Multi-wave UV-photocatalysis system (UVA+UVC+VUV/Cu-N-TiO2) for efficient inactivation of microorganisms in ballast water

2021 ◽  
Vol 11 (9) ◽  
pp. 1608-1614
Author(s):  
Zheng Lu ◽  
Yinhao Wang ◽  
Shun Zhang ◽  
Kun Zhang ◽  
Yue Shi ◽  
...  
Keyword(s):  
Water Treatment ◽  
Ballast Water ◽  
Uv Light ◽  
Catalyst Activity ◽  
Treatment System ◽  
Light Quantum ◽  
Hydraulic Residence Time ◽  
Water Treatment System ◽  
Ballast Water Treatment ◽  
Microorganism Inactivation

Ballast Water Treatment System (BWTS) is a system designed to remove biological organisms from ballast water. However, the existing BWTSs often have problems in practical applications. In this study, a multiwave ultraviolet (UV)-modified TiO2 photocatalyst biological inactivation system (longwave UV, UVA+shortwave UV, UVC+vacuum UV, VUV/Cu-N-TiO2) for microorganism inactivation in ballast water was established. The results showed that the UVA+UVC+VUV/Cu-N-TiO2 system improved the UV light quantum yield and catalyst activity in the photocatalytic reaction and fully utilized the synergistic inactivation effect of Cu-N-TiO2 photocatalyst+ multiwave UV light (UVA, UVC, and VUV) on microorganisms. Compared with 8 other photocatalytic systems, the logarithmic algae removal rate and logarithmic sterilization rate of the UVA+UVC+VUV/Cu-N-TiO2 system increased to 1.78 log and 5.86 log, respectively. The turbidity of the seawater affected the microorganism inactivation to a certain extent. The humic acid concentration should be controlled below 2 mg L−1 for the UVA+UVC+VUV/Cu-N-TiO2 system to inactivate microalgae more effectively. The multiwave UV photocatalytic system could significantly increase the lipid peroxidation products in microbial cells, rapidly reduce superoxide dismutase (SOD) activity, and degrade a large amount of chlorophyll within a short hydraulic residence time (HRT). Severe damage to the microbial cell membrane can destroy the normal functions of cells, resulting in the death of microorganisms. In conclusion, the UVA+UVC+VUV/Cu-N-TiO2 system is a potential new ballast water treatment system.

scholarly journals ATP assay for rapid onboard testing to detect living microorganisms in Ballast Water

2017 ◽  
Author(s):  
Seungshic Yum ◽  
Bong Gil Hyun ◽  
Kitae Rhie ◽  
Kyoungsoon Shin
Keyword(s):  
Water Management ◽  
Water Treatment ◽  
Cell Volume ◽  
Ballast Water ◽  
Treatment System ◽  
Diatom Species ◽  
Water Treatment System ◽  
Atp Assay ◽  
Ballast Water Treatment ◽  
Ballast Water Management

Rapid and simple analytical methods for viable microorganism detection in ballast water are required to evaluate the efficiency of ballast water treatment system. During the course of systematic investigation of the cytotoxicity and apoptosis assays, it was found that the adenosine triphosphate (ATP) and luminescence based cell viability assay, in other word, an ATP assay was the most sensitive and applicable to ballast water management (BWM). The assay was applied to cultured microalgae samples, and it could detect the existence of 5 viable cells in 100 μl. Comparably low luminescent values were detected in two cultured diatom species than in cultured dinoflagellates. This result might be caused by the small cell volume in diatom species. Following a regression model between ATP concentration and cell volume, an ATP guideline (876 – 109246 relative luminescence units: RLU) was developed for the evaluation of treated ballast water. ATP assay was also applied to the evaluation of ballast water treatment system (BWTS). The luminescence value which obtained from the ATP assay also showed a good correlation with the presence of living natural plankton cells with comparably low luminescence values than the cultured species. The low ATP concentration in natural plankton cells may reflect a decline in their biological activity because of extended exposure to dark conditions. ATP assay could be a suitable method for the monitoring of ballast water management compliance even though the results of this study need further validation.

The Experimental Study on the UV Ballast Water Treatment System

2014 ◽  
Vol 1010-1012 ◽  
pp. 704-707 ◽  
Author(s):  
Jing Ming Dong ◽  
Shao Long Yang ◽  
Jin Yang Sun ◽  
Xin Xiang Pan
Keyword(s):  
Escherichia Coli ◽  
Experimental Study ◽  
Water Treatment ◽  
Ballast Water ◽  
Treatment System ◽  
Test Results ◽  
Water Treatment System ◽  
Ballast Water Treatment ◽  
Test Organisms ◽  
Circulation Volume

A UV ballast water treatment system was built in this paper. Nitzschiaclosteriumminutissima, Dunaliellasalina and Escherichia coli were selected as the test organisms to run the tests. The test results show that the inactivation ratio for the Escherichia colican close to 100%, when using 5UV lamps and the circulation volume was 5m3/h. While the inactivation ratio for the Nitzschiaclosteriumminutissima and Dunaliellasalina were 86.67% and 82.10%respectively. The investigation provides a better understanding of the UV ballast water treatment further.

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