Monitoring and control of biological activity in Permasep® seawater RO plants

• Published in: Desalination Vol. 65; pp. 331 - 359
• Main Authors: Applegate, Lynn E., Erkenbrecher, Carl W.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 1987; Elsevier
• Subjects: Applied sciences; Drinking water and swimming-pool water. Desalination; Exact sciences and technology; Marine; Pollution; Water treatment and pollution; Drinking water treatment; Chlorination; Methodology; Desalination; Water quality standard; Surface water; Check; Reverse osmosis; Pretreatment; Biological activity; Seawater
• ISSN: 0011-9164; 1873-4464
• DOI: 10.1016/0011-9164(87)90141-X

For seawater RO plants, biological activity is dependent on site-specific factors such as temperature, organic and inorganic nutrients, pollution and surface water runoff. These site-specific factors are discussed along with the effect of biofouling (accumulation of slime and biomass) on RO performance, proper monitoring techniques for biological activity, pretreatment of source water to control biological fouling, cleaning to remove slime and biomass and procedures for proper storage of RO plants during shutdown to prevent biofouling. Microbiological analyses are used to measure the biological activity. Although numerous microbiological techniques are available for the analysis of water and wastewater, it is critical that the appropriate ones be used for seawater. Clearly, direct microscopy is the best method to measure the biological activity. Routine monitoring of the biological activity must be performed to determine the efficacy of the pretreatment system and to give early indications of any biofouling in the B-10 permeators. Based on the data obtained from routine monitoring, value judgements can be made with respect to operational changes needed in the pretreatment and the need to disinfect and clean the B-10 permeators. The biological activity in Permasep® B-10 seawater permeators can be controlled by using proper precautions, the proper pretreatment of the source water and adherence to proper operating procedures. Control of the biological activity in Permasep® B-10 seawater RO plants will significantly enhance long-term successful performance of the permeators.