Degradation Of Ibuprofen Research Articles

Bacterial Degradation of Ibuprofen: Insights into Metabolites, Enzymes, and Environmental Fate Biodegradation of Ibuprofen by Achromobacter Species

In recent years, pharmaceuticals have emerged as pollutants due to their incomplete degradation in sewage treatment plants and their ability to cause physiological problems in humans even at low doses. Understanding the environmental fate of pharmaceutical pollutants and the mechanisms involved in their degradation is crucial for developing strategies to mitigate their impact on ecosystems and human health. In this study, the degradation of pharmaceutical compound ibuprofen was achieved by employing two bacterial strains, Achromobacter spanius strain S11 and Achromobacter piechaudii S18, previously isolated from contaminated water. These strains were capable of degrading ibuprofen as their sole carbon source. The study aimed to identify intermediate metabolites, determine the enzymes involved, and detect specific genes related to ibuprofen degradation. Different concentrations of ibuprofen, temperatures, and pH levels were tested. Both A. spanius S11 and A. piechaudii S18 successfully degraded ibuprofen. A. spanius S11 showed a degradation efficiency of 91.18% after only 72 h and reached 95.7% after 144 h, while A. piechaudii S18 exhibited degradation efficiencies of 72.39% and 73.01% after three and seven days, respectively. The LC-MS technique was used to identify biodegradation metabolites produced by A. spanius S11. The results indicated that the first step was hydroxylation followed by oxidation via the combination of monooxygenases that catalyze the C-H hydroxylation and dehydrogenases. Furthermore, the detection of intermediate metabolites of trihydroxyibuprofen suggested that the biodegradation of ibuprofen by A. spanius S11 can occur through multiple mechanisms. The highest enzyme activities were recorded for catechol 1,2-dioxygenase, 4.230 ± 0.026 U/mg, followed by laccase, 2.001 ± 0.215 U/mg. This study demonstrates the potential of Achromobacter strains, particularly A. spanius (S11), in degrading ibuprofen. These findings provide insights into the ibuprofen degradation process, intermediate metabolites, and relevant genes.

Oxygen Vacancies and Lattice Distortion Synergistically Enhanced Piezocatalysis of CaZn2(BO3)2 for Nonantibiotic Pharmaceutical Degradation.

Piezocatalysis, an emerging green and advanced oxidation technology, has recently been widely researched in environmental treatment. However, the limited polarization efficiency of the piezocatalyst is a serious bottleneck for its practical application. The search for an excellent piezocatalyst with a high piezoelectric coefficient and abundant reactive sites remains an urgent task that needs to be developed. Herein, a piezocatalyst, CaZn2(BO3)2 (CZBO), obtained by quenching has an excellent piezocatalysis, which exhibited superior activity for ibuprofen (IBP) and carbamazepine (CBZ) removal with 100% and 83.8% efficiency under ultrasonic cavitation (120 W, 40 kHz) within 36 min, respectively. The outstanding piezocatalytic degradation was attributed to the strong polarization of the material under the synergistic effect of oxygen vacancies (OVs) and lattice distortion, which effectively facilitated the generation of a high concentration of reactive oxygen species (ROS). The lattice distortion induced by O-deficient [BO3] plane units can promote the e- and h+ pair separation and transportation, and the OVs with abundant electron-rich regions can significantly decrease O-O bond activation energy, thus collaboratively contributing to the high production of ROS for IBP and CBZ degradation. This work provides a simple avenue for enhancing piezoelectric polarization based on the OVs and lattice distortion and proposes insights into the reaction mechanisms for degrading nonantibiotic pharmaceuticals in wastewater.

Novel Carbon@BaMoZrFe12O19 photocatalytic peroxymonosulfate activation for ibuprofen removal

This study reports a successful synthesis of a novel Carbon@BaMoZrFe12O19 M-hexaferrite photocatalyst (NPs) using the coprecipitation method. Afterthat, the NPs were used as an activator for peroxymonosulfate (PMS) to remove ibuprofen (IBU) from water. NPs were subjected for a thorough characterization process utilizing various analytical techniques including XRD, FTIR, UV, PL TEM, SEM/EDS, and X-ray photoelectron spectroscopy (XPS). Significantly, the utilization of NPs for PMS activation demonstrated a notable improvement in the elimination of IBU under visible light. The research conducted a thorough investigation into the effects of various parameters, such as activating systems, initial pH, inorganic salts, IBU contents, and water matrix on the efficiency of IBU degradation. The significance of reactive oxygen species, such as sulfate and hydroxyl radicals, as well as singlet oxygen, in the removal of IBU, was clarified by chemical quenching tests. In addition, NPs exhibited competent magnetic separation and reprocessing capacities. The magnetic NPs revealed excellent constancy and recyclability, by sustaining degrading productivity after five consecutive cycles. Therefore, the present study offers a significant contributions to the understanding of photocatalytic degradation for organic pollutants through the utilization of magnetic photocatalysts.

Heterogeneous Catalytic Ozonation of Pharmaceuticals: Optimization of the Process by Response Surface Methodology.

Batch heterogeneous catalytic ozonation experiments were performed using commercial and synthesized nanoparticles as catalysts in aqueous ozone. The transferred ozone dose (TOD) ranged from 0 to 150 μM, and nanoparticles were added in concentrations between 0 and 1.5 g L-1, with all experiments conducted at 20 °C and a total volume of 240 mL. A Ce-doped TiO2 catalyst (1% molar ratio of Ce/Ti) was synthesized via the sol-gel method. Response surface methodology (RSM) was applied to identify the most significant factors affecting the removal of selected pharmaceuticals, with TOD emerging as the most critical variable. Higher TOD resulted in greater removal efficiencies. Furthermore, it was found that the commercially available metal oxides α-Al2O3, Mn2O3, TiO2, and CeO2, as well as the synthesized CeTiOx, did not increase the catalytic activity of ozone during the degradation of ibuprofen (IBF) and para-chlorobenzoic acid (pCBA). Carbamazepine (CBZ) and diclofenac (DCF) are compounds susceptible to ozone oxidation, thus their complete degradation at 150 μM transferred ozone dose was attained. The limited catalytic effect was attributed to the rapid consumption of ozone within the first minute of reaction, as well as the saturation of catalyst active sites by water molecules, which inhibited effective ozone adsorption and subsequent hydroxyl radical generation (●OH).

Cosmic-Ray Radiation Effects on Ibuprofen Tablet Formulation Inside and Outside of the International Space Station.

In extreme environments people will have different needs for medicine(s), making it crucial to understand how such environments affect drug efficacy. Ibuprofen, commonly used in tablet formulation on Earth, could fail in space despite standard pharmaceutical packaging. We introduce the concept of 'space medicines', where solid-dosage forms protect the pharmaceutical from accelerated degradation in spaceflight. We simulate dose(s) in International Space Station (ISS) through radionuclide and photon experiments, and establish the impact of alpha, beta and gamma rays. We demonstrate that tablet formulation protects from impact of alpha and beta rays; however, gamma rays decompose ibuprofen even when 'masked'. We systematically analyse 19 tablet compositions inside and outside the ISS to determine the effect of compositional changes in the tablet matrix. We confirm that the iron oxide-shielded tablets show minimal degradation (〈10%) inside the ISS, compared to moderate reductions (〉10%) for other formulations, with one exception. The tablets exhibited significantly greater ibuprofen degradation (〉 30-50%) outside ISS, due to harsh conditions. Significantly, we found that flavour have shielding potential by scavenging free radicals. We conclude that ibuprofen efficacy is adversely affected in space, and these effects are expected to worsen on missions to deeper space destinations.

Construction a flow through catalytic ozonation system with activated sludge based ceramsite for enhanced ibuprofen removal

Emerging contaminants had drawn much attention due to their ubiquitous occurrence in aquatic environment, and their potential negative effects. In this study, a flow catalytic ozonation system with activated sludge based ceramsite was established, and its catalytic performance was evaluated for degradation of ibuprofen (IBU). Firstly, the proportion of activated sludge and fly ash was 1:1 based on Reliy model for successfully preparation of ceramsite which could catalyze ozone to completely remove IBU within 10 min, while degradation ratio was just 19.9 % in ozonation system. The effects of operational conditions including initial concentration of IBU, ozone dosage, hydraulic retention time, and pH were considered to further verify the applicability of the system. The prepared ceramsite could not only enhance ozone dissolution, but also promote the decomposition of ozone to produce more •OH, which was contributed by metal ions active sites and surface hydroxyl groups. And the contribution of •OH for IBU degradation was about 95.3 % indicating that the •OH played an important role in degradation. The inorganic ions except CO32−/HCO3− and phosphates had less effect on catalytic performances. Furthermore, the degradation products and possible pathways were proposed. The catalytic ozonation system could effectively control the toxicity of the treatment solution. This study not only provided new ideas for resource utilization, but also provided advisable practice application of heterogeneous catalysts for dealing with wastewater.

Nitrite sensitized photolysis of ibuprofen in the liquid and ice phases: Roles of reactive species and influences of the main dissolved components

This study evaluated the kinetics, mechanisms, toxicity assessment, and influencing factors of ibuprofen (IBP) photolysis induced by nitrite (NO2–) in the liquid and ice phases. The photon-flux-normalized rate constant for IBP photolysis (kIBP*) increased monotonically with increasing NO2– concentrations in the liquid and ice phases. kIBP* in the ice phase was decreased by 21.5–29.9 %, as compared with those obtained with the same NO2– concentration in the liquid phase. Reactive nitrogen species (RNS) contributed more to NO2–-sensitized photolysis of IBP than hydroxyl radicals (•OH) in the liquid and ice phases, and the contributions of RNS to IBP degradation in the ice phase were higher than those in the liquid phase. The NO2–-sensitized photolysis mechanisms of IBP in the ice phase seemed to be similar to those in the liquid phase, including hydroxylation, nitration, nitrosation, decarboxylation, side-chain cleavage and ketonization. The reactions of IBP with RNS were more favored in the ice phase due to higher photon flux, leading to greater generation of photoproducts with higher toxicity. Bicarbonate (HCO3–) inhibited NO2–-sensitized photolysis of IBP. Although dissolved organic matter (DOM) itself could induce IBP photolysis, it exhibited an inhibitory effect on NO2–-sensitized photolysis of IBP. For the real water and ice samples containing low NO2– concentrations (≤ 3.6 μM) and medium DOM concentrations (2.6–5.1 mg C/L), DOM played a more important role in IBP photolysis than NO2– in the liquid phase and particularly in the ice phase. kIBP* for the real samples in the ice phase were 32.1–136.4 % higher than those in the liquid phase.

Insight into the performance and mechanism of N,O,S-codoped porous carbon based CO single-atom catalysts in organic oxidation through peroxymonosulfate activation

Single-atom catalysts (SACs) are charming for heterogeneous Fenton-like processes due to their unique and adjustable electron structure. Developing novel SACs and elucidating their mechanisms are critical for the development of water purification techniques. Herein, we present an N,O,S-codoped carbon based Co SAC (CoSA-N-CO,S) synthesized by anchoring isolated Co atoms onto porous carbon derived from low-cost protic salt. This catalyst exhibits significant efficiency in activating peroxymonosulfate (PMS) for rapid ibuprofen (IBU) degradation, achieving approximately 98.2 % within 10 min at a concentration of 0.2 g/L catalyst and 2 mM PMS, under ambient pH and at 30 °C, and demonstrates excellent reusability. Intensive studies reveal that the highly active atomic Co sites are favorable for activating PMS to produce both radical (SO4− and OH) and nonradical 1O2, while the electron-rich O and S sites contribute to PMS reduction to generate SO4− and OH. The CoSA-N-CO,S/PMS system leverages the synergy between radical and nonradical oxidation across multiple active sites, resulting in exceptional resistance to interference and high efficiency in degradation and mineralization of diverse organic pollutants. This study develops a novel single-atom catalyst for wastewater treatment and elucidates the mechanism behind PMS activation by a carbon-based cobalt single atom catalyst.

Optimization of TiO2-natural hydrogels for paracetamol and ibuprofen degradation in wastewaters.

Agarose/micrometer titanium dioxide (TiO2) beads were essayed to test the photocatalytic capacity of two of the most widely prescribed drugs worldwide: paracetamol and ibuprofen. Although the initial tests demonstrated promising degradation rates for both drugs, the presence of turbidity, due to TiO2 leakage, during the photocatalytic essays induced to improve the stability of the photocatalytic composites. Among the different strategies adopted to strengthen such materials, crosslinking with citric acid and the use of alternative gelling agents: gellan, agargel™, and agar were chosen. Composites obtained by merging both strategies were characterized and employed to degrade both drugs under a simulated light that mimics the solar spectrum (indoor). Considering the superior degradation rates obtained when agar and agarose were used to shape the titanium oxide particles (up to 70-75% of drug destruction), such composites were subjected to a more realistic experiment (outdoor): solar illumination, tap water, and higher volumes, that should facilitate its ulterior scale up as a real wastewater depollution procedure. Degradation rates between 80 and 90% are attained under such conditions for both drugs.

Radiolysis performance of ibuprofen using ionizing processes: kinetics and energy consumption

ABSTRACT Ionizing technologies are used for disinfection and treatment of different industrial wastewaters. For this purpose, the radiolytic degradation of ibuprofen (IBP), selected within the main detected pharmaceuticals in different water locations with different concentrations, was investigated. Irradiation was performed with a gamma irradiator (60Co) and with electron beam accelerator. The degree of ibuprofen degradation was monitored following the evolution of its absorbance, the residual concentration by HPLC, carbon oxygen demand and total organic carbon. The degradation of IBP was higher than the removal of TOC or COD and reached 95% according to residual concentration. This pollutant (at 0.1 mM) was totally degraded when irradiated at 3 kGy and needed higher doses (7–10 kGy) for the highest concentrations (0.8–1 mM). The addition of 1 mM of persulfate ion remarkably enhanced IBP degradation by around 2 and 2.8 times for 5 and 10 kGy, respectively. Pseudo-first-order reaction kinetics could be used to depict the degradation process of IBP in all conditions. Electrical energy per order (EEO) was estimated under various conditions. The smallest EEO was obtained when gamma radiation and persulfate ion were combined. The possible degradation pathways of IBP were proposed. The results achieved in this study can be used to optimize large-scale application of nuclear techniques in water treatment in particular in treating pharmaceutical effluents.

Insights of sulfur in sulfidated zerovalent iron for activating of dissolved oxygen and CaO2-generated H2O2: Improving iron electron selectivity and utilization

Sulfidated zerovalent iron (S-ZVI) has been extensively used for the degradation of pollutants under anaerobic conditions. However, the investigation of the ability and mechanism of S-ZVI to regulate the catalytic oxidation of pollutants under aerobic conditions has been overlooked. In this study, we revealed the mechanism of enhanced ibuprofen (IBP) degradation by decomposition and activation by S-ZVI under aerobic conditions using CaO2 as a slow-release oxygenate. Specifically, the S-ZVI/CaO2 showed a 2.98-fold increase in rate compared to ZVI/CaO2 within the previous 15 min of reaction. Two reaction stages of enhanced IBP degradation by the S-ZVI/CaO2 system were observed. In the initial stage, the shell layer on the surface of S-ZVI activates dissolved oxygen in water to form H2O2 through a continuous one-electron process. This process effectively prevents the oxidation of ZVI while enhancing the electron selectivity of ZVI and facilitates the decomposition of CaO2, resulting in the production of more H2O2. Subsequently, sulfur on the surface of S-ZVI acts as an electron shuttle in the second stage, facilitating the activation of H2O2 and improving the electron utilization of ZVI. This finding clarifies the mechanism of pollutant degradation by S-ZVI under aerobic conditions and provides a strategy for enhancing pollutant degradation.

Spectroscopic Analysis of the Effect of Ibuprofen Degradation Products on the Interaction between Ibuprofen and Human Serum Albumin.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are one of the most commonly used groups of medicinal compounds in the world. The wide access to NSAIDs and the various ways of storing them due to their easy accessibility often entail the problem with the stability and durability resulting from the exposure of drugs to external factors. The aim of the research was to evaluate in vitro the mechanism of competition between ibuprofen (IBU) and its degradation products, i.e., 4'-isobutylacetophenone (IBAP) and (2RS)-2-(4- formylphenyl)propionic acid (FPPA) during transport in a complex with fatted (HSA) and defatted (dHSA) human serum albumin. The research was carried out using spectroscopic techniques, such as spectrophotometry, infrared spectroscopy and nuclear magnetic resonance spectroscopy. The comprehensive application of spectroscopic techniques allowed, among others, for the determination of the binding constant, the number of classes of binding sites and the cooperativeness constant of the analyzed systems IBU-(d)HSA, IBU-(d)HSA-FPPA, IBU-(d)HSA-IBAP; the determination of the effect of ibuprofen and its degradation products on the secondary structure of albumin; identification and assessment of interactions between ligand and albumin; assessment of the impact of the presence of fatty acids in the structure of albumin and the measurement temperature on the binding of IBU, IBAP and FPPA to (d)HSA. The conducted research allowed us to conclude that the presence of ibuprofen degradation products and the increase in their concentration significantly affect the formation of the IBU-albumin complex and thus, the value of the association constant of the drug, changing the concentration of its free fraction in the blood plasma. It was also found that the presence of an ibuprofen degradation product in a complex with albumin affects its secondary structure.

Peroxysulfur species-mediated enhanced oxidation of micropollutants by ferrate(VI): Peroxymonosulfate versus peroxydisulfate

Many studies have shown that Peroxymonosulfate (PMS) works synergistically with ferrate (Fe(VI)) to remove refractory organic compounds in a few minutes. However, little has been reported on the combined effects of peroxydisulfate (PDS) and Fe(VI). Since PDS is stable and cost effective, it is of practical significance to study the reaction mechanism and conditions of the PDS/Fe(VI) system. The results of the study indicate that the intermediate Fe(II) is formed during the decomposition of Fe(VI), which is then rapidly oxidized. Due to the asymmetry of the PMS molecular structure, PMS can rapidly trap Fe(II) (kPMS/Fe(II)= 3 × 104 M−1∙s−1), whereas PDS cannot (kPDS/Fe(II)= 26 M−1∙s−1). Hydroxylamine hydrochloride (HA) can reduce Fe(VI) and Fe(III) to Fe(II) to excite PDS to produce SO4•−. Acetate helps to detect Fe(II), but does not help PDS to trap Fe(II). Active species such as SO4•−, •OH, 1O2, and Fe(IV), Fe(V) are present in both systems, but in different amounts. In the PMS/Fe(Ⅵ) system, all these active species react with ibuprofen (IBP) and degrade IBP within several minutes. The effects of the initial pH, PMS or Fe(VI) dosage, and different amounts of IBP on the removal rate of IBP were investigated. According to the intermediates detected by the GC-MS, the degradation process of IBP includes hydroxylation, demethylation and single bond breakage. The degradation pathways of IBP were proposed. The degradation of IBP in tap water and Songhua River was also investigated. In actual water treatment, the dosage needs to be increased to achieve the same results. This study provides a basis and theoretical support for the application of PMS/Fe(Ⅵ) and PDS/Fe(VI) system in water treatment.

Synthesis and full-spectrum-responsive photocatalytic activity from UV/Vis to near-infrared region of S-O decorated YMnO3 nanoparticles for photocatalytic degradation of ibuprofen.

The oxalic acid complexation method and sulfuric acid heat treatment method were used to synthesize the YMnO3 (YMO) and YMO-SO4 2- (YMO-SO) photocatalysts. The YMO-SO photocatalyst maintained the crystal structure of YMO, but the particle size increased slightly and the optical band gap decreased significantly. The YMO-SO photocatalyst demonstrates a wide range of light absorption capabilities, covering ultraviolet, visible and near-infrared light. The photocatalytic activity of YMO-SO was investigated with ibuprofen as the target pollutant. The YMO-SO photocatalyst exhibits high ultraviolet (UV), visible and near-infrared photocatalytic activity. Experiments with different environmental parameters confirmed that the best catalyst content was 1g/L, the best drug concentration was 75mg/L and the best pH value was 7. The capture experiment, free radical detection experiment and photocatalytic mechanism analysis confirmed that the main active species of YMO-SO photocatalyst were hole and superoxide free radical.

Ferromanganese oxide-functionalized TiO2 for rapid catalytic ozonation of PPCPs through a coordinated oxidation process with adjusted composition and strengthened generation of reactive oxygen species

Ferromanganese oxide (MFOx) was first utilized to functionalize TiO2 and an MFOx@TiO2 catalyst was developed for catalytic ozonation for rapid attack of pharmaceutical and personal care products (PPCPs) with adjusted reactive oxygen species (ROSs) composition and strengthened ROSs generation. Unlike Al2O3, which strongly relied on adsorption and was significantly influenced by MFOx loading, synergistic catalytical effects of MFOx and TiO2 were observed, and optimal MFOx doping of 2 wt% and MFOx@TiO2 dosage of 500 ppm were obtained for catalyzing ozonation. In ibuprofen (IBP) degradation, MFOx@TiO2-catalyzed ozonation (MFOx@TiO2/O3) obtained 2.0-, 4.7- and 6.9-folds the kobs of TiO2/O3, MFOx/O3 and bare ozonation (B/O3). Stronger O3 decomposition was observed by MFOx@TiO2 over bare TiO2 with the participation of redox pairs Fe(II)/Fe(III) and Mn(II)/Mn(III)/Mn(IV) and increased surface oxygen vacancies (SOVs) from 9.8 % to 33.7 % was detected. The results revealed that Fe(II), Mn(II) and Mn(III) with low valance accelerated Ti(III) generation from Ti(VI), obtaining an unprecedented high Ti(III) composition occupying 35.3 % of the total Ti atoms. Ti(III) catalyzed the direct reduction of SOVs-O2 to •O2–, and it accelerated the formation of Ti(VI)-OH and Ti(VI)-O which catalyzed O3 decomposition into •O2–. •O2– was found to primarily initiate IBP degradation with nucleophilic addition and dominated over 66 % IBP removal. The enhanced •O2– generation further strengthened •OH and 1O2 production. MFOx@TiO2/O3 obtained 17 %, 21 % and 30 % higher TOC removal over TiO2/O3, MFOx/O3 and B/O3, respectively. Acute toxicity tests confirmed the effective toxicity control of organics by MFOx@TiO2/O3 process (inhibition rate: 10.9 %). Degradation test of atenolol and sulfamethoxazole confirmed the catalytic effects of MFOx@TiO2. MFOx@TiO2 performed strong resistance to water matrix in application test and showed good stability and reusability. The study proposed an effective catalyst for strengthening the ozonation process on PPCPs degradation and provided an in-depth understanding of the mechanisms and characteristics of the MFOx@TiO2 catalyst and MFOx@TiO2/O3 process.

Sulfite activation by non-thermal plasma coupled with Fe2+ for ibuprofen degradation: In-depth insight into activation energy barrier and mechanism

This paper underscores the pivotal role of Fe2+ in influencing the degradation of ibuprofen (IBP) within non-thermal plasma (NTP) activated sulfite (S) system. At 200 μM Fe2+ dosage, the rate of IBP degradation can attain 94.8 %. In contrast to the absence of Fe2+, there was a 43.1 % increase in the rate of IBP degradation. The quenching experiment indicates that SO4·− and ·OH constitute the principal species in the system. This phenomenon predominantly stems from the Fenton-like reaction, expediting the conversion of H2O2 to ·OH. Additionally, the activation of sulfite by the Fe2+ and NTP promotes a concurrent increase in SO4·−. The introduction of Fe2+ results in the detection of a substantial quantity of ·OH and SO4·− in the system, validated through direct detection and electron spin resonance (ESR) signals. According to the density functional theory (DFT), the energy barrier of NTP/Fe2+ activation sulfite is lower than that of NTP system activation. By comparing the specific degradation pathways of NTP/S/Fe2+ and NTP/S systems, it can be concluded that the degradation of pollutants in NTP/S/Fe2+ system mainly depends on the action of active free radicals (·OH and SO4·−), while that in NTP/S system is mainly due to non-free radicals.

Ibuprofen degradation by mixed bacterial consortia: Metabolic pathway and microbial community analysis

Degradation of ibuprofen, one of the most consumed drugs globally, by a mixed bacterial consortium was investigated. A contaminated hospital soil was used to enrich a bacterial consortium possessing the ability to degrade 4 mg/L ibuprofen in 6 days, fed on 6 mM acetate as a supplementary carbon source. Maximum ibuprofen degradation achieved was 99.51%, and for optimum ibuprofen degradation modelled statistically, the initial ibuprofen concentration, and temperature were determined to be 0.515 mg/L and 35 °C, respectively. The bacterial community analyses demonstrated an enrichment of Pseudomonas, Achromobacter, Bacillus, and Enterococcus in the presence of ibuprofen, suggesting their probable association with the biodegradation process. The biodegradation pathway developed using open-source metabolite predictors, GLORYx and BioTransformer suggested multiple degradation routes. Hydroxylation and oxidation were found to be the major mechanisms in ibuprofen degradation. Mono-hydroxylated metabolites were identified as well as predicted by the bioinformatics-based packages. Oxidation, dehydrogenation, super-hydroxylation, and hydrolysis were some other identified mechanisms.

Biological degradation of organic micropollutants in GAC filters–temporal development and spatial variations

The capacity for organic micropollutant removal in granular activated carbon (GAC) filters for wastewater treatment changes over time. These changes are in general attributed to changes in adsorption, but may in some cases also be affected by biological degradation. Knowledge on the degradation of organic micropollutants, however, is scarce. In this work, the degradation of micropollutants in several full-scale GAC and sand filters was investigated through incubation experiments over a period of three years, using 14C-labeled organic micropollutants with different susceptibilities to biological degradation (ibuprofen, diclofenac, and carbamazepine), with parallel 16S rRNA gene sequencing. The results showed that the degradation of diclofenac and ibuprofen in GAC filters increased with increasing numbers of bed volumes when free oxygen was available in the filter, while variations over filter depth were limited. Despite relatively large differences in bacterial composition between filters, a degradation of diclofenac was consistently observed for the GAC filters that had been operated with high influent oxygen concentration (DO >8 mg/L). The results of this comprehensive experimental work provide an increased understanding of the interactions between microbial composition, filter material, and oxygen availability in the biological degradation of organic micropollutants in GAC filters.

Visible-light-driven photocatalytic degradation of ibuprofen by Cu-doped tubular C3N4: Mechanisms, degradation pathway and DFT calculation

The copper-modified tubular carbon nitride (CTCN) with higher specific surface area and pore volume was prepared by a simple in-situ hydrolysis and self-assembly. Increased ∼4.7-fold and ∼2.3-fold degradation rate for a representative refractory water pollutant (Ibuprofen, IBP) were achieved with low-energy light source (LED, 420 ± 10 nm), as compared to graphitic carbon nitride (GCN) and tubular carbon nitride (TCN), respectively. The high efficiency of IBP removal was supported by narrow band gap (2.15 eV), high photocurrent intensity (1.10 μA/cm2) and the high surface -OH group (14.75 μg/cm3) of CTCN. According to analysis of the various reactive species in the degradation, the superoxide radical (•O2−) played a dominant role, followed by •OH and h+, responsible for IBP degradation. Furthermore, Fukui functions were employed to predict the active sites of IBP, and combined with the HPLC-MS/MS results, possible mechanisms and pathways for photocatalytic degradation were indicated. This study will lay an important scientific foundation and a possible new approach for the treatment of emerging aromatic organic pollutants in visible-light-driven heterogeneous catalytic oxidation environment.

Unexpectedly enhanced degradation of acetaminophen by sulfoxides probe in Fe(II)-activated persulfate oxidation: The mechanism and the selectivity

Sulfoxides are widely recognized as probes for identifying and evaluating the generation and contribution of high-valent metals in advanced oxidation processes. However, this paper was surprising to find that the presence of sulfoxides selectively enhanced the degradation of specific pollutants in the Fe(II)/PS system. Represented by methyl phenyl sulfoxide (PMSO), scavenging experiments for active species showed that the presence of PMSO transformed the mechanism from radical dominated (55.60 %) to nonradical dominated (60.91 %), greatly improving the anti-interference ability of the system. Determining the concentration of Fe(Ⅱ) and total iron (Fetot) in solution revealed that the presence of PMSO improved the utilization efficiency of Fe(II) and PS by enhancing the redox reaction between Fe(II) and PS, and resulted in the generation of Fe(IV) more favorably than the generation of SO4·− and ·OH. Additionally, comparing the proven high-valent iron dominated Fe(II)/PI system with the free radical dominated Fe(II)/PS system of this paper, it was revealed that the selectively enhanced oxidation of PMSO specifically targets the free radical dominated system. Experiments have shown that the degradation of acetaminophen, ibuprofen, phenol, and p-chlorophenol was enhanced by PMSO, while the degradation of norfloxacin, primidone, chloramphenicol, sulfamethoxazole, p-nitrophenol, benzoic acid, and nitrobenzene was inhibited. Based on density functional theory (DFT) calculations, PMSO has a selectively enhanced degradation effect for organic pollutants with ionization potential (IP) below 8.66 eV, and vice versa, it has an inhibitory effect. The present study provides new insights into the contribution of sulfoxide to the assessment of high-valent metals and sheds new light on the mechanism of active species.