Surface plasmon resonance imaging sensor for detection of photolytically and photocatalytically degraded glyphosate

Glyphosate is one of the most widely used pesticides, which, together with its primary metabolite aminomethylphosphonic acid, remains present in the environment. Many technologies have been developed to reduce glyphosate amounts in water. Among them, heterogeneous photocatalysis with titanium dioxide as a commonly used photocatalyst achieves high removal efficiency. Nevertheless, glyphosate is often converted to organic intermediates during its degradation. The detection of degraded glyphosate and emerging products is, therefore, an important element of research in terms of disposal methods. Attention is being paid to new sensors enabling the fast detection of glyphosate and its degradation products, which would allow the monitoring of its removal process in real time. The surface plasmon resonance imaging (SPRi) method is a promising technique for sensing emerging pollutants in water. The aim of this work was to design, create, and test an SPRi biosensor suitable for the detection of glyphosate during photolytic and photocatalytic experiments focused on its degradation. Cytochrome P450 and TiO2 were selected as the detection molecules. We developed a sensor for the detection of the target molecules with a low molecular weight for monitoring the process of glyphosate degradation, which could be applied in a flow-through arrangement and thus detect changes taking place in real-time. We believe that SPRi sensing could be widely used in the study of xenobiotic removal from surface water or wastewater.Web of Science2223art. no. 921

Innovative technology for ammonia abatement from livestock buildings using advanced oxidation processes

The feasibility of using advanced oxidation processes (AOPs) for abatement of ammonia from livestock buildings was exam ined in a series of pilot plant experiments. In this study, all the experiments were conducted in a two-step unit containing a dry photolytic reactor (UV185/UV254/O3) and a photochemical scrubber (UV254/H2O2). The unit efciency was tested for two initial ammonia concentrations (20 and 35 ppmv) and three diferent air fows (150, 300 and 450 m3 ·h−1). While the frst step removes mainly organic pollutants that are often present together with ammonia in the air and ammonia only partially, the second step removes around 90% of ammonia emissions even at the highest fow rate of 450 m3 ·h−1. Absorbed ammonia in the aqueous phase can be efectively removed without adjusting the pH (i.e. without the addition of other additives) using UV and ozone. Complete removal of ammonia was achieved after 15 h of irradiation. In order to assess the price efciency of the suggested technology and to be able to compare it with other methods the fgures-of-merit were determined. The price needed for lowering ammonia emission by one order of magnitude is 0.002 € per cubic meter of treated air at the highest fow rate of 450 m3 ·h−1 and for initial ammonia concentrations of 20 ppmv. These fndings demonstrate that AOPs are a promising method for ammonia abatement from livestock buildings which are rarely using any waste air treatment method.Web of Science2271610160

Catalytic oxidation of ammonia over cerium-modified copper aluminium zinc mixed oxides

Copper-containing mixed metal oxides are one of the most promising catalysts of selective catalytic oxidation of ammonia. These materials are characterized by high catalytic efficiency; however, process selectivity to dinitrogen is still an open challenge. The set of Cu-Zn-Al-O and Ce/Cu-Zn-Al-O mixed metal oxides were tested as catalysts of selective catalytic oxidation of ammonia. At the low-temperature range, from 250 & DEG;C up to 350 & DEG;C, materials show high catalytic activity and relatively high selectivity to dinitrogen. Samples with the highest Cu loading 12 and 15 mol.% of total cation content were found to be the most active materials. Additional sample modification by wet impregnation of cerium (8 wt.%) improves catalytic efficiency, especially N-2 selectivity. The comparison of catalytic tests with results of physicochemical characterization allows connecting the catalysts efficiency with the form and distribution of CuO on the samples' surface. The bulk-like well-developed phases were associated with sample activity, while the dispersed CuO phases with dinitrogen selectivity. Material characterization included phase composition analysis (X-ray powder diffraction, UV-Vis diffuse reflectance spectroscopy), determination of textural properties (low-temperature N-2 sorption, scanning electron microscopy) and sample reducibility analysis (H-2 temperature-programmed reduction).Web of Science1421art. no. 658

Ověření možnosti použití biofiltru pro čištění odpadních vzdušnin

Import 07/02/2010Prezenční546 - Institut environmentálního inženýrstvívýborn

Degradation of styrene from waste gas stream by advanced oxidation processes

Waste-air treatment is experimentally investigated by advanced oxidation processes utilizing UV irradiation combined with ozone and hydrogen peroxide. The effect of operating parameters, such as an initial concentration of styrene and flow rate of gas, on the removal of styrene is studied in a photochemical pilot plant unit. The conversion of styrene decreases with an increasing initial styrene concentration and with a decreasing retention time (higher flow rate) of waste gas. The highest conversion of styrene (87%) is achieved under lower initial styrene concentration (100 ppm) and lower flow rate (42m(3) h(-1)). The energy per order is also calculated for the advanced oxidation process. Electrical energy per order is calculated for all the experimental conditions and it was found that the energy consumption is of about 0.070 kW h m(-3) per order, for the 87% styrene removal at 100 ppm of initial styrene concentration and 42m(3) h(-1) flow rate. The combination of UV irradiation and ozone is significantly more efficient with lower electrical energy need per order in comparison with combination of UV irradiation and hydrogen peroxide. Therefore, the advanced oxidation process represents a promising treatment technology for the management of waste-air and the pilot plant unit designed for high flow rates of waste-gas streams is suitable for an industrial use.Web of Scienceart. no. 190012

Photochemical treatment (UV/O3+UV/H2O2) of waste gas emissions containing organic pollutants in pilot plant unit

A continuous flow photochemical pilot plant unit containing a dry photolytic/photooxidation reactor UV185/ UV254/O3 and an aqueous photochemical UV254/H2O2 reactor was used to remove VOC from the waste gas stream with a high flow rate. The efficiency of this system was thoroughly studied through the control of reaction conditions, the detection of intermediates, and the analysis of reaction products during the degradation of styrene, xylene, and their mixture. The conversion of the model substances depends on the initial concentration of the pollutant, the flow rate, and the type of pollutant. The highest conversion after passing through the whole pilot plant unit was achieved at an initial pollutant concentration 50 ppmv and a flow rate 100 m3 center dot h-1, which is related to the residence time in the system. The conversion of styrene, xylene and their mixture after passing through the whole unit for the 100 m3 center dot h-1 flow rate was 74%, 46% and 52%, respectively. Although the first dry photolytic/photooxidation reactor using UV185/UV254/O3 was more efficient for styrene degradation, the aqueous photochemical UV254/H2O2 part was more suitable for xylene degradation. These experimental results are in the agreement with carbon balance, which confirmed the outlet air contained only unconverted model pollutant (styrene, xylene or their mixture) and CO2. Figures of merit were calculated in order to evaluate the price efficiency of the technology. This study presents an effective AOPs system for the degradation of VOCs from waste gas streams with a high flow rate and provides an insight into their degradation pathways.Web of Science16328227

Surface Plasmon Resonance Imaging Sensor for Detection of Photolytically and Photocatalytically Degraded Glyphosate

Glyphosate is one of the most widely used pesticides, which, together with its primary metabolite aminomethylphosphonic acid, remains present in the environment. Many technologies have been developed to reduce glyphosate amounts in water. Among them, heterogeneous photocatalysis with titanium dioxide as a commonly used photocatalyst achieves high removal efficiency. Nevertheless, glyphosate is often converted to organic intermediates during its degradation. The detection of degraded glyphosate and emerging products is, therefore, an important element of research in terms of disposal methods. Attention is being paid to new sensors enabling the fast detection of glyphosate and its degradation products, which would allow the monitoring of its removal process in real time. The surface plasmon resonance imaging (SPRi) method is a promising technique for sensing emerging pollutants in water. The aim of this work was to design, create, and test an SPRi biosensor suitable for the detection of glyphosate during photolytic and photocatalytic experiments focused on its degradation. Cytochrome P450 and TiO2 were selected as the detection molecules. We developed a sensor for the detection of the target molecules with a low molecular weight for monitoring the process of glyphosate degradation, which could be applied in a flow-through arrangement and thus detect changes taking place in real-time. We believe that SPRi sensing could be widely used in the study of xenobiotic removal from surface water or wastewater

Degradation of ammonia from gas stream by advanced oxidation processes

The reduction of ammonia emissions from air was experimentally investigated by advanced oxidation processes (AOPs) utilizing the combination of ultraviolet irradiation with ozone. The influence of operating conditions such as initial ammonia concentration and flow rate of gas on the reduction of ammonia concentration was investigated in homemade photochemical unit. The conversion of ammonia decreased with increasing initial concentration of ammonia and with increasing flow rate of air (decreasing retention time). The highest conversion of ammonia (97%) was achieved under lower initial concentration of ammonia (30 ppm) and lower flow rate of air (28 m(3)/h). The energy per order was evaluated for the advanced oxidation process too. The energy consumption was about 0.037 kWh/m(3)/order for the 97% ammonia conversion at 30 ppm of initial ammonia concentration and 28 m(3)/h flow rate of air. Based on the results, the advanced oxidation process combining the UV irradiation and ozone was effective for mitigation of ammonia concentration and presents a promising technology for the reduction of odor emissions from livestock buildings. Moreover, the AOPs are suitable for application for high flow rate of air, especially for ammonia abatement from livestock buildings, where very high efficiency is expected.Web of Scienc

Organobeidellites for removal of anti-inflammatory drugs from aqueous solutions

Diclofenac (DC) and ibuprofen (IBU) are widely prescribed non-steroidal anti-inflammatory drugs, the consumption of which has rapidly increased in recent years. The biodegradability of pharmaceuticals is negligible and their removal efficiency by wastewater treatment is very low. Therefore, the beidelitte (BEI) as unique nanomaterial was modified by the following different surfactants: cetylpyridinium (CP), benzalkonium (BA) and tetradecyltrimethylammonium (TD) bromides. Organobeidellites were tested as potential nanosorbents for analgesics. The organobeidellites were characterized using X-ray powder diffraction (XRD), Infrared spectroscopy (IR), Thermogravimetry and differential thermal analysis (TG/DTA) and scanning microscopy (SEM). The equilibrium concentrations of analgesics in solution were determined using UV-VIS spectroscopy. The intercalation of surfactants into BEI structure was confirmed both using XRD analysis due to an increase in basal spacing from 1.53 to 2.01 nm for BEI_BA and IR by decreasing in the intensities of bands related to the adsorbed water. SEM proved successful in the uploading of surfactants by a rougher and eroded organobeidellite surface. TG/DTA evaluated the decrease in dehydration/dehydroxylation temperatures due to higher hydrophobicity. The Sorption experiments demonstrated a sufficient sorption ability for IBU (55-86%) and an excellent ability for DC (over 90%). The maximum adsorption capacity was found for BEI_BA-DC (49.02 mg & BULL;g(-1)). The adsorption according to surfactant type follows the order BEI_BA > BEI_TD > BEI_CP.Web of Science1111art. no. 310