5 research outputs found
Photocatalytic degradation of antiepileptic drug carbamazepine with bismuth oxychlorides (BiOCl and BiOCl/AgCl composite) in water: Efficiency evaluation and elucidation degradation pathways
No full textInternational audienceThe heterogeneous photocatalytic degradation of carbamazepine (CBZ) was investigated in the presence of BiOCl/AgCl composite photocatalyst under simulated sunlight irradiation in water. BiOCl/AgCl composite showed higher photocatalytic activity than pure BiOCl for CBZ degradation. The photocatalytic mechanism analysis was based on byproducts identification by LC-MS-QT of and active species trapping or inhibiting experiments. The results revealed that the first step of the transformation mainly results in an electron transfer implying positive holes and to a lesser extent in hydroxyl radical's involvement. The enhanced photocatalytic performance of BiOCl/AgCl was proved to be related to the suitable conduction and valence band interaction that extends optical response range but also improves the efficient separation of photoinduced electron-hole pairs. BiOCl/AgCl composite totally removed CBZ from natural surface water after 30 min irradiation, suggesting its potential application to wastewater treatments. Eight intermediate products were identified demonstrating that CBZ transformation occurs through two main routes from CBZ radical cation, hydroxylation of ring (aromatic or seven membered rings), followed by further oxidation, rearrangement ring and hydroxylation. (C) 2016 Elsevier B.V. All rights reserved
Emerging contaminants detected in aquaculture sites in Java, Indonesia
No full textInternational audiencePharmaceuticals of emerging concern (acetaminophen (ACM), trimethoprim (TMP), oxytetracycline (OTC), and sulfamethoxazole (SMX)) were detected in water samples from aquaculture environments and nonaquaculture sites in four regions located on the northern coast of Central Java. ACM was the most prevalent pharmaceutical, with a mean concentration ranging from not detected (n.d.) to 5.5 ± 1.9 ngL−1 (Brebes). Among the target antibiotics (TMP, OTC, SMX), OTC was the most ubiquitous, with a mean concentration varying from n.d. to 8.0 ± 3.3 ngL−1. Correlation analysis demonstrated that there was a significant correlation between TMP and SMX concentrations. Based on ecological risk assessment evaluation, the use of OTC requires serious consideration, as it presented high health risks to algae, while ACM, TMP, and SMX posed an insignificant to moderate risk to algae, invertebrates, and fish. The findings obtained from this study highlight OTC as an emerging contaminant of prominent concern. More attention needs to be given to managing and planning for the sustainable management of shrimp farms, particularly in the northern part of Central Java
Beach macro-litter monitoring and floating microplastic in a coastal area of Indonesia
No full textInternational audienceQualitative analysis of the structures of the polymers composing floating plastic debris was performed using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and the aging of the debris was assessed by measuring carbonyl group formation on the particle surfaces. Plastic material made up > 75% of the 2313 items collected during a three-year survey. The size, shape and color of the microplastic were correlated with the polymer structure. The most abundant plastic materials were polypropylene (68%) and low-density polyethylene (11%), and the predominant colors of the plastics were white, blue and green. Cilacap Bay, Indonesia, was contaminated with microplastic at a concentration of 2.5 mg·m 3. The carbonyl index demonstrated that most of the floating microplastic was only slightly degraded. This study highlights the need to raise environmental awareness through citizen science education and adopting good environmental practices
Insights in the Aqueous and Adsorbed Photocatalytic Degradation of Carbamazepine by a Biosourced Composite: Kinetics, Mechanisms and DFT Calculations
No full textInternational audienceAlthough the degradation of carbamazepine (CBZ) in the aqueous phase was widely studied for a better comprehension of its photocatalytic behavior in the aqueous solution, the knowledge about its photodegradation adsorbed on solid surfaces is yet very limited. In this work, the combination of two processes (adsorption and photocatalysis) has been applied for the degradation of CBZ adsorbed on TiO2 and activated carbon AC/TiO2 and aqueous phase. The degradation efficiency of CBZ could reach 100%, and 99% in CBZ dissolved and adsorbed parts, respectively. Moreover, the CBZ mineralization starts at 4 h of irradiation. Hydroxy radical (·OH) has an essential role in CBZ degradation, and It accompanies a synergistic effect of the photogenerated hole (h+) and oxygen active species during the reaction. Thereafter, the transformation products and possible degradation pathways of CBZ were identified by LC/MS-Qtof. Density functional theory calculation successfully predicts the degradation mechanism of CBZ molecule by means of Fukui indexes, including the ring hydroxylation, photocyclization, C–C and C–N bond cleavage processe
Environmental Sample Stability for Pharmaceutical Compound Analysis: Handling and Preservation Recommendations
No full textInternational audienceEfficient and resilient techniques for handling samples are essential for detecting pharmaceutical compounds in the environment. Tis study explores a method for preserving water samples during transport before quantitative analysis. Te study investigates the stability of 17α-ethynylestradiol (EE2), acetaminophen (ACM), oxytetracycline (OTC), sulfamethoxazole (SMX), and trimethoprim (TMP) after preconcentration within solid-phase extraction (SPE) cartridges. Trough various experiments involving diferent holding times and storage temperatures, it was determined that four pharmaceutical compounds remained stable when stored for a month at 4 °C and for six months when stored at-18 °C in darkness. Storing these compounds in SPE cartridges at-18 °C seemed efective in preserving them for extended periods. In addition, ACM, TMP, OTC, EE2, and SMX remained stable for three days at room temperature. Tese fndings establish guidelines for appropriate storage and handling practices of pharmaceutical compounds preconcentrated from aqueous environmental samples using SPE
