scholarly journals Photocatalytic Removal of Pharmaceuticals from Greywater

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1125
Author(s):  
Bukola Ojobe ◽  
Radek Zouzelka ◽  
Barbora Satkova ◽  
Magdalena Vagnerova ◽  
Alzbeta Nemeskalova ◽  
...  
Keyword(s):  
Membrane Bioreactor ◽  
Quality Standards ◽  
Heterogeneous Photocatalysis ◽  
Additional Treatment ◽  
Anatase Tio2 ◽  
Radical Scavenger ◽  
Oh Radical ◽  
Complete Degradation ◽  
Photocatalytic Removal ◽  
High Concentrations

High concentrations of pharmaceuticals have been detected in greywater effluents treated using up-to-date technologies. Finding a suitable additional treatment before this effluent is reused is urgently needed to ensure the reused water meets quality standards. This paper reports the use of heterogeneous photocatalysis on anatase and rutile nanopowders to remove naproxen, metformin and sulfamethoxazole, at practically relevant concentrations found in membrane bioreactor (MBR)-treated greywater. A low anatase concentration of 400 mg L−1 was sufficient to efficiently degrade the pharmaceuticals listed above, with complete degradation observed in 5 h. The effect of background species presented in greywater was, to some extent, comparable to that of the OH-radical scavenger. These results prove that photocatalysis using anatase TiO2 is a feasible additional treatment for greywater recycling.

Complete degradation of high concentrations of tetrachloroethylene by a methanogenic consortium in a fixed-bed reactor

1998 ◽  
Vol 62 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Nathalie Cabirol ◽  
François Jacob ◽  
Joseph Perrier ◽  
Bruno Fouillet ◽  
Paul Chambon
Keyword(s):  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Complete Degradation ◽  
High Concentrations ◽  
Methanogenic Consortium

PHOTOCATALYTIC REMOVAL OF PHENOL OVER MESOPOROUS ZnO/TiO2 COMPOSITES

2018 ◽  
Vol 80 (2) ◽  
Author(s):  
Klinsmann Cheong Lee Khang ◽  
Mohd Hayrie Mohd Hatta ◽  
Siew Ling Lee ◽  
Leny Yuliati
Keyword(s):  
Pore Size ◽  
Uv Light ◽  
Average Pore Size ◽  
Anatase Tio2 ◽  
Light Irradiation ◽  
Molar Ratio ◽  
Average Pore ◽  
Uv Light Irradiation ◽  
Photocatalytic Removal ◽  
Mesoporous Zno

A series of mesoporous ZnO/TiO2 composites were successfully synthesized using cetyltrimethylammonium bromide surfactant. The composites of different Zn:Ti molar ratios (0.5:1, 0.75:1, and 1:1) were prepared by impregnating ZnO onto mesoporous TiO2. XRD results verified co-existence of both anatase TiO2 and hexagonal wurtzite ZnO in the ZnO/TiO2 composites. Based on the Tauc plots, all the composites showed almost the same band gap energy of approximately 3.21 eV. The fourier transform infrared spectroscopy results successful covering of ZnO on the surface of the TiO2 as the hydrophilicity property of TiO2 decreased remarkably with the loading of ZnO in the composites. N2 adsorption-desorption isotherms of the samples exhibited type-IV isotherm with a hysteresis loop. The Barrett-Joyner-Halenda pore size distribution revealed that the average pore size of the composites was around 3.6 nm, indicating the formation of mesopores dominantly in the samples. The photocatalytic removal of phenol over the samples under UV light irradiation after 3 h decreased in the order: ZnO/TiO2 composites > anatase TiO2 (with surfactant) > anatase TiO2 (without surfactant) > ZnO. The composite with Zn:Ti molar ratio of 0.75:1 has achieved the highest photocatalytic activity of 36.5% in the removal of phenol under UV light irradiation for 3 h.

scholarly journals Antioxidant and Pro-Oxidant Activities of Melatonin in the Presence of Copper and Polyphenols In Vitro and In Vivo

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 903 ◽  
Author(s):  
Jiajia Wang ◽  
Xiaoxiao Wang ◽  
Yufeng He ◽  
Lijie Jia ◽  
Chung S. Yang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Hydroxyl Radical ◽  
Density Functional ◽  
Antioxidant Activities ◽  
Chelating Agent ◽  
Redox System ◽  
Radical Scavenger ◽  
Dual Function ◽  
High Concentrations

Melatonin is a well-documented antioxidant. Physicochemical analysis using the density functional theory suggests that melatonin is a copper chelating agent; however, experimental evidence is still in demand. The present study investigated the influence of melatonin on reactive oxygen species (ROS) generated from polyphenol autoxidation in the presence of copper. Surprisingly, we found that melatonin paradoxically enhanced ROS formation in a redox system containing low concentrations of copper and quercetin (Que) or (−)-epigallocatechin-3-gallate (EGCG), due to reduction of cupric to cuprous ion by melatonin. Addition of DNA to this system inhibited ROS production, because DNA bound to copper and inhibited copper reduction by melatonin. When melatonin was added to a system containing high concentrations of copper and Que or EGCG, it diminished hydroxyl radical formation as expected. Upon addition of DNA to high concentrations of copper and Que, this pro-oxidative system generated ROS and caused DNA damage. The DNA damage was not prevented by typical scavengers of hydroxyl radical DMSO or mannitol. Under these conditions, melatonin or bathocuproine disulfonate (a copper chelator) protected the DNA from damage by chelating copper. When melatonin was administered intraperitoneally to mice, it inhibited hepatotoxicity and DNA damage evoked by EGCG plus diethyldithiocarbamate (a copper ionophore). Overall, the present study demonstrates the pro-oxidant and antioxidant activities of melatonin in the redox system of copper and polyphenols. The pro-oxidant effect is inhibited by the presence of DNA, which prevents copper reduction by melatonin. Interestingly, in-vivo melatonin protects against copper/polyphenol-induced DNA damage probably via acting as a copper-chelating agent rather than a hydroxyl radical scavenger. Melatonin with a dual function of scavenging hydroxyl radical and chelating copper is a more reliable DNA guardian than antioxidants that only have a single function of scavenging hydroxyl radical.

scholarly journals APLIKASI MEMBRANE BIOREACTOR (MBR) UNTUK PROSES DAUR ULANG AIR LIMBAH

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Taty Hernaningsih
Keyword(s):  
Waste Water ◽  
Water Quality ◽  
Wastewater Treatment ◽  
Water Treatment ◽  
Membrane Bioreactor ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Quality Standards ◽  
Waste Water Treatment Plant ◽  
Recycled Waste

The population is growing rapidly result to increased demand for drinking water while the other side of this situation causes to the increasing amount of wastewater. Waste water treatment plant has been built in several major cities in Indonesia to overcome the problem of pollution.  Wastewater treatment plant only treats wastewater to tackle environmental pollution without being able to overcome the shortage of clean water community. Therefore, to solve the existing problems will be considered any further processing with recycled waste water treatment. One technology that may be developed for this purpose is the system of Membrane Bioreactor (MBR). This has been widely applied as an advanced unit of wastewater treatment and serves as a unit of processing recycled waste water. The MBR system has advantages such as: it only takes a little bit of land, can treat wastewater with discharge varying quality and process wastewater with high pollutant removal efficiency. MBR were investigated using a membrane filter submerged in the reactor. Membrane module is hollow fiber with a form of polymeric membrane materials. Research has been done on wastewater treatment with a combination of conventional WWTP as preliminary and advanced processing unit with MBR since March 4, 2014 until June 2014. The effluent quality  of result research proved that  the treated water quality meets  water quality standards are set with  Permenkes RI N0.416/Menkes/Per/IX/1990, dated 3 September 1990. The nitrification and denitrification also proceed well so that the concentration of nitrite and nitrate meet the quality standards. In addition, the percentage removal of heavy metals (arsenic, cadmium, chromium, selenium, lead) can reach 99%. Keywords: MBR, wastewater reuse, BOD5, COD, HRT dan SRT

Pilot-scale testing membrane bioreactor for wastewater reclamation in industrial laundry

2002 ◽  
Vol 46 (4-5) ◽  
pp. 67-76 ◽  
Author(s):  
M. Andersen ◽  
G.H. Kristensen ◽  
M. Brynjolf ◽  
H. Grüttner
Keyword(s):  
Membrane Bioreactor ◽  
Hydraulic Retention Time ◽  
Cross Flow ◽  
Pilot Scale ◽  
Cationic Polymer ◽  
Additional Treatment ◽  
Wastewater Reclamation ◽  
Membrane Cleaning ◽  
Cross Flow Velocity

A pilot-scale study of membrane bioreactor treatment for reclamation of wastewater from Berendsen Textile Service industrial laundry in Søborg, Denmark was carried out over a 4 month period. A satisfactory COD degradation was performed resulting in a low COD in the permeate (<50 mg/l). To obtain satisfactory treatment, addition of nitrogen was necessary. The biodegradability of the permeate was very low (BOD5<2 mg/l). A hydraulic retention time of 1 d turned out to be sufficient at a sludge concentration of 10 g MLSS/l. Through addition of a cationic polymer, a satisfactory dewaterability of the sludge was reached. Membrane tests showed that operating at a trans-membrane pressure of 3 bar and a cross-flow velocity of 4 m/s, a flux of 120 l/m2h can be expected without using chemicals for membrane cleaning. The quality of the permeate was very good when comparing to the reuse quality demands of water to the wash processes. Reuse of the permeate in all rinsing steps requires additional treatment through reverse osmosis.

The Influence of High Concentrations of Fluoride on the Electrosynthesis of Peroxodisulfates at β-PbO2 Anodes

1990 ◽  
Vol 45 (6) ◽  
pp. 892-896 ◽  
Author(s):  
Irene Scheler ◽  
Dietrich W. Wabner
Keyword(s):  
Current Efficiency ◽  
Polarization Curves ◽  
Ozone Formation ◽  
Oh Radical ◽  
Fluorosulfonic Acid ◽  
High Current ◽  
Impedance Measurements ◽  
Acidic Sulfate ◽  
High Concentrations

During electrolysis with β-PbO2 anodes in acidic sulfate electrolytes high current efficiencies of peroxodisulfate are obtained (60-70%) when high amounts of fluoride (1 Mol · 1-1 to 3 Mol · 1-1) are added to the electrolyte. This reaction is examined by means of current efficiency of peroxodisulfate, rate of ozone formation, polarization curves, and impedance measurements. The reason for the high current efficiencies is the formation of fluorosulfonic acid in the electrolyte and its reaction with the OH-radical (from the discharge of H2O) to form HSO4-radicals.

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