Degradation By-products Research Articles

Application of Fe-ethylene diamine tetraacetic acid complex to enhance the electrocatalytic activation of peroxymonosulfate under neutral pH condition for removal of refractory naphthenic acids

In this work, ethylene diamine tetraacetic acid (EDTA) was applied as a chelating agent to stabilize Fe(III)/Fe(II) cycle to effectively activate peroxymonosulfate (PMS) in an electrochemical (EC) co-catalytic system for elimination of naphthenic acids (NAs) under neutral pH condition. 1-Adamantanecarboxylic acid (ACA) was applied as the model compound for NAs that are persistent contaminants in petroleum industrial wastewater. In the PMS/EC/Fe(III)-EDTA system, complete removal of ACA has been achieved in 20-min reaction under neutral pH condition. Degradation mechanisms were investigated via electron paramagnetic resonance (EPR) analysis, probe experiments and quenching experiments to reveal the reactive species •OH, SO4•− and 1O2 for ACA removal, the production of which have been significantly facilitated by the introduction of EDTA complex. A new pathway has been found for the production of 1O2 via several intermediates including hydrogen peroxide and superoxide radicals. Density functional theory (DFT) calculations and mass spectrometry analysis were applied to predict ACA degradation pathways and byproducts. Decarboxylation, hydroxyl substitution and carbonyl substitution byproducts of ACA were detected. The PMS/EC/Fe(III)-EDTA system suffered nonimportant influence at the presence of humic acid, H2PO4-, HCO3–, NO3– and Cl- for ACA removal. Overall results demonstrate the effectiveness and reliability of the PMS/EC/Fe(III)-EDTA system for efficient removal of NAs in petroleum wastewater in natural environment under neutral pH condition.

Engineering commercial activated carbon with carbonyl site for activation of peroxymonosulfate and degradation of tetracycline

Reduction of antibiotics in water by active of peroxymonosulfate (PMS) using low-cost metal-free activated carbon (AC) is an effective route to a better future. Herein, we report a new activated carbon (AC-12) by incorporating carbonyl (CO) into commercial AC to efficiently activate PMS and degrade tetracycline (TC). The AC-12/PMS system degrades 97.6 % of TC within 10 min, superior to sole AC (39 %), PMS (11.5 %), and AC/PMS system (61.1 %), respectively. The pseudo-first-order kinetic constant of AC-12/PMS is 0.372 min−1, 4.27-fold higher than AC/PMS. Furthermore, AC-12/PMS exhibits outstanding performance in TC degradation across various environmental factors (e.g., water bodies, pH, ions, and organics). Capture tests and electron spin resonance (ESR) spectroscopy indicate that TC degradation over AC-12/PMS predominantly involves synergistic interactions between superoxide radicals (O2−) and singlet oxygen (1O2), contributing nearly 100 % to TC removal. Additionally, high-performance liquid chromatography-mass spectrometry (HPLC-MS) elucidates potential degradation pathways and by-products. This study underscores the utility of AC-12 with carbonyl sites as an exemplary metal-free catalyst for PMS activation, highlighting its advantages of cost-effectiveness, facile regeneration, environmental friendliness, and excellent stability.

A sustainable activated carbon fiber/TiO2 cathode for the photoelectro-Fenton treatment of pharmaceutical pollutant enalapril

In this work, a TiO2-decorated electrode was fabricated by dip coating activated carbon fibers (ACF) with TiO2, which were then used as a cathode for the photoelectro-Fenton (PEF) treatment of the pharmaceutical enalapril, an angiotensin-converting enzyme inhibitor that has been detected in several waterways. The TiO2 coating was found to principally improve the electrocatalytic properties of ACF for H2O2 production via the 2-e- O2 reduction, in turn increasing enalapril degradation by PEF. The effect of the current density on the mineralization of enalapril was evaluated and the highest TOC removal yield (80.5% in 3 h) was obtained at 8.33 mA cm−2, in the presence of 0.5 mmol L−1 of Fe2+ catalyst. Under those conditions, enalapril was totally removed within the first 10 min of treatment with a rate constant k = 0.472 min−1. In contrast, uncoated ACF only achieved 60% of TOC removal in 3 h at 8.33 mA cm−2. A degradation pathway for enalapril mineralization is proposed, based on the degradation by-products identified during treatment. Overall, the results demonstrate the promises of TiO2 cathodes for PEF, a strategy that has often been overlooked in favor of photoelectrocatalysis (PEC) based on TiO2-modified photoanodes.

Graphene oxide-induced CuO reduction in TiO2/CaTiO3/Cu2O/Cu composites for photocatalytic degradation of drugs via peroxymonosulfate activation

Contamination of water bodies is a global environmental and human health issue. Conventional water treatment systems cannot efficiently eliminate organic contaminants, particularly drugs. Photocatalysis is a promising, environmentally friendly oxidation process for the removal of such compounds. A key point is the choice of material to be used as photocatalyst. Here, TiO2/CaTiO3/Cu2O/Cu composites were fabricated by adding different amounts (x) of graphene oxide (GO) (x wt% = 1, 3, and 5 %) to CaCu3Ti4O12 powder using the solid-state synthesis method. The produced pellets were sintered under inert nitrogen atmosphere at 1100 °C for 3 h. X-ray diffraction analysis showed that the Cu metal amount was increased upon GO addition, and the UV–Vis diffuse reflectance spectroscopy showed that the spectral response was extended to the visible range. Then, high performance liquid chromatography assessment of paracetamol degradation by a photocatalytic cell using TiO2/CaTiO3/Cu2O/Cu composites with different GO amounts showed that the removal efficiency was increased upon introduction of 0.5 mM peroxymonosulfate (PMS) as active component to generate SO4‾ radicals. After 3 h under visible light, 96 % of 10 ppm paracetamol was degraded by the composite with 3 % of GO (1 cm2 surface photocatalyst) compared with 50 % by the composite without GO in the same experimental conditions (PMS in 210 mL of aqueous solution). Free radical trapping and the acute toxicity of potential degradation by-products were also investigated. Our results indicate that TiO2/CaTiO3/Cu2O/Cu with 3 % GO displays long-term stability and durability for the photocatalytic removal of pharmaceutical pollutants from wastewater.

Identifying the Degradation Products of Dexamethasone for COVID‐19 Treatment in Mexico City's Wastewater: Theory and Experiments

AbstractQuantum chemistry calculations were performed to elucidate the reaction sites and degradation routes of dexamethasone. Flow Injection Analysis Electrospray Fourier‐Transform Ion Cyclotron Resonance Mass Spectrometry (FIA‐ESI‐FTCIR‐MS) was used to identify dexamethasone and its byproducts in Mexico City's wastewater, guided by results from ab‐initio calculations on the bond energy analysis and thus propose possible degradation routes. Products of hydroxylation/reduction, decarbonylation/formylation and defluorination reactions were identified. The results of this study contribute to the identification of the degradation products of drugs commonly used in the treatment of COVID‐19 in urban areas. Through wastewater analysis and computationally assisted Mass‐Spectrometry techniques, an alternative approach is presented to identify byproducts in complex matrices when analytical standards are unavailable or in case of limited understanding on the stability of the degradation byproducts in aqueous medium.

Application of artificial intelligence for the optimization of advanced oxidation processes to improve the water quality polluted with pharmaceutical compounds

Sulfamethoxazole and metronidazole are emerging pollutants commonly found in surface water and wastewater. These compounds have a significant environmental impact, being necessary in the design of technologies for their removal. Recently, the advanced oxidation process has been proven successful in the elimination of this kind of compounds. In this sense, the present work discusses the application of UV/H2O2 and ozonation for the degradation of both molecules in single and binary systems. Experimental kinetic data from O3 and UV/H2O2 process were adequately described by a first and second kinetic model, respectively. From the ANOVA analysis, it was determined that the most statistically significant variables were the initial concentration of the drugs (0.03 mmol L−1) and the pH = 8 for UV/H2O2 system, and only the pH (optimal value of 6) was significant for degradation with O3. Results showed that both molecules were eliminated with high degradation efficiencies (88–94% for UV/H2O2 and 79–98% for O3) in short reaction times (around 30–90 min). The modeling was performed using a quadratic regression model through response surface methodology representing adequately 90 % of the experimental data. On the other hand, an artificial neural network was used to evaluate a non-linear multi-variable system, a 98% of fit between the model and experimental data was obtained. The identification of degradation byproducts was performed by high-performance liquid chromatography coupled to a time mass detector. After each process, at least four to five stable byproducts were found in the treated water, reducing the mineralization percentage to 20% for both molecules.

Facilitated Visible-Light-Driven Peroxymonosulfate Activation by a Co-Fe Layered Double Hydroxide Derived p-n Heterostructure for Sulfadiazine Degradation: Affecting Parameters, Kinetics, and Mechanistic Insights.

The utilization of multivalence ionic metal species generated through a peroxymonosulfate (PMS)-assisted photocatalytic system is a promising platform for the selective degradation of water contaminants. However, achieving an effective electron transport and enhanced separation efficiency for these metal species is a daunting challenge. Thus, our current study addresses this challenge by using a Co-Fe-based layered-double-hydroxide template to synthesize a Co3O4/FeCo2O4 p-n heterojunction composite via a simple monosynthetic route. The resultant composite is thoroughly validated through advanced characterization techniques that efficiently activate PMS for sulfadiazine (SDZ) degradation under visible light, achieving a remarkable degradation efficiency of up to 90%. This accomplishment is attributed to factors including intimate interfacial contact, excellent light harvesting, mesoporosity, and oxygen vacancies within the composite. The formation of a distinct p-n heterojunction following the S-scheme charge dynamic significantly enhances photogenerated carrier separation and reduces charge recombination. The research delves into comprehensive investigations including degradation studies, active species trapping experiments, parameter exploration, and in-depth liquid chromatography-mass spectrometry for analysis of the degradation byproducts and pathway. Induced oxygen vacancies, strategically placed active surface sites, and mesoporosity in the Co3O4/FeCo2O4 composite synergistically boosted the sluggish PMS activation, leading to enhanced SDZ degradation. This study introduces a new perspective by demonstrating the potential of a single-material, mixed-metal oxide-based p-n heterojunction photocatalytic system following the S-scheme charge-transfer route for SDZ degradation. The findings contribute toward emphasizing the importance of tailored composite materials in tackling persistent contaminants.

High-performance MnO2 embedded fly ash zeolite applied for effective mineralization of bisphenol-A and sorption of congo red: Mechanism, real water application, and toxicity assessment

In this work, bisphenol A (BPA) and Congo red (CR) were eliminated using a hydrothermally produced flyash zeolite-embedded MnO2 (FAZ-MnO2) composite. Methods like X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the as-prepared composite. With a higher specific surface area of 384.85 m2/g, FAZ-MnO2 outperformed MnO2 and FAZ, which had surface areas of 46.84 and 28.46 m2/g, respectively. Likewise, the maximum adsorption capacity of FAZ-MnO2 towards BPA and CR was 172.19, and 293.91 mg/g respectively, which was higher than their pristine counterparts. The efficiency was observed to be enhanced due to inclusion of MnO2 into FAZ framework that served as active adsorption sites to remove BPA and CR. The removal of BPA occurs through adsorption followed by oxidation and mineralization due to presence of MnO2. Wheras, CR removal is dominated by adsorption process including covalent bonding, hydrogen bonding, and electrostatic interactions. Humic acid improved the elimination of BPA and CR, and FAZ-MnO2 showed good stability and recyclability with outstanding performance even after five cycles. FAZ-MnO2 can also effectively remove CR and BPA from various real water matrix. Eventually, the degradation byproducts were evaluated, and the lethality of those byproducts as well as the composite was assessed. The findings indicate that the eco-friendly composite studied has the potential to remove organic contaminants from water bodies.

The mechanism of photodegradation reaction of different dissociation forms of tetrabromobisphenol S in water with free radicals and the ecotoxicity evaluation of related products

Tetrabromobisphenol S (TBBPS) is a widely used brominated flame retardant that has attracted environmental concern due to its abundant presence in water. The objective of this study is to systematically analyze the direct photolysis and degradation mechanisms of TBBPS in two different dissociation forms in water, as well as to evaluate their toxicological effects induced by •OH, 1O2, and •NO2 radicals. The degradation mechanism of TBBPS is investigated with density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods, and the toxicity of the degradation products is assessed through toxicological studies. The results of the study indicate that the OH-addition and H-abstraction reactions are favorable pathways for •OH-induced TBBPS degradation. The H-abstraction reaction of TBBPS0 with •OH was more favorable than the •OH addition reaction. However, in the degradation of TBBPS−, the •OH addition reaction was favored over the H-abstraction reaction. Additionally, the indirect photolysis of TBBPS by 1O2 and •NO2 in water was found to be easier for TBBPS− compared to TBBPS0, with degradation mechanisms involving Br-substitution and NO2-addition reactions. The higher Ea values calculated indicate that the degradation of TBBPS by 1O2 and •NO2 in water has been a secondary reaction. The direct photolysis reaction pathway of TBBPS in water has involved the cleavage of the S1–C7 and S1–C16 bonds. For TBBPS0 in the S1/T1 states, the primary reaction pathway is the cleavage of the S1–C16 bond, while for TBBPS−, the primary reaction pathway is the cleavage of the S1–C7 bond. Furthermore, the computational toxicology results indicate a slight increase in the toxicity levels of most products, highlighting the significance of investigating the degradation byproducts of TBBPS in greater detail.

All-plastics distributed Bragg reflectors for sensing and thermal shielding applications

Year by year, the importance of plastic nanostructures in photonics is increasing. Indeed, polymers represent an interesting alternative to more traditional metal oxides, being easily processable and allowing for light, free-standing and flexible structures. In the field of energy efficiency and sustainability, we bring in two positive examples of the use of plastic photonic crystals: sensing and thermal shielding. In sensing they allow for easy detection of analytes, such as the byproducts of food degradation; a colour change identifies the spoilage, with possible application of these plastic sensors in smart packaging applications. On the other hand, they can be of interest for thermal shielding applications. Indeed, they can be engineered as thin, transparent films able to reduce indoor heating by sunlight and in turn the energy consumption related to the use of air conditioning.

Detection of insulation degradation by-products in transformer oil using ZnO coated IDC sensor

Abstract Condition monitoring of oil-immersed in-service transformers to facilitate preventive maintenance is still a challenge. Monitoring of 2-Furfuryldehyde (2-FAL), released in the transformer oil as a result of paper insulation degradation, and moisture ingress can provide insight into the health of the insulation of transformers. Since 2-FAL and moisture are high dielectric constant contamination, capacitive sensor-based detection is a potential solution. A novel Inter digital Capacitive (IDC) sensor is reported in this paper to measure the concentration of 2-FAL and moisture uses Zinc Oxide (ZnO) as a sensing film. The sensor shows good sensitivity, approximately linear characteristics, and low characteristic drift.

Effective BPA degradation in water: the integration of bimetallic UiO-66 Ce-Zr.

In this work, a bimetallic MOF UiO-66 Ce-Zr to degrade bisphenol A (BPA) in water was synthesised. The material exhibited a remarkable degradation efficiency of 84.3% under UV irradiation for 240 minutes. Combining cerium (Ce) and zirconium (Zr) in the MOF structure enhanced the catalytic activity and reinforced its structural stability. Comprehensive characterisation was performed using PXRD, FT-IR, SEM-EDS, XPS, and N₂ adsorption-desorption isotherms. Scavenger tests confirmed that hydroxyl (˙OH) and superoxide (˙O₂⁻) radicals played a crucial role in the photocatalysis. The material demonstrated excellent reusability, maintaining high performance over three cycles with minimal structural changes. Furthermore, a toxicological evaluation of the degradation by-products was conducted using UPLC-MS, reaffirming the potential of the material as an efficient water treatment system. This study underscores the potential of UiO-66 Ce-Zr as a stable and effective photocatalyst for water treatment applications, particularly in removing emerging pollutants such as BPA.

Tapping the Tunisian sunlight's potential to remove pharmaceuticals in tap water and secondary effluents: A comparison of Ag2O/TiO2 and BiOI photocatalysts and toxicological insights

In this study, BiOI microspheres and the Ag2O/TiO2 heterostructure were synthesized to photocatalytically degrade atenolol (ATL) and carbamazepine (CBZ) in tap water and secondary effluent under Tunisian summer season sunlight. The materials were characterized through XRD, SEM, TEM and DRS. The Ag2O/TiO2 material excelled by completely removing both pharmaceuticals from tap water within 180 min of irradiation, while less than 20 % of CBZ persisted in effluent after 3 h of irradiation. Stability tests using the Ag2O/TiO2 heterostructure over five reaction cycles indicated consistent degradation rates for ATL (k ranged from 3.1 × 10-2 to 5.9 × 10-2 min−1). Conversely, CBZ degradation rates increased from k = 6.4 × 10-3 min−1 to k = 1.8 × 10-2 min−1 in the fifth cycle. This increase was attributed to changes in the oxidation state of silver nanoparticles deposited on TiO2. Quenching tests identified OH radicals as dominant in photocatalytic degradation, followed by photo-holes for CBZ, and O2− radicals for ATL. Through LC-MS/MS, degradation byproducts were identified, allowing for proposed degradation kinetics. Lastly, the toxicity of the byproducts was estimated using the ECOSAR model, displaying a decrease in the toxicity of hydroxylated intermediates, while aminated species represented higher potential for acute and chronic toxicity.

Induced S-scheme CoMn-LDH/C-MgO for advanced oxidation of amoxicillin under visible light

The development of low-cost photostable heterostructures with robust interfacial contact is critical for competent photoactivity and practical applications. The solid-state approach was successfully employed for fabrication of novel stacked oval-shaped CoMn-LDH/C-MgO composites with Mn-O-Mg bridges for efficient interfacial charge separation induced by S-scheme charge transfer for degradation of amoxicillin (AMX). The persulfate (PS) activation mechanism was confirmed by Raman analysis using bond length relationship to peak shifts. PS activation rate was 1.8 times of CoMn-LDH/PS for the S-scheme heterojunction with a 99.97 ± 0.16 % removal efficiency after 60 min of irradiation at pH 5.2. S-scheme photocatalytic ozonation increased AMX mineralization rate by up to 8 times compared to ozonation. Antimicrobial studies confirmed bacterial growth inhibition of composites and the by-products of AMX degradation had reduced bacterial growth inhibition compared to AMX. This work demonstrated the development of an S-scheme CoMn-LDH/C-MgO heterojunction as a visible light heterogeneous photocatalyst for degradation of pharmaceuticals.

Influence of layered degradable straw drainage system on eco-treatment of dredged sludge under vacuum preloading

In response to the long-term non-degradation and environmental pollution caused by the use of horizontal plastic drainage boards, a new approach is proposed in this study, which involves employing horizontal straw drainage system under vacuum preloading treatment for dredging sludge. Through laboratory model tests, the results show that horizontal straw drainage system exhibited excellent performance in treating dredged sludge, with an optimal spacing design of 40–60 cm. During the vacuum preloading test, the straw drainage system continuously degraded, and the degradation by-products of straw, in turn, enriched elements like nitrogen, phosphorus, potassium, etc., in the soil. The two processes of the degradation of straw drainage system and the eco-reinforcement of dredged sludge interacted actively with each other. Finally, a new reinforcement method for on-site dredging sludge was proposed by installing layered straw drainage boards. Therefore, straw drainage system was highly recommended for field application, due to their cost-effective and environmentally friendly characteristics.

Mitigating Postfrying Degradation Factors of Fats and Oils through the Development of Bagasse-Based Adsorbent

The quality of fats and oils is a critical aspect of the food processing industry and consumer health. Fat degradation, particularly through oxidation, impacts various quality parameters, including color, taste, flavor, aroma, quality, and appearance. To address this issue, a study was conducted using five degraded fats/oil (DF/O) commodities as the target for an adsorption process. These commodities were chosen because of their high level of degradation by-products. The study used sugarcane bagasse (SCB) to develop five different treatments of indigenous adsorbents activated with various NaOH concentrations. Analyses including iodine number, adsorbent yield, and scanning electron microscope were performed to identify the potential of the prepared concentrations. Results showed that the indigenous adsorbent created with 1.0% NaOH was the most effective. The alkali treatment had a positive impact on the samples, but the SCB 10% was found to be the most efficient in reducing the degradation value of the treated samples. The findings of this study suggest that the use of indigenous adsorbents, particularly those prepared with SCB 10%, can be an effective way to reduce fat degradation and enhance the quality of fats and oils in the food processing industry. This approach can also address consumer health concerns related to fat and oil quality.

Enhancing production and purity of 9-OH-AD from phytosterols by balancing metabolic flux of the side-chain degradation and 9-position hydroxylation in Mycobacterium neoaurum.

9α-Hydroxyandroster-4-ene-3,17-dione (9-OH-AD) is a representative steroid drug intermediate that can be prepared by phytosterols (PS) biotransformation with mycobacteria in a resting cell-cyclodextrin system. In this study, over-expression of 17β-hydroxysteroid dehydrogenase (Hsd4A)was testified to enhance the side-chain degradation of PS and to reduce the incomplete degradation by-products. Meanwhile, the complete degradation product 4-androstene-3,17-dione (AD)was increased due to the lack of 3-Ketosteroid 9α-Hydroxylase (KshA1) activities. To increase the production and purity of 9-OH-AD, the metabolic pathway of the side-chain degradation of PS and 9-position hydroxylationwas modulated by balancing the over-expression of Hsd4A and KshA1 in mycobacteria and reducing the bioconversion rate via lowering the ratio of PS and cyclodextrin. The production and purity of 9-OH-AD in brothwere improved from 22.18gL-1 and 77.13% to 28.27gL-1 and 87.84%, with a molar yield of 78.32%.

Toxicity of glyphosate and its degradation products in aquatic ecosystems: a review

Context: The intensifying utilization of glyphosate has provoked global scientific concern due to the potential large-scale impact on ecosystems. In 2015, the International Agency for Research on Cancer (IARC) reclassified glyphosate and its degradation byproduct, aminomethylphosphonic acid (AMPA), as Category 2A, indicating probable human carcinogenicity. Knowledge Gap: A review of the existing literature reveals a relative scarcity of information on the aquatic impact of glyphosate and its degradation products. Purpose: To determine the scope and implications of the impact of glyphosate and its degradation products on aquatic ecosystems, in order to better understand their ecotoxicological effects and provide a foundation for future research and policy decisions in this area. Methodology: A systematic review of ecotoxicological studies published in Spanish and English over the last 12 years was conducted to assess the effects of glyphosate and its degradation products on aquatic ecosystems and the risks to various species. Approximately 95 documents were reviewed, including data from 69, addressing toxicity, biodegradation, contamination, and international regulations. Results: Studies have shown that chronic exposure to glyphosate can alter the metabolism in fish and affect the life cycle of organisms such as Daphnia Magna. The composition of glyphosate, along with its adjuvants, can increase its toxicity and pose risks to the aquatic ecosystem, making it crucial to understand the specific formulations and their concentrations. Conclusions: The increased use of glyphosate raised global scientific concerns due to its potential impact on ecosystems, with the IARC classifying it as possibly carcinogenic to humans. Studies showed acute toxicity to aquatic organisms and highlighted the need for risk assessment methodologies for long-term impacts on ecosystems and human.

Visible Light-Assisted Degradation of Sulfamethoxazole on 2D/0D Sulfur-Doped Bi2O3/MnO2 Z-Scheme Heterojunction Immobilized Photocatalysts.

Retrieving the spent photocatalysts from the reaction system is always a challenging task. Therefore, the present work is focused on immobilizing sulfur-doped-Bi2O3/MnO2 (S-BOMO) heterojunction photocatalysts over different support matrices and evaluating their performance for the removal of sulfamethoxazole (SMX) in water under visible light. Our findings revealed S-BOMO coated clay beads (S-BOMO CCB) achieving more than 86% (240 min) SMX degradation ∼3, ∼1.3, and ∼2 times higher compared to S-BOMO coated on the different substrates, including glass beads, floating stones, and polymer material substrates, respectively. Mott-Schottky measurements confirmed the construction of the Z-scheme heterojunction involving MnO2 and 2S-Bi2O3. This Z-scheme mechanism, along with its narrow band gap of 1.58 eV, resulted in a rapid spatial transfer of the photogenerated charge carriers between the semiconductors and is believed to enhance the overall photocatalytic activity of the nanocomposite. Radical trapping and electron paramagnetic resonance results clearly established the active role of hydroxyl radicals and hydrogen peroxide in the degradation of SMX. Further, the 2S-BOMO CCB demonstrated excellent stability and photocatalytic activity over multiple runs. According to the sensitivity analysis and the results of anion effect experiments, phosphate and sulfate ions exhibit a significant impact on sulfamethoxazole degradation. Toxicity analysis revealed that 2S-BOMO CCB and sulfamethoxazole degradation byproducts were apparently innocuous. Additionally, the practical applicability of 2S-BOMO CCB was examined in various real water matrices, with the degradation efficiency followed the order: tap water < groundwater < surface water < hospital wastewater < municipal wastewater < pharmaceutical industry wastewater. The economic assessment revealed the reduction in the overall cost of the immobilized 2S-BOMO following the recovery process. Overall, the findings of this work provided critical insights into the synthesis and performance of incredibly effective and stable immobilized photocatalysts for the degradation of pharmaceutical pollutants.

Xylitol Production by Debaryomyces hansenii in Extracted Olive Pomace Dilute-Acid Hydrolysate

The extracted olive pomace (EOP) is an industrial lignocellulosic by-product of olive pomace oil extraction, currently mainly used for energy production through combustion. In this work, the hemicellulosic fraction of EOP was selectively hydrolyzed by diluted acid hydrolysis to obtain pentose-rich hydrolysates that can potentially be upgraded by Debaryomyces hansenii, targeting xylitol production. The monosaccharides and degradation by-products released along the pre-treatment were quantified and several detoxification methods for the removal of potentially toxic compounds were evaluated, including pH adjustment to 5.5, the use of anion-exchange resins, adsorption into activated charcoal, concentration by evaporation, and membrane techniques, i.e., nanofiltration. The latter approach was shown to be the best method allowing the full removal of furfural, 41% of 5-hydroxymethylfurfural, 54% of acetic acid, and 67% of the phenolic compounds present in the hydrolysate. The effects of the supplementation of both non-detoxified and detoxified hydrolysates were also assessed. The non-detoxified hydrolysate, under aerobic conditions, supported the yeast growth and xylitol production at low levels. Supplementation with the low-cost corn steep liquor of the nanofiltration detoxified hydrolysate showed a higher xylitol yield (0.57 g/g) compared to the non-detoxified hydrolysate. The highest xylitol productivity was found in hydrolysate detoxified with anionic resins (0.30 g/L·h), which was 80% higher than in the non-detoxified culture medium. Overall, the results showed that EOP dilute acid hydrolysates can efficiently be used for xylitol production by D. hansenii if detoxification, and supplementation, even with low-cost supplements, are performed.