scholarly journals Enhanced photocatalytic oxidation of reactive dye using manganese catalyst complex

2021 ◽  
pp. 19-19
Author(s):  
Simona Vajnhandl ◽  
Lidija Skodic ◽  
Marjana Simonic ◽  
Aleksandra Lobnik ◽  
Julija Volmajer-Valh
Keyword(s):  
Photocatalytic Oxidation ◽  
Advanced Oxidation Processes ◽  
Vibrio Fischeri ◽  
Degradation Products ◽  
Reactive Dye ◽  
Gas Chromatography Mass Spectrometry ◽  
Treatment Efficiency ◽  
Reaction Solution ◽  
Catalyst Complex ◽  
High Resolution Gas Chromatography

In this work, the treatment efficiency of advanced oxidation processes H2O2/UV enhanced by the addition of a manganese catalyst complex (MnTACN) was investigated on a model dye solution and a real dye-house effluent. The experimental results were evaluated in terms of absorbance (A) and total organic carbon (TOC) reduction. The major degradation products of the model dye solution were identified by high resolution gas chromatography/mass spectrometry analyses. In addition, the toxicity of the final reaction solution after H2O2/UV/MnTACN treatment to Vibrio fischeri bacteria was determined. The results showed that the addition of the H2O2/UV/MnTACN system at in different concentrations of the catalyst solution increased enhance the decolourization rate compared to H2O2/UV for both the model dye solution and real dye-house effluent.

scholarly journals Efficiency of advanced oxidation processes in lowering bisphenol A toxicity and oestrogenic activity in aqueous samples

2014 ◽  
Vol 65 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Maja Plahuta ◽  
Tatjana Tišler ◽  
Mihael Jožef Toman ◽  
Albin Pintar
Keyword(s):  
Chemical Analysis ◽  
Bisphenol A ◽  
Photocatalytic Oxidation ◽  
Advanced Oxidation Processes ◽  
Vibrio Fischeri ◽  
Advanced Oxidation ◽  
Aqueous Samples ◽  
Yeast Saccharomyces Cerevisiae ◽  
Oxidation Processes ◽  
Set Up

Summary Bisphenol A (BPA) is a well-known endocrine disruptor with adverse oestrogen-like effects eliciting adverse effects in humans and wildlife. For this reason it is necessary to set up an efficient removal of BPA from wastewaters, before they are discharged into surface waters. The aim of this study was to compare the efficiency of BPA removal from aqueous samples with photolytic, photocatalytic, and UV/H2O2 oxidation. BPA solutions were illuminated with different bulbs (halogen; 17 W UV, 254 nm; and 150 W UV, 365 nm) with or without the TiO2 P-25 catalyst or H2O2 (to accelerate degradation). Acute toxicity and oestrogenic activity of treated samples were determined using luminescent bacteria (Vibrio fischeri), water fleas (Daphnia magna), zebrafish embryos (Danio rerio), and Yeast Estrogen Screen (YES) assay with genetically modified yeast Saccharomyces cerevisiae. The results confirmed that BPA is toxic and oestrogenically active. Chemical analysis showed a reduction of BPA levels after photolytic treatment and 100 % conversion of BPA by photocatalytic and UV/H2O2 oxidation. The toxicity and oestrogenic activity of BPA were largely reduced in photolytically treated samples. Photocatalytic oxidation, however, either did not reduce BPA toxic and oestrogenic effects or even increased them in comparison with the baseline, untreated BPA solution. Our findings suggest that chemical analysis is not sufficient to determine the efficiency of advanced oxidation processes in removing pollutants from water and needs to be complemented with biological tests.

scholarly journals Photocatalytic Pretreatment of Commercial Lignin Using TiO2-ZnO Nanocomposite-Derived Advanced Oxidation Processes for Methane Production Synergy in Lab Scale Continuous Reactors

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 54
Author(s):  
Yu-Ming Chu ◽  
Hafiz Muhammad Asif Javed ◽  
Muhammad Awais ◽  
Muhammad Ijaz Khan ◽  
Sana Shafqat ◽  
...  
Keyword(s):  
Photocatalytic Oxidation ◽  
Advanced Oxidation Processes ◽  
Synergistic Effects ◽  
Oxidation Products ◽  
Methane Yield ◽  
Zno Nanoparticle ◽  
Coumaric Acid ◽  
Stirred Tank Reactors ◽  
Lignin Oxidation ◽  
Constant Operation

The photocatalytic pretreatment of lignocellulosic biomass to oxidize lignin and increase biomass stability has gained attention during the last few years. Conventional pretreatment methods are limited by the fact that they are expensive, non-renewable and contaminate the anaerobic digestate later on. The present study was focused to develop a metal-derived photocatalyst that can work with visible electromagnetic spectra light and oxidize commercial lignin liquor. During this project the advanced photocatalytic oxidation of lignin was achieved by using a quartz cube tungsten T3 Halogen 100 W lamp with a laboratory manufactured TiO2-ZnO nanoparticle (nanocomposite) in a self-designed apparatus. The products of lignin oxidation were confirmed to be vanillic acid (9.71 ± 0.23 mg/L), ferrulic acid (7.34 ± 0.16 mg/L), benzoic acid (6.12 ± 0.17 mg/L) and p-coumaric acid (3.80 ± 0.13 mg/L). These all products corresponded to 85% of the lignin oxidation products that were detectable, which is significantly more than any previously reported lignin pretreatment with even more intensity. Furthermore, all the pretreatment samples were supplemented in the form of feedstock diluent in uniformly operating continuously stirred tank reactors (CSTRs). The results of pretreatment revealed 85% lignin oxidation and later on these products did not hinder the CSTR performance at any stage. Moreover, the synergistic effects of pretreated lignin diluent were seen that resulted in 39% significant increase in the methane yield of the CSTR with constant operation. Finally, the visible light and nanoparticles alone could not pretreat lignin and when used as diluent, halted and reduced the methane yield by 37% during 4th HRT.

scholarly journals Heterogeneous Photo-Fenton Catalytic Degradation of Practical Pharmaceutical Wastewater by Modified Attapulgite Supported Multi-Metal Oxides

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 156
Author(s):  
Manjing Lu ◽  
Jiaqi Wang ◽  
Yuzhong Wang ◽  
Zhengguang He
Keyword(s):  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Catalytic Degradation ◽  
Gas Chromatography Mass Spectrometry ◽  
Pharmaceutical Wastewater ◽  
High Concentration ◽  
Modified Attapulgite ◽  
Cod Removal Rate ◽  
Pre Treatment ◽  
Almost All

Chemical synthetic pharmaceutical wastewater has characteristics of high concentration, high toxicity and poor biodegradability, so it is difficult to directly biodegrade. We used acid modified attapulgite (ATP) supported Fe-Mn-Cu polymetallic oxide as catalyst for multi-phase Fenton-like ultraviolet photocatalytic oxidation (photo-Fenton) treatment with actual chemical synthetic pharmaceutical wastewater as the treatment object. The results showed that at the initial pH of 2.0, light distance of 20 cm, and catalyst dosage and hydrogen peroxide concentration of 10.0 g/L and 0.5 mol/L respectively, the COD removal rate of wastewater reached 65% and BOD5/COD increased to 0.387 when the reaction lasted for 180 min. The results of gas chromatography-mass spectrometry (GC-MS) indicated that Fenton-like reaction with Fe-Mn-Cu@ATP had good catalytic potential and significant synergistic effect, and could remove almost all heterocycle compounds well. 3D-EEM (3D electron microscope) fluorescence spectra showed that the fluorescence intensity decreased significantly during catalytic degradation, and the UV humus-like and fulvic acid were effectively removed. The degradation efficiency of the nanocomposite only decreased by 5.8% after repeated use for 6 cycles. It seems appropriate to use this process as a pre-treatment for actual pharmaceutical wastewater to facilitate further biological treatment.

Photo-degradation of butyl parahydroxybenzoate by using TiO2-supported catalyst

2013 ◽  
Vol 67 (10) ◽  
pp. 2141-2147 ◽  
Author(s):  
Patrick Atheba ◽  
Patrick Drogui ◽  
Brahima Seyhi ◽  
Didier Robert
Keyword(s):  
Flow Rate ◽  
Photocatalytic Oxidation ◽  
Supported Catalyst ◽  
Operating Conditions ◽  
Treatment Efficiency ◽  
Optimal Operating ◽  
Photo Degradation ◽  
Photochemical Process ◽  
Recirculation Flow ◽  
High Treatment

The present work evaluates the potential of the photocatalysis (PC) process for the degradation of butylparaben (BPB). Relatively high treatment efficiency was achieved by comparison to photochemical process. Prior to photocatalytic degradation, adsorption (AD) of BPB occurred on the titanium dioxide (TiO2)-supported catalyst. AD was described by Langmuir isotherm (KL = 0.085 L g−1, qm = 4.77 mg g−1). The influence of angle of inclination of the reactor, pH, recirculation flow rate and initial concentration of BPB were investigated. The PC process applied under optimal operating conditions (recirculation flow rate of 0.15 L min−1, angle of inclination of 15°, pH = 7 and 5 mg L−1 of BPB) is able to oxidize 84.9–96.6% of BPB and to ensure around 38.7% of mineralization. The Langmuir–Hinshelwood kinetic model described well the photocatalytic oxidation of BPB (k = 7.02 mg L−1 h−1, K = 0.364 L mg−1).

Effect of advanced oxidation processes on the toxicity of municipal landfill leachates

2004 ◽  
Vol 49 (4) ◽  
pp. 273-277 ◽  
Author(s):  
B. Slomczynska ◽  
J. Wasowski ◽  
T. Slomczynski
Keyword(s):  
Organic Compounds ◽  
Advanced Oxidation Processes ◽  
Vibrio Fischeri ◽  
Advanced Oxidation ◽  
Optimal Conditions ◽  
Toxicity Evaluation ◽  
Landfill Leachates ◽  
Oxidation Processes ◽  
Municipal Landfill ◽  
Pre Treatment

The aim of the present study was to assess the effect of advanced oxidation processes (AOPs) (oxidation ozone and peroxide/ozone) on the toxicity of leachates from municipal landfill for Warsaw, Poland, using a battery of tests. AOPs used to pre-treat leachates were carried out in laboratory conditions after their coagulation with the use of FeCl3. The effects of the pre-treatment of leachates using the method of coagulation with FeCl3 depended on the concentration of organic compounds and with optimal conditions of the process ranged from 40 to 70%. Further pre-treatment of the leachates after coagulation, involving the use of oxidation with O3 and H2O2/O3, did not cause significant decrease of leachate toxicity. The data of this study demonstrated the usefulness of the battery of tests using Daphnia magna, Artemia franciscana, Scenedesmus quadricauda and Vibrio fischeri for the toxicity evaluation of raw and pre-treated leachates.

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