Refractory Organics Research Articles

A Broad Set of Solar and Cosmochemical Data Indicates High C-N-O Abundances for the Solar System

Abstract We examine the role of refractory organics as a major C carrier in the outer protosolar nebula and its implications for the compositions of large Kuiper Belt objects (KBOs) and CI chondrites. By utilizing Rosetta measurements of refractory organics in comet 67P/Churyumov–Gerasimenko, we show that they would make up a large fraction of the protosolar C inventory in the KBO-forming region based on the current widely adopted solar abundances. However, this would free up too much O to form water ice, producing solid material that is not sufficiently rock-rich to explain the uncompressed density of the Pluto–Charon system and other large KBOs; the former has been argued as the most representative value we have for the bulk composition of large KBOs. This inconsistency further highlights the solar abundances problem—an ongoing challenge in reconciling spectroscopically determined heavy-element abundances with helioseismology constraints. By employing a new data set from solar CNO neutrinos and solar wind measurements of C, N, and O, we show that the uncompressed density of the Pluto–Charon system can be reproduced over a wide range of scenarios. We show that a lack of sulfates in Ryugu and Bennu samples implies a lower amount of water ice initially accreted into CI chondrite parent bodies than previously thought. These data are found to be consistent with the solar C/O ratio implied by the new data set. Our predictions can be tested by future neutrino, helioseismology, and cosmochemical measurements.

Effective periodate activation by the ball-milled bimetallic zero-valent iron/manganese oxides catalyst for sulfamethoxazole degradation

Developing a green and efficient catalyst for oxidant activation to tackle refractory organics pollution is challenging for water purification. In this study, we prepared a zero-valent iron-based bimetallic catalyst (ZVI/Mn3O4) for periodate (PI) activation using a simple and convenient ball-milling method. Electrochemical characterization and theoretical calculations confirm that the synergy between Fe and Mn enables the ZVI/Mn3O4 system to exhibit higher electron transfer efficiency compared to its individual components. Consequently, the ZVI/Mn3O4/PI system demonstrated enhanced PI activation and significantly improved removal of sulfamethoxazole (SMX), with reaction rates being 18.61 to 57.01 times higher than the comparison systems. The influence of various physicochemical parameters on SMX removal was investigated, confirming the wide tolerance ZVI/Mn3O4/PI system towards multiple aqueous matrices. Furthermore, the scalability of this system for industrial applications was validated through the preparation of larger batches of catalysts (4.21 g per batch) and testing in a custom-designed magnetic plate continuous-flow reactor. Quenching experiments and electron spin resonance tests confirmed that •O2– and 1O2 were the primary reactive species responsible for SMX degradation, with no toxic iodine byproducts detected, attributed to the carefully designed catalyst, which optimized the interaction between PI and the catalyst. Based on these findings, a potential catalytic mechanism and degradation pathway were proposed, highlighting ZVI's role as an electron pump to enhance Mn3O4's activation of PI. Additionally, toxicity assessments via prediction, zebrafish cultivation, wheat germination, and E. coli culture confirmed the excellent detoxification capability of ZVI/Mn3O4/PI system for SMX degradation. Overall, this work provides a new research paradigm for the convenient manufacture of ZVI-based catalysts and the development of advanced techniques for PI activation in water purification.

Sustainable bioenergy potential of peat-moss derived hydrothermal aqueous phase: Insights into methane production and organic transformation

Achieving Sustainable Development Goal 7 (SDG-7) by exploring bioenergy production from peat-moss derived hydrothermal aqueous phase (HAPs) through anaerobic digestion (AD). This study investigated six combinations of hydrothermal conversion temperature (HCT) and residence time (HCRT). Methane yields varied significantly, with the highest (256 mL/g COD) achieved at 200 °C:4h, while the lowest (97 mL/g COD) was at 320 °C:4h due to formation of toxic and refractory organics. Microtox analysis showed acute toxicity > 98 % for all HAPs. Notably, higher HCT and HCRT led to more complex and diverse organic patterns, promoting the formation of humus-like substances, ester, alkane alcohols, and aromatics. GC–MS analysis revealed a 23 % increase in aldehyde and ketone compounds at 320 °C:4h. Continuous experiments confirmed 29 % COD removal efficiency at 320 °C:4h and identified 13 refractory organics, highlighting challenges in biodegradability. These findings provided valuable insights for optimizing AD processes, enhancing bioenergy production, and advancing sustainable energy solutions in alignment with SDG-7.

Nanotechnology strategy for inhibition of PARP1 and IL-17A-associated with neurotoxicity in rats exposed to hospital wastewater.

Hospital wastewater (HWW) poses a serious hazard to human health security concerning its high susceptibility to neurodegeneration. Water sources and ecosystems are exposed to a complicated pollution load from a variety of refractory organics and pharmaceutical active composites. This study evaluates the treated newly developed nanocomposite (NiFe2O4) HWW on the neural injury induced by HWW action in rats. Three groups of male Wistar rats were distributed, with eight rats in each: group I: tap water served as a control; group II: HWW; and group III: nano-HWW. Each group was intragastrical administrated with each type of water (2.5 ml/100 g b.wt/6 h) for 28 consecutive days. The open field test and Morris Water Maze assessed behavioral activity and spatial learning 2 days before the last day. The research demonstrated that HWW treated with nanocomposite (NiFe2O4) may exert decreased risks of the neural impairment effect of HWW. This improvement was achieved by reducing the neurotoxicity by lowering nitric oxide contents, lipid peroxidation, acetylcholinesterase, interleukin-17A (IL-17A), and poly(ADP-ribose) polymerase1(PARP1) while restoring the antioxidant biomarkers and neurotransmitter levels (β-endorphin, norepinephrine, dopamine, and serotonin) of the treated groups in the cortex and brainstem and enhancement of the histopathology of the cortex as well. In conclusion, this study introduced a newly developed nanotechnology application for treating HWW to protect from neural injury. The findings of this research have significant value for policymakers, Ministry of Health management, and environmental organizations in their selection of suitable techniques and procedures to optimize hospital wastewater treatment efficiency.

Enhanced nitrogen removal from secondary effluent of municipal wastewater using denitrification filter: Feasibility of refractory organics as a carbon source

Conventional advanced nitrogen removal in municipal wastewater is hindered by the limited availability of carbon sources in the secondary effluent. However, refractory organics present in it had the potential to serve as intrinsic carbon sources after hydrolysis for nitrogen removal via simultaneous denitrification and partial-denitrification anammox (PDA) processes. To assess this potential, a denitrification filter was set up in this study to evaluate its feasibility of concurrent processes. Results showed that increasing influent ammonium (NH4+-N) from 1.0 to 7.0 mg/L increased total nitrogen (TN) removal from 52.4 % to 89.9 %. Simultaneous occurrence of PDA and denitrification process were confirmed by the actual chemical oxygen demand (COD) consumption (0.8–1.2 mg/mg TN removal) from non-fluorescent organics. The presence of the anammox, hydrolytic and denitrifying bacteria further supported the achievement of nitrogen removal through PDA and denitrification processes by utilizing hydrolytic products biodegraded from refractory organics.

Two-way role of iron-carbon in biochemical reactions: microelectrolysis and enhanced activity of aerobic granular sludge for efficient refractory wastewater treatment

Industrial wastewater contained a large amount of refractory organics, and single treatment processes had limitations. This study investigated the mechanism of refractory organics removal using iron-carbon built-in coupled activated sludge (ICAS) and explored the role and function of iron-carbon (IC) within the ICAS system. The aerobic granular sludge (AGS) cultivated with IC exhibited a loose surface and a tight interior structure. Iron in the AGS concentrated near the outer layer to form a crust, which protected the inner microorganisms. IC promoted EPS secretion and regulated the abundance of positive and negative signaling molecules to maintain AGS stability. Experiments using quinoline as a model refractory organic showed that both physical adsorption by IC and biological adsorption by sludge rapidly fixed a large amount of pollutants, providing a buffer capacity for the system. The iron mineral crust on the AGS surface enhanced quinoline adsorption. Hydroxylation was the first step in quinoline degradation, with IC upregulating the genes iorA/B, qorB, and wrbA involved in this process, and the relative abundances of quinoline-degrading bacteria. Both pyridine ring opening and benzene ring cleavage occurred in the single IC system, and the microelectrolysis process produced •OH and [H], which made degradation pathway for quinoline through IC more complex than microbial degradation. Although the IC-mediated pathway accounted for only a small part of overall quinoline removal in the ICAS system, the ICAS system not only preserved the microelectrolysis process but also enhanced microbial metabolic activity. This work provided insights into the synergistic removal of pollutants and maintenance of AGS stability by the ICAS process, ensuring efficient treatment of refractory organic wastewater.

Efficient photo-Fenton-like degradation of tetracycline hydrochloride using Co-In2O3 nanotubes: Insights into mechanism and performance

Photo-Fenton-like process is effective towards refractory organics removal for its strong oxidation capacity. Herein, cobalt-doped indium oxide (Co-In2O3) with nanotube morphology was prepared and was taken as photo-Fenton-like catalyst. In the presence of peroxymonosulfate (PMS), Co-In2O3 nanotubes exhibited excellent photo-Fenton-like activity with tetracycline hydrochloride (TC-HCl) degradation of 98.8 % in 40 min. The visible light driving Co-In2O3/PMS system showed the reaction rate constants of 0.0998 min−1, which was 6 folds of the In2O3/PMS/vis system. Experimental results combining with theoretical chemical calculation demonstrated that the doping of Co can effectively reduce the band gap of In2O3, thus leading to stronger visible light absorption capability. The presence of oxygen vacancies (OVs) disrupted the symmetry and integrity of the catalyst structure and achieved electron enrichment at the reactive site. Simultaneously, Co doping and an appropriate amount of OVs strengthened chemisorption for PMS (from −0.652 eV to −4.224 eV) and higher electron density difference (from 0.49 e– to 0.68 e−). Our findings provide insight on the contribution role of cobalt doping and OVs in improving photo-Fenton-like catalytic efficiency.

Experimental Investigation on Photocatalytic Degradation of Refractory Organics in Biologically Treated Tannery Effluent Using Photocatalysis

There is a pressing demand for the introduction of environmentally safe technologies for the industries that supply the basic needs of industrialized societies. Advanced Oxidation Processes may become one of the answers to these uprising pollution management problems in the near future. The present investigation aimed to reduce the refractory organics present in the biologically treated (Activated Sludge Process) tannery effluent using Photocatalysis. The optimum time, pH, dosage of H2O2, and mass of NPAC required for the effective treatment using photocatalysis were found to be 60 mins, 8, 0.2 mg.L-1, and 1g. 100 mL-1, respectively. Although the efficiency of homogeneous photocatalysis was found to be higher than that of heterogeneous photocatalysis, the biodegradability was higher in the latter, with a value of 0.26. The experimental results have proved that photocatalysis could be a promising technology to reduce the refractory organics present in the tannery effluent.

Multilayered photo-bioanode for simultaneous conversion of CO2 and industrial refractory organics into bioelectricity in a microbial fuel cell system

CO2 and toxic wastewater were converted into bioelectricity through photo-bioanode in a microbial fuel cell (MFCs). Photo-bioanode provided multifunctional regions due to four distinct layers: the first layer integrates a Fe-doped graphitic carbon nitride photocatalyst. In contrast, the second layer contains refractory organics (RO) degrading microbes. Sequentially, the third layer consists of CO2-consuming bacteria and the fourth layer accommodates exoelectrogens. The first layer not only generated plentiful electrons upon illumination but also quenched electrons from the inner layers, facilitating the degradation of RO. The second layer transformed RO into ions (NH4, NO3/NO2) and C6H12O6, sequentially transported into the third and fourth layers. Within the third layer, CO2-consuming bacteria utilized CO2 leaked from the exoelectrogenic layer, effectively curbing its accumulation in the fourth layer. Here, exoelectrogens employed ions and C6H12O6 as their energy source, producing an electricity output 1.4 times greater than the benchmark. This synergistic performance yielded a voltage of 2.5 V, a current of 2.8A, and a power yield of 1.98 W/organic loading rate (OLR). Thus, the unique layered structure of the photo-bioanode facilitated the self-development of distinct microbial communities, thereby formulating a multifunctional and highly dynamic system with zero-liquid discharge.

Periodate activation via metals and metal-based complexes: progress in degradation properties and mechanisms

ABSTRACT Residuals of refractory organics in water create a deep hazard to the water environment and human health, hence it is urgent to develop efficient approaches to remove refractory organics. Being a novel oxidizer, periodate (PI, IO4-) is considered to be stable and efficient in advanced oxidation processes for degrading refractory organics, such as antibiotics, dyes, pesticides, etc. Since the activity of PI alone is low, it is necessary to activate the PI to form active species in effectively removing organics. The studies of PI activation via monometallic, bimetallic, metal oxides, metal complexes, etc., have obtained more concerns owing to the high efficiency in decomposing organics. However, no reviews related to these studies have been published in recent years. This review summarized the properties and uses of PI, analyzed degradation properties and mechanisms of various metals and metal-based complexes in activating PI to remove refractory organics, and highlighted the limitations of these processes as well as the future research directions.

Nonradical peroxymonosulfate activation via high-level pyrrolic-nitrogen and electron-deficient carbon at 2D ultrathin carbonaceous nanosheets for efficient BPA removal

Activation of persulfate by N-doped carbon is an emerging advanced oxidation process (AOP) for removing organic pollutants from water via singlet oxygen (1O2)-dominated non-radical way, however, the efficient generation of 1O2 is a hot topic worth deep exploration. In this study, glucose was used as an additional carbon and oxygen of prefabricated supramolecular melamine-cyanuric acid precursor, the final co-thermal polymerization products completely changed from conventional graphitic carbon nitride to ultrathin carbonaceous materials when the mass of glucose up to 0.72 g. The simple one-pot strategy can easily generate active electron-deficient carbon sites due to nitrogen and oxygen doping by modulating the electronic structure of the carbon framework, which is critical for the activation of peroxymonosulfate (PMS) to produce 1O2. The glucose content can adjust the degree of disorder of the amorphous carbonaceous nanosheet, and significantly improve the exposure of active pyrrolic nitrogen sites (27.47 %) and doped oxygen through the defective structure, which is another essential factor for the generation of 1O2 in the activation of PMS. The MCAG-0.72/ PMS exhibited excellent performance in BPA degradation, 95 % BPA (20 mg L−1) can be removed in 60 min with 1.0 mM PMS with reaction constant k=0.0209 min−1. Furthermore, MCAG-0.72 also demonstrated excellent BPA degradation in different actual water metrics and performance well in the four consecutive cycles. This study provides a novel convenient strategy to synthesize cost-effective N/O co-doped carbonaceous material for efficient activating PMS to remove refractory organics in water and wastewater, it sheds light on practical large-scale industrial applications in PMS-based AOPs.

Application of the sono-Fenton/UV process on the treatment of table olive processing wastewater

AbstractThe Mediterranean Basin economies of Spain, Italy, Greece, and Turkey depend on the table olive and olive oil industries. Table olive processing wastewater characteristics and quantity depend on olive varietal and processing methods. Olives and processing methods provide phenol, suspended particles, dissolved inorganic solids, and refractory organics. Due of its complexity, conventional methods struggle to tackle table olive processing wastewater. A novel approach to enhanced oxidation processes integrates many ways to boost hydroxyl radical formation and scale up efficiency. UV assisted sono-Fenton process as a modified Fenton process was applied to table olive washing wastewater to achieve high formation of hydroxyl radicals. When UV assisted sono-Fenton experiments executed to determine the optimum reaction conditions, the effects of hydrogen peroxide, ferrous ion concentrations and reaction time on the oxidation of table olive washing wastewater investigated by using a statistical experimental design. Chemical oxygen demand (COD), total organic carbon (TOC) and phenol removal efficiencies were examined by keeping the pH constant. The UV assisted sono-Fenton process achieved 53% phenol, 68% TOC, and 80% COD removal efficiencies. The results show that the UV assisted sono-Fenton process can treat effectively table olive processing wastewater. Optimum reaction conditions for the UV assisted sono-Fenton process were determined. UV assisted sono-Fenton process provides a significant reduction in reaction time and minimizes the costs of process associated with low chemical requirements. So, these optimum reaction conditions were resulted in low sludge production at the UV assisted sono-Fenton process while treating table olive processing wastewater.

Electrochemical Hydrogenation of Refractory Organics in Wastewater

Wastewater treatment is an essential process for the sustainable development of a society. The handling and degrading of different refractory and toxic organic pollutants heavily relies on conventional biodegradation. Herein, we developed an electrochemical hydrogenation method to enhance the biodegradability of organic substrates, which subsequently improves their availability to other biological-driven processes, namely denitrification. The strategy presents an unprecedented "kill-two-birds-with-one-stone" strategy to simultaneously deal with excessive organic components and nitrate's presence in wastewater. The strategy was discovered by comparing the biodegradability of some organic compounds and their hydrogenation forms. It was found that the hydrogenation product was much more bioavailable. Motivated by this discovery, we synthesized a carbon-supported Ru electrode by electrodepositing Ru on activated carbon cloth (ACC), named Ru/ACC. After that, 4-chlorophenol was used to optimize the experimental conditions, and Ru/ACC electrodes successfully converted 99.9% of 4-chlorophenol with an overall yield reached 90.9%. After that, the Ru/ACC electrodes proved efficient in transferring various wastewater organic pollutants. Besides, the electrochemical hydrogenation effect on biochemical degradation and denitrification was studied. It is significant for the electrochemical hydrogenation method to be applied to wastewater treatment.

Biochar assisted synthesis of α-MnO2 nanowires with superior performance for non-radical activation of peroxymonosulfate

Non-radical activation of peroxymonosulfate (PMS) is a promising water treatment technology for removing refractory organics, but its mechanism is still ambiguous and the development of highly efficient catalyst is still a challenge. Herein, α-MnO2 nanowires were synthesized by a hydrothermal method with the assistance of biochar and their performance for PMS activation was studied. The characterization results show that the addition of biochar had little effect on the crystal phase and valence state of MnO2 but significantly reduced the size of nanowires. These nanowires had mesoporous structure, high surface area and oxidation ability, resulting in their superior performance for removing organic pollutants with PMS activation. The degradation of phenol by α-MnO2-PMS followed first order kinetics with an activation energy of 14.82 kJ mol−1. Electron paramagnetic resonance and radical scavenging experiments demonstrated that this activation process followed the non-radical mechanism. The quenching effect of scavengers led to the misleading role of singlet oxygen. In fact, surface activated PMS (MnO2–PMS*) rather than singlet oxygen was the reactive species. Weak acidic condition was conducive for the formation of MnO2–PMS* complexes. This catalyst exhibited good reusability and high activity for removing various organic pollutants, and the common substances in real water had little effect on its performance, suggesting its potential application in wastewater treatment.

Multi-win situation of wastewater purification, carbon emission reduction and resource utilization: Conversion of refractory organics and nitrate to urea and ammonia in a flow-through electrochemical integrated system

The advanced oxidation process is an efficient technology for the degradation and detoxification of refractory organics to ensure water safety. However, most researches focus on improving pollutant degradation but overlook carbon emission and resource utilization. In this study, a flow-through electrochemical integrated system was constructed to simultaneously realize bisphenol A (BPA) oxidation into small non-toxic organics and CO2, and generated CO2 coupled with nitrate-containing wastewater conversion to urea and ammonia on a porous cathode (Zr-Fe/CN). The synergistic effect between anodic BPA oxidation with cathodic CO2 and NO3−reduction improves the electron utilization efficiency and thus increasing the BPA degradation, urea yield rate (UYR) and NH3 yield rate (NYR) by 13.4 % 18.4 % and 8.3 %, respectively. Furthermore, the flow-through operation mode significantly increased the mass transfer efficiency and quickly carried generated CO2 from the anode into the cathode to improve CO2 utilization efficiency. Compared to the parallel plate electrode reactor, the BPA degradation efficiency, UYR and NYR in the flow-through reactor increased from 59.46 % to 84.49 % (the initial concentration of BPA was 40 mg/L), 9.94 mmol h−1g−1 to 19.55 mmol h−1g−1, and 80.31 mmol h−1g−1 to 106.06 mmol h−1g−1 within 60 min, respectively. Moreover, the total carbon conversion efficiency (from BPA to urea) increased from 20.2 % to 42.4 % and the total Faraday efficiency (FE) increased from 78.6 % to 96.3 %. This work provides a multi-win strategy of harmless, resource-based and carbon emission reduction for wastewater treatment.

Unveiling the microbial co-metabolism behavior for electrical-driven degradation of phenol in bioanode

Uncovering the behavior of microbial co-metabolism will provide a vision of microbial mutualistic mechanisms for degrading refractory organics by bioanode and expedite the application of microbial electrochemical technology. Here, microbial co-metabolism is established by adding acetate sodium and is used to stimulate the electrical-driven degradation (e-degradation) of phenol by bioanode. The efficiency of e-degradation for 50 mg L−1 phenol achieved 24.8 % and the total electron recovery was improved by 289 ± 40 % compared with that without microbial co-metabolism. This improvement is found for the e-degradation of 20 mg L−1, 30 mg L−1, and 100 mg L−1 phenol. A big external resistance would inhibit the metabolism of exoelectrogens and lead to a decrease in electron recovery. Abundant exoelectrogens (Geobacter spp. and Pseudomonas spp.) are enriched in bioanode with microbial co-metabolism and the biofilm can perform extracellular electron transport through various pathways with the mid-potential of −0.24 V and −0.42 V, respectively. In addition, elevated amounts of intermediates for phenol e-degradation further demonstrate that microbial co-metabolism stimulates the conversion of phenol in bioanode. The insights gained from this study will assist in disclosing microbial interaction behavior in degrading refectory pollutants by bioanode.

Feasibility of intimately coupled CaO-catalytic-ozonation and bio-contact oxidation reactor for heavy metal and color removal and deep mineralization of refractory organics in actual coking wastewater

Considering the challenges for both single and traditional two-stage treatments, advanced oxidation and biodegradation, in the treatment of actual coking wastewater, an intimately coupled catalytic ozonation and biodegradation (ICOB) reactor was developed. In this study, ICOB treatment significantly enhanced the removal of Cu2+, Fe3+, and color by 39 %, 45 %, and 52 %, respectively, outperforming biodegradation. Catalytic ozonation effectively breaking down unsaturated organic substances and high-molecular-weight dissolved organic matter into smaller, more biodegradable molecules. Compared with biodegradation, the ICOB system significantly increased the abundances of Pseudomonas, Sphingopyxis, and Brevundimonas by ∼ 96 %, ∼67 %, and ∼ 85 %, respectively. These microorganisms, possessing genes for degrading phenol, aromatic compounds, polycyclic aromatics, and sulfur metabolism, further enhanced the mineralization of intermediates. Consequently, the ICOB system outperformed biodegradation and catalytic ozonation treatments, exhibiting chemical oxygen demand removal rate of ∼ 58 % and toxicity reduction of ∼ 47 %. Overall, the ICOB treatment showcases promise for practical engineering applications in coking wastewater treatment.

Molybdenum disulphide nanoparticles accelerate the transformation of levofloxacin in planting soil upon exposure

The use of nanocatalytic particles for the removal of refractory organics from wastewater is a rapidly growing area of environmental purification. However, little has been done to investigate the effects of nanoparticles on soil-plant systems with antibiotic contamination. This work assessed the effect of molybdenum disulfide (MoS2) on the soil-Phragmites communis system containing levofloxacin (LVX). The results showed that the addition of MoS2 had restoration potential for stressed plant. The MoS2 with catalytic activity promoted the transformation of LVX in rhizosphere soils. The transformation pathways of LVX in the different exposure groups were proposed. The continuous output of radicals in the high MoS2 dosage group facilitated the transformation of LVX to small molecule compounds, which were eventually mineralized. Moreover, the electron-density-difference analysis revealed the easier flow of electrons from the MoS2 surface towards the LVX molecules. This finding provides theoretical support for the application of nanocatalytic particles in ecological environments.

Real-time ozonation monitoring and control in wastewater tertiary treatment: An ultraviolet-visible monitoring approach

To address the challenge of refractory organics removal in wastewater tertiary treatment, this study investigates the application of ozonation, coupled with Ultraviolet-Visible (UV–Vis) spectroscopy, for enhanced tertiary treatment in a wastewater treatment plant (WWTP) in Qingdao, China. Our approach integrates ozonation with real-time UV–Vis spectral monitoring to precisely control ozone dosing, targeting the effective degradation of persistent organics characterized by high Chemical Oxygen Demand (COD) values. Through the deployment of mathematical models, including Linear Discriminant Analysis (LDA) and Support Vector Machine (SVM), we developed a robust two-step ozone dosing control model. The model's efficacy is validated by its ability to predict the need for ozonation with a high degree of accuracy (94.29 % for LDA), significantly optimizing the ozonation process. Key findings indicate that this method not only achieves substantial removal of recalcitrant organics (with COD removal rates varying between 16 % and 71 %) but also offers considerable energy savings and operational cost reductions by adjusting ozone dosing in real-time based on water quality data. This study presents a novel, sustainable approach to improving WWTP efficiency and compliance, showcasing the potential of integrating advanced oxidation processes with precision monitoring techniques for environmental protection and water reuse initiatives.

Bimetallic cobalt-cerium oxides activated fenton-like process for organic contaminant removal: Role of high-valent cobalt species modulated by oxygen vacancies

Cobalt-cerium bimetallic oxides (CoCeOx) with rich oxygen vacancies (OVs) were prepared by solvothermal method for peroxymonosulfate (PMS) activation efficiently, and the effect of OVs on reactive species formation was discussed. Carbamazepine (CBZ), a widely used anti-epileptic drug, also a typical pharmaceutical and personal care products (PPCPs) in the water environment, could be removed by 98 % in 40 min with low addition of CoCeOx and PMS in the CoCeOx/PMS system. Through a series of quenching experiments and electron paramagnetic resonance, it was confirmed that the main reactive species for decontamination were high-valent cobalt oxygen species (Co(IV)). Through the OVs detection and the contribution calculation of radicals and non-radicals on CBZ removal, it was found that OVs promoted the transformation from radicals to non-radicals (mainly Co(IV)) in the systems. In addition, cerium doping played an important role in promoting Co (II) / Co (III) cycle and OVs regeneration. Density functional theory (DFT) calculation revealed the formation process of Co(IV), and further proved that OVs could promote the formation of Co(IV). Evaluated by quantitative structure–activity relationship (QSAR) analysis, the ecotoxicity of CBZ and its main intermediates was significantly decreased. Overall, this study deepens the understanding of OVs promoting the formation of high-valent metal oxygen species (HVMO), as well as provides feasibility for the removal of refractory organics in wastewater.