimum conditions: CTEB=1mgL−1, CTiO2=550 mg L−1, I=650Wm−2. By means of high resolution accurate mass liquid chromatography (HR-LC–MS) and gas chromatography–mass spectroscopy (GC–MS) nine transformation products were identified. The transformation of TEB pathways was found to proceed through tert-butyl chain cleavage, hydroxylation, oxidation and dechlorination pathways. Scavenging experiments showed that the degradation mechanism of TEB was mainly driven by HO• and h+. Finally, the application of an acute toxicity test (Vibrio fischeri) to selected water samples resulted in a non-inhibitory effect of the bacterial bioluminescence.
Congenital lumbar herniae: a systematic review Tasis, N.; Tsouknidas, I.; Antonopoulou, M. I. ...
Hernia : the journal of hernias and abdominal wall surgery,
12/2022, Letnik:
26, Številka:
6
Journal Article
Recenzirano
Purpose
Congenital lumbar hernia is defined as the protrusion of intraperitoneal or extraperitoneal viscera through a defect of the posterior abdominal wall, present at birth. The aim of our study ...was to perform a systematic review of this rare pathology, with emphasis on surgical decision-making.
Methods
The English literature (2000–2020) was reviewed, using PubMed, EMBASE and GoogleScholar databases, combining the terms “hernia”, “lumbar”, “flank”, “Grynfeltt”, “Petit” and “congenital”. Overall, 35 studies were included, describing 85 patients.
Results
Mean age was 9.7 ± 20.7 months (range 1 day–10 years). 55.7% were males and 44.3% were females. All patients presented electively, with flank bulging as the main symptom. Superior lumbar triangle (Grynfeltt) herniae accounted for 41.8%, inferior lumbar triangle (Petit) herniae for 32.8%, whereas 25.4% were classified as diffuse. A left-sided hernia was observed in 47%, a right-sided in 42.4%, while 10.6% were bilateral. 71.8% of the patients had associated anatomical anomalies, mainly the lumbocostovertebral syndrome. Most patients (83.3%) were treated surgically, while 16.7% conservatively with surveillance. In 93.3%, the surgical approach was open, with laparoscopy employed in 6.7% of cases. The majority (71.7%) underwent primary suture repair of the hernia defect, whereas a mesh was required in 28.3%. Post-operative morbidity was 6.7% and recurrence rate was 3.3% at a mean follow-up of 26.4 months.
Conclusion
Congenital lumbar hernia is a rare pathology in the paediatric population, with only 85 cases reported since 2000. Although the diagnosis is frequently straightforward, it should raise the suspicion for associated congenital anomalies and further investigation is required, with cross-sectional imaging. Surgical repair is usually performed during the first year, to allow for symmetrical torso development.
The photocatalytic reduction of Cr(VI) using pyrolytic char/TiO
2
(PC/TiO
2
) composite catalyst under simulated solar irradiation was studied. Response surface methodology (RSM) and experimental ...design were used for modeling the removal kinetics and for the optimization of operational parameters. RSM was developed by considering a central composite design with four input variable, i.e. catalyst concentration, initial concentration of Cr(VI), pH, and % (
v
/
v
) methanol concentration for assessing individual and interactive effects. A quadratic model was established as a functional relationship between four independent variables and the removal efficiency of Cr(VI). It was found that all selected variables have significant effect on Cr(VI) removal efficiency; however, the pH, the % concentration of methanol, and their interaction exhibited the major effects. Within the studied experimental ranges, the optimum conditions for maximum Cr(VI) removal efficiency (72.1 %) after 60 min of photocatalytic treatment were: catalyst concentration 55 mg L
−1
, Cr(VI) concentration 20 mg L
−1
, pH 4, and 5 % (
v
/
v
) methanol concentration. Under optimum conditions, Cr(VI) reductive removal followed pseudo-first-order kinetics, and nearly complete removal took place within 90 min. The results revealed the feasibility and the effectiveness of PC/TiO
2
as photocatalyst in reduction reactions due to their ability of e
−
–h
+
pair separation increasing the transfer of the photogenerated e
−
to the catalyst’s surface and thus the reduction of Cr(VI).
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•Cytarabine degradation by TiO2/SSL, TiO2/S2O82−/SSL and TiO2/H2O2/SSL processes.•The effect of operational parameters and addition of oxidants was studied.•Hydroxylation and ...oxidation were found as the main transformation routes before ring cleavage.•OH radicals were the major oxidant species based on scavenging experiments.•Microtox bioassay toxicity increased at the first stages but nearly eliminated at the end-stages.
The photochemical degradation of antineoplastic drug cytarabine (CY) by TiO2 photocatalysis under simulated solar light (SSL) radiation, TiO2/S2O82−/SSL and TiO2/H2O2/SSL processes was investigated in the present study. Experimental results indicated that CY was quickly degraded in all the studied treatments and degradation kinetics were dependent by all studied variables (i.e. catalyst dose, initial CY concentration, pH, oxidant concentration). In addition to kinetic studies, the transformation products (TPs) generated during the treatments were investigated using liquid chromatography coupled to high resolution mass spectrometry while mineralization was also followed by ion chromatography and total organic carbon measurements. Based on the identification of TPs and scavenging experiments, the major transformation routes followed were hydroxylation and subsequent oxidation, in all studied treatments. Microtox bioassay was applied before and during the TiO2 photocatalytic process, in order to investigate the potential risk of CY and its TPs to aqueous organisms. The obtained results showed an increase in the acute toxicity in the first stages and a continuously decrease afterwards, leading to very low toxicity levels within 360min of TiO2/SSL treatment. Overall results indicated that photocatalytic degradation of CY can lead to its complete elimination and detoxification of the solution.
In the present study, the photocatalytic activity of TiO2-based photocatalysts toward degradation and mineralization of the anti-cancer drug 5-fluorouracil (5-FU) in aqueous phase was investigated ...under simulated solar and visible irradiation. Commercial TiO2 (P25) and N/S-doped TiO2 catalysts synthesized by a simple sol–gel method were used as photocatalysts. TiO2 P-25 was found to be the most photoactive catalyst for the removal of 5-FU, under simulated solar irradiation. Among N/S-doped TiO2 catalysts, the one with molar Ti:N/S ratio equal to 0.5 was the most efficient under simulated solar irradiation. In contrast, under visible irradiation the catalyst with equimolar Ti:N/S ratio showed the highest performance for the removal of 5-FU. Scavenging experiments revealed that HO radicals and h+ were the major reactive species mediating photocatalytic degradation of 5-FU using TiO2 P-25 and N/S-doped TiO2 catalysts, under simulated solar irradiation. On the other hand, the essential contribution of 1O2 and O2− in the degradation of 5-FU under visible light was proved. The transformation products (TPs) of 5-FU, were identified by LC-MS-TOF suggesting that defluorination followed by hydroxylation and oxidation are the main transformation pathways, under all the studied photocatalytic systems.
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•Photocatalytic degradation of 5-fluorouracil using TiO2-based photocatalysts was studied.•N/S-doped TiO2 catalysts was proved efficient for the removal of 5 fluorouracil.•Defluorination followed by hydroxylation and oxidation are the main transformation pathways.•HO radicals are the main reactive radicals under simulated solar light.•1O2 and O2− oxidant species contributed significantly under visible light.
In the present study the photocatalytic degradation of a toxic priority pollutant, PCP, in the presence of N-F codoped TiO2 was explicitly investigated. The efficiency of the process to remove PCP ...was monitored for the first time through combined evaluation of several aspects: the kinetic study of the PCP degradation, identification of transformation products by a combination of mass spectrometric techniques (HR-LC-MS and GC-MS), assessment of total mineralization during the process, and evaluation of the genotoxicity and ecotoxicity of the initial and treated solutions applying the cytokinesis block micronucleus (CBMN) assay and Microtox assay, respectively. On the basis of identified products, a proposed degradation pathway is presented, involving mainly oxidative dechlorination reactions. Genotoxicity and ecotoxicity studies clearly demonstrated the efficiency of the photocatalytic process in the detoxification as well as in the elimination of genotoxicity and cytotoxicity of the irradiated solutions.
