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Epoxiconazole (EPO) is classified as a persistent organic pollutant due to its ability to persist in the environment for prolonged periods. Its degradation is pivotal in mitigating its environmental impact. This investigation focuses on assessing the degradation of EPO using various methodologies, namely Fenton, photo-Fenton, solar photo-Fenton, and solar photolysis, conducted in both Milli-Q water and groundwater. These experiments encompassed evaluations at both the standard pH typically used in photo-Fenton reactions and the natural pH levels inherent to the respective aqueous environments. Additionally, EPO degradation products were analyzed after a 60-min reaction. Notably, in systems utilizing groundwater, the inclusion of additional iron was unnecessary, as the naturally occurring iron content in the groundwater facilitated the intended processes. Specifically, in Milli-Q water, solar photo-Fenton demonstrated an EPO degradation efficiency of 97%. Furthermore, the substitution of Milli-Q water with groundwater in Fenton-like processes did not significantly affect the efficacy of EPO degradation. These findings underscore the potential of solar photo-Fenton as an economically viable and environmentally sustainable strategy for EPO degradation. [ABSTRACT FROM AUTHOR]

This study aims to investigate the role of hydrogen peroxide (HP) continuous dosage in removing Paracetamol (PCT) from different water matrices using the solar photo-Fenton process. Different parameters in the HP dosage strategies (initial HP pulse, dosing time, and HP concentration) were systematically analysed to assess their impacts on pollutant removal (XPCT), oxidant specific consumption (YHP/PCTt), and toxicity levels (I(%)). The analysis involved various water matrices (ultrapure water UW, groundwater GW, anion matrix AW, and synthetic pharmaceutical wastewater IW0.01 or IW0.1), which were firstly treated in a laboratory reactor and subsequently scaled up to a solar prototype. After laboratory testing, the most effective reaction configuration (maximum XPCT and YHP/PCTt close to the stoichiometric one) was chosen as the starting point for scaling up the reaction system. Using the solar reactor setup, complete PCT conversion was achieved within just 60 min of reaction time (UW matrix). However, under IW0.1 condition and employing the same HP dosing strategy, a XPCT of 95.4 % was attained but at 180 min of reaction, highlighting the significant influence of the real matrix. Additionally, the I(%) remained high towards the end of the reaction (close to 60 %), attributed to the presence of hydroquinone in the system, demanding longer reaction times to completely reduce the toxicity when working with industrial wastewater. This comprehensive approach aims to close the gap between lab results and practical applications, offering crucial insights to address pharmaceutical wastewater pollution.

The textile industry is one of the major water consumers. Considering the large volume of water consumption, the textile industry is one of the producers of industrial wastewater. The dye removal from the wastewater generated by the textile industry is carried out in various ways, including physical, chemical, and biological methods or a combination thereof. Studies on wastewater treatment have devoted much attention to advanced oxidation processes. The solar photo-Fenton method has many applications for pollutant removal from aqueous solutions. The present study was conducted on the wastewater of Borujerd Textile Company (Borujerd city–Iran). The experiments were designed and performed using response surface methodology based on the Box–Behnken method. Solar lamp intensity (0–300 w/m2), process time (60–240 min), hydrogen peroxide concentration (100–600 mg/L), and iron ion concentration (10–60 mg/L) were selected as the operational variables. In addition, the removal rate of chemical oxygen demand was considered as the response of experimental design. Under optimal conditions (namely, I SL = 150 W m 2 , t = 157 min , C H 2 O 2 = 600 mg L and C F e 2 + = 60 mg L ), the chemical oxygen demand removal rate reached the highest (i.e., 79.54%). [ABSTRACT FROM AUTHOR]

The increasing occurrence of micropollutants in natural water bodies has medium to long-term effects on both aquatic life and human health. The aim of this study is to optimize the degradation of two pharmaceutical pollutants of emerging concern: amoxicillin and acetaminophen in aqueous solution at laboratory and pilot scale, by solar photo-Fenton process carried out at neutral pH using ethylenediamine-N,N′-disuccinic acid (EDDS) as a complexing agent to maintain iron in solution. The initial concentration of each compound was set at 1 mg/L dissolved in a simulated effluent from a municipal wastewater treatment plant (MWTP). A factorial experimental design and its surface response analysis were used to optimize the operating parameters to achieve the highest initial degradation rate of each target. The evolution of the degradation process was measured by ultra-performance liquid chromatography (UPLC/UV), obtaining elimination rates above 90% for both contaminants. Statistical study showed the optimum concentrations of Fe(III) at 3 mg/L at an Fe-EDDS ratio of 1:2 and 2.75 mg/L H2O2 for the almost complete removal of the target compounds by solar photo-Fenton process. Validation of the experimental design was successfully carried out with actual MWTP effluent spiked with 100 μg/L of amoxicillin and acetaminophen, each at pilot plant scale. [ABSTRACT FROM AUTHOR]

One of the biggest problems the world is currently experiencing is wastewater treatment. Numerous pollutants are released into water bodies by enormous amounts of effluents from varied sources. This paper provides a concise summary of the state of the art in AOPs, biological treatment, and their efficient application for the degradation of the numerous recalcitrant organic contaminants found in wastewater. The employment of a photoreactor is necessary for the efficient execution of the majority of photocatalytic processes. This review examines the effectiveness of several reactor configurations with varying geometries. Integrating different AOPs and AOPs with biological approaches for degrading pollutants in wastewater was also discussed. It is important to emphasize that an integrated AOP/biological system produces by-products that are not hazardous, uses little energy, and completely degrades pollutants. The review also outlines the challenges and issues of wastewater treatment for an environmentally and economically feasible process. [ABSTRACT FROM AUTHOR]

This work aimed to demonstrate Cu2O/Al2O3 as a catalyst of the photo-Fenton process in the UV and visible spectra. Cu2O nanoparticles were synthesized by laser ablation in liquid and supported on Al2O3. The catalytic activity of the resulting solid was assessed in the mineralization of bisphenol A (BPA). The studied variables were type of Al2O3 α   and   γ , Cu content (0.5 and 1%), and H2O2 concentration (1, 5, and 10 times the stoichiometric amount). The response variables were BPA concentration and total organic carbon (TOC) removal percentage. The presence of Cu2O nanoparticles (11 nm) with an irregular sphere-like shape was confirmed by transmission electron microscopy (TEM) and their dispersion over the catalytic surface was verified by energy-dispersed spectroscopy (EDS). These particles improve ·OH radical production, and thus a 100% removal of BPA is achieved along with ca. 91% mineralization in 60 min. The BPA oxidation rate is increased one order of magnitude compared to photolysis and doubles that for H2O2 + UV. An increase of 40% in the initial oxidation rate of BPA was observed when switching from α-Al2O3 to γ-Al2O3. 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, acetaldehyde, and acetic acid are the BPA oxidation by-products identified using LC/MS and based on this a reaction pathway was proposed. Finally, it was also concluded that the synthesized catalyst exhibits catalytic activity not only in the UV spectrum but also in the visible one under circumneutral pH. Therefore, Cu2O/Al2O3 can be recommended to conduct a solar photo-Fenton reaction that can degrade other types of molecules. [ABSTRACT FROM AUTHOR]

This study shows the effectiveness of the wastewater treatment from a municipal slaughterhouse that has undergone a previous biological treatment applying a sequence of stages, reaching a 75% of elimination of the chemical oxygen demand (COD) using sedimentation in combination with coagulation–flocculation, using 0.5 g/L FeCl3 which is one of the best known inorganic coagulants. Then, the elimination of COD was around 98% adding the Fenton process in which 1,000 mg/L H2O2 and FeSO4 were used. In addition to the COD, other water quality parameters were measured to evaluate the level of purification of the test samples, such as solids of different types, pH, DOC and so on. With the above process, it can be noted that the Fenton process produced a slight improvement in the effluent quality by using a solar concentrator in the now-called photo-Fenton process, reaching around 99% of COD removal (0.36 g/L), 91% of total suspended solids (0.32 g/L) and 89% of dissolved organic carbon (0.20 g/L). These results were the best achieved within a proposed treatment train for this type of complex wastewater. Moreover, this last part of the process adds an improvement by the usage of renewable energy sources such as sunlight. HIGHLIGHT This article deals with work on real wastewater treatment under real working conditions, such as the use of sunlight. In addition, a parabolic solar concentrator built from reused material was used. So the project has elements of sustainability.;

The comparison of the solar heterogeneous photocatalysis (SHP) and solar photo Fenton (SPF) processes were carried out in a compound parabolic collector reactor, using methyl orange as a model pollutant, and the scaled-up parameters were estimated. As preliminary tests, both processes were carried out at laboratory scale (volume of 200 mL) and the accumulated energy (Qv) was registered to achieve high degradation and mineralization rates. The dye degradation by SHP in the solar reactor (volume of 30 L) was carried out using TiO2 Degussa P25 until a Qv = 300 kJ m−2 was reached. Under acidic condition, color removal of 95% and mineralization of 64% were achieved. The resulting reaction rates were kapp = 0.2311 L kJ−1 and kapp = 0.0768 L kJ−1, respectively. On the other hand, dye degradation by SPF was faster than SHP since 99% color removal and 76.5% mineralization were achieved at Qv = 10 kJ m−2. Both processes were highly efficient in color removal and mineralization rates, at both scales. However, the SPF degradation was achieved at lower accumulated energy. The treatment capacity factor (Ct) required for the scaling-up of the solar reactor calculated for the SPF process is Ct = 6.41 kgTOC m−2 y−1, and the area required for the treatment of a hypothetical textile effluent considering 1000 m3 y−1 and initial TOC of 800 mg L−1 is 125 m2. These results suggest that SPF is an alternative of feasible implementation for the sanitation of textile effluents. [ABSTRACT FROM AUTHOR]

In this study, a stochastic model was applied to investigate the degradation of landfill leachate by solar photo-Fenton processes. The coefficient of determination (R2) between experimental and predicted data ranged from 0.9958–0.9995. The optimal conditions for the initial phase (lasting 5–22 min) were high Fe2+ level, low pH level, and intermediate H2O2 level. For the second phase, optimal leachate degradation percentages were obtained by maintaining the pH, increasing H2O2, and decreasing Fe2+ to the lowest level. Determination of optimal reaction conditions (such as pH, Fe2+, and H2O2 values) for both degradation phases is of paramount importance for process scale-up. The major contribution of this study was the development of a tool that considers the effects of one or more reactions on organic carbon degradation. This was achieved by assessing the significance of the effects of experimental conditions on model parameters for the fast and slow steps of leachate degradation by advanced oxidation processes. [ABSTRACT FROM AUTHOR]

The grape juice production generates an industrial wastewater that has a high concentration of organic matter and several polyphenols, such as ethanol. Therefore, the discharge of this wastewater can produce environmental problems. The aim of this work was to determine the optimal concentration of the reagents involved in a solar photo-Fenton process in the treatment of wastewater coming from juice. The process was analysed in a factorial design, as a function of H2O2 (900, 1000, 1100 mg/L) and Fe2+ (90, 100, 110 mg/L) concentration. The grape juice wastewater presents high organic content (20,500 mg/L COD and 5.4 mg/L polyphenols). Also, the presence of alcohols such ethanol, ethyl acetate and 2-metil-1-propanol was confirmed. The results showed that highest COD (>27%) and polyphenols removal (>36%) were obtained in experiments with 1100 mg H2O2/L and 100 mg Fe2+/L. In treatments with higher COD removal, 2-metil-1-propanol was detected as an intermediate of ethanol oxidation. These results proved that solar photo-Fenton is a suitable approach for treating the refractory organic matter from grape juice. [ABSTRACT FROM AUTHOR]

In this work are presented and discussed the results related to the obtaining of the best conditions for the treatment of a real paint wastewater by combining the chemical coagulation methods and solar photo-Fenton process. The best conditions for the coagulation-flocculation process involved the use of 8 mL of chemical coagulant (ferric chloride) for every 1.0 L of wastewater. At this condition, total removal of turbidity and color (visual inspection) of the wastewater were achieved. For the solar photo-Fenton process, the concentration of Fe2+ and H2O2 at 105 mg L-1 and 2.0 g L-1, respectively, resulted in the complete removal of organic matter and odor (olfactory perception). Therefore, the combined use of these techniques in the treatment of the real paint wastewater presented quite relevant results from the environmental standpoint, as evidenced by the reduction/elimination of important environmental parameters, with the real possibility of disposal and/or reuse proposals of treated water. DOI: http://dx.doi.org/10.17807/orbital.v11i2.1365

[Display omitted] A novel green composite catalyst was prepared by doping CuFe 2 O 4 nanoparticles in the malt bagasse biochar. Composites with different ratios of malt biochar and CuFe 2 O 4 were produced and characterized by XRD, FE-SEM, EDS, HR-TEM, UV–vis, and Zeta potential. The results revealed that CuFe 2 O 4 was successfully supported on the malt biochar surface. The prepared composites showed the band gap energies were narrower than of CuFe 2 O 4 , increasing the photocatalytic activity. At 60 min of heterogeneous photo-Fenton, tests under visible light indicated CuFe 2 O 4 removed 39 % of the rhodamine B color, while composites CFO1B3, CFO1B1, and CFO3B1 removed 88 %, 81 %, and 44 % of the dye, respectively. The recycling of the CFO1B3 composite indicated that it can be used in eight cycles without major losses in efficiency. In sunlight, the CFO1B3 composite achieved efficiencies of 100 % for 10 mg L−1 and 50 mg L−1 of rhodamine B at 10 and 20 min of reaction, respectively. In the proposed mechanism, it was verified that the radical OH, O 2 − and h+ were the predominant reactive species involved in the degradation to intermediates of low m/z. Results showed that the novel composite formed is a promising photocatalyst for removing organic pollutants in water. [ABSTRACT FROM AUTHOR]

The study compared the technical efficiency and economic cost of five advanced oxidation processes (Fenton, UV photo-Fenton, solar photo-Fenton, UV/TiO2/H2O2 and FeGAC/H2O2) for degradation of the pesticides chlorpyrifos cypermethrin and chlorothalonil in aqueous solution. The highest degradation in terms of COD and TOC removals and improvement of the biodegradability (BOD5/COD ratio) index (BI) were observed to be (i) Fenton - 69.03% (COD), 55.61% (TOC), and 0.35 (BI); (ii) UV photo-Fenton -78.56% (COD), 63.76% (TOC) and 0.38 (BI); (iii) solar photo-Fenton - 74.19% (COD), 58.32% (TOC) and 0.36 (BI); (iv) UV/TiO2/H2O2 - 53.62% (COD), 21.54% (TOC), and 0.26 (BI); and (v) the most technical efficient and cost effective process was FeGAC/H2O2. At an optimum condition (FeGAC 5 g/L, H2O2 100 mg/L, and reaction time of 60 min at pH 3), the COD and TOC removal efficiency were 96.19 and 85.60%, respectively, and the biodegradation index was 0.40. The degradation rate constant and cost were 0.0246 min-1 and $0.74/kg TOC, respectively. The FeGAC/H2O2 process is the most technically efficient and cost effective for pretreatment of the pesticide wastewater before biological treatment.

Natural effluents with marked variation in their chemical composition over decomposition time in the matrix from which they are generated have a complex composition and are not totally known in most cases. Landfill leachate can be considered an effluent with complex composition, requiring imminent and more comprehensive studies on organic load degradation. Such complexity of numerous organic compounds (most of them recalcitrant humic and fulvic substances) demands a large number of kinetic equations to satisfactorily describe the temporal evolution of such conversion. Thereby, this work aims to study a kinetic approach grounded on previously consolidated chemical reactions of radical generation through the photo-Fenton mechanism. A molar balance was developed for each species in a batch photo-Fenton process and the resulting ordinary differential equations were numerically solved in MATLABTM. The kinetic model satisfactorily described an organic load conversion of the effluent under the various experimental conditions studied herein. Experimental trends could be represented by a free-radical mechanism and a degradation rate equation of first order for organic carbon, hydroxyl radical and H+. The model fittings revealed a hydroxyl radical/organic carbon stoichiometric ratio of 2:1. The kinetic study has confirmed the importance of pH levels for the reaction medium, and indicated that degradation rate depends on the medium organic composition, which provided an exponential function of conversion for the degradation rate coefficient. The model simulations corroborated the positive effect of sunlight on the radical generation through FeO H 2 + decomposition reaction with a rate coefficient in the range 4 × 10−3–2 × 10−1 s−1. [ABSTRACT FROM AUTHOR]

The efficiency of solar photo-Fenton treatment is related to ambient conditions, as it depends on solar irradiance levels and operation temperature, consequently, it is highly influenced by plant location. In this context, solar photo-Fenton feasibility in three Sunbelt cities (Tabernas -Spain-, Arica -Chile- and Doha -Qatar-) for the treatment of industrial wastewater has been analysed. Process performance was simulated by means of a semi-empirical photo-Fenton model comparing the results obtained with yearly average ambient conditions and the most unfavourable monthly ambient conditions. This data was used with scaling-up purposes in order to determine the photoreactor size and reservoir tank volume needed for each case. Finally, an economical assessment was carried out. Doha presented the lowest total costs (TC), 2.23 €/m3, followed by Arica with 2.45 €/m3 and Tabernas with 2.67 €/m3 for the method based on yearly averages. For the most unfavourable ambient conditions method, the TCs were slightly higher resulting in 2.29, 2.55 and 3.11 €/m3, respectively. Cost breakdowns were analogous independently of scaling-up method and location, being amortization costs (ACs) more influenced by location than operation costs (OCs). Image 1 • Photo-Fenton has been simulated in different locations (model inputs: UV-A and T). • Two different plant scaling-up strategies have been analysed through treatment cost. • Lowest cost found for Doha followed by Arica and Tabernas (2.23, 1.45 and 2.67 €/m3, respectively). • Higher cost where ambient T changes drastically between summer and winter. • Total costs more influenced by amortization costs (≈60%) than by operation costs (≈40%). [ABSTRACT FROM AUTHOR]

This paper contains a multidisciplinary approach that will contribute to design and properly evaluate a treatment line for complex biorecalcitrant wastewaters. To demonstrate this approach a specific industrial wastewater (cork boiling wastewater, CBW) was used. A treatment line based on a coagulation-flocculation step followed by an Advanced Oxidation Process (AOP) (solar photo-Fenton) and combined with an aerobic biological system was evaluated. Applied microbiological techniques: optical microscopy, plate count, DNA extraction and qPCR, indicated that some communities disappeared after the activated sludge adaptation period to the partially treated wastewater, while communities that did not disappear were damaged: 2-log reduction of total heterotrophic bacteria (THB) and a decrease in DNA concentration from 200 ng/μL to 65 ng/μL were observed. Therefore, chemical and microbiological results obtained along the set of experiments, suggested the inefficiency of the combined treatment option between solar photo-Fenton and advanced aerobic biological systems for CBW. This led to the necessity of applying solar photo-Fenton without combining with biotreatment and with the objective of improving the effluent quality enough for being reused in the own industry. Toxicity tests, based on different organisms (after coagulation-flocculation followed by solar photo-Fenton), showed increase on acute toxicity (from 46% to 71% by respirometric assays) and the development of chronic toxicity (from 21–29% to 83–90% also measured by respirometric assays), made evident the incompatibility of this type of wastewater with a biological treatment even after the application of an AOP. Unlabelled Image • Combination of coagulation-flocculation/solar photo-Fenton/aerobic bio-treatment was not successful. • Advanced microbiological analysis showed breakage on specific species after 6 days. • DNA concentration analysis clearly indicated the biotreatment non-feasibility. • Chronic toxicity was generated after partial oxidation of cork boiling wastewater. [ABSTRACT FROM AUTHOR]

The degradation of fluoxetine was studied by means of three advanced oxidation photochemical processes: photo Fenton (FFS), photo electro Fenton (FEFS) and photocatalysis with TiO2 (FCS), mediated by solar radiation. Experiments were run with 100 mL solutions in a reaction vessel and in the case of FEFS, the reactor was equipped with an IrO2 / RuO2 anode and an air diffusion graphite cathode for continuous peroxide production. In all cases, degradation, the mineralization of fluoxetine and toxicity were monitored. The FFS process showed the highest speed of degradation and mineralization, as well as the greater efficiencies in the degradation and mineralization. The pH in the FFS process defined the scope of the mineralization, evidencing that acidic pH achieves greater mineralization by avoiding the formation of complexes and hydroxides typical of a higher pH. The FCS process presents high efficiency, but slow kinetics. Beer yeast toxicity decreases as degradation byproducts are generated in all evaluated processes. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Very diluted Olive Mill Wastewater could be used as a natural chelating agent. • Iron (5 mg/L) is kept in solution at circumneutral pH by natural polyphenols. • Solar photo-Fenton using natural chelates could treat microcontaminants. Abstract The potential of polyphenols, present in olive mill wastewater (OMW), to act as iron chelators in photo-Fenton reaction without water acidification for the treatment of different microcontaminants in water has been studied. OMW containing 6.3 g/L of phenols has been dosed from 1:100 to 1:1500 in water containing 200 μg/L of terbutryn, chlorfenvinphos, pentachlorophenol and diclofenac. Experiments were performed in compound parabolic collector (CPC) solar pilot plant installed in Plataforma Solar de Almería using Fe 0.1 mM and H 2 O 2 50 mg L−1. The total irradiated area was 3.08 m2 and the total volume 39 L. Results indicated that iron was forming a stable complex with components of OMW along different pH values. > 90% degradation of the four microcontaminants was achieved with solar photo-Fenton at circumnetutral pH adding OMW 1:1200 for keeping iron in solution, allowing to operate a photo-Fenton process without acidifying wastewater. It leads to an alternative to using artificial-synthetic iron-complexing ligands. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The solar stability of the Fe(III)-EDDS complex was verified for two matrixes. • Doehlert design models explained more than 95% of results in different matrixes. • Solar photo-Fenton process at pH 7.0 is efficient for pharmaceuticals degradation. • It was related Toxicity and biodegradability of transformation products. • Degradations pathways for the main transformation products were proposed. Abstract This paper demonstrates the effectiveness of Fe(III)-EDDS complex for degradation of pharmaceutical compounds in a solar photo-Fenton-like process at neutral pH in two different aqueous matrixes. Electrochemical experiments were performed to monitor the formation and stability of the complex, as a function of the amount of complexing agent and pH. Eight compounds, including diazepam, dipyrone, fluoxetine, furosemide, nimesulide, paracetamol, progesterone, and propranolol, were analyzed in distilled water and simulated wastewater, at initial concentrations of 500 μg L−1. By applying Doehlert matrix design and the response surface methodology the optimal experimental conditions were found to be 0.28 mmol L−1 Fe(III)-EDDS and 5.00 mmol L−1 H 2 O 2 , with a ratio of 1:2 for Fe(III)-EDDS. The most persistent transformation products (TPs) generated during the treatment process were investigated using liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. 16 TPs were identified and classified as having high toxicity (according to the Cramer rules), low biodegradability (according to the START scheme), and possible carcinogenicity and/or mutagenicity. Most of the compounds were degraded in the first minutes of treatment, and most of the identified TPs had been successfully removed at the end of the process. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • 7 antibiotics were subjected to solar photo-Fenton treatment in urban wastewater. • Solar photo-Fenton was effective in ARB and ARGs elimination. • Increased toxicity towards D. magna was observed during solar photo-Fenton. • The application of GAC to solar photo-Fenton treated flow eliminated toxicity. • Combination of solar photo-Fenton and GAC removed antibiotics from wastewater. Abstract This work evaluated the removal of a mixture of antibiotics from urban wastewater, by a combined process consisting of solar photo-Fenton (SPF) followed by granular activated carbon (GAC). The effects of the SPF process were investigated at a toxicological, microbiological and genomic level, using species of plants and aquatic organisms, bacteria, antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs). The results demonstrated that SPF could completely degrade antibiotics present in two types of effluent deriving from a conventional activated sludge system (CAS) and a membrane bioreactor (MBR), operated at the optimum oxidant dose ([H 2 O 2 ] CAS = 100 mg/L; [H 2 O 2 ] MBR = 50 mg/L) and illumination time (t CAS = 115 min; t MBR = 111 min) at acidic pH (2.8–2.9). Moreover, total disinfection was achieved by the SPF process, as cultivable bacteria, including ARB, were inactivated after 60 min of treatment, disabling also the bacterial regrowth after 24 h of storage of the treated effluent. Furthermore, SPF was shown to be effective in degrading the cellular DNA of the effluent, which was reduced to the detection limit after 60 min of treatment in both effluents. The abundance of 16S rRNA was found to be preferentially decreased by the SPF in the MBR-treated effluent (8 folds) compared to the CAS-treated effluent (7.4 folds). The abundance of bla OXA , bla CTX-M , qnrS , sul 1, and tet M genes was decreased to the limit of quantification after 60 min of SPF treatment in both effluents. However, the SPF treated flow resulted in increased toxicity, probably due to the oxidation of the dissolved effluent organic matter of the wastewater leading to the formation of toxic products. Therefore, SPF-treated samples collected at different time intervals (30, 60, 90, 120, and 180 min) were subjected to adsorption onto GAC (500 mg/L), and the removal of both the toxicity and the residual antibiotics remaining after SPF, was explored. The combined processes (30 min SPF; 15 min GAC) provided almost complete removal of toxicity and elimination of antibiotics, ensuring wastewater decontamination. [ABSTRACT FROM AUTHOR]

In this study, a co-precipitation method was used for the synthesis of undoped ferrites (Fe2O3/Fe3O4-R) and nickel-doped ferrites from nickel reagents (NiFe2O4-R) and from nickel recycled from spent Ni-MH batteries (NiFe2O4-B). Ferrite structure and composition were confirmed by X-ray diffraction and inductively coupled plasma optical emission spectrometry. Energy dispersive X-ray analysis showed the presence of iron, oxygen, and nickel in the surface composition of the nickel-doped ferrites. Scanning electron microscopy showed agglomerated particles of different sizes and shapes. Transmission electron microscopy revealed spherical particles of 50 nm. NiFe2O4-B is a multifunctional material that can be used as a catalyst and pseudocapacitor. The catalytic properties of NiFe2O4-B were analyzed by measuring the decolorization of methylene blue (MB) in a photo-Fenton process under solar radiation. Pseudocapacitive properties, analyzed by cyclic voltammetry, showed that NiFe2O4-B composites exhibit favorable characteristics for application as electrochemical pseudocapacitors. [ABSTRACT FROM AUTHOR]

In this work are presented and discussed the results related to the obtaining of the best conditions for the treatment of a real paint wastewater by combining the chemical coagulation methods and solar photo-Fenton process. The best conditions for the coagulation-flocculation process involved the use of 8 mL of chemical coagulant (ferric chloride) for every 1.0 L of wastewater. At this condition, total removal of turbidity and color (visual inspection) of the wastewater were achieved. For the solar photo-Fenton process, the concentration of Fe2+ and H2O2 at 105 mg L-1 and 2.0 g L-1, respectively, resulted in the complete removal of organic matter and odor (olfactory perception). Therefore, the combined use of these techniques in the treatment of the real paint wastewater presented quite relevant results from the environmental standpoint, as evidenced by the reduction/elimination of important environmental parameters, with the real possibility of disposal and/or reuse proposals of treated water. [ABSTRACT FROM AUTHOR]

The depuration of landfill leachate (LL) was evaluated by solar advanced oxidation processes (AOPs) (photo-Fenton + O 3 and photo-Fenton + O 2) and adsorption processes, using activated carbon made from fish scales, as either post-treatment or pre-treatment of advanced oxidation process. Also, the effect in the reduction of toxicity of LL depurated under these methods was evaluated. The activated carbon Brunauer-Emmett-Teller (BET) surface area is 1.8329 m2/g and the adsorption average pore width is 12.79833 nm, considered as a mesoporous material. When AOPs were used as treatment and adsorption was used as post-treatment of the LL, a removal of 67%, 98%, 98.9%, 83.3% and 99.6% of chemical oxygen demand (COD), colour, copper, iron and ABS 254 , respectively, was obtained. When the adsorption process was applied as AOP pre-treatment, the removal of organic matter was better in comparison to the results of the adsorption process as AOPs post-treatment. This resulted in a removal of COD, colour, copper, iron and ABS 254 of 75.4%, 99.4%, 94.4%, 68.3% and 98.1%, respectively. When the AOPs were followed the adsorption process, a germination index (GI) of 126%, 122% and 116% was obtained. This was higher than the results obtained by LL treated with PF + O 2 in a solution concentration of 1%, 3% and 10%, respectively. When PF + O 3 was used at a concentration solution of 1%, 3% and 10%, similar GI values were obtained (122%, 113% and 114%, respectively). The EC 50 is very low for raw LL, but this value increases as the LL is treated. A very high EC 50 is obtained for the adsorption process and for AOPs following the adsorption process, going from 1.8 to 21.0 V/V. Adsorption as pre-treatment helps removing colour and metals from LL, thus enhancing the performance of solar AOPs. [ABSTRACT FROM AUTHOR]

Cytarabine (CY) is an anticancer drug which has been identified in wastewater influents, effluents, and surface waters. In the present study, the degradation of CY under simulated solar light (SSL), by photo-Fenton (Fe3+/H2O2/SSL) and photo-Fenton-like processes (Fe3+/S2O82−/SSL and [Fe(C2O4)3]3−/H2O2/SSL), was investigated. The major parameters affecting the applied treatments (e.g., concentration of CY, Fe3+, H2O2, and S2O82−) were optimized and CY's complete removal was achieved within 45 min for all techniques used. Mineralization studies indicated that [Fe(C2O4)3]3−/H2O2/SSL treatment was the most efficient procedure since faster kinetics are achieved and higher mineralization percentage is reached compared to the other techniques used. Furthermore, 12 transformation products (TPs) were identified during the applied processes, by high resolution mass spectrometry, four of which were identified for the first time, indicating that CY molecule undergoes hydroxylation and subsequent oxidation, during the applied processes. Moreover, predictions of acute and chronic ecotoxicity of CY and its TPs on fish, daphnia, and green algae were conducted, using in silico quantitative structure activity relationship (QSAR) calculations. According to these predictions, the TPs generated during the studied treatments may pose a threat to aquatic environment. Finally, the efficiency of CY degradation by photo-Fenton and photo-Fenton-like treatment in real wastewater was evaluated, under the optimized conditions, which resulted in lower degradation rate constants compared to ultrapure water. [ABSTRACT FROM AUTHOR]

Abstract This work reports the use of ferrioxalate complexes to assist solar photo-Fenton treatment of pentachlorophenol (PCP) in aqueous medium at mild pH, which inhibits the precipitation of iron hydroxides and allows working at a low iron dosage. The experimental parameters were optimized by assessing the effect of initial concentrations of H 2 O 2 (0–2.5 mM) and Fe(II) (2–10 mg/L), pH (3.0–9.0) and iron/oxalic acid molar ratios (1:0–1:13.5) on total organic carbon (TOC) removal. Ferrioxalate-assisted solar photo-Fenton achieved 97.5% mineralization in 120 min, clearly outperforming conventional Fenton and solar photo-Fenton. The presence of photosensitive ferrioxalate complexes accounted for the enhancement, as a result of Fe(II) regeneration that accelerated the hydroxyl radical (OH) production. The time course of H 2 O 2 and Fe(II) concentrations was evaluated under different iron/oxalic acid ratios. The five carboxylic acids determined by ion-exclusion HPLC and the eight aromatic by-products identified by GC-MS allowed the proposal of a degradation pathway that included hydroxylation, dechlorination and dimerization steps. Complete chloride ion release was achieved after 90 min of treatment. Highlights • Up to 97.5% mineralization achieved by ferrioxalate-assisted solar photo-Fenton process. • Similar TOC abatement was obtained within pH range 3.0–6.0 • Complete dechlorination of PCP at 90 min using low iron dosage (5 mg/L) at pH 5.0 • Fe(III) was maintained soluble, being efficiently reduced to Fe(II) in the presence of oxalate. • Up to 8 aromatic products found by GC-MS: hydroxylation, dechlorination and dimerization. [ABSTRACT FROM AUTHOR]

Abstract Scarcity of water and concerns about the ecotoxicity of micro-contaminants are driving an interest in the use of advanced tertiary processes in wastewater treatment plants. However, the life cycle environmental implications of these treatments remain uncertain. To address this knowledge gap, this study evaluates through life cycle assessment the following four advanced process options for removal of micro-contaminants from real effluents: i) solar photo-Fenton (SPF) operating at acidic pH; ii) acidic SPF coupled with nanofiltration (NF); iii) SPF operating at neutral pH; and iv) neutral SPF coupled with NF. The results show that acidic SPF coupled with NF is the best option for all 15 impacts considered. For example, its climate change potential is almost three times lower than that of the neutral SPF process (311 vs 928 kg CO 2 eq./1000 m3 of treated effluent). The latter is the worst option for 12 impact categories. For the remaining three impacts (acidification, depletion of metals and particulate matter formation), acidic SPF without NF is least sustainable; it is also the second worst option for seven other impacts. Neutral SPF with NF is the second worst technology for climate change, ozone and fossil fuel depletion as well as marine eutrophication. In summary, both types of SPF perform better environmentally with than without NF and the acidic SPF treatment is more sustainable than the neutral version. Thus, the results of this work suggest that ongoing efforts on developing neutral SPF should instead be focused on further improvements of its acidic equivalent coupled with NF. These results can also be used to inform future development of policy related to the removal of micro-contaminants from wastewater. Graphical abstract Unlabelled Image Highlights • First LCA of acidic/neutral solar photo-Fenton (SPF) with/without nanofiltration • Coupling SPF with nanofiltration (NF) reduces environmental impacts by 24%–67%. • Acidic SPF treatment is environmentally more sustainable than the neutral version. • GWP of neutral SPF without NF is 3 times higher than of the acidic version with NF. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Continuous open channel reactor for solar photo-Fenton treatment of wastewater. • Average residence time is 5 min for waste water flow rate of 1.5 LPM. • Computational fluid dynamics was used for hydrodynamic analysis. • Response surface methodology was used to formalize reactor performance. • Primary pollutants were recorded to degrade by more than 94% in 1 h. Abstract Design, hydrodynamic modeling and performance characterization of a low cost, non-concentrating type solar-collector-reactor has been presented in this article. The reactor comprises of interconnected parallel channels, which are open at the top to receive sunlight. Because of its modular structure, the reactor can be easily scaled up to any required size. The hydrodynamic features of the reactor were investigated using computational fluid dynamic simulation along with the standard residence time distribution analysis. Primary performance characterization study was conducted in solar photo-Fenton remediation of two model pollutants, namely Trypan blue dye and Dichlorvos pesticide. Under optimum parametric conditions of pH, FeSO 4 -H 2 O 2 dosage ratio and inlet concentration, the primary pollutants were recorded to degrade by more than 94%, which clearly marks the efficacy of the proposed design. In addition to the simulated wastewater, the reactor performance was also tested in treatment of effluent obtained from jute dyeing unit, where 58% COD reduction was achieved. [ABSTRACT FROM AUTHOR]

Cu 2 FeSnS 4 (CFTS) particles were synthesized via a simple and versatile solvothermal route. The material was employed as a catalyst for the degradation of tartrazine dye from aqueous solution through the solar photo-Fenton process, reaching 95% of dye degradation at 50 min of reaction time. Powders containing a mesoporous structure with high surface area and total pore volume were obtained. The catalyst showed high chemical stability and degradation efficiency of tartrazine dye after five recycles. Therefore, CFTS shows intrinsic characteristics for potential application as a solar photo-Fenton catalyst in the tartrazine degradation from aqueous solution. [ABSTRACT FROM AUTHOR]

Simultaneous application of solar photo-Fenton and ozonation (SPFO) for the efficient treatment of real wastewaters was studied. Four different industrial effluents were selected for the study: landfill leachate, pharmaceutical effluent and two textile wastewaters, in order to demonstrate the effectiveness and versatility of the proposed technology. SPFO performance was compared with individual processes (either solar photo-Fenton or ozonation), as well as the hybrid Fenton and ozonation treatment. In highly polluted wastewaters, combined strategies led to higher organic matter removal than O3 and photo-Fenton processes applied individually. Solar light favoured catalyst regeneration, allowing removal efficiencies up to 67% of chemical oxygen demand (COD) and 62% of total organic carbon (TOC) (in the case of textile wastewaters) using an initial concentration of only 10 mg Fe2+ L-1. The reduction of catalyst consumption, along with the absence of sludge production (since Fe2+ removal from the effluent is not required), led to a significant decrease in operational costs (up to 1.22 € kg-1 COD removed) when combined Fenton and ozonation was applied under solar light. SPFO results in a versatile, effective and economically efficient technology, thus postulating as a promising alternative for reducing the organic load of highly polluted industrial effluents prior to biological treatment. [ABSTRACT FROM AUTHOR]

Transformation products and toxicity patterns of microcystin-LR (MC-LR), a common cyanotoxin in freshwaters, during degradation by solar photo-Fenton process were studied in the absence and presence of two major water components, namely fulvic acid and alkalinity. The transformation products m / z 795, 835, 515/1030 and 532 can be formed through attack of OH on the conjugated carbon double bonds of Adda. Transformation products with m / z 1010, 966 and 513 can be generated through the attack of OH on the methoxy group of Adda. The transformation products m / z 783, 508 and 1012 can be originated from the attack of OH on the cyclic structure of MC-LR. Transformation products ( m / z 522, 1028, 1012, 1046 and 514) formed after hydroxylation of the aromatic ring with OH were also identified in this study. The toxicity study revealed that fulvic acid and alkalinity strongly influence the toxicity profiles of solar photo-Fenton treated MC-LR. Fulvic acid enhanced the detoxification whereas low level total alkalinity (1.8 mg L −1 CaCO 3 ) inhibited the detoxification of MC-LR by solar photo-Fenton process as assessed by protein phosphatase-1 (PP-1) inhibition assay. This work provides insights on the utility of solar photo-Fenton destruction of MC-LR in water based on transformation products and toxicity data. [ABSTRACT FROM AUTHOR]

The intensification of the solar photo-Fenton system with ferrioxalate photoactive complexes and ultrasound applied to the mineralization of 15 mg/L carbamazepine aqueous solution (CBZ) was evaluated. The experiments were carried out in a solar compound parabolic collector (CPC) pilot plant reactor coupled to an ultrasonic processor. The dynamic behavior of hydroxyl radicals generated under the different studied reaction systems was discussed. The initial concentrations of hydrogen peroxide and ferrous/oxalic acid and pH were found to be the most significant variables (32.79%, 25.98% and 26.04%, respectively). Under the selected optimal conditions ([H 2 O 2 ] 0 = 150 mg/L; [Fe 2+ ] 0 = 2.5 mg/L/[(COOH) 2 ] 0 = 12.1 mg/L; pH = 5) CBZ was fully degraded after 5 min and 80% of TOC was removed using a solar photo-Fenton system intensified with ferrioxalate (SPFF). However, no improvement in the mineralization using SPFF process combined with ultrasound was observed. More mild pH conditions could be used in the SPFF system if compared to the traditional photo-Fenton (pH 3) acidic systems. Finally, a possible reaction pathway for the mineralization of CBZ by the SPFF system was proposed and therein discussed. [ABSTRACT FROM AUTHOR]

The study compared the technical efficiency and economic cost of five advanced oxidation processes (Fenton, UV photo-Fenton, solar photo-Fenton, UV/TiO2/H2O2 and FeGAC/H2O2) for degradation of the pesticides chlorpyrifos, cypermethrin, and chlorothalonil in aqueous solution. The highest degradation in terms of COD and TOC removals and improvement of the biodegradability (BOD5/COD ratio) index (BI) were observed to be (i) Fenton - 69.03% (COD), 55.61% (TOC), and 0.35 (BI); (ii) UV photo-Fenton - 78.56% (COD), 63.76% (TOC) and 0.38 (BI); (iii) solar photo-Fenton - 74.19% (COD), 58.32% (TOC) and 0.36 (BI); (iv) UV/TiO2/H2O2 - 53.62% (COD), 21.54% (TOC), and 0.26 (BI); and (v) the most technical efficient and cost effective process was FeGAC/H2O2. At an optimum condition (FeGAC 5 g/L, H2O2 100 mg/L, and reaction time of 60 min at pH 3), the COD and TOC removal efficiency were 96.19 and 85.60%, respectively, and the biodegradation index was 0.40. The degradation rate constant and cost were 0.0246 min-1 and $0.74/kg TOC, respectively. The FeGAC/H2O2 process is the most technically efficient and cost effective for pretreatment of the pesticide wastewater before biological treatment. [ABSTRACT FROM AUTHOR]

• An efficient photo-Fenton catalyst was prepared from wastewater treatment plant sludge. • Hydroxyl radical formation was confirmed by the coumarin method. • Trimethoprim and sulfamethoxazole degradation occurred via hydroxyl radical attack. • Solar irradiation promoted total organic carbon removal from the effluent. • The catalyst was effective for antibiotics degradation and effluent disinfection. An environmentally friendly strategy for recycling sewage sludge is proposed based on the thermal generation of a magnetic material for use as a catalyst in the photo-Fenton process. The main elements present in the catalyst were silicon, aluminum, oxygen, carbon, phosphorus, and iron, and the specific area was 35.53 m2 g−1. X-ray photoelectron spectroscopy and scanning electron microscopy analyses showed that there was no apparent alteration of the catalyst surface after the photo-Fenton process. Photo-Fenton experiments performed under UV irradiation revealed complete degradation of trimethoprim (TMP) and sulfamethoxazole (SMZ) in purified water after 180 min, with the catalytic activity maintained for at least 4 cycles. A comparison was made of the degradation of pollutants in sewage treatment plant effluents under artificial UV and solar irradiation. Under solar irradiation, at pH 3.5, total degradation of TMP and SMZ was achieved, together with TOC removal of up to 21%, showing SLC-600 as a potential low-cost catalyst to be used in photo-Fenton process. [ABSTRACT FROM AUTHOR]

Although Membrane Distillation (MD) has been extensively studied for desalination, it has other applications like removing all kinds of solutes from water and concentrating non-volatile substances. MD offers the possibility of producing a clean stream while concentrating valuable compounds from waste streams towards their recovery, or emerging contaminants and pathogens present in wastewater in order to facilitate their chemical elimination. This paper analyses the elimination of bacterial spores from contaminated water with MD and the role of MD in the subsequent treatment of the concentrate with photo-Fenton process. The experiments were performed at Plataforma Solar de Almería (PSA) using a plate and frame bench module with a Permeate Gap Membrane Distillation (PGMD) configuration. Tests were done for two different kinds of spores in two different water matrixes: distilled water with 3.5 wt% of sea salts contaminated with spores of Bacillus subtilis ( B. subtilis ) and wastewater after a secondary treatment and still contaminated with Clostridium sp. spores. An analysis of the permeate was performed in all cases to determine its purity, as well as the concentrated stream and its further treatment in order to assess the benefits of using MD. Results showed a permeate free of spores in all the cases, demonstrating the viability of MD to treat biological contaminated wastewater for further use in agriculture. Moreover, the results obtained after treating the concentrate with photo-Fenton showed a shorter treatment time for the reduction of the spore concentration in the water than that when only photo-Fenton was used. [ABSTRACT FROM AUTHOR]

This work evaluated the feasibility of a photo-Fenton-like process using persulfate (PS) and ferrous iron (Fe2+) under simulated solar radiation for degrading the herbicide atrazine (ATZ, 6-Chloro-N-ethyl-N′-isopropyl-1,3,5-triazine-2,4-diamine) and inactivatingE. coli. Milli Q water, lake water, and diluted wastewater effluents were spiked both simultaneously and separately with ATZ (4 mg/L) andE. coli(105CFU/mL), and exposed to treatment. A method for determining the average irradiance throughout the water media in the UV(A+B) range of the Xe lamp emission was developed for bench-scale experiments. These values were used to calculate the UV(A+B) fluences and the solar UV(A+B) energy doses per unit of volume (QUV(A+B), kJ/L). The obtained kinetic data were presented versus energy dose. Treatment of lake water at near-neutral pH was ineffective via the photo-Fenton-like process, attaining only 20% ATZ removal and 1-log reduction ofE. coli. In Milli Q water and wastewater, the complete degradation of ATZ in the absence of bacteria was observed at an average energy dose of 1.5 kJ/L (60 min), while in the presence of cells the degradation efficiency was ∼60%. When ATZ was present,E. coliinactivation was also affected in Milli Q water, with 1.4-log reduction (93%) at a dose of 1.6 kJ/L (60 min), whereas in wastewater complete inactivation was achieved at a lower dose of 1.3 kJ/L (45 min). The energy requirements on aQUV(A+B)basis for simultaneous 90% ATZ removal and 99.99%E. coliinactivation in Milli Q water and wastewater were shown to be less than 10 kJ/L. This suggests the solar/PS/Fe2+system is promising for simultaneous treatment and disinfection of wastewater effluents. [ABSTRACT FROM PUBLISHER]

The present study is about the use of ferrioxalate photoactive complexes as a strategy to drive a photo-Fenton reaction at mild pH conditions, applied to the oxidation of antibiotic levofloxacin (LEV) in pure water and spiked in urban wastewater after secondary treatment. The oxidation ability of the solar photo-Fenton mediated by ferrioxalate complexes (SPFF) was evaluated at different pH values (3.0 to 6.0) for an iron/oxalate molar ratio of 1:3 and using low iron contents (1.0 and 2.0 mg Fe 3+ L −1 ). Additionally, the effect of LEV concentration (2–20 mg L −1 ), iron:oxalate molar ratio (1:3, 1:6 and 1:9), temperature (15–45 °C), UVA irradiance (27.8-59.9 W UV m −2 ), presence of inorganic ions (Cl − , SO 4 2− , HCO 3 − , NH 4 + ), radical scavengers (sodium azide, humic acid and D-mannitol), and others organic ligands, namely citrate and malate, on the SPFF method at pH 5.0 was also assessed. Although the conventional solar photo-Fenton (CSPF) reaction showed similar results to SPFF for pH values ≤ 4, an almost 3.3-fold and 5.7-fold increase in the LEV degradation rate at pH 5.0 and 6.0, respectively, were observed for SPFF when compared to CSPF. This is mainly attributed to the higher photoactivity and solubility of ferrioxalate complexes when compared with ferric ion-water complexes. On the other hand, ferrioxalate complexes exhibited higher photoactivity on LEV removal than ferricitrate and ferrimalate. The presence of phosphate ions in the urban wastewater affected negatively the reaction rate, mainly due to the precipitation of iron as FePO 4(s) , hence a H 2 O 2 /UVC process at different conditions was also explored as an alternative. A pilot-scale assay under natural solar irradiation showed similar results to the ones obtained in the lab-scale photoreactor. Oxalic, formic, citric, and tartronic acids were identified as residual acids in SPFF at pilot scale. [ABSTRACT FROM AUTHOR]

Solar photo-Fenton represents an innovative and low-cost option for the treatment of recalcitrant industrial wastewater, such as the textile wastewater. Textile wastewater usually shows high acute toxic and variability and may be composed of many different chemical compounds. This study aimed at optimizing and validating solar photo-Fenton treatment of textile wastewater in a semi-pilot compound parabolic collector (CPC) for toxicity removal and wastewater reclamation. In addition, treated wastewater reuse feasibility was investigated through pilot tests. Experimental design performed in this study indicated optimum condition for solar photo-Fenton reaction (20 mg L of Fe and 500 mg L of HO; pH 2.8), which achieved 96 % removal of dissolved organic carbon (DOC) and 99 % absorbance removal. A toxicity peak was detected during treatment, suggesting that highly toxic transformation products were formed during reaction. Toxic intermediates were properly removed during solar photo-Fenton (SPF) treatment along with the generation of oxalic acid as an ultimate product of degradation and COS increase. Different samples of real textile wastewater were treated in order to validate optimized treatment condition with regard to wastewater variability. Results showed median organic carbon removal near 90 %. Finally, reuse of treated textile wastewater in both dyeing and washing stages of production was successful. These results confirm that solar photo-Fenton, as a single treatment, enables wastewater reclamation in the textile industry. [ABSTRACT FROM AUTHOR]

A new hybrid system that integrated a photovoltaic (PV) panel with a solar photo-Fenton (SPF) reactor was constructed to treat wastewater and generate electricity for the first time. The decolorization and photovoltaic performances of the hybrid system were tested outdoors by discoloring three dyes: Acid Red 26 (AR26), Malachite Green (MG) and Reactive Blue 4 (RB4). Lab scale experiments also had been done to confirm the impact of temperature on the SPF process. The lab scale results show that SPF process was more efficiency for decoloring the different dyes, compared with dark Fenton. The SPF followed a pseudo-first-order reaction and the reaction rate constant was improved about 3.5, 4.5 and 0.61 times for AR26, RB4 and MG respectively as the wastewater temperature increased from 20 to 50 °C. The decolorization difficulty of the three dyes followed this order: MG > AR26 > RB4. The results of the hybrid systems tested outdoors show that 200 mg/L MG had achieved 98.6% color removal after 3 h of treatment at a low catalyst dose (Fe 2+ = 5 mg/L) under sunlight. For 100 mg/L MG, 99.3% color removal was observed after 70 min. The treatment time required for decolorization of AR26 and RB4 was more shorter. In the present of the water layer, the wastewater temperature was increased and that of the hybrid system was decreased. The average output power of the hybrid system was more than 12 W and sufficient to drive the system during all of the outdoor experiments. Our results suggest that the system could realize decolorization of different dyes and automatic operation. [ABSTRACT FROM AUTHOR]

The goal of this paper was to evaluate the effectiveness of solar photo-Fenton (Fe2+/H2O2/UV-vis) treatment that is able to degrade heavy metal contents (Cu, Cd, Cr, Fe, Ni, Pb and Zn) and pathogenic microbial population (Fecal Coliform/100 mL) present in municipal wastewater with minimal iron and H2O2 concentrations. Photo-Fenton experiments were performed in a solar parabolic trough reactor (PTR). Three level factorial design and response surface method (RSM) was used for characterization and optimization of the process in which a response of interest is influenced by four key variables (pH, solar exposure time, catalyst dose (Fe2+/Fe3+), and amount of oxidant (H2O2)). The performance of advanced oxidant process was investigated in terms of percentage degradation of heavy metals and Fecal Coliform (FC) bacteria present in municipal wastewater. The result shows that variables have significant effect on the degradation process of municipal wastewater. Photocatalytic degradation efficiency was found to be dependent on optimized catalyst dose (Fe2+ 100 mg/L) and amount of oxidant (H2O2 500 mg/L). Analysis of variance (ANOVA) exhibited a high coefficient ( R2 = 0.72-0.89), thereby indicating a satisfactory fit between the experimental results. The statistical model of solar photo-Fenton has shown excellent performance. Excessive hydrogen peroxide and iron have shown scavenging effects on hydroxyl radicals and reduced degradation of micro-pollutants present in wastewater. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 448-459, 2017 [ABSTRACT FROM AUTHOR]

The solar photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution at a natural pH (pH = 5) using ferrioxalate as iron source was investigated. The kinetic model proposed and validated in a previous contribution was used to predict the reactants concentrations during the oxidation process in a non-concentrating pilot-plant solar reactor. The effects of hydrogen peroxide to 2,4-D initial concentration ratios ( R), temperature, and radiation levels were studied. Furthermore, the spectral UV/visible and broadband solar radiation fluxes incident on the reactor window were evaluated by the Simple Model for the Atmospheric Radiative Transfer of Sunshine (SMARTS2) code. The complete destruction of 2,4-D and its main intermediate 2,4-dichlorophenol (2,4-DCP) was achieved in all the experimental runs in only 90 and 120 min of reaction, respectively. In agreement with these results, a reduction of toxicity in the system (expressed as % of inhibition of Vibrio fischeri) for longer times to 90 min of reaction was attained. It is important to emphasize the good agreement between kinetic model results and experimental data obtained. [ABSTRACT FROM AUTHOR]

Industrial preparation of cork consists of its immersion for approximately 1 hour in boiling water. The use of herbicides and pesticides in oak tree forests leads to absorption of these compounds by cork; thus, after boiling process, they are present in wastewater. Cork boiling wastewater shows low biodegradability and high acute toxicity involving partial inhibition of their biodegradation when conventional biological treatment is applied. In this work, a treatment line strategy based on the combination of advanced physicochemical technologies is proposed. The final objective is the reuse of wastewater in the cork boiling process; thus, reducing consumption of fresh water in the industrial process itself. Coagulation pre-treatment with 0.5 g/L of FeCl attained the highest turbidity elimination (86 %) and 29 % of DOC elimination. Similar DOC removal was attained when using 1 g/L of ECOTAN BIO (selected for ozonation tests), accompanied of 64 % of turbidity removal. Ozonation treatments showed less efficiency in the complete oxidation of cork boiling wastewater, compared to solar photo-Fenton process, under the studied conditions. Nanofiltration system was successfully employed as a final purification step with the aim of obtaining a high-quality reusable permeate stream. Monitoring of unknown compounds by LC-QTOF-MS allowed the qualitative evaluation of the whole process. Acute and chronic toxicity as well as biodegradability assays were performed throughout the whole proposed treatment line. [ABSTRACT FROM AUTHOR]

The present study aims to assess the removal of 3-amino-5-methylisoxazole (AMI), a recalcitrant by-product resulting from the biological breakdown of some pharmaceuticals, applying a solar photo-Fenton process assisted by ferrioxalate complexes (SPFF) (Fe/HO/oxalic acid/UVA-Vis) and classical solar photo-Fenton process (SPF) (Fe/HO/UVA-Vis). The oxidation ability of SPFF was evaluated at different iron/oxalate molar ratios (1:3, 1:6, and 1:9, with [total iron] = 3.58 × 10 mM and [oxalic acid] = 1.07 × 10, 2.14 × 10 and 3.22 × 10 mM, respectively) and pH values (3.5-6.5), using low iron contents (2.0 mg Fe L). Additionally, the use of other organic ligands such as citrate and ethylenediamine-N,N′-disuccinic acid (EDDS) was tested. The oxidation power of the classical SPF was assessed at different pH values (2.8-4.0) using 2.0 mg Fe per liter. Furthermore, the effect of AMI concentration (2-20 mg L), presence of inorganic ions (Cl, SO , NO , HCO , NH ), and radical scavengers (sodium azide and D-mannitol) on the SPF method at pH 3.5 was also assessed. Experiments were done using a lab-scale photoreactor with a compound parabolic collector (CPC) under simulated solar radiation. A pilot-scale assay was conducted using the best operation conditions. While at near neutral pH, an iron/oxalate molar ratio of 1:9 led to the removal of 72 % of AMI after 90 min of SPFF, at pH 3.5, an iron/oxalate molar ratio of 1:3 was enough to achieve complete AMI degradation (below the detection limit) after 30 min of reaction. The SPF process at pH 3.5 underwent a slower AMI degradation, reaching total AMI degradation after 40 min of reaction. The scale up of SPF process showed a good reproducibility. Oxalic and oxamic acids were identified as the main low-molecular-weight carboxylic acids detected during the pilot-scale SPF reaction. [ABSTRACT FROM AUTHOR]

Among the various classes of pharmaceuticals, antineoplastic agents require particular attention. This work investigates the degradation of the anticancer drugs anastrozole (ANZ) and methotrexate (MTX) by the solar photo-Fenton (SPF) process under different experimental conditions and in different aqueous matrices. Tentative identification of the treatment transformation products (TPs) was performed by suspect screening, employing a purpose-built database containing thirty-three TPs from ANZ and MTX. The experimental condition that achieves the most favorable degradation of ANZ and MTX in real hospital wastewater was pH 5 and multiples additions of Fe2+. This condition provided a reduction of ANZ and MTX of 30 % and 70 %, respectively. Eighteen MTX TPs and five ANZ TPs were tentatively identified in the analyzed samples. After tentative identification, quantitative structure-activity relationship ((Q)SAR) in silico methods were used to predict eight endpoints of environmental risk of the selected analytes. When different possible structures could be proposed, all the possibilities were considered, resulting in fifty-nine structures evaluated. TOPSIS multicriteria decision-making method was used to rank the compounds according to their environmental concern, based on (Q)SAR predictions. As main results, TOPSIS ranking showed that all ANZ TPs and most MTX TPs showed higher environmental risk potential than the parent compounds. The findings highlighted the importance of qualitative tentative identification of TPs and their monitoring throughout treatments, as well as risk assessment using various endpoints simultaneously. The proposed approach can provide objective and holistic evaluation of treatment processes. [Display omitted] [ABSTRACT FROM AUTHOR]

The extensive use of Chlorpyrifos (CP) as insecticide has raised concern to their hazardous impact on human health and ecosystems. Bioremediation has been proved as one of the key eco-compatible method for reducing these environmental toxicants. This study explores and evaluate the effectiveness of a combined process including solar Photo-Fenton process followed by bacterial degradation using Ochrobactrum sp. CPD-03 for effective CP degradation in wastewater. Moreover, the in vivo molecular biotoxicity of CP and degraded CP has been evaluated with embryonic zebrafish. The solar Photo-Fenton treatment showed CP degradation efficiency of ∼42 % in 4 h and ∼92 % in 96 h with combined bacterial degradation process. In vivo biotoxicity analysis showed increased survivability of embryonic zebrafish exposed to CP with CPD-03 in water with lesser morphological abnormalities. The mechanistic molecular analysis showed decreased acetylcholinesterase inhibition and GST activity in embryos exposed to CP with CPD-03 for a lesser apoptosis due to influential intrinsic interaction with metabolic proteins. The study advocated to the use of solar Photo-Fenton process followed by bacterial degradation for an efficient ecological degradation of CP for effective reduction of in vivo biotoxicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The aim of the present study was to evaluate and compare the effectiveness of two solar-based processes (solar/HO and solar photo-fenton) for the inactivation of E. coli in simulated domestic wastewater. Different HO concentrations were applied for solar/HO process (5, 10, 50 and 150 mg/L) and for solar photo-fenton process (10, 30 and 50 mg/L) at different light intensities (200 W/m and 500 W/m) in glass beakers under solar simulator. The application of light at 200 W/m and 500 W/m showed no difference on the removal time in the absence of hydrogen peroxide. However, in the presence of HO, removal times decreased significantly with the elevation of light intensity. When HO concentration was increased, the removal times decreased consistently for solar photofenton process and solar/HO process both at 200 W/m and 500 W/m, except for the process with solar/50 mg/L HO at 500 W/ m. These results imply that solar/HO and solar photo-fenton processes may be a good alternative for disinfection of domestic wastewaters which contains high amounts of organic and inorganic materials. [ABSTRACT FROM AUTHOR]