scholarly journals Photodegradation of Trace Trichloronitromethane in Water under UV Irradiation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Lin Deng ◽  
Zhiren Wu ◽  
Caiqian Yang ◽  
Yung-Li Wang
Keyword(s):  
Humic Acid ◽  
Light Intensity ◽  
Uv Light ◽  
Control Strategies ◽  
Chloride Ions ◽  
Source Control ◽  
Photochemical Degradation ◽  
Nitrate Ions ◽  
Photodegradation Rate ◽  
Water And Wastewater

This study’s objective was to study the photodegradation of TCNM (trichloronitromethane) in water under UV light. The effects of light intensity, nitrate ions, chloride ions, humic acid, and pH on the photochemical degradation of TCNM were investigated under the irradiation of low pressure mercury lamp (λ= 254 nm, 12 W). The photodegradation rate of TCNM was found to increase with increasing the concentration of nitrate ions, chloride ions, humic acid, pH, and light intensity. The photodegradation of TCNM was examined at pH 6.0 with initial concentrations (C0) of TCNM at 10.0–200.0 µg/L. The overall rate of degradation of TCNM was modeled using a pseudofirst-order rate law. Finally, the proposed mechanism involved in the photodegradation of TCNM was also discussed by analysis. Results of this study can contribute to the development of new source control strategies for minimization of TCNM risk at drinking water and wastewater utilities.

Future Directions in Instrumentation, Control and Automation in the Water and Wastewater Industry

1993 ◽  
Vol 28 (11-12) ◽  
pp. 9-14 ◽  
Author(s):  
Troy D. Vassos
Keyword(s):  
Control Strategies ◽  
Treatment Plant ◽  
Dynamic Modelling ◽  
Simulation Software ◽  
Plant Performance ◽  
Limiting Factors ◽  
Time Data ◽  
Training Environment ◽  
Factors Affecting ◽  
Water And Wastewater

The need to optimize treatment plant performance and to meet increasingly stringent effluent criteria are two key factors affecting future development of instrumentation, control and automation (ICA) applications in the water and wastewater industry. Two case studies are presented which highlight the need for dynamic modelling and simulation software to assist operations staff in developing effective instrumentation control strategies, and to provide a training environment for the evaluation of such strategies. One of the limiting factors to date in realizing the potential benefits of ICA has been the inability to adequately interpret the large number of existing instrumentation inputs available at treatment facilities. The number of inputs can exceed the number of control loops by up to three orders of magnitude. The integration of dynamic modelling and expert system software is seen to facilitate the interpretation of real-time data, allowing both quantitative (instrumented) and qualitative (operator input) information to be integrated for process control. Improvements in sensor reliability and performance, and the development of biological monitoring sensors and control algorithms are also discussed.

scholarly journals TiO2 BEADS FOR PHOTOCATALYTIC DEGRADATION OF HUMIC ACID IN PEAT WATER

2011 ◽  
Vol 11 (3) ◽  
pp. 253-257 ◽  
Author(s):  
Winarti Andayani ◽  
Agustin N M Bagyo
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Oxalic Acid ◽  
Chemical Oxygen Demand ◽  
Photocatalytic Degradation ◽  
Uv Light ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Color Intensity ◽  
Before And After

Degradation of humic acid in aqueous solution containing TiO2 coated on ceramics beads under irradiation of 254 nm UV light has been conducted in batch reactor. The aim of this experiment was to study photocatalytic degradation of humic acid in peat water. The irradiation of the humic acid in aqueous solution was conducted in various conditions i.e solely uv, in the presence of TiO2-slurry and TiO2 beads. The color intensity, humic acid residue, conductivity and COD (chemical oxygen demand) of the solution were analyzed before and after irradiation.  The compounds produced during photodegradation were identified using HPLC. The results showed that after photocatalytic degradation, the color intensity and the COD value of the solution decreased, while the conductivity of water increased indicating mineralization of the peat water occurred. In addition, oxalic acid as the product of degradation was observed.

scholarly journals Oxytetracycline Mineralization inside a UV/H2O2 System of Advanced Oxidation Processes: Inorganic By-Product

2021 ◽  
Vol 16 (2) ◽  
pp. 302-309
Author(s):  
Anisa Ur Rahmah ◽  
Sabtanti Harimurti ◽  
Kiki Adi Kurnia ◽  
Abdul Aziz Omar ◽  
Thanabalan Murugesan
Keyword(s):  
Advanced Oxidation Processes ◽  
Chloride Ions ◽  
The Body ◽  
Photochemical Degradation ◽  
Water Stream ◽  
Agricultural Industry ◽  
Oxidation Processes ◽  
By Products ◽  
Open Access Article ◽  
H2o2 System

Oxytetracycline (OTC) was widely used antibiotic in agricultural industry. However, most of them were secreted from the body and entered the water stream, due to low absorption. The occurrence of the antibiotics in water stream may led to serious health hazards. Hence, finding the effective method that capable to achieve total mineralization of antibiotic-contaminated wastewater, followed by the production of benign inorganic and organic by-product, was necessarily deemed. Photochemical degradation method, such as: UV/H2O2 system, was capable to achieve total mineralization of OTC at its optimized condition. In this paper, inorganic by-products of OTC mineralization inside a UV/H2O2 system at its optimum condition were analyzed. The presence of nitrate, ammonium, chloride ions, and chlorine were detected at the sample solution after mineralization. The presence of these inorganic by-product has proven that the experimental setup chosen was capable to achieve total mineralization. In addition, possible routes of the inorganic by-products detachment from the OTC’s structure, were also presented. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 

scholarly journals FOTODEGRADASI ZAT WARNA TEKSTIL METHYLENE BLUE DAN CONGO RED MENGGUNAKAN KOMPOSIT ZnO-AA DAN SINAR UV

Jurnal Kimia ◽  
2016 ◽  
Author(s):  
Ni Putu Diantariani ◽  
Iryanti Eka Suprihatin ◽  
Ida Ayu Gede Widihati
Keyword(s):  
Methylene Blue ◽  
Zinc Oxide ◽  
Activated Carbon ◽  
Congo Red ◽  
Uv Light ◽  
Carbon Composite ◽  
Textile Dyes ◽  
Initial Concentration ◽  
Photodegradation Rate ◽  
Radiation Time

Research on  photodegradation of textile dyes  of methylene blue (MB) and congo red (CR) using ZnO-Activated Carbon composite and ultraviolet (UV) light has been done. This research included synthesis zinc oxide (ZnO), synthesis ZnO-Activated Carbon, and the application of composite to degrade textile dyes of MB and CR. In this research studied the effect of pH, concentration and time of UV radiation  towards photodegradation percentages  of dyes. Then it determined the rate and the effectivity of photodegradation of MB and CR dyes using ZnO-Activated Carbon composite. The result showed that  photodegradation of MB reach optimal condition at pH 11 with radiation time 4 hour, whereas CR is at pH 5 with the same radiation time. The more initial concentration of MB and CR applicated, the lower of photodegradation percentages. Constanta of photodegradation rate of MB and CR dyes using ZnO-Activated Carbon composite are 0.8316 and 1.4938 hour-1 respectively. ZnO-Activated Carbon composite as a photocatalyst can degrade effectively MB and CR dyes with photodegradation percentages of 99.40±0.23 % and 99.61±0.24% respectively.

Characteristics of coagulation-flocculation of humic acid with effective performance of polymeric flocculant and inorganic coagulant

2003 ◽  
Vol 47 (1) ◽  
pp. 89-95 ◽  
Author(s):  
J. Yu ◽  
D.D. Sun ◽  
J.H. Tay
Keyword(s):  
Humic Acid ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Molecular Size ◽  
Aluminium Sulphate ◽  
Fouling Control ◽  
Effective Performance ◽  
Water And Wastewater ◽  
Pre Treatment ◽  
Flocculation Process

Ferric chloride and aluminium sulphate as coagulants and positive charged flocculants PDDMAC ((PDDMAC = poly (diallyldimethylammonium chloride) were used for pre-treatment of water and wastewater for removing humic substance prior to RO membrane filtration. It was found that a combination of flocculant and coagulant enhanced the coagulation-flocculation process and humic acid removal. The optimum conditions of coagulation-flocculation were established in reference to the ratio of humic acid and coagulant. Zeta potential and the ratio of E4/E6 were investigated to explore the possible micro-mechanisms of coagulation-flocculation. The ratios of E4/E6 show the molecular size variations using different coagulants and flocculants, which are expected to benefit membrane-fouling control.

scholarly journals Treatment of High-Strength Animal Industrial Wastewater Using Photo-Assisted Fenton Oxidation Coupled to Photocatalytic Technology

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1553 ◽  
Author(s):  
Jae Hong Park ◽  
Dong Seok Shin ◽  
Jae Kwan Lee
Keyword(s):  
Light Intensity ◽  
Removal Efficiency ◽  
Industrial Wastewater ◽  
Uv Light ◽  
High Strength ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Animal Wastewater

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.

scholarly journals Dual-Wavelength (UV and Blue) Controlled Photopolymerization Confinement for 3D-Printing: Modeling and Analysis of Measurements

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1819 ◽  
Author(s):  
Jui-Teng Lin ◽  
Da-Chuan Cheng ◽  
Kuo-Ti Chen ◽  
Hsia-Wei Liu
Keyword(s):  
Light Intensity ◽  
Blue Light ◽  
Uv Light ◽  
Numerical Data ◽  
Coupling Factor ◽  
Dual Wavelength ◽  
Continuous Exposure ◽  
Initiator Concentration ◽  
Modeling And Analysis ◽  
Inhibition Effect

The kinetics and modeling of dual-wavelength (UV and blue) controlled photopolymerization confinement (PC) are presented and measured data are analyzed by analytic formulas and numerical data. The UV-light initiated inhibition effect is strongly monomer-dependent due to different C=C bond rate constants and conversion efficacies. Without the UV-light, for a given blue-light intensity, higher initiator concentration (C10) and rate constant (k’) lead to higher conversion, as also predicted by analytic formulas, in which the total conversion rate (RT) is an increasing function of C1 and k’R, which is proportional to k’[gB1C1]0.5. However, the coupling factor B1 plays a different role that higher B1 leads to higher conversion only in the transient regime; whereas higher B1 leads to lower steady-state conversion. For a fixed initiator concentration C10, higher inhibitor concentration (C20) leads to lower conversion due to a stronger inhibition effect. However, same conversion reduction was found for the same H-factor defined by H0 = [b1C10 − b2C20]. Conversion of blue-only are much higher than that of UV-only and UV-blue combined, in which high C20 results a strong reduction of blue-only-conversion, such that the UV-light serves as the turn-off (trigger) mechanism for the purpose of spatial confirmation within the overlap area of UV and blue light. For example, UV-light controlled methacrylate conversion of a glycidyl dimethacrylate resin is formulated with a tertiary amine co-initiator, and butyl nitrite. The system is subject to a continuous exposure of a blue light, but an on-off exposure of a UV-light. Finally, we developed a theoretical new finding for the criterion of a good material/candidate governed by a double ratio of light-intensity and concentration, [I20C20]/[I10C10].

Temperature and Salinity Effects on Photocatalytic Performance of Cerium Doped Zinc Oxide

2020 ◽  
Vol 307 ◽  
pp. 223-228
Author(s):  
Wan Rafizah Wan Abdullah ◽  
Lee Chia Siang ◽  
Maishara Syazrinni Rooshde ◽  
Mohd Sabri Mohd Ghazali
Keyword(s):  
Photocatalytic Performance ◽  
Catalyst Surface ◽  
Uv Light ◽  
Operating Temperature ◽  
Chloride Ions ◽  
Photocatalytic Efficiency ◽  
Electron Hole ◽  
Doped Zno ◽  
The Stability ◽  
Uv C

Cerium (Ce) doped ZnO is a promising material for advanced photocatalysis. It is useful for inducing the treatment of many organic pollutants in water. However, the stability of its performance under varying temperature and saline condition has never been not fully assessed. In this study, powder form photocatalyst comprising 99.0 mol% ZnO and 1 mol% CeO2 has been synthesized via modified citrate gelation technique and solid-state sintering at 1200 °C for 5 hours. The conversion of Ce doped ZnO from its precursors has been confirmed using XRD, SEM, and EDX techniques. The photocatalytic efficiency of the synthesized Ce doped ZnO under UV-C light (λ=265 nm) was determined. In the experiment, the operating temperature was varied between 25 to 40 °C, and the salinity of the treated solution was increased from 0 to 40 g/L NaCl. The findings revealed that the photocatalytic efficiency of Ce doped ZnO under UV light improved from 78.2% to 88.6% as the temperature increased from 25 to 40 °C. The performance of Ce doped ZnO decreased from 86.7% to 36.7% when the salinity increased from 0 g/L to 40 g/L. The elevation of temperature encouraged the photogeneration of electron-hole pairs on catalyst surface while the presence of chloride ions in treated medium caused scavenging of hydroxyl radicals or hole.

Kinetic Study of Photoinitiated Frontal Polymerization. Influence of UV Light Intensity Variations on the Conversion Profiles

2010 ◽  
Vol 43 (1) ◽  
pp. 177-184 ◽  
Author(s):  
N. Hayki ◽  
L. Lecamp ◽  
N. Désilles ◽  
P. Lebaudy
Keyword(s):  
Light Intensity ◽  
Kinetic Study ◽  
Uv Light ◽  
Frontal Polymerization
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