Optimization of Operating Conditions for Ultrafiltration Units

• Published in: Thermal engineering Vol. 68; no. 10; pp. 777 - 784
• Main Authors: Panteleev, A. A., Panteleev, An. A., Bobinkin, V. V., Lysenko, S. E., Smirnov, V. B.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.10.2021; Springer Nature B.V
• Subjects: Alkaline cleaning; Backwash; Chelating agents; Chelation; Cross flow; Deaeration; Engineering; Engineering Thermodynamics; Filtration; Heat and Mass Transfer; Hydraulic models; Membranes; Optimization; Power plants; Ultrafiltration; Water purification; Water quality; Water treatment; Water Treatment and Water Chemistry; Water treatment plants; optimization of ultrafiltration unit cleaning; formulas for calculating backwashing time; ultrafiltration unit cleaning; hydraulic model of backwashing; ultrafiltration unit regime; ultrafiltration
• ISSN: 0040-6015; 1555-6301
• DOI: 10.1134/S0040601521090056

Parameters affecting the effectiveness of cleaning ultrafiltration membranes are considered. A simple hydraulic model of the backwashing regime is proposed. The formulas obtained for calculating the backwashing time enabled optimization of this process. Results are presented of studying the operating condition in ultrafiltration units. To effectively select the regimes of filtration and of direct and backwashing, the authors propose to employ laboratory ultrafiltration modules and the calculation procedure developed by them. A hydraulic model of the backwashing process and a phenomenological model of deposit formation within the fiber are illustrated. The formulas are presented for calculating backwash time, which can help us to optimize the backwashing process and reduce the associated operating costs. It is demonstrated that the distribution of deposits in a membrane fiber can be analyzed using simple filtration models, one of which is presented in this study. It has been demonstrated that most deposits are accumulated at the center of the fiber with the dead-end filtration mode. Hence, it would be reasonable to use cross-flow filtration to control this process. An engineering correlation convenient for practical application is proposed for calculating the Langelier index using the measured water quality indicators. The Langelier index is useful to substantiate whether acid washings are required or not required. It has been demonstrated that, with considerably unstable source water, prefiltration in a filter with a granular bed upstream the ultrafiltration unit stabilizes the quality and deaeration of the treated water. Acid or alkaline cleaning operations based on chemicals containing chelating agents to be performed twice a year have also been demonstrated to significantly increase the stability of the ultrafiltration unit. Practical recommendations are given for introducing the ultrafiltration regime, which were implemented at the water treatment plant of the Novocherkassk District Power Plant (GRES).