scholarly journals Disinfection of roof harvested rainwater for potable purpose using pilot-scale solar photocatalytic fixed bed tubular reactor

2017 ◽  
Vol 18 (1) ◽  
pp. 49-59 ◽  
Author(s):  
S. Saran ◽  
P. Arunkumar ◽  
S. P. Devipriya
Keyword(s):  
Tap Water ◽  
Sol Gel ◽  
Fixed Bed ◽  
Tubular Reactor ◽  
Oxygen Demand ◽  
Drinking Water Treatment ◽  
Silver Ions ◽  
Pilot Scale ◽  
Pure Tio2 ◽  
Solar Irradiation

Abstract The potable use of harvested rainwater is limited, mainly due to contamination with various pathogenic microorganisms. Disinfection of microorganisms by solar photocatalysis is emerging as a promising technique for drinking water treatment. The present study deals with the preparation of Ag-doped TiO2 by the sol gel method, and its immobilization over the inner surface of the Pyrex glass pipes used in fabrication of pilot-scale reactors. The solar photocatalytic efficiency of the reactors was tested for the disinfection of microorganisms in tap water and roof harvested rainwater. The photocatalytic experiments under solar irradiation illustrate that doping with silver ions significantly increases the inactivation rate of all microorganisms compared with pure TiO2 and direct photolysis. The inactivation efficiency against various microorganisms was found in the following decreasing order: E. coli>MS-2 phage>Aspergillus spores. The roof harvested rainwater was completely disinfected in addition to chemical oxygen demand (COD) removal, within 120 minutes of solar irradiation. The experimental cycle was repeated several times to study the stability of the reactor. The pilot-scale solar photocatalytic fixed bed tubular reactors were found to be very effective for the disinfection of rainwater for potable use.

Treatment of winery wastewaters in a membrane submerged bioreactor

2007 ◽  
Vol 56 (2) ◽  
pp. 63-69 ◽  
Author(s):  
P. Artiga ◽  
M. Carballa ◽  
J.M. Garrido ◽  
R. Méndez
Keyword(s):  
Tap Water ◽  
Oxygen Demand ◽  
Biomass Concentration ◽  
Pilot Scale ◽  
White Wine ◽  
Hollow Fibre ◽  
Organic Loading Rate ◽  
Wine Production ◽  
Solids Concentration ◽  
Start Up

Wine production is seasonal, and thus the wastewater flow and its chemical oxygen demand (COD) concentrations greatly vary during the vintage and non-vintage periods, as well as being dependant on the winemaking technologies used, e.g. red, white or special wines production. Due to this seasonal high variability in terms of organic matter load, the use of membrane biological reactors (MBR) could be suitable for the treatment of such wastewaters. MBR offers several benefits, such as rapid start up, good effluent quality, low footprint area, absence of voluminous secondary settler and its operation is not affected by the settling properties of the sludge. A pilot scale hollow fibre MBR system of 220 L was fed by adequately diluting white wine with tap water, simulating wastewaters generated in wineries. The COD in the influent ranged between 1,000 and 4,000 mg/L. In less than 10 days after the start up, the system showed a good COD removal efficiency. The COD elimination percentage was always higher than 97% regardless of the organic loading rate (OLR) applied (0.5–2.2 kg COD/m3 d), with COD concentrations in the effluent ranging between 20 and 100 mg/L. Although the biomass concentration in the reactor increased from 0.5 to 8.6 g VSS/L, the suspended solids concentration in the effluent was negligible. Apparent biomass yield was estimated in 0.14 g VSS/g COD.

scholarly journals Intensification of Dihydroxybenzenes Degradation over Immobilized TiO2 Based Photocatalysts under Simulated Solar Light

2020 ◽  
Vol 10 (21) ◽  
pp. 7571
Author(s):  
Szymon Malinowski ◽  
Ivana Presečki ◽  
Igor Jajčinović ◽  
Ivan Brnardić ◽  
Vilko Mandić ◽  
...  
Keyword(s):  
Large Scale ◽  
Kinetic Modelling ◽  
Tubular Reactor ◽  
Reactor Design ◽  
Pilot Scale ◽  
Pure Tio2 ◽  
Simulated Solar Light ◽  
Film Formulation ◽  
Parabolic Collector ◽  
Photocatalytic Films

The work is focused on the assessment of possible methods for intensification of photocatalytic degradation of common water borne pollutants. Solar photocatalysis poses certain limitations for large scale application with several possible reactor designs which have shown an optimal performance. In the current study, a comparison between two types of pilot scale reactors was made: a flat-plate cascade reactor (FPCR) and tubular reactor with a compound parabolic collector (CPC). Apart from the reactor design, another aspect of possible intensification was a photocatalyst formulation. The efficiency of photocatalytic films that consisted of pure TiO2 nanoparticles was compared to the efficiency of films that consisted of TiO2/CNT composites. Intensification assessment was performed via detailed kinetic modelling, combining the optical properties of films, irradiation conditions and reactor mass balance. Intensification was expressed via intensification indices. Results showed the advantage of the CPC-based reactor design and an unbiased effect of sensitizing agent (CNT) in the photocatalytic film formulation.

Comparison on Permanganate and Ozone as Pre-Oxidation Agents

2014 ◽  
Vol 955-959 ◽  
pp. 3408-3413 ◽  
Author(s):  
Hong Wei Sun
Keyword(s):  
Drinking Water ◽  
Treatment Process ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Turbidity Removal ◽  
Trihalomethane Formation Potential ◽  
Water Treatment Process ◽  
Oxidation Reactor

Comparative study on permanganate and ozone as pre-oxidation agents were performed on pilot scale with traditional drinking water treatment process, chemical oxygen demand (COD), total organic carbon (TOC), UV254, turbidity, trihalomethane formation potential (THMFP) were examined at each reactor’s effluent. The results show that at pre-oxidation reactor, the total organic remained stable after by the two agents, while for UV254, pre-ozonation has a removal rate of 34%, comparing that of 17% by permanganate. At the sedimentation process, 0.4 mg/L permanganate improves the removal rate of turbidity and COD by 0.99 % and 8.4%, respectively; while a positive COD removal of 11.8 % was achieved by 0.9 mg/L pre-ozonation, and an average of-10.08% turbidity removal was achieved at applied dosage (0.5, 0,9 and 1.5 mg/L), which can be made up for in the followed sand filtration reactor. Both permanganate and pre-ozonation show higher removal rate of THMFP for the finished water.

Study on the Solar Photocatalytic Degradation Characteristics of Phenol by the Double-Skin Sheet Reactor with Immobilized Catalyst

2011 ◽  
Vol 374-377 ◽  
pp. 859-864
Author(s):  
Jie Rui Li ◽  
Shao Hua Lin ◽  
Zong Liang Gu
Keyword(s):  
High Efficiency ◽  
Tap Water ◽  
Sol Gel ◽  
Drinking Water Treatment ◽  
Main Body ◽  
First Order ◽  
Immobilized Catalyst ◽  
New Type ◽  
Double Skin ◽  
Apparent Reaction Rate

A new type of a non-light concentrating solar photoreactor with immobilized catalyst was developed, where a flat and transparent structured box made of polymethylmethacrylate comprised the main body, and immobilized TiO2 membrane supported on glass fiber net with sol-gel method was used as catalyst. Phenol was used as model pollutant to evaluating the device performance. The limitation of mass transfer was diminished when the circular flux exceeded 2L/min. The apparent reaction kinetics was first order with respect to the phenol concentration, and the apparent kinetic constants decreased with the increase of initial concentration. The linear dependence between apparent reaction rate and radiation density flux was found from 12.8 to 47.6 W/m2. The new reactor, which treated phenol in tap water with high efficiency, has a promising prospective in real drinking water treatment.

Preparation and Characterization of Photocatalytic TiO2/CdS Nanocomposite Loaded on Multi-Walled Carbon Nanotues (MWCNTs)

2012 ◽  
Vol 184-185 ◽  
pp. 1114-1119
Author(s):  
Ou Yang Ke ◽  
Xie Shan ◽  
Xiao Ou Ma
Keyword(s):  
Sol Gel ◽  
Pure Tio2 ◽  
Anatase Tio2 ◽  
Solar Irradiation ◽  
Simulated Solar Light ◽  
Solar Light Irradiation ◽  
Cubic Phases ◽  
Composite Photocatalysts ◽  
Simulated Solar Irradiation

Multi-walled carbon nanotues (MWCNTs)/TiO2/CdS composite photocatalysts were prepared by sol–gel method in order to investigate its photocatalytic activity under simulated solar irradiation. MWCNTs/TiO2/CdS composite photocatalysts were characterized by the methods of SEM, XRD, TG and UV–vis. The results showed that MWCNTs/TiO2/CdS composites were mainly composed of anatase-TiO2 and little CdS cubic phases. the composite can cause an pronounced red shift of UV–vis spectra compared with pure TiO2. The degradation of MO by MWCNTs/TiO2/CdS composite photocatalysts under simulated solar light irradiation was studied. The results showd that the presence of MWCNTs and CdS can enhance the photoefficiency of TiO2.

APLIKASI PROSES DIGESTASI ANAEROBIK LUMPUR BIOLOGI INSTALASI PENGOLAHAN AIR LIMBAH INDUSTRI KERTAS

2014 ◽  
Vol 4 (02) ◽  
Author(s):  
Rina S. Soetopo ◽  
Sri Purwati ◽  
Henggar Hardiani ◽  
Mukharomah Nur Aini ◽  
Krisna Adhitya Wardhana
Keyword(s):  
Oxygen Demand ◽  
Total Solid ◽  
Pilot Scale ◽  
Organic Content ◽  
Solid Content ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Total Solid Content ◽  
Average Value

A continuous pilot scale study has been conducted to investigate the effectiveness of anaerobic digestion of biological sludge. The sludge has a total solid content of 0.53% - 1.1%, pH of 7.20 to 7.32. Its organic content is about 97 %, The research were conducted in two stages, which are acidification (performed in 3 m3 the Continously Stirred Tank Reactor/CSTR at pH of 5.5 to 6.0) and methanation (performed in 5 m3 the Up Flow Anaerobic Sludge Blanket/UASB reactor at pH 6.5 to 7.0). The retention time (RT) was gradually shortened from 6 days to 1 day for acidification and from 8 days to 2 days for methanation. The results showed that operating the CSTR at the RT of 1 day and the organic loading of 8.23 g Volatile Solid (VS)/m3.day could produce Volatile Fatty Acid (VFA) at an average value of 17.3 g/kg VS.day. Operating the UASB reactor at the RT of 2 days and the organic loading (Chemical Oxygen Demand/COD) of 2.4 kg COD/m3.day could produce biogas at an average value of 66.3 L/day, with an average methane content of 69.9%, methane rate of 0.17 L CH4/g COD reduction or 19.06 L CH4/kg VS. Furthermore, methanation could reduce COD at an average value of 51.2 %, resulting in the effluent average value of COD filtrate and COD total of 210.1 mg/L and 375.2 mg /L, respectively.Keywords: acidification, methanation, CSTR, UASB, biogas ABSTRAKPercobaan digestasi anaerobik lumpur IPAL biologi industri kertas secara kontinyu skala pilot telah dilakukan di industri kertas dengan tujuan mengkaji efektivitas proses digestasi anaerobik dalam mengolah lumpur tersebut. Lumpur yang digunakan memiliki total solids sekitar 0,53% – 1,1%, pH netral (7,20 – 7,32) dengan komponen utama senyawa organik sekitar 97%. Percobaan dilakukan dalam dua tahap yaitu asidifikasi dalam reaktor CSTR berkapasitas 3 m3 pada pH 5,5 – 6,0 dan metanasi dalam reaktor UASB berkapasitas 5 m3 pada pH 6,5 – 7,0. Percobaan dilakukan dengan waktu retensi yang dipersingkat secara bertahap dari 6 hari ke 1 hari untuk proses asidifikasi dan dari 8 hari ke 2 hari untuk proses metanasi. Hasil percobaan menunjukkan bahwa pengoperasian reaktor CSTR dengan waktu retensi 1 hari dan beban organik 8,3 g VS/m3.hari dapat menghasilkan VFA rata-rata 17,3 g/kg VS.hari dengan kisaran 8,36 – 30,59 g/kg VS.hari, sedangkan pengoperasian reaktor UASB pada waktu retensi 2 hari dan beban organik 2,4 kg COD/m3.hari dapat menghasilkan biogas rata-rata 66,3 L/hari dengan kadar metana rata-rata 69,9% atau 0,17 L CH4/g COD reduksi atau 19,06 L CH4/kg VS. Selain itu proses metanasi dapat menurunkan COD terlarut rata-rata 51,2%, dengan konsentrasi efluen COD terlarut  rata-rata 210,1 mg/L dan COD total rata-rata 375,2 mg/L.Kata kunci: asidifikasi, metanasi, CSTR, UASB, biogas

scholarly journals Enhanced Photocatalytic Activity of CuWO4 Doped TiO2 Photocatalyst Towards Carbamazepine Removal under UV Irradiation

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Component Part ◽  
Energy Yield ◽  
Mechanical Agitation ◽  
X Ray

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.

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