Sulfamethazine In Water Research Articles

Degradation of sulfamethazine in water in thermally activated persulfate process

BackgroundThe thermally activated persulfate (TAP) process was utilized to degrade sulfamethazine in water. MethodsThe effects of temperature, Na2S2O8 dosage, initial concentration of sulfamethazine, and the presence of salt (NaCl and NaNO3) and natural organic matter (humic acid) on the degradation of sulfamethazine in the TAP process were studied. Significant FindingsThe degradation of sulfamethazine in the TAP process was closely fitted by a pseudo-first-order kinetic model. At pH 6, the degree and rate of degradation of sulfamethazine at 70 °C considerably surpassed those at 40 °C with diverse Na2S2O8 dosages. At 70 °C and pH 6, raising the Na2S2O8 dosage from 1 mM to 8 mM increased the degree and rate of degradation of sulfamethazine; but excess Na2S2O8 (16 mM) limited them. However, lower temperatures eliminated this limitation. The degree and rate of degradation of sulfamethazine were higher at 70 °C and pH 6 when the initial concentration of sulfamethazine was lower. The Arrhenius equation was utilized to calculate the apparent activation energy at diverse Na2S2O8 dosages. The apparent activation energy for the degradation of sulfamethazine increased from 91 kJ/mol to 150 kJ/mol as the Na2S2O8 dosage was raised from 1 mM to 8 mM. However, the apparent activation energy for the degradation of sulfamethazine was reduced to 120 kJ/mol as the Na2S2O8 dosage was raised further to 16 mM. Radical quenching tests indicate that the most important radical in the degradation of sulfamethazine at 70 °C and pH 6 was SO4•−. At 70 °C and pH 6, the presence of salt (NaCl and NaNO3) and humic acid (HA) exhibited various influences on the degradation of sulfamethazine. The degree of degradation of sulfamethazine (10 mg/L) in the TAP process (70 °C and pH 6) reached 100% at 3 min at an Na2S2O8 dosage of 8 mM with a corresponding rate constant of 1.4003 min−1. Accordingly, the TAP process can be utilized in the effective treatment of sulfamethazine-contaminated water.

Novel CoOOH-based fluorescent aptasensor for rapid and sensitive detection of sulfamethazine in environmental samples

Sulfamethazine (SMZ) has been widely used in animal husbandry and exposed to water and soil environments, posing potential threat to human health and ecological environment. Hence, we designed a CoOOH-based aptasensor, the fluorescence resonance energy transfer between FAM-labeled aptamer and CoOOH was used to sensitively and selectively detect SMZ in water and soil environments. Molecular docking and molecular dynamics simulations were used to predict binding mechanisms of SMZ and aptamer. Under optimized conditions, the aptasensor exhibited high sensitivity and selectivity with a linear range of 5–40 ng/mL and a limit of detection of 2.43 ng/mL. The recoveries of the aptasensor were 84.6–115.8% in water and soil samples with relative standard deviations below 9%, and the detection results were highly consistent with high-performance liquid chromatography. Therefore, this developed aptasensor was a reliable tool and could be applied to monitoring of SMZ in environmental samples.

Graphene shell-encapsulated copper-based nanoparticles (G@Cu-NPs) effectively activate peracetic acid for elimination of sulfamethazine in water under neutral condition

In this study, a graphene shell-encapsulated copper-based nanoparticles (G@Cu-NPs) was prepared and employed for peracetic acid (PAA) activation. The characterization of G@Cu-NPs confirmed that the as-prepared material was composed of Cu0 and Cu2O inside and encapsulated by a graphene shell. Experimental results suggested that the synthesized G@Cu-NPs could activate PAA to generate free radicals for efficiently removing sulfamethazine (SMT) under neutral condition. The formation of graphene shells could strongly facilitated electron transfer from the core to the surface. Radical quenching experiments and electron spin resonance (ESR) analysis confirmed that organic radicals (R-O•) and hydroxyl radicals (•OH) were generated in the G@Cu-NPs/PAA system, and R-O• (including CH3CO3• and CH3CO2•) was the main contributor to the elimination of SMT. The possible SMT degradation pathways and mechanisms were proposed, and the toxicity of SMT and its intermediates was predicted with the quantitative structure-activity relationship (QSAR) analysis. Besides, the effects of some key parameters, common anions, and humic acid (HA) on the removal of SMT in the G@Cu-NPs/PAA system were also investigated. Finally, the applicability of G@Cu-NPs/PAA system was explored, showing that the G@Cu-NPs/PAA system possessed satisfactory adaptability to treat different water bodies with admirable reusability and stability.

Activation of sulfite via zero-valent iron-manganese bimetallic nanomaterials for enhanced sulfamethazine removal in aqueous solution:Key roles of Fe/Mn molar ratio and solution pH

In this study, the nano zero-valent iron-manganese (NZVIM) bimetallic materials with different Fe/Mn molar ratios were synthesized by one-step liquid-phase reduction method and utilized to activate sulfite for the elimination of sulfamethazine (SMT) at different pH (3.0, 6.0, and 8.0). It was found the optimum Fe/Mn molar ratio was different under different solution pH conditions. The sulfite could be efficiently activated by nano zero-valent iron (NZVI) and NZVIM with Fe/Mn = 2:1 and 1:1 to remove SMT with a high removal efficiency at pH 3.0. While the NZVIM/sulfite system corresponding to Fe/Mn ratios of 1:1 and 2:1, respectively, could degrade SMT more efficiently than the NZVI/sulfite system at neutral and alkaline conditions. The improvement of degradation efficiency of SMT may result from the addition of Mn element. On the one hand, the ability of direct electron transfer inside the NZVIM particles might be enhanced, and on the other hand, Mn(II) promoted the conversion of Fe(III) to Fe(II), thereby enhancing the ability of free radical generation. Besides, electron spin resonance (ESR) analysis and the radical quenching experiments confirmed that •OH was the primary radicals that responsible for SMT elimination. Then the intermediates of SMT were identified by high-performance liquid chromatography mass spectrometry (LC-MS) and possible degradation pathways were proposed. Additionally, the developmental toxicity and bioaccumulation factors of SMT and its possible intermediates were predicted by quantitative structure–activity relationship (QSAR) analysis. In addition, the effect of some typical coexisting components (Cl−, HCO3−, HA) in water was examined. The effectiveness of NZVIM/sulfite system for SMT removal in two actual water matrices (i.e., tap water and river water) was investigated. These results indicated that the NZVIM/sulfite system is viable and effective for the elimination of SMT in water, and the Fe/Mn molar ratio and solution pH are two critical factors influencing the performance of the NZVIM/sulfite system.

A comparative study of activation of peroxymonosulfate and peroxydisulfate by greigite (Fe3S4) for the degradation of sulfamethazine in water

In this study, greigite (Fe3S4) was used to activate peroxymonosulfate (PMS) and peroxydisulfate (PDS) for sulfamethoazine (SMT) degradation in water. The possible influencing factors such as oxidant concentration, sulfur sources, iron sources and initial pH were investigated.Experimental results showed that SMT could be completely removed at 0.1 mM PMS in 15 min in Fe3S4/PMS system. 96.7% of SMT was removed at 1.0 mM PDS in 60 min in Fe3S4/PDS system.Both systems had good performance over a wide pH range of 3–9. In addition, different sulfur sources could affect the crystal structure, morphology and composition of the synthesized catalysts, while different iron sources had little influence. Quenching experiments and electron paramagnetic resonance (EPR) test evidenced that the activation of PMS and PDS by Fe3S4 was a multi-reactive oxygen species process with the coexistence of •OH, SO4•−, O2•− and 1O2. SO4•− was the main active species in the Fe3S4/PMS system, while SO4•− and •OH were the main free radicals in the Fe3S4/PDS system. X-ray photoelectron spectroscopy (XPS) experiments showed that Fe(II) on Fe3S4 surface effectively activated PMS and PDS, and S2− species were key factors controlling Fe(II) regeneration and subsequent activation of PMS and PDS.However, the consumption of Fe(II) and S2− in Fe3S4/PDS system was higher than that in Fe3S4/PMS system. In addition, in the two systems, the degradation intermediates of SMT and their practical application were also evaluated.This study provided a systematic evaluation of the performance of Fe3S4/PMS and Fe3S4/PDS systems for treatment of antibiotic contaminated water.

Degradation of sulfamethazine in water by sulfite activated with zero-valent Fe-Cu bimetallic nanoparticles

In this work, zero-valent Fe-Cu bimetallic nanoparticles were synthesized using a facile method, and applied to activate sulfite for the degradation of sulfamethazine (SMT) from the aqueous solution. The key factors influencing SMT degradation were investigated, namely the theoretical loading of Cu, Fe-Cu catalyst dosage, sulfite concentration and initial solution pH. The experimental results showed that the Fe-Cu/sulfite system exhibited a much better performance in SMT degradation than the bare Fe0/sulfite system. The mechanism and possible degradation pathway of SMT in Fe-Cu/sulfite system were revealed. The reactive radicals that played a dominant role in the SMT degradation process were •OH and SO4•-, while the loading of Cu induced the synergistic effect between Fe and Cu. The redox cycle between Cu(I)/Cu(II) remarkably contributed to the conversion of Fe(III) to Fe(II), greatly enhancing the catalytic performance of Fe-Cu bimetal. In real groundwater applications, the Fe-Cu/sulfite system also exhibited satisfactory SMT degradation. The 30-day aging tests of Fe-Cu particles demonstrated that the aging of catalyst was not obviously affecting the removal of SMT. Furthermore, the reusability of catalyst was evidenced by the recycling experiments. This study provides a promising application of bimetal activated sulfite for enhanced contaminant degradation in groundwater.

A Comparative Study of Activation of Peroxymonosulfate and Peroxydisulfate by Greigite (Fe3s4) for the Degradation of Sulfamethazine in Water

A Comparative Study of Activation of Peroxymonosulfate and Peroxydisulfate by Greigite (Fe3s4) for the Degradation of Sulfamethazine in Water

Degradation of Sulfamethazine in Water by Sulfite Activated with Zero-Valent Fe-Cu Bimetallic Nanoparticles

Degradation of Sulfamethazine in Water by Sulfite Activated with Zero-Valent Fe-Cu Bimetallic Nanoparticles

Enhanced activation of sulfite by a mixture of zero-valent Fe-Mn bimetallic nanoparticles and biochar for degradation of sulfamethazine in water

Due to the inherent disadvantages of homogeneous transition metal-activated sulfite system, such as narrow pH range, slow Fe3+/Fe2+ circulation and low electron transfer efficiency, the heterogeneous system of zero-valent Fe-Mn bimetallic nanoparticles (ZVFMB) physically mixed with biochar (BC) to activate sulfite(S(IV)) was developed to improve the removal of sulfamethazine (SMT). The results showed that the heterogeneous ZVFMB-BC/S(IV) system could rapidly degrade 92% of SMT within 15 min, because of the formation of a large number of active radicals, mainly hydroxyl radicals (62.2%). Through in-depth discussion, we found that due to the obvious defect structure (ID/IG = 2.05) and abundant phenolic hydroxyl groups on the surface of biochar, biochar was fully qualified for the roles of electron shuttle and electron donor, which were verified by various characterization methods such as FTIR, Raman and linear sweep voltammetry (LSV). Startlingly, it was worth mentioning that biochar can be activated in situ in the oxidation process to form micropores and increase the surface area and pore volume, which facilitated the rapid degradation of SMT. Moreover, this system also shows excellent performance in other water bodies, such as simulated groundwater under neutral or weak acidic conditions and water bodies with other pollutants (e.g., SBD, CBZ, ATZ). All in all, compared to the traditional Fe/Mn ions activated sulfite system, this system has a wide range of pH tolerance, high electron transfer efficiency and excellent degradation rate, showing great potential for application in the degradation of organic pollutants.

An Ultrasensitive Label-Free Fluorescent Aptasensor Platform for Detection of Sulfamethazine.

PurposeSulfamethazine (SMZ) exposed in the environment can enter the human body through the food chain and pose a serious threat to human health. Therefore, it is important to develop a rapid and sensitive method for detecting SMZ in environmental samples. In order to fastly and quantitatively detect SMZ in environmental samples, we developed a label-free fluorescent aptasensor based on specific aptamer (SMZ1S) and fluorescence resonance energy transfer (FRET) between gold nanoparticles (AuNPs) and rhodamine B (RhoB).MethodsIn the absence of SMZ, SMZ1S was adsorbed on the surface of AuNPs, which led to dispersion of the AuNPs in high concentration saline solution, thus effectively quenching the fluorescence of RhoB. With the increase of the SMZ concentration, the specific binding of SMZ1S and SMZ led to the aggregation of AuNPs in the presence of NaCl, which reduced the quenching of RhoB fluorescence and increased the fluorescence intensity. The sensitivity and linearity curve of the label-free fluorescent aptasensor were determined with different concentrations of sulfamethazine standard solutions. The specificity of this fluorescent aptasensor was determined by replacing sulfamethazine with different antibiotics. In addition, the actual water and soil samples were spiked and recovered.ResultsUnder optimized conditions, the proposed fluorescent aptasensor demonstrated a good linear detection of SMZ in binding buffer from 1.25 ng mL−1 to 40 ng mL−1 and the limit of detection was 0.82 ng mL−1. The spiked recoveries for SMZ were 94.4% to 108.8% with a relative standard deviation of 1.8–10.3% in water and soil samples, respectively.ConclusionThe label-free fluorescent aptasensor investigated in the current study is a promising tool to detect and quantify SMZ in water and soil samples.

Mass-production of iron nanopowders by liquid-phase reductive precipitation in a rotating packed bed with blade packings

Iron nanopowders were mass-produced using liquid-phase reductive precipitation and a rotating packed bed (RPB) with blade packings. The effects of the concentration of the reactants, iron valence, iron source, rotational speed, and flow rates of the reactants on the characteristics of the iron nanopowders were studied. The highest mass-production rate was around 13 kg/day, which was obtained using an FeCl2 concentration of 0.2 mol/L, an NaBH4 concentration of 0.4 mol/L, a rotational speed of 1800 rpm, a flow rate of aqueous FeCl2 of 0.9 L/min, and a flow rate of aqueous NaBH4 of 0.9 L/min. The mean size of the iron nanopowders that were mass-produced using this process was 42 nm, as determined by TEM. Therefore, an RPB with blade packings can be effectively used in the commercial production of iron nanopowders. The degradation of sulfamethazine (SMT) by persulfate in water was used to evaluate the activity of the iron nanopowders in the activation of persulfate. At 25 °C, a degradation time of 30 min, an initial SMT concentration of 10 mg/L, an iron nanopowders dosage of 0.028 g/L, and an Na2S2O8 concentration of 0.24 g/L, the efficiency of degradation of SMT by the mass-produced iron nanopowders was 97%, which greatly exceeded the 9% that was achieved using commercial iron nanopowders that had been purchased from Alfa Aesar. The results herein indicate that the mass-produced iron nanopowders with persulfate is highly effective for degrading SMT in water.

Effectiveness of using nanoscale zero-valent iron and hydrogen peroxide in degrading sulfamethazine in water

This investigation elucidates the performance of using nanoscale zero-valent iron (nZVI) and hydrogen peroxide (H2O2) in the degradation of sulfamethazine in water. nZVI was mass-produced using the reductive precipitation method in a rotating packed bed with blade packings. The dependences of the degradation efficiency of sulfamethazine on pH, H2O2 concentration, nZVI dosage, and initial sulfamethazine concentration were assessed. The degradation efficiency of sulfamethazine at pH 3 substantially exceeded those at other pH 5, 7, 9, and 11. An optimal H2O2 concentration for degrading sulfamethazine (10 mg/L) at pH 3 and an nZVI dosage of 28 mg/L was 1 mmol/L. The degradation efficiency of sulfamethazine increased as the nZVI dosage was increased and the initial sulfamethazine concentration was decreased. The degradation efficiency of sulfamethazine (10 mg/L) within 5 min was 99% at pH 3 with an H2O2 concentration of 1 mmol/L and an nZVI dosage of 28 mg/L. However, the degradation efficiency of sulfamethazine (10 mg/L) using the nZVI/H2O2 process with commercial nZVI from Sigma-Aldrich was 4% at 5 min under the same conditions. Accordingly, the nZVI/H2O2 process with the mass-produced nZVI has considerable potential for the enhanced degradation of sulfamethazine in water.

Performance of a large reactor in degrading sulfamethazine in water using UV and persulfate

This study evaluates the performance of a large reactor in the degradation of sulfamethazine (SMT) in water using UV and persulfate (PS), as well as the effects of UV wavelength, PS concentration, initial SMT concentration, and addition of anions on this process. The degradation efficiency and rate of SMT using the UV-254 nm/PS process were higher than those using the UV-365 nm/PS process. The degradation efficiency of SMT using the UV-254 nm/PS process increased with PS concentration. However, PS at high concentration inhibited the SMT degradation rate using the UV-254 nm/PS process. Reducing the initial SMT concentration increased the degradation efficiency and rate of SMT under UV-254 nm. The SMT degradation using the UV-254 nm/PS process in a large reactor followed pseudo-first-order kinetics. Radical scavenging tests revealed that SO4− dominated in the SMT degradation using the UV-254 nm/PS process in a large reactor. Adding anions decreased the degradation efficiency and rate of SMT using the UV-254 nm/PS process in the order NO3− > SO42− > Cl−. In the UV-254 nm/PS process, SMT (5 mg/L) was completely degraded in 2 min at a PS concentration of 10 mM without the addition of anions. Therefore, a large reactor with high PS concentrations is very effective in degrading SMT in water using the UV-254 nm/PS process.

Prediction of Thermodynamic and Structural Properties of Sulfamerazine and Sulfamethazine in Water Using DFT and ab Initio Methods

The acid-ionization constant (pKa) is an important physico-chemical property of molecules. In this research work, the ab initio and density functional theory (DFT) methods, in combination with the polarized continuum model (PCM), were used to calculate the acid-ionization constant of sulfamethazine (SMZ) and sulfamerazine (SMR) solved in water. For these molecules, the calculated pKa value is in relatively good agreement with the experimental one. Also, in these calculations some structural properties such as dihedral angle between the indicated atoms: D, bond lengths between the indicated atoms: d, Bohr radius: a˳, intermolecular hydrogen bond: IHB, and total atomic charge: au have been determined. These data can be used in nano drug modeling of sulfamethazine and sulfamerazine.

Iodine-enhanced ultrasound degradation of sulfamethazine in water

This study investigated sulfamethazine (SMT) ultrasound degradation, enhanced by iodine radicals, generated by potassium iodide (KI) and hydrogen peroxide (H2O2) in situ. The results showed that the ultrasound/H2O2/KI (US/H2O2/KI) combination treatment achieved an 85.10 ± 0.45% SMT removal (%) in 60 min under the following conditions: pH = 3.2, ultrasound power of 195 W, initial SMT concentration of 0.04 mmol·L−1, H2O2 concentration of 120 mmol·L−1, and KI concentration of 2.4 mmol·L−1. UV-Vis spectrophotometric monitoring of molecular iodine (I2) and triiodide (I3−) revealed a correlation between the SMT degradation and the iodine change in the solution. Quenching experiments using methanol, t-butanol and thiamazole as radical scavengers indicated that iodine radicals, such as I and I2−, were more important than hydroxyl radicals (HO) for SMT degradation. SMT degradation under the US/H2O2/KI treatment followed pseudo-first order reaction kinetics. The activation energy (Ea) of SMT degradation was 7.75 ± 0.61 kJ·mol−1, which suggested the reaction was controlled by the diffusion step. Moreover, TOC removal was monitored, and the obtained results revealed that it was not as effective as SMT degradation under the US/H2O2/KI system.

Accelerated degradation of sulfamethazine in water by VUV/UV photo-Fenton process: Impact of sulfamethazine concentration on reaction mechanism

The degradation of sulfamethazine (SMN) by VUV/UV photo-Fenton (VPF) process was investigated with a mini-fluidic VUV/UV photoreaction system. Compared with the conventional UV photo-Fenton process, the VPF process significantly enhanced the degradation and mineralization of SMN, because the VUV irradiation photolyzed H2O and accelerated the redox cycle of Fe3+/Fe2+ to generate more reactive oxygen species (ROS). Initial pH and concentrations of SMN, H2O2, Fe3+, inorganic anions (NO3−, HCO3−, and Cl−), and humic acid all considerably impacted SMN degradation in the VPF process. In particular, the initial SMN concentration significantly affected the absorption distributions of UV and VUV photons in the reaction solution, thus inducing a different reaction mechanism. At a lower SMN concentration (1.8μM), most of UV and VUV photons were absorbed by Fe3+ and H2O, respectively, so indirect oxidation by ROS mainly accounted for SMN degradation. However, at a higher SMN concentration (90μM), 89.2% of UV photons and 59.0% of VUV photons were absorbed by SMN, so direct photolysis also played an important role. In addition, HO and HO2 were identified as the main ROS in the VPF process. This study demonstrates that the VPF process can effectively remove organic micropollutants from water.

The Reusable g-Fe2O3/SiO2/TiO2: Preparation and Photocatalytic Activity for the Degradation of Sulfamethazine in Water

In order to photo- degrade sulfamethazine in the UV, a new photocatalytic microsphere was prepared. The magnetic -Fe2O3/SiO2/TiO2 microspheres prepared using the ultrasonic-assisted modified Stber method and sol-gel method, has super paramagnetic and high photocatalytic activity verified by using XRD and UV-vis analysis. The -Fe2O3/SiO2/TiO2 could be reused at least five times without any appreciable reduction of photocatalytic efficiency and the degradation rate of sulfamethazine could reach to 95% on UV irradiated for 1hr with -Fe2O3/SiO2/TiO2. So -Fe2O3/SiO2/TiO2 had good reusability. At the same time, the degradation mechanism of -Fe2O3/SiO2/TiO2 composites was suggested as that •OH played a relatively larger role in sulfamethazine photodecomposition, and h+ and •O2 − were the main active species for the decomposition of sulfamethazine.

Tissue concentrations of sulfamethazine and tetracycline hydrochloride of swine (Sus scrofa domestica) as it relates to withdrawal methods for international export

The use of water medications is a common practice in the US swine industry to treat and prevent infections in swine herds with minimal labor and without risk of needle breakage. There are concerns that FDA-approved withdrawal times (WDT) may be inadequate for several water medications when exporting pork products to countries where MRLs (maximum residue limits) are lower than US tolerance levels. In this study, withdrawal intervals (WDI) were estimated for pigs when dosed with tetracycline and sulfamethazine in water. The WDI were calculated using the FDA tolerance method (TLM) and a population-based pharmacokinetic method (PopPK). The estimated WDIs (14–16days using TLM) were similar to the approved WDT of 15days for sulfamethazine. However, the PopPK method extended WDIs for both sulfamethazine (19–20days) and tetracycline (12days) compared to the currently approved WDTs in the U.S. This study also identified potential differences in WDI between weanling and finisher pigs. In conclusion, the TLM may not always provide adequate WDT for foreign export markets especially when MRLs differ from tolerance levels approved for US markets. However, PopPK methods can provide conservative WDIs in situations with considerable variability in medication exposure such as with administration in water.

Enhanced sulfamethazine removal by steam-activated invasive plant-derived biochar

Recent investigations have shown frequent detection of pharmaceuticals in soils and waters posing potential risks to human and ecological health. Here, we report the enhanced removal of sulfamethazine (SMT) from water by physically activated biochar. Specifically, we investigated the effects of steam-activated biochars synthesized from an invasive plant (Sicyos angulatus L.) on the sorption of SMT in water. The properties and sorption capacities of steam-activated biochars were compared with those of conventional non-activated slow pyrolyzed biochars. Sorption exhibited pronounced pH dependence, which was consistent with SMT speciation and biochar charge properties. A linear relationship was observed between sorption parameters and biochar properties such as molar elemental ratios, surface area, and pore volumes. The isotherms data were well described by the Freundlich and Temkin models suggesting favorable chemisorption processes and electrostatic interactions between SMT and biochar. The steam-activated biochar produced at 700°C showed the highest sorption capacity (37.7mgg−1) at pH 3, with a 55% increase in sorption capacity compared to that of non-activated biochar produced at the same temperature. Therefore, steam activation could potentially enhance the sorption capacities of biochars compared to conventional pyrolysis.

Homogeneous photo‐Fenton mineralization of the antibiotic sulfamethazine in water under UV‐A, visible and solar irradiation

AbstractBACKGROUNDThe presence of pharmaceutical residues in the aquatic environment is an emerging issue due to their uncontrolled release and accumulation in the environment that may affect living organisms, ecosystems and public health. As a result, efforts are being made to develop methods to inactivate or eliminate this class of substance in the environment.RESULTSThe homogeneous photocatalytic degradation of sulfamethazine (SMT), a sulfanilamide drug, has been investigated in aqueous solutions using artificial and solar illumination. The effects of initial concentration of H2O2 (10–400 mg L‐1), Fe3+ (3.5–28 mg L‐1), SMT (10–40 mg L‐1), as well as temperature (280–323 K) on mineralization rates were evaluated in a bench‐scale Pyrex reactor for the photo‐Fenton/UV‐A and photo‐Fenton/Vis processes. SMT degradation was accompanied by the release of inorganic nitrogen and sulphate ions. Experiments under natural sunlight conditions were performed in a pilot‐scale, fountain reactor at light intensities between 0.49 and 2.83 mW cm‐2.CONCLUSIONSAn increase in the level of the parameters had a positive effect, with photo‐Fenton/UV‐A (at 0.94 × 10−4 einstein L−1 min−1 light flux provided by a 9 W lamp at 366 nm maximum response) being more effective than photo‐Fenton/Vis (at 0.88 × 10−4 einstein L−1 min−1 also provided by a 9 W lamp at 440 nm maximum response). Illumination for 120 min in the case of the pilot‐scale reactor at 2 mW cm‐2 intensity led to more than 70% mineralization of 20 mg L‐1 SMT, thus showing that process scale‐up is feasible. © 2013 Society of Chemical Industry