Low-pressure Mercury Vapor Lamp Research Articles

Effect of ferric salt addition on UV/electro-chlorine advanced oxidation process

ABSTRACT This study discussed the effect of ferric salt addition on UV/electro-chlorine advanced oxidation process using a train of electrolytic and UV flow cells with an ozone-free low-pressure mercury vapour lamp (total irradiance:0.60 W at 254 nm). Ferric salt addition enhanced 1,4-dioxane degradation at an electrolytic current of 0.100 A. By contrast, an inhibitory effect of ferric salt addition was observed at a current of 0.500 A. The enhanced accumulation of free chlorine at a current of 0.500 A directly decreased the 1,4-dioxane degradation rate by scavenging reactive radicals like HO˙ and Cl˙. However, at an electrolytic current of 0.100 A, UV irradiance was relatively excessive for electrochemical chlorine production. The excess UV energy enhanced the photoreduction of FeOH2+, followed by the Fenton-type reaction of Fe2+ and HOCl, which produced HO˙ and consumed free chlorine. As a result, the free chlorine concentration decreased, and the reaction efficiency between the reactive radicals and 1,4-dioxane improved. Thus, the addition of ferric salt to a UV/electro-chlorine system is recommended when the UV irradiance in the system is excessive compared to the electrochemical chlorine supply.

Reflection of UVC wavelengths from common materials during surface UV disinfection: Assessment of human UV exposure and ozone generation

The COVID-19 pandemic has promoted interest in using devices emitting ultraviolet-C (UVC) irradiation (200–280 nm) for surface disinfection to reduce pathogen transmission, especially in occupied public spaces. While UVC devices have been shown to be highly effective against various pathogens, there are safety concerns when using conventional UVC devices for surface disinfection, including human exposure of reflected UVC irradiation and ozone generation. Emerging Far UVC devices (emitting at 200–230 nm), like the krypton chloride (KrCl*) excimer, have the potential to be safely applied in occupied spaces due to their minimal adverse effects on skin and eyes. In this study, UV reflection of 21 common materials was documented and compared using a filtered KrCl* excimer (installed with a bandpass filter at 222 nm), an unfiltered KrCl* excimer, and a conventional low-pressure mercury vapor lamp. The safety of Far UVC devices was evaluated based on the irradiance and spectrum of reflected UV irradiation and ozone generation measured at various locations around the device. Our results show that most common materials can reflect UV irradiation, among which some metals tend to have greater reflection. The Far UVC devices, especially the filtered KrCl* excimer, should be safe to be applied in occupied spaces for effective surface disinfection, with limited ozone generation and no health risk from reflected UV irradiation. However more caution is needed when using unfiltered KrCl* devices and conventional UV 254 nm light. This study provides urgently needed data on UV reflection of common materials and guidance for safety assessments of UVC devices for surface disinfection in occupied spaces.

Evaluating the impact of ultraviolet C exposure conditions on coliphage MS2 inactivation on surfaces.

The COVID-19 pandemic has raised interest in using devices that generate ultraviolet C (UVC) radiation as an alternative approach for reducing or eliminating microorganisms on surfaces. Studies investigating the efficacy of UVC radiation against pathogens use a wide range of laboratory methods and experimental conditions that can make cross-comparison of results and extrapolation of findings to real-world settings difficult. Here, we use three different UVC-generating sources - a broad-spectrum pulsed xenon light, a continuous light-emitting diode (LED), and a low-pressure mercury vapour lamp - to evaluate the impact of different experimental conditions on UVC efficacy against the coliphage MS2 on surfaces. We find that a nonlinear dose-response relationship exists for all three light sources, meaning that linear extrapolation of doses resulting in a 1-log10 (90%) reduction does not accurately predict the dose required for higher (e.g. 3-log10 or 99.9%) log10 reductions. In addition, our results show that the inoculum characteristics and underlying substrate play an important role in determining UVC efficacy. Variations in microscopic surface topography may shield MS2 from UVC radiation to different degrees, which impacts UVC device efficacy. These findings are important to consider in comparing results from different UVC studies and in estimating device performance in field conditions.

Inactivation of biofilm-bound bacterial cells using irradiation across UVC wavelengths

Opportunistic pathogens (OPs), such as Pseudomonas spp., Legionella spp., and mycobacteria, have been detected in biofilms in drinking water distribution systems and water storage tanks and pose potential risks to finished drinking water quality and safety. Emerging UV technologies, such as UV light emitting diodes (LEDs) and krypton chloride (KrCl*) excimers, could provide an alternative to chemical-based secondary disinfection (i.e., chlorine or chloramines) for controlling biofilm-bound OPs. UV systems offer long lifetimes, ability to select wavelength, small size with high power density, and limited-to-no disinfection by-product formation. In this study, inactivation of biofilm-bound Pseudomonas aeruginosa cells across different maturities was investigated using five UVC devices with different peak emission wavelengths, including a KrCl* excimer (222 nm), a low pressure mercury vapor lamp (254 nm), and three UV LEDs (260 nm, 270 nm, and 282 nm). The UV transmittance and absorbance through the biofilm structure was also documented for the first time using a unique approach. Our results show all UVC devices can inactivate biofilm-bound P. aeruginosa cells up to a point, among which the UV LED with peak emission at 270 nm provided the best disinfection performance. UV sensitivities of biofilm-bound cells decreased with biofilm maturity and while initial rates of inactivation were high, no more than 1.5-2.5 log reduction was possible. Re-suspended biofilm bacteria in aqueous solution were highly sensitive to UV, reaching greater than 6 log reduction. UV shielding by biofilm constituents was observed and was likely one of the reasons for UV resistance but did not fully explain the difference in UV sensitivity between biofilm-bound cells versus planktonic cells. This study improves upon fundamental knowledge and provides guidance for innovative designs using emerging UV technologies for biofilm and pathogen control in water distribution systems.

KINETIC STUDIES OF DEGRADATION OF BENZOIC ACID AND SALICYLIC ACID THROUGH OZONATION, PEROXONE, PHOTOOZONATION AND PHOTOPEROXONE

In this study, benzoic acid and salicylic acid in their aqueous solutions were treated by ozonation, photo-ozonation, photoperoxone and photoperoxone processes. A batch photoreactor with 8W low pressure mercury vapour lamp was used to carry out the experiments for examining the effects of various combinations of ozone, H2O2 and UV and their rates of degradation were compared. The concentration of the substrate was determined with an UV-visible spectrophotometer. The photodegradation processes conformed to first-order kinetics. The degradation rate of the two substrates is as follows: photoperoxone (UV/O3/H2O2)> photoozonation(UV/O3)> peroxone(O3/H2O2)> ozonation(O3).

Microbiological Evaluation of the Disinfecting Potential of UV-C and UV-C Plus Ozone Generating Robots.

This study examined the microbicidal activity of ultraviolet (UV)-C185–256-nm irradiance (robot 1) and ozone generated at UV-C185-nm by low-pressure mercury vapor lamps (robot 2) adapted to mobile robotic devices for surface decontamination, which was achieved in less than 1 h. Depending on their wall structure and outer envelopes, many microorganisms display different levels of resistance to decontaminating agents. Thus, the need for novel disinfection approaches is further exacerbated by the increased prevalence of multidrug-resistant bacteria, as well as the potential of novel microorganisms, with the ability to cause disease outbreaks. To set up a rapid and effective approach for microorganisms propagation prevention, we focused on the effects of UV-C and ozone on a distinct microorganism survival ratio. A set of microorganisms, including Escherichia coli, Micrococcus luteus, Saccharomyces cerevisiae, Trichoderma harzianum, and Bacillus subtilis, were used to evaluate the disinfection power of UV-C and UV-C plus ozone generating robots. UV-C disinfection can be suited to ad hoc tasks, is easy to operate, requires low maintenance, does not have the need for the storage of dangerous chemicals, and does not produce by-products that may affect human health and the environment. The robotic cumulative irradiation technology developed (fluence accumulated values of 2.28 and 3.62 mJ cm−2, for robot 1 and 2, respectively), together with the production of ozone (with a maximum peak of 0.43 ppm) capable of reaching UV-C shaded surfaces, and analyzed in the current study, despite being designed for the need to reduce the risk of epidemic outbreaks in real-life scenarios, represents a versatile tool that could be employed for air and surface disinfection within many circumstances that are faced daily.

Photocatalytic degradation of cephalexin by UV activated persulfate and Fenton in synthetic wastewater: optimization, kinetic study, reaction pathway and intermediate products.

We used Low pressure mercury vapor lamp activated of Sodium Persulfate (UV/SPS) and Fenton processes in two separate reactors to comparison of cephalexin (CPX) degradation in aqueous solution. The effect of pH, initial concentration of SPS, concentration of CPX, concentration of H2O2 and concentration of Fe2+ on the degradation of CPX were investigated. The residue of CPX and metabolites were determined by HPLC and GC/MS. The Total Organic Carbon (TOC) analysis was utilized for surveying the mineralization of CPX. Biodegradability of CPX in both advanced oxidation processes was evaluated by BOD5/COD in optimum condition. The results indicated that the maximum CPX removal was obtained at pH3, H2O2 3mM, concentration of initial CPX 10mg/L and by increasing the doses of SPS from 0.1 to 0.2mM, the degradation of CPX was enhanced. In this study, the most important factors for AOP efficiency was concentration of initial CPX; and then pH in UV/SPS and H2O2 in Fenton processes. The TOC measurements indicate that the UV/SPS and Fenton can efficiently mineralize CPX. CPX removed enough to achieve suitable biodegradability for a further biological process. Too, analysis of generated intermediates during the degradation of CPX was conducted by GC/MS method and a degradation pathway was proposed.

Use of Ultrasound and Ultraviolet Radiation in Hybrid Methods for Water Disinfection

Hybrid photochemical methods are considered for water disinfection in which treatment with ultraviolet (UV) and ultrasonic (US) radiations are combined (US/UV) and applied consecutively or simultaneously; the use of catalysts is also included. The literature survey shows that inactivation of pathogenic microorganisms in aquatic media by high-frequency US (>100 kHz) has not been studied adequately, whereas only low-frequency (<100 kHz) US and low-pressure mercury vapor lamps (254 nm) were used in hybrid US/UV methods. Irradiation with high-frequency US generates reactive oxygen species (primarily hydroxyl radicals) in greater proportions, and a synergistic effect is observed when UV irradiation is included in treatment. Therefore, the use of high-frequency US and mercury-free UV sources in hybrid oxidizing systems, including those based on Fenton-like processes, is promising for intensifying disinfection processes and improving their effectiveness.

Inactivation of Bacillus anthracis and Bacillus atrophaeus spores on different surfaces with ultraviolet light produced with a low‐pressure mercury vapor lamp or light emitting diodes

To obtain quantitative efficacy data of two ultraviolet light (UVC) technologies for surface inactivation of Bacillus anthracis Ames and Bacillus atrophaeus spores. Spores were deposited onto test coupons and controls of four different materials, via liquid suspension or aerosol deposition. The test coupons were then exposed to UVC light from either a low-pressure mercury vapor lamp or a system comprised of light emitting diodes, with a range of dosages. Positive controls were held at ambient conditions and not exposed to UVC light. Following exposure to UVC, spores were recovered from the coupons and efficacy was quantified in terms of log10 reduction (LR) in the number of viable spores compared to that from positive controls. Decontamination efficacy varied by material and UVC dosage (efficacy up to 5·7 LR was demonstrated). There was no statistical difference in efficacy between the two species or between inoculation methods. Efficacy improved for the LED lamp at lower relative humidity, but this effect was not observed with the mercury vapor lamp. This study will be useful in determining whether UVC could be used for the inactivation of B. anthracis spores on different surface types.

Photodecomposition of methyl iodide as pretreatment for adsorption of radioiodine species in used nuclear fuel recycling operations

This work presents novel photochemical reactors with integrated titania photocatalyst for the UV photodecomposition of gaseous methyl iodide present in simulated vessel off-gas (VOG) in a nuclear fuel reprocessing facility. Continuous flow reactors composed of fluorinated ethylene propylene (FEP) were designed and constructed to allow transmission of UV light into the reactor while also providing resistance to the corrosive nature of methyl iodide. Titania nanotube photocatalyst increases methyl iodide photolysis rate by two orders of magnitude compared to that with UV light alone. The rate constant for methyl iodide photolysis with and without catalyst directly depends on the intensity of the light at the location of the reaction, which is inversely proportional to the distance from the linear light source. The titania photocatalyst is significantly active at low light intensity where no detectable reaction occurs in absence of catalyst. For example, at an initial concentration of 400 ppb methyl iodide, a residence time of 9 s, and a light intensity of 0.5 mW/cm2, conversions with and without titania photocatalyst are >99% and 0%, respectively. The UV light source is a low-pressure mercury vapor lamp with primary emission at 254 nm, the wavelength that is in the range of highest cross-sectional absorbance for methyl iodide. Parameters investigated in this work include UV lamp to reactor distance (light intensity), impact of humidity, gas phase composition, and catalyst form (nanotube vs powder). This work also demonstrates that titania possesses a characteristic activation period on the order of approximately one hour to reach its full steady-state activity.

Study of degradation of p-toluic acid by photo-oxidation, peroxidation, photo-peroxidation and photo-fenton processes

p-Toluic acid is a major content of terephthalic acid wastewater and is a cause of secondary water pollution. p-Toluic acid in aqueous solution was degraded by using photo-fenton, photo-peroxidation, photo-oxidation and peroxidation processes. A low-pressure mercury vapour lamp was taken in combination with different oxidants to degrade p- toluic acid in this study. Substrate concentration was fixed by utilizing a UV–Visible spectrophotometer. The results indicated that photo-fenton process achieved degradation rate due to synergistic effect between UV and Fe2+/H2O2. The degradation rate follow the sequence: photofenton (UV/ Fe2+/H2O2) > photo-peroxidation (UV/H2O2) > photo-oxidation (UV) > peroxidation (H2O2). The photodegradation processes were adhered to first order dynamics.

Removal of azithromycin from wastewater using advanced oxidation processes (UV/H2O2) and moving-bed biofilm reactor (MBBR) by the response surface methodology (RSM)

Antibiotics are among the major concerns in terms of environmental control due to their cumulative properties, adverse health effects on humans, and development of drug resistance. The present study aimed to investigate the efficiency of the combination of UV/H2O2 and moving-bed biofilm reactor (MBBR) systems in the removal of azithromycin from aqueous solutions using the response surface methodology (RSM). In the UV/H2O2 process, a low-pressure mercury vapor lamp with the power of eight Watts, wavelength of 254 nanometers, and intensity of 1.02 mw/cm2 was used to determine the effects of pH, azithromycin concentration, hydrogen peroxide concentration, and contact time on the removal efficiency of azithromycin. According to the obtained results, the highest removal efficiency in the UV/H2O2 process was obtained with the azithromycin concentration of 2 mg/L. Therefore, 2 mg/L of azithromycin was selected as the optimal concentration with the highest removal efficiency. Following that, the optimal concentration of azithromycin was injected into the MBBR reactor. In the combined process of UV/H2O2 and MBBR, the highest removal efficiency of azithromycin was 91.2%. Therefore, it could be concluded that the combined system of UV/H2O2 and MBBR had the highest efficiency in the removal of azithromycin from aqueous solutions.

A comparative study for the removal of imidacloprid insecticide from water by chemical-less UVC, UVC/TiO2 and UVC/ZnO processes.

Chloronicotinic insecticide are a class of pesticides that are commonly used as insecticides. Among the frequently used chloronicotinic pesticide, imidacloprid (IM) was developed in 1986. The residual of this insecticide or any pesticides may have serious public health threats. Both degradation and mineralization of the imidacloprid (IM) in aqueous solution was studied under various experimental conditions using different advanced oxidation processes namely, ultraviolet C (UVC), UVC + TiO2, and UVC + ZnO. All the experiments were performed using a lab-scale batch photoreactor with a working volume of 100mL equipped with low-pressure mercury vapor lamp (9W, 18cm long, Philips Co.), emitting UV radiation with maximum intensity at 254nm. The possible intermediates and a reaction pathway for photocatalytic degradation of the IM were also evaluated. It was observed that under optimal condition for UVC/TiO2 process (C0 = 100mg/L, pH = 7.5, t = 20min, TiO2 dose = 100mg/L), IM was effectively degraded (88.15%) and followed the first order kinetics model. The degradation efficiency increased with increasing of illumination time and is more favorable in alkaline pH compared to acidic pH. Degradation of the IM in photocatalytic process was compared with photolysis showing a significant synergy effect in the case of the photocatalytic degradation process, leading at 20min illumination time to a 36.7% increase of the IM removal efficiency in comparison to the single UVC. The GC/MS chromatograms before and after treatment confirmed the effectiveness of the UVC/TiO2 process in simplifying the nature of IM and its conversion to more simple and degradable compounds. The heterogeneous UVC/TiO2 process was found to be an efficient chemical-less method that is appropriate for degradation of IM from aqueous phase.

Stabilization of perfluoropolyethers (PFPEs) with acyl fluoride and carboxylic acid end-groups by UV-irradiation

Perfluoropolyethers (PFPEs) with acyl fluoride and carboxylic acid end-groups obtained by photo-oxidation of 1,1,2,3,3,3-hexafluoro-1-propene (HFP) were subjected for ultraviolet (UV) stabilization. Effects of various stabilization parameters such as the type of lamp, lamp wattage, contact area and lamp distance on stabilization time, viscosity and molecular weight were studied in detail. High-pressure mercury vapor (HPMV) lamps and low-pressure mercury vapor (LPMV) lamps were used to carry out UV stabilization of unstabilized PFPEs. By increasing the lamp wattage, stabilization time decreased, but the weight loss of PFPEs increased. Among HPMV and LPMV UV lamps, LPMV lamps were more effective to carry out stabilization of PFPEs. Structural changes after UV stabilization were analyzed by FTIR and 19F-NMR analysis. FTIR and NMR analysis confirmed the complete removal of the acyl fluoride group. Thermal stability of stabilized and unstabilized PFPEs was also studied by thermogravimetric analysis (TGA).

Photocatalytic degradation of metformin and amoxicillin in synthetic hospital wastewater: effect of classical parameters

In this study, photocatalytic degradation of synthetic hospital wastewater containing two pharmaceutical contaminants, namely amoxicillin trihydrate (a commonly used antibiotic) and metformin HCl (a widely used diabetic medicine), was carried out using a laboratory-scale photoreactor (200 mL), TiO2 as photocatalyst, and 125 W low-pressure mercury vapour lamp emitting UV rays at 365 nm. The response surface methodology based on face-centred central composite design was used to optimize the independent variables, namely the initial concentrations of contaminants (10–50 mg/L), TiO2 dosage (250–1250 mg/L), initial pH (3–11), and reaction time (30–150 min). Results showed that both amoxicillin and metformin removals were influenced by all the four variables individually and also by the interaction between these variables. Response surface and overlaid contour plots were used to evaluate the optimum conditions. It was found that the maximum removal of amoxicillin (90%) and metformin (98%) could occur when the pH is 7.6, TiO2 dosage is 563 mg/L, and reaction time is 150 min for an initial concentration of the contaminants at 10 mg/L. Further experiments were conducted to evaluate the characteristics of photocatalytic degradation. Low adsorption of contaminants on TiO2 surface and negligible degradation of contaminants using acetonitrile as solvent suggest that hydroxyl radical attack could be the predominant pathway in the removal process. The COD and TOC analyses of the samples confirmed the mineralization of the compounds to more than 60%.

Degradation of 2,4-dichlorophenoxyacetic acid by photolysis and photo-Fenton oxidation

This work aimed at comparing different UV and H2O2 based advanced oxidation processes (AOPs) −photolysis, UV/H2O2, and photo-Fenton reaction- for the degradation of 2,4-dichlorophenoxyacetic acid (2,4-D), a common ingredient of phytosanitary products. The influence of oxidant dose (H2O2), catalyst type and concentration, pollutant concentration, water matrix and irradiation spectrum was also analyzed. Under reference conditions (25 mg/L of 2,4-D in osmosed water), photo-Fenton oxidation using Fe2+ salt, initial pH value of 2.6 and a low-pressure mercury vapor lamp (10 W, λ = 254 nm) yielded more than 85% of pollutant mineralization in one hour, as compared to 60% and less than 10% for UV/H2O2 and photolysis, respectively. Such a performance could be achieved in 10 min only when applying optimal concentration range for Fenton’s reagent (2 to 5 times the stoichiometric amount of H2O2 and oxidant-to-catalyst molar ratio from 25 to 40). Conversely, addition of a ZSM-5 zeolite bearing iron active sites albeit catalyzing Fenton oxidation at natural pH – did not bring additional benefit to UV/H2O2 process. Use of wastewater treatment plant effluent as aqueous matrix or irradiation in the UVA-visible range somewhat lowered the fficiency of the homogeneous photo-Fenton process. Nonetheless, bench scale experiments under sunlight gave promising results for 2,4 D remediation in wastewater, leading to over 80% conversion of the pollutant within ten minutes.

Magnesium diboride: An effective light-to-heat conversion material in solid-state

We report herein a giant light-to-heat transduction observed in bulk magnesium diboride (MgB2) on exposure to incoherent, continuous wave, broadband light-sources. The heat-flow from the sample was accurately determined using photocalorimetry, to register an ultrahigh value of 45 W/g upon irradiation with a low-pressure mercury vapour lamp (λ ∼ 250–450 nm; irradiance ∼800 mW/cm2) with a photo-to-thermal conversion efficiency of about 83% (with an error of ±1.86%). As a practical application, light-induced heat was used to generate electrical power using a thermoelectric generator (open voltage ∼125 mV, when illuminated by a solar simulator). The bulk MgB2 powder was found to be photo-stable under different irradiation conditions, and the photothermal effect was found to be highly reproducible.

Degradation of microalgae from freshwater by UV radiation

Abstract Algae (Chlorella, Microcystis, Oocystis and Scenedesmus) degradation by ultraviolet radiation has been investigated. The radiation source was a low pressure mercury vapor lamp which emits monochromatic radiation at 254 nm. Experiments include initial algae concentration variation. After a period of exposure to UV radiation, algal mass concentration was reduced by more than 80%. The results were interpreted under Line Source Spherical Emission model, so quantum yield was the appropriate target variable for explaining the process. Global quantum yields are determined for Chlorella, Microcystis, Oocystis and Scenedesmus being 7.75 × 104, 3.65 × 105, 2.28 × 105, 1.74 × 104 μg E−1, respectively.

Evaluating UV-C LED disinfection performance and investigating potential dual-wavelength synergy

A dual-wavelength UV-C LED unit, emitting at peaks of 260 nm, 280 nm, and the combination of 260|280 nm together was evaluated for its inactivation efficacy and energy efficiency at disinfecting Escherichia coli, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus spores, compared to conventional low-pressure and medium-pressure UV mercury vapor lamps. The dual-wavelength unit was also used to measure potential synergistic effects of multiple wavelengths on bacterial and viral inactivation and DNA and RNA damage.All five UV sources demonstrated similar inactivation of E. coli. For MS2, the 260 nm LED was most effective. For HAdV2 and B. pumilus, the MP UV lamp was most effective. When measuring electrical energy per order of reduction, the LP UV lamp was most efficient for inactivating E. coli and MS2; the LP UV and MP UV mercury lamps were equally efficient for HAdV2 and B. pumilus spores. Among the UV-C LEDs, there was no statistical difference in electrical efficiency for inactivating MS2, HAdV2, and B. pumilus spores. The 260 nm and 260|280 nm LEDs had a statistical energy advantage for E. coli inactivation.For UV-C LEDs to match the electrical efficiency per order of log reduction of conventional LP UV sources, they must reach efficiencies of 25–39% or be improved on by smart reactor design. No dual wavelength synergies were detected for bacterial and viral inactivation nor for DNA and RNA damage.

Treatment of an industrial stream containing vinylcyclohexene by the H2O2/UV process.

Petrochemical industries generate wastewaters containing pollutants that can severely impact the biological treatment systems. Some streams from specific production units may contain nonbiodegradable or toxic compounds that impair the performance of the wastewater treatment plant and should be segregated and treated by specific techniques. In this work, the utilization of chemical oxidation (H2O2/UV) was investigated for removing 4-vinylcyclohexene (VCH) from a liquid stream coming from the production of hydroxylated liquid polybutadiene (HLPB). Besides VCH, this stream also contains ethanol, hydrogen peroxide, and many other organic compounds. Experiments were carried out in a small-scale photochemical reactor (0.7L) using a 25-W low-pressure mercury vapor lamp. The photochemical reactor was operated in batch, and the reaction times were comprised between 10 and 60min. Assays were also performed with a synthetic medium containing VCH, H2O2, and ethanol to investigate the removal of these substances in a less complex aqueous matrix. By-products formed in the reaction were identified by gas chromatography and mass spectroscopy (GC-MS). VCH was significantly removed by the oxidation process, in most assays to undetectable levels. Ethanol removal varied from 16 to 23% depending on the reaction conditions. Acetic acid, acetaldehyde, and diols were detected as by-products of the industrial wastewater stream oxidation. A drop on the toxicity of the industrial stream was also observed in assays using the organism Artemia salina.