Solar disinfection for the post-treatment of greywater by means of a continuous flow reactor

2011 ◽  
Vol 64 (5) ◽  
pp. 1178-1185 ◽  
Author(s):  
Natália Pansonato ◽  
Marcos V. G. Afonso ◽  
Carlos A. Salles ◽  
Marc Á. Boncz ◽  
Paula L. Paulo
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Low Cost ◽  
Pilot Scale ◽  
Batch Mode ◽  
Total Coliforms ◽  
Solar Disinfection ◽  
E Coli ◽  
Pet Bottles ◽  
Solar Radiation Intensity

SODIS (solar disinfection) is a low-cost alternative for water decontamination. The method is based on the exposure of water, contained in PET bottles, to direct sunlight, and mainly its UV-A and infrared components. The present research studied SODIS as a low cost alternative for the inactivation of Escherichia coli (E. coli) in treated greywater, aiming at its reuse for more noble applications. Experiments were performed in (i) batch mode (2 L PET-bottles), testing the effect of turbidity on system efficiency and, (ii) in a continuous pilot-scale reactor prototype (51 L, using interconnected 2 L-PET bottles), testing hydraulic retention times (HRT) of 18 and 24 h. Samples were exposed to an average solar radiation intensity of 518 W/m2. The results obtained indicate that the SODIS system has potential for total coliforms and E. coli inactivation in the pre-treated greywater, reaching 2.1 log units E. coli inactivation in batch experiments for low turbidity samples (21 NTU), and >2 log units inactivation of total coliforms (and E. coli, when present) for the 24 h HRT-continuous prototype. The continuous flow prototype needs more testing and structural improvements to cope with the difficulties posed by algae growth, as they complicate maintaining conditions of constant flow and make frequent maintenance inevitable.

Solar Disinfection Kinetic Design Parameters for Continuous Flow Reactors

2005 ◽  
Vol 129 (1) ◽  
pp. 111-118 ◽  
Author(s):  
Laurence W. Gill ◽  
Orlaith A. McLoughlin
Keyword(s):  
Continuous Flow ◽  
Flow Reactor ◽  
Design Parameters ◽  
Small Scale ◽  
Inactivation Kinetics ◽  
Flow Reactors ◽  
Solar Disinfection ◽  
E Coli ◽  
Continuous Flow Reactors ◽  
K 12

The main UV dose-related kinetic parameters influencing solar disinfection have been investigated for the design of a continuous flow reactor suitable for a village-scale water treatment system. The sensitivities of different pathogenic microorganisms under solar light in batch processes have been compared in order to define their relative disinfection kinetics with E. coli used as a baseline organism. Dose inactivation kinetics have been calculated for small scale disinfection systems operating under different conditions such as reflector type, flow rate, process type, photocatalytic enhancement, and temperature enhancement using E. coli K-12 as a model bacterium. Solar disinfection was shown to be successful in all experiments with a slight improvement in the disinfection kinetic found when a fixed TiO2 photocatalyst was placed in the reactor. There was also evidence that the photocatalytic mechanism prevented regrowth in the post-irradiation environment. A definite synergistic solar UV∕temperature effect was noticed at a temperature of 45°C. The disinfection kinetics for E. coli in continuous flow reactors have been investigated with respect to various reflector shapes and flow regimes by carrying out a series of experiments under natural sunlight. Finally, photocatalytic and temperature enhancements to the continuous flow process have been evaluated.

Bio-crude oil from hydrothermal liquefaction of wastewater microalgae in a pilot-scale continuous flow reactor

2019 ◽  
Vol 294 ◽  
pp. 122184 ◽  
Author(s):  
Feng Cheng ◽  
Jacqueline M. Jarvis ◽  
Jiuling Yu ◽  
Umakanta Jena ◽  
Nagamany Nirmalakhandan ◽  
...  
Keyword(s):  
Crude Oil ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Pilot Scale ◽  
Hydrothermal Liquefaction ◽  
Continuous Flow Reactor

scholarly journals Performance of three pilot-scale hybrid constructed wetlands for total coliforms and Escherichia coli removal from primary effluent – a 2-year study in a subtropical climate

2014 ◽  
Vol 13 (2) ◽  
pp. 446-458 ◽  
Author(s):  
Florentina Zurita ◽  
Alejandra Carreón-Álvarez
Keyword(s):  
Escherichia Coli ◽  
Constructed Wetlands ◽  
Pilot Scale ◽  
World Health ◽  
First Year ◽  
Subtropical Climate ◽  
Total Coliforms ◽  
E Coli ◽  
Stage System ◽  
Health Organization

Three pilot-scale two-stage hybrid constructed wetlands were evaluated in order to compare their efficiency for total coliforms (TCol) and Escherichia coli removal and to analyze their performances in two 1-year periods of experimentation. System I consisted of a horizontal flow (HF) constructed wetland (CW) followed by a stabilization pond. System II was also configured with a HF CW as a first stage which was then followed by a vertical flow (VF) CW as a second stage. System III was configured with a VF CW followed by a HF CW. In the first year of evaluation, the HF–VF system was the most effective for TCol removal (p < 0.05) and achieved a reduction of 2.2 log units. With regard to E. coli removal, the HF–VF and VF–HF systems were the most effective (p < 0.05) with average reductions of 3.2 and 3.8 log units, respectively. In the second year, the most effective were those with a VF component for both TCol and E. coli which underwent average reductions of 2.34–2.44 and 3.44–3.74 log units, respectively. The reduction achieved in E. coli densities, in both years, satisfy the World Health Organization guidelines that require a 3–4 log unit pathogen reduction in wastewater treatment systems.

Pilot Scale Two-phase Continuous Flow Biodiesel Production via Novel Laminar Flow Reactor−Separator

2009 ◽  
Vol 23 (5) ◽  
pp. 2750-2756 ◽  
Author(s):  
Matthew B. Boucher ◽  
Clifford Weed ◽  
Nicholas E. Leadbeater ◽  
Benjamin A. Wilhite ◽  
James D. Stuart ◽  
...  
Keyword(s):  
Laminar Flow ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Pilot Scale ◽  
Biodiesel Production ◽  
Two Phase

scholarly journals Fabrication of potable and eco-friendly solar disinfection (sodis) unit and its performance analysis

2021 ◽  
Vol 8 (1) ◽  
pp. 41-50
Author(s):  
Malavika J P ◽  
Shobana C
Keyword(s):  
Drinking Water ◽  
Solar Energy ◽  
Water Samples ◽  
Polluted Water ◽  
Contaminated Water ◽  
Treated Water ◽  
Solar Disinfection ◽  
E Coli ◽  
Pet Bottles ◽  
Disinfection Unit

Solar disinfection (SODIS) is a technique, which involves utilization of solar energy to make safe drinking water from biologically contaminated water. In the conventional SODIS method, the PET bottles are filled with polluted water and exposed to the sunlight for a certain period depending upon the local weather conditions. However much more effective disinfection system is needed to overcome the problems of inefficient utilization of available solar energy and the health risk posed by treating the water using chemicals during the purification process.  Hence, the present work aims in designing a portable solar disinfection unit that can efficiently use solar energy by manually adjusting the unit according to sunlight availability. Along with it, incorporation of the additional eco-friendly unit with water purifying plants Vetiveria zizanioides (Vetiver) and Hemidesmus indicus (Nannari) is done to achieve high efficiency in producing potable water from biologically contaminated water. The contaminated water samples treated in the solar disinfection unit and eco-friendly water purifying unit are analyzed for the presence of total coliforms and E-coli by using the Most probable Number method and P/A analysis, respectively. A reduction in 99.74% of total coliform count and absence of E-coli was observed in the treated water samples.  The physicochemical analysis was carried out to ensure the suitability of treated water for consumption and the results revealed a notable reduction in the parameters, and all the parameters came under the permissible range of IS drinking water characteristics. The designed system can be used to disinfect the contaminated water sample most efficiently, thereby making the water suitable for consumption.

scholarly journals Sanitizing action of triple-strength vinegar against Escherichia coli on lettuce

2018 ◽  
Vol 36 (3) ◽  
pp. 414-418 ◽  
Author(s):  
Giovanna C Souza ◽  
Wilma A Spinosa ◽  
Tereza CRM Oliveira
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Low Cost ◽  
Titratable Acidity ◽  
Total Acidity ◽  
Total Coliforms ◽  
E Coli ◽  
Total Titratable Acidity ◽  
Carcinogenic Effects ◽  
Interesting Alternative

ABSTRACT Vegetable sanitization protocols recommend the use of chlorine, which has adverse effects on the environment and carcinogenic effects on humans. Acetic acid is an interesting alternative to chlorine because it possesses no risk to human health and is widely available in the form of vinegar. This study aimed to evaluate the sanitizing action of vinegar, 130 g L-1 total titratable acidity expressed as acetic acid, on lettuce. Vinegar was chosen because it is a low-cost product widely available in the Brazilian market. The minimum inhibitory concentration and minimum bactericidal concentration of vinegar against Escherichia coli were 2.5 and 15 g L-1 total acidity, respectively. Lettuce leaves artificially contaminated with E. coli or naturally contaminated with total coliforms were washed with water and immersed in vinegar solution (15 g L-1 total acidity) for 15 min. This period was sufficient to reduce E. coli counts in artificially contaminated samples and total coliforms in naturally contaminated samples. There were no visual changes in lettuce leaves, which indicates that vinegar at 15 g L-1 total acidity can be used to sanitize vegetables without affecting their appearance.

scholarly journals Ring-Opening of Epoxides with Amines for Synthesis of β-Amino Alcohols in a Continuous-Flow Biocatalysis System

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1419
Author(s):  
Li-Hua Du ◽  
Miao Xue ◽  
Meng-Jie Yang ◽  
Yue Pan ◽  
Ling-Yan Zheng ◽  
...  
Keyword(s):  
Continuous Flow ◽  
High Efficiency ◽  
Flow Reactor ◽  
Low Cost ◽  
Amino Alcohols ◽  
Thermomyces Lanuginosus ◽  
Synthetic Approach ◽  
Promising Alternative ◽  
Alcohol Synthesis ◽  
Ring Opening Of Epoxides

An efficient method for the preparation of β-amino alcohols catalyzed by lipase TL IM from Thermomyces lanuginosus in a continuous-flow reactor was developed. The eco-friendly biocatalyst combined with continuous-flow reaction technology displayed high efficiency in the synthesis of β-amino alcohols. The benign reaction conditions (35 °C) and short residence time (20 min), together with the use of low cost and readily available starting materials, make this synthetic approach a promising alternative to current β-amino alcohol synthesis.

Effectiveness of solar disinfection (SODIS) in rural coastal Bangladesh

2015 ◽  
Vol 13 (4) ◽  
pp. 1113-1122 ◽  
Author(s):  
Md. Atikul Islam ◽  
Abul Kalam Azad ◽  
Md. Ali Akber ◽  
Masudur Rahman ◽  
Indrojit Sadhu
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Coastal Area ◽  
Rainwater Harvesting ◽  
Low Cost ◽  
Treatment Technology ◽  
Solar Disinfection ◽  
E Coli ◽  
Alternative Water ◽  
Alternative Water Supply

Scarcity of drinking water in the coastal area of Bangladesh compels the inhabitants to be highly dependent on alternative water supply options like rainwater harvesting system (RWHS), pond sand filter (PSF), and rain-feed ponds. Susceptibility of these alternative water supply options to microbial contamination demands a low-cost water treatment technology. This study evaluates the effectiveness of solar disinfection (SODIS) to treat drinking water from available sources in the southwest coastal area of Bangladesh. A total of 50 households from Dacope upazila in Khulna district were selected to investigate the performance of SODIS. Data were collected in two rounds to examine fecal coliform (FC) and Escherichia coli (E. coli) contamination of drinking water at the household water storage containers and SODIS bottles, and thereby determined the effectiveness of SODIS in reducing fecal contamination. All water samples were analyzed for pH, electrical conductivity, turbidity and salinity. SODIS significantly reduced FC and E. coli contamination under household conditions. The median health risk reduction by SODIS was more than 96 and 90% for pond and RWHS, respectively. Besides, turbidity of the treated water was found to be less than 5 NTU, except pond water. Only 34% of the participating households routinely adopted SODIS during the study.

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