In this account, the reactive oxygen species (ROS) were comprehensively reviewed, which were based on electro-Fenton and photo-Fenton processes and correlative membrane filtration technology. ...Specifically, this review focuses on the fundamental principles and applications of advanced oxidation processes (AOPs) based on a series of nanomaterials, and we compare the pros and cons of each method and point out the perspective. Further, the emerging reviews regarding AOPs rarely emphasize the involved ROS and consider the convenience of radical classification and transformation mechanism, such a review is of paramount importance to be needed. Owing to the strong oxidation ability of radical (e.g., •OH, O2•-, and SO4•-) and non-radical (e.g., 1O2 and H2O2), these ROS would attack the organic contaminants of emerging concern, thus achieving the goal of environmental remediation. Hopefully, this review can offer detailed theoretical guidance for the researchers, and we believe it able to offer the frontier knowledge of AOPs for wastewater treatment plants (WWTPs).
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•ROS in AOPs, and its correlative radical classification as well as transformation mechanism were also discussed.•The electron-Fenton and photo-Fenton were reviewed and expected to replace conventional Fenton process in WWTPs.•PMS activation regarding ROS conversion mechanism and catalyst reusability as well as possible application were presented.•The future development challenges and outlook were put forward.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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Minimizing the variability of any process can become a way to reduce costs and at the same time keep the process stable. The use of the Normal Boundary Intersection (NBI) algorithm to ...construct the Pareto frontier can be applied to a better choice of a particular setup that can give the process a better response and less variability. The objective of this research is to propose the modelling and optimization for the maximum removal of the Chemical Oxygen Demand (COD) and the minimization of the variance associated the COD removal, to the UV/TiO2/O3 process, in the treatment of Eriochrome Black T. The factors studied in the COD removal were: pH, ozonator power, ozone flow and reaction time. The process of modelling used the response surface through the Central Compound Design (CCD) arrangement. In addition to the optimization, a Pareto Frontier using the NBI algorithm was utilized. The optimized results showed a COD removal of 33.7 ± 1.29 obtained X* = 7.7; 160 W; 5.6 L min−1; 22.6 min. The confirmation of this point belonging to the Pareto frontier from the validation of the method was performed within a 95% confidence interval, the number of experiments being determined from the power sample size, comparing the ratio between the variances, weights w1 = 1 and w2 = 0.45.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Adverse outcome pathways represent structured knowledge of toxicity.•Toxicity information are very dispersed.•Artificial intelligence tools help to identify and compile toxicity ...knowledge.•AOP-helpFinder support the weight of evidence approach.
To support the use of alternative methods in regulatory assessment of chemical risks, the concept of adverse outcome pathway (AOP) constitutes an important toxicological tool. AOP represents a structured representation of existing knowledge, linking molecular initiating event (MIE) initiated by a prototypical stressor that leads to a cascade of biological key event (KE) to an adverse outcome (AO). Biological information to develop such AOP is very dispersed in various data sources. To increase the chance of capturing relevant existing data to develop a new AOP, the AOP-helpFinder tool was recently implemented to assist researchers to design new AOP. Here, an updated version of AOP-helpFinder proposes novel functionalities. The main one being the implementation of an automatic screening of the abstracts from the PubMed database to identify and extract event-event associations. In addition, a new scoring system was created to classify the identified co-occurred terms (stressor-event or event-event (which represent key event relationships) to help prioritization and support the weight of evidence approach, allowing a global assessment of the strength and reliability of the AOP. Moreover, to facilitate interpretation of the results, visualization options are also proposed. The AOP-helpFinder source code are fully accessible via GitHub, and searches can be performed via a web interface at http://aop-helpfinder-v2.u-paris-sciences.fr/.
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•Membrane-based treatments and AOP combination was assessed for wastewater reclamation.•MBR and MBBR-MBR can regenerate wastewater with highest quality set in ...2018/0169/COD.•Pharmaceuticals in urban wastewater can be completely removed using MBBR-MBR + AOP.•The heterotrophic kinetics of biomass is affected by the presence of pharmaceuticals.
This research was performed to assess the production of reclaimed water from urban wastewater in membrane bioreactor – advanced oxidation process (MBR-AOP) and moving bed biofilm reactor – membrane bioreactor – advanced oxidation process (MBBR-MBR-AOP) combined treatments to study the effect of biofilm incorporation. Both combined treatments were operated at the same conditions (10 h of hydraulic retention time, 6500 mg/L of mixed liquor suspended solids and 25 mg/L of hydrogen peroxide dosage over 15 min). Additionally, the removal capacity of some pharmaceuticals (carbamazepine, ciprofloxacin and ibuprofen) and their impact on the kinetic behaviour of the biomass in both systems were evaluated. From the results, it was found a membrane-based bioreactor can achieve both wastewater secondary treatment and pre-treatment for advanced oxidation process, so both MBR-AOP and MBBR-MBR-AOP treatments have a great potential to produce high quality reclaimed water (biological oxygen demand <0.5 mgO2/L, suspended solids <1 mg/L, turbidity <1 NTU and no presence of E. coli), according to European Commission proposal 2018/0169/COD. The addition of carriers improved the biodegradation of the most persistent pharmaceuticals in the biological treatment (from 69.20 ± 1.54% to 75.14 ± 2.71% for carbamazepine and from 60.41 ± 2.16 to 63.14 ± 2.70% for ciprofloxacin). It had, as a consequence, the MBBR-MBR-AOP system showing a complete degradation of pharmaceuticals after 5 min AOP treatment compared to the MBR-AOP system. The loss of biomass in the MBR-AOP (from 5233.45 to 4451.92 mg/L) and the increase of the substrate degradation rate for organic matter in both treatments (from 37.27 to 41.42 and from 30.25 to 33.19 mgO2/(L·h) in MBR-AOP and MBBR-MBR-AOP, respectively) are some of the consequences of pharmaceuticals in urban wastewater.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Methylene blue is a refractory pollutant commonly present in textile wastewater. This study tests the feasibility of TiO2/graphene oxide (GO) composite in enhancing photocatalytic degradation of MB ...in synthetic wastewater with respect to scientific and engineering aspects. To enhance its removal, we vary the composition of the composite based on the TiO2 weight. Under UV–vis irradiation, the effects of photocatalyst's dose, pH, and reaction time on MB removal by the composites are evaluated under optimum conditions, while any changes in their physico-chemical properties before and after treatment are analyzed by using TEM, SEM, XRD, FTIR and BET. The photodegradation pathways of the target pollutant by the composite and its removal mechanisms are also elaborated. It is found that the same composite with a 1:2 wt ratio of GO/TiO2 has the largest surface area of 104.51 m2/g. Under optimum reactions (0.2 g/L of dose, pH 10, and 5 mg/L of pollutant's concentration), an almost complete MB removal could be attained within 4 h. This result is higher than that of the TiO2 alone (30%) under the same conditions. Since the treated effluents could meet the strict discharge standard limit of ≤0.2 μg/L set by China's regulation, subsequent biological treatments are unnecessary for completing biodegradation of remaining oxidation by-products in the wastewater effluents.
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•The GO/TiO2 composite (w/w = 1:2) has the highest surface area of 104.51 m2/g.•Optimized conditions: 0.2 g/L of dose, pH 10, and 5 mg/L of MB concentration.•An almost complete removal of MB (99%) could be attained within 4 h.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Contaminants in water pose a significant challenge as they are harmful and difficult to treat using conventional methods. Therefore, various new methods have been proposed to degrade organic ...pollutants in water, among which the photo-Fenton process is considered promising. In recent years, Fe-based metal-organic frameworks (Fe-MOFs) have gained attention and found applications in different fields due to their cost-effectiveness, non-toxic nature, and unique porous structure. Many researchers have applied Fe-MOFs to the photo-Fenton process in recent years and achieved good results. This review focuses on describing different strategies for enhancing the performance of Fe-MOFs in the photo-Fenton process. Also, the mechanism of MOF in the photo-Fenton process is described in detail. Finally, prospects for the application of Fe-MOFs in photo-Fenton systems for the treatment of organic pollutants in water are presented. This study provides information and ideas for researchers to use Fe-MOFs to remove organic pollutants from water by photo-Fenton process.
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•Various enhancement methods of Fe-MOF in photo-Fenton process are described.•Catalytic mechanism of Fe-MOFs in photo Fenton process was discussed.•Potential application prospects and challenges of Fe-MOFs in photo Fenton process prospect.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Advanced oxidation processes are low-cost, highly efficient, and eco-friendly technologies in the removal of organic pollutants in wastewater using hydroxyl radicals for oxidation. Hydroxyl radicals ...possess high oxidation potential and can react with organic compounds, resulting in the complete mineralization of these compounds into carbon dioxide, water, and inorganic salt or their conversion into other compounds. The present investigation deals with the removal of tetracycline from water using simulated ultraviolet radiation and hydrogen peroxide, assessing the effect of operational parameters like the solution's initial pH, retention time, hydrogen peroxide dosage in terms of chemical oxygen demand (COD) removal from the standard aqueous solution of tetracycline. Results indicate that alkaline conditions and larger hydrogen peroxide dosage negatively affect the degradation. The removal efficiency of 68 % was achieved at 150 min of batch reaction under optimum conditions: pH = 4, and a dose of hydrogen peroxide of 0.3 ml per 100 ml of the solution to be treated. At optimum conditions, LC-MS/MS (liquid chromatography tandem mass spectrometry) analysis results showed a reduction in initial concentration of aqueous solution of tetracycline. Photocatalytic degradation followed pseudo-first-order kinetics with the rate constant (k) of 0.0061 min-1. Photocatalysis based on hydrogen peroxide is effective in the degradation of tetracycline in an aqueous solution and can be applied as a pretreatment of hospital wastewater containing tetracycline residues.
An adverse outcome pathway (AOP) is a compact representation of the available mechanistic information on observed adverse effects upon environmental exposure. Sharing of events across individual AOPs ...has led to the emergence of AOP networks. Since AOP networks are expected to be functional units of toxicity prediction, there is current interest in their development tailored to specific research question or regulatory problem. To this end, we have developed a detailed workflow to construct an endocrine-relevant AOP (ED-AOP) network based on the existing information available in AOP-Wiki. We propose a cumulative weight of evidence (WoE) score for each ED-AOP based on the WoE scores assigned to key event relationships (KERs) by AOP-Wiki, revealing gaps in AOP development. Connectivity analysis of the ED-AOP network comprising 48 AOPs reveals 7 connected components and 12 isolated AOPs. Subsequently, we apply standard network measures to perform an in-depth analysis of the two largest connected components of the ED-AOP network. Notably, the graph-theoretic analyses led to the identification of important events including points of convergence or divergence in the ED-AOP network. These findings can suggest potential adverse outcomes and facilitate the development of new endpoints or assays for chemical risk assessment. Detailed analysis of the largest component in the ED-AOP network gives insights on the systems-level perturbations caused by endocrine disruption, emergent paths, and stressor-event associations. In sum, the derived ED-AOP network can provide a broader view of the biological events disrupted by endocrine disruption, as well as facilitate better risk assessment of environmental chemicals.
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•Filtration of 48 high-confidence endocrine-relevant AOPs from AOP-Wiki•Development of endocrine-relevant adverse outcome pathway (ED-AOP) network•Graph-theoretic analysis of the ED-AOP network reveals 7 connected components•Exploration of endocrine-mediated system-level perturbations in the ED-AOP network•Identification of chemical stressors and emerging paths in the ED-AOP network
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Increasing concern over microplastics has recently brought increased attention to studies on microplastic toxicity. Here, we conduct a systematic review on toxicity of microplastics that focuses on ...identifying data gaps in the mechanisms of microplastic toxicity. We observe that microplastic toxicology research thus far has focused on ecotoxicity using apical endpoints and only a few studies deal with toxicity mechanisms. Based on this review, we propose putative Adverse Outcome Pathways (AOPs) applicable to microplastic management to understand microplastic toxicity. We matched toxicity mechanisms and apical endpoints to a key event (KE) and adverse outcome (AO) information from the AOP Wiki. Overall, our results suggest that the molecular initiating event (MIE) was reactive oxygen species (ROS) formation and the AO was increased mortality, decreased growth and feeding, and reproduction failure. However, there are a limited number of studies on toxicity mechanisms of microplastics and, therefore, evidence concerning the relationship between KEs is not sufficient. Clearly, more studies on toxicity mechanisms are required to fill these gaps in data. This study also suggests that the AOP framework is a suitable tool to integrate existing data from various literature sources and can identify data gaps in microplastic toxicity mechanisms.
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•Microplastic toxicity mechanisms in terms of ecotoxicity and human health toxicity were reviewed.•Microplastic toxicology research has focused on ecotoxicity using apical endpoints.•Toxicity mechanisms matched with KE from the AOP Wiki and putative AOPs were proposed.•MIE is ROS formation and AOs are increasing mortality, reduction of growth, and reproduction failure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cadmium is a prominent toxic heavy metal that contaminates both terrestrial and aquatic environments. Owing to its high biological half-life and low excretion rates, cadmium causes a variety of ...adverse biological outcomes. Adverse outcome pathway (AOP) networks were envisioned to systematically capture toxicological information to enable risk assessment and chemical regulation. Here, we leveraged AOP-Wiki and integrated heterogeneous data from four other exposome-relevant resources to build the first AOP network relevant for inorganic cadmium-induced toxicity. From AOP-Wiki, we filtered 309 high confidence AOPs, identified 312 key events (KEs) associated with inorganic cadmium from five exposome-relevant databases using a data-centric approach, and thereafter, curated 30 cadmium relevant AOPs (cadmium-AOPs). By constructing the undirected AOP network, we identified a large connected component of 18 cadmium-AOPs. Further, we analyzed the directed network of 59 KEs and 82 key event relationships (KERs) in the largest component using graph-theoretic approaches. Subsequently, we mined published literature using artificial intelligence-based tools to provide auxiliary evidence of cadmium association for all KEs in the largest component. Finally, we performed case studies to verify the rationality of cadmium-induced toxicity in humans and aquatic species. Overall, cadmium-AOP network constructed in this study will aid ongoing research in systems toxicology and chemical exposome.
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•Derivation and characterization of AOP network relevant for cadmium toxicity•Systematic workflow to identify 309 high confidence AOPs from AOP-Wiki•Integrative data-centric approach to identify 312 KEs associated with cadmium•Identification of 30 high confidence AOPs relevant for cadmium-induced toxicity•Leveraged AI tools to associate cadmium with KEs in largest component of cadmium-AOP network
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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