Study on Marine Bacteria Inactivation by UV Radiation Combined with Multi-pore Ceramic Filtration

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Manxia Zhang ◽  
Xiaojia Tang ◽  
Xiaomei Wu ◽  
Na Li ◽  
Ran Yu ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Marine Bacteria ◽  
Transmission Rate ◽  
Economic Feasibility ◽  
Uv Treatment ◽  
Experimental Conditions ◽  
Bacteria Inactivation ◽  
Low Efficiency ◽  
Uv Dose ◽  
Ceramic Filtration

AbstractUV is one of well-established ways to deal with bacteria in water. However, when applying on marine bacterium inactivation in ballast water, it shows low efficiency due to the existence of large amounts of plankton. To recover high transmission rate of seawater, plankton are required to be removed before UV radiation. Considering technical and economic feasibility, a novel method of multi-pore ceramic filtration (MPCF) is used as a primary treatment before UV radiation. The study compared UV treatment with MPCF & UV treatment at different flow rates and alga concentrations. The results showed that less than 40% marine bacteria can be inactivated by single UV radiation for the existence of large amounts of algae, while up to 100% inactivation rates were observed by MPCF & UV treatment at high alga concentration. According to the results of orthogonal tests, optimal experimental conditions including UV dose were detected. With the combination of MPCF, lethal UV dose for marine bacteria inactivation can reduce to 8 mW·s·cm

Micro-pore Ceramic Filter and UV System as Ballast Water Treatment: Preliminary Study on Chlorella Removal and Bacteria Inactivation

2008 ◽  
Vol 11 (1) ◽  
Author(s):  
Manxia Zhang ◽  
Ningwei Xu ◽  
Chang li Li ◽  
Yatong Wang ◽  
Yimin Zhu
Keyword(s):  
Water Treatment ◽  
Uv Radiation ◽  
Ballast Water ◽  
Ceramic Filter ◽  
Flow Rates ◽  
Bacteria Inactivation ◽  
Combination System ◽  
Ballast Water Treatment ◽  
Preliminary Study ◽  
Ceramic Filtration

AbstractA combination system of micro-pore ceramic filtration and UV radiation was built up for ballast water treatment. Two treatment methods, single micro-pore ceramic filtration and micro-pore filtration and UV radiation, were studied in the research, respectively. Chlorella removal rates and total oceanic bacteria inactivation rates were measured at different flow rates (0.6 ~ 4.7 m

scholarly journals INFLUENCE OF UV RADIATION ON THE TRANSFORMATION OF MONOAND DICHLORAMINES IN WATER OF SWIMMING POOLS IN FULL-SCALE TESTS AND IN THE EXPERIMENT

2020 ◽  
Vol 99 (3) ◽  
pp. 230-234
Author(s):  
Zoya I. Zholdakova ◽  
Yana I. Lebed-Sharlevich ◽  
Nadezda I. Belyaeva ◽  
Roman A. Mamonov
Keyword(s):  
Uv Radiation ◽  
Active Chlorine ◽  
Swimming Pools ◽  
Subsequent Reaction ◽  
Uv Treatment ◽  
Pool Water ◽  
Before And After ◽  
Aquarium Water ◽  
Uv Dose ◽  
Full Scale Tests

Introduction. The use of chlorine-containing reagents for disinfection of water in swimming pools may lead to the formation of chloramines, both worsening the organoleptic properties of water and affecting the health of swimmers. To reduce the content of chloramines in pool water, UV radiation can be used. The aim of work is investigation of the effect of UV radiation on the transformation of mono- and dichloramines in water. Material and methods. The study was conducted on water samples from children’s pools, as well as in a model experiment on aquarium water with sodium hypochlorite added. Samples were irradiated with ultraviolet at doses of 40, 80 and 120 mJ/cm2. Before and after UV treatment, the content of chloramines was determined in all samples. Results. UV dose 40 mJ/cm2 was found to be insufficient for the destruction of mono- and dichloramine in water. During UV treatment with a dose 80 mJ/cm2 a decrease in the content of monochloramines and an increase in the content of dichloramines were observed. These processes were depended on the initial concentration of active chlorine in the samples. Conclusion. Thus, an effective UV dose to reduce the concentration of monochloramines in water with a concentration of active chlorine of 0.5 mg/l is 80 mJ/cm2. However, standard UV equipment used for disinfection of pool water cannot guarantee a reduction of chloramine concentration as it is usually designed for the minimum required UV dose (25-40 mJ/cm2). In addition, the effect of UV at this dose on water with a high content of active chlorine led to a significant increase in the content of dichloramines, which is supposedly associated with the destruction of proteins in water under the influence of UV radiation and the subsequent reaction of amino acids with active chlorine.

Influence of UV radiation on the transformation of mono- and dichloramines in water of swimming pools in full-scale tests and in the experiment

2020 ◽  
Vol 99 (3) ◽  
pp. 230-234
Author(s):  
З.И. I. Жолдакова ◽  
Яна Ивановна Лебедь-Шарлевич ◽  
Н.И. I. Беляева ◽  
Р.А. A. Мамонов
Keyword(s):  
Uv Radiation ◽  
Active Chlorine ◽  
Swimming Pools ◽  
Subsequent Reaction ◽  
Uv Treatment ◽  
Pool Water ◽  
Before And After ◽  
Aquarium Water ◽  
Uv Dose ◽  
Full Scale Tests

Introduction. The use of chlorine-containing reagents for disinfection of water in swimming pools may lead to the formation of chloramines, both worsening the organoleptic properties of water and affecting the health of swimmers. To reduce the content of chloramines in pool water, UV radiation can be used. The aim of work is investigation of the effect of UV radiation on the transformation of mono- and dichloramines in water. Material and methods. The study was conducted on water samples from children’s pools, as well as in a model experiment on aquarium water with sodium hypochlorite added. Samples were irradiated with ultraviolet at doses of 40, 80 and 120 mJ/cm2. Before and after UV treatment, the content of chloramines was determined in all samples. Results. UV dose 40 mJ/cm2 was found to be insufficient for the destruction of mono- and dichloramine in water. During UV treatment with a dose 80 mJ/cm2 a decrease in the content of monochloramines and an increase in the content of dichloramines were observed. These processes were depended on the initial concentration of active chlorine in the samples. Conclusion. Thus, an effective UV dose to reduce the concentration of monochloramines in water with a concentration of active chlorine of 0.5 mg/l is 80 mJ/cm2. However, standard UV equipment used for disinfection of pool water cannot guarantee a reduction of chloramine concentration as it is usually designed for the minimum required UV dose (25-40 mJ/cm2). In addition, the effect of UV at this dose on water with a high content of active chlorine led to a significant increase in the content of dichloramines, which is supposedly associated with the destruction of proteins in water under the influence of UV radiation and the subsequent reaction of amino acids with active chlorine.

UV Irradiation of Shell Eggs: Effect on Populations of Aerobes, Molds, and Inoculated Salmonella typhimurium

1997 ◽  
Vol 60 (6) ◽  
pp. 639-643 ◽  
Author(s):  
FUENG-LIN KUO ◽  
JOHN B. CAREY ◽  
STEVEN C. RICKE
Keyword(s):  
Salmonella Typhimurium ◽  
Uv Radiation ◽  
Uv Light ◽  
The Other ◽  
Uv Exposure ◽  
Microbial Populations ◽  
Aerobic Bacteria ◽  
Fluorescent Light ◽  
Uv Treatment ◽  
Shell Eggs

The effects were investigated of 254-nm UV radiation on populations of Salmonella typhimurium, aerobes, and molds on the shells of eggs. In the first experiment, the CFU of attached S. typhimurium cells on unwashed clean shell eggs were determined after 0, 1, 3, 5, and 7 min of UV treatment (620 μW/cm2) on both ends of the egg. All UV treatments significantly reduced S. typhimurium CFU (P < .01). UVtreatment (620 μW/cm2) in 1-min alternating light and dark cycles for 5 min (three light and two dark) was compared to 0, 3, and 5 min of UV treatment. No significant differences in microbial populations were observed among light and dark cycles and the other UV treatments. In a subsequent experiment, the same UV treatments were utilized to evaluate photoreactivation. After UV exposure, eggs were exposed to 1 h of fluorescent light or I h of darkness or cultured immediately. S. typhimurium CFU were significantly (P < .01) reduced by the UV treatments. However, no significant differences between microbial populations exposed to UV treatment and UV radiation plus photoreactivation were detected. For studies of aerobic bacteria and molds, different UV treatment times (0, 15, and 30 min) at the intensity of 620 μW/cm2 and different intensities (620, 1350, and 1720 μW/cm2) for 15 min were evaluated. Mold CFU per egg were either 0 or 1 for all UV treatments and a 99% reduction of CFU of aerobic bacteria per egg were observed for all UV treatments. It appears from these studies that UV light can significantly reduce populations of S. typhimurium, aerobes, and molds on shell eggs.

scholarly journals Effectiveness of a New Drainage System for Decreasing Erosion in Road Hillslopes

2021 ◽  
Vol 14 ◽  
pp. 117862212098872
Author(s):  
María Fernández-Raga ◽  
Iván García-Díez ◽  
Julian Campo ◽  
Julio Viejo ◽  
Covadonga Palencia
Keyword(s):  
Service Life ◽  
Drainage System ◽  
Economic Feasibility ◽  
Scale Model ◽  
Maintenance Cost ◽  
Road Maintenance ◽  
Experimental Conditions ◽  
Traditional System ◽  
Strategic Value ◽  
On The Road

Water is one of the most important erosive agents in roadside hillslopes. When these are built with ineffective drainage systems, erosion occurs, reducing road’s service life. However, these systems are not receiving the appropriate importance, given their strategic value. Therefore, a new drainage system called ‘branched’ is proposed in this study. Its technical and economic feasibility is compared with those of the traditional system, which consists of drainages with lines that follow maximum hillslope, to assess differences in relation to erosion, construction and maintenance costs, and service life. Different parameters were analysed, such as the average velocity of water (mm−1) running through the channels, its average specific energy (kJ), and its drag force (N). A scale model was constructed and used to test these factors before implementing it in natural terrain for testing it under field conditions. According to the theoretical and measured results, these factors were lower in the branched drainage than in the traditional one (from 24% to 34% in speed, from 37% to 60% in energy, and from 51% to 73% in force). The service life of hillslopes with a branched system of up to 0.5 m high and 1:2 grade is significantly longer than in those with a traditional drainage. Although the initial economic expense for the construction of the branched system is higher (€3534/m3 as opposed to €2930/m3 for the traditional one), its maintenance cost will be lower than the traditional one (€1230/m3 per year for the branched one as opposed to €1332/m3 per year for the traditional one). Consequently, under our experimental conditions, the proposed drainage will be profitable from the eighth year of construction, saving on the road maintenance in the following 15 years of service life.

scholarly journals Application of Bar Adsorptive Microextraction for the Determination of Levels of Tricyclic Antidepressants in Urine Samples

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3101
Author(s):  
Mariana N. Oliveira ◽  
Oriana C. Gonçalves ◽  
Samir M. Ahmad ◽  
Jaderson K. Schneider ◽  
Laiza C. Krause ◽  
...  
Keyword(s):  
Tricyclic Antidepressants ◽  
Matrix Effects ◽  
Activated Carbons ◽  
Process Efficiency ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Low Efficiency

This work entailed the development, optimization, validation, and application of a novel analytical approach, using the bar adsorptive microextraction technique (BAμE), for the determination of the six most common tricyclic antidepressants (TCAs; amitriptyline, mianserin, trimipramine, imipramine, mirtazapine and dosulepin) in urine matrices. To achieve this goal, we employed, for the first time, new generation microextraction devices coated with convenient sorbent phases, polymers and novel activated carbons prepared from biomaterial waste, in combination with large-volume-injection gas chromatography-mass spectrometry operating in selected-ion monitoring mode (LVI-GC-MS(SIM)). Preliminary assays on sorbent coatings, showed that the polymeric phases present a much more effective performance, as the tested biosorbents exhibited low efficiency for application in microextraction techniques. By using BAμE coated with C18 polymer, under optimized experimental conditions, the detection limits achieved for the six TCAs ranged from 0.2 to 1.6 μg L−1 and, weighted linear regressions resulted in remarkable linearity (r2 > 0.9960) between 10.0 and 1000.0 μg L−1. The developed analytical methodology (BAμE(C18)/LVI-GC-MS(SIM)) provided suitable matrix effects (90.2–112.9%, RSD ≤ 13.9%), high recovery yields (92.3–111.5%, RSD ≤ 12.3%) and a remarkable overall process efficiency (ranging from 84.9% to 124.3%, RSD ≤ 13.9%). The developed and validated methodology was successfully applied for screening the six TCAs in real urine matrices. The proposed analytical methodology proved to be an eco-user-friendly approach to monitor trace levels of TCAs in complex urine matrices and an outstanding analytical alternative in comparison with other microextraction-based techniques.

Multiple Keratoacanthomas Arising Post-UVB Therapy

2004 ◽  
Vol 8 (4) ◽  
pp. 239-243 ◽  
Author(s):  
Kenneth J. Craddock ◽  
Jaggi Rao ◽  
Gilles J. Lauzon ◽  
Victor A. Tron
Keyword(s):  
Adverse Effect ◽  
Squamous Cell Carcinoma ◽  
Skin Cancer ◽  
Cell Carcinoma ◽  
Uv Radiation ◽  
Squamous Cell ◽  
Etiologic Agent ◽  
Etiologic Factor ◽  
Uv Treatment ◽  
Uvb Phototherapy

Background: Ultraviolet (UV) radiation is known to be an important etiologic agent in the development of skin cancer. Keratoacanthoma is an unusual, well-described cutaneous neoplasm that resembes squamous cell carcinoma but spontaneously resolves. Rarely, multiple keratoacanthomas may develop. Objective We present a case of multiple keratoacanthomas in a patient with psoriasis who had received UVB phototherapy. These lesions were hyperkeratotic papules, many of which spontaneously resolved and demonstrated the histologic characteristics of keratoacanthoma. Conclusion: We believe that UV radiation is the most likely etiologic factor in this patient's development of multiple keratoacanthomas. We wish to bring to the attention of clinicians this unusual adverse effect of UV treatment.

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