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Potential of microbial growth control in water hydraulic systems by UV‐irradiation and filtration
Author(s) -
Soini Sari M,
Koskinen Kari T,
Vilenius Matti J,
Puhakka Jaakko A
Publication year - 2002
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.656
Subject(s) - filtration (mathematics) , microorganism , biofouling , bacterial growth , chemistry , environmental science , bacteria , hydraulic pressure , pulp and paper industry , hydraulic retention time , environmental engineering , environmental chemistry , effluent , biology , mathematics , engineering , biochemistry , membrane , mechanical engineering , statistics , genetics
Water hydraulic systems use water as a pressure medium and, thus, do not pose such adverse environmental impacts as oil hydraulics. Microbial deterioration of the pressure medium and biofouling of the surfaces restrict the applicability of the water‐based technology. The potential of microbial growth control by UV‐irradiation and filtration was studied in a pilot‐scale water hydraulic system. The UV‐irradiation (25 m Ws cm −2 ) of the pressure medium reduced the total viable counts of bacteria by 1–2 log 10 cfu cm −3 , whereas the total microbial cell numbers and the numbers of surface‐attached microorganisms remained unaffected. Prefiltration (1.2 µm, absolute) of the pressure medium decreased the total microbial cell number in the water phase and retarded the attachment of bacteria. The filtration during the operation (2 µm, absolute) decreased the total numbers of microbial cells and the total viable counts in the pressure medium, and microbial attachment on the surfaces. Microbial attachment was not prevented by filtration. The microbial water quality obtained by pre‐ and on‐line filtration of the pressure medium was sufficient to ensure the long‐term operation of the water hydraulic system assuming that clean work practices are complied with in assembly and during the operation. © 2002 Society of Chemical Industry