Application of x-ray fluorescence spectrometry in assesment of ultrafiltration membrane surface condition at water pre- treatment units of thermal power plants

The objects of the study were the Doy Chemical hollow-fiber ultrafiltration membranes which were use for preparation of make-up water for the Novocherkasskaya Regional Thermal Power Plant (RTPP).

We tried out a possibility of applying the X-ray fluorescence spectrometry to study the condition of the spent non-recoverable ultrafiltration membranes in order to identify the causes of their irreversible destruction. The ARL Quant’X X-ray fluorescence energy dispersive spectrometer of Thermo Scientific (USA) was used in the study.

Thin cuts of the Doy Chemical hollow-fiber ultrafiltration membranes were used in the experiments, which had worked for more than three years in the field conditions of the feed water of the Don River, Russia.

The analysis of the obtained samples spectra allowed us to assume that the membranes were irreversibly contaminated by iron bacteria. Basing on the conclusions made during the analysis of X-ray fluorescence spectra we developed and tested in field conditions one of the optimization variants for technological pretreatment scheme. This scheme enables a significant increase in the service life of ultrafiltration membranes, even when the feed water is heavily contaminated by bacteria. Field tests of the modernized technology were carried out at Novocherkasskaya RTPP during 2016-2018 and showed a significant increase in the service life of the membrane modules. At the same time, the quality of the filtrate, productivity and pressure drops at the cascades of ultrafiltration units fully corresponded to the normative values even in conditions of deteriorated quality of the feed river water.

It has been proved that aggressive regeneration of ultrafiltration membranes that have worked for a long time under the conditions of feed water having increased values of the total microbial number and high values of permanganate oxidation does not allow one to restore their initial state. In this case the main cause of ultrafiltration membranes contamination is iron, which is present in colloidal and bacterial forms in the pores and on the membranes surfaces. In the conditions of the Novocherkasskaya RTPP, in addition to timely flushing and chemical regeneration of ultrafiltration membranes, the necessity of organizing a preliminary treatment of the feed water with reagents having a prolonged bactericidal effect is accepted.

1. Apel PYu, Bobreshova OV, Volkov AV, et al. Perspektivy razvitiya membrannoj nauki. Razvitiya membrannoj nauki 2019; 9(2): 59-80. (In Russ).

2. Veselovskaja EV, Shishlo AG. Povyshenie ekologicheskih pokazatelej vodopodgotovitel'nyh ustanovok teploenergeticheskih predpriyatij. University News. North-Caucasian Region. Technical Sciences Series. 2016.-N. 4. pp 36-41.

3. Veselovskaya EV, Shishlo AG. Opyt primeneniya perspektivnyh tekhnologij vodopodgotovki na otechestvennyh teplovyh elektrostanciyah// Izvestiya vuzov, Sev.-Kavk. region. Tekhnologiya nauki. 2016; (2):31-34.(In Russ).

4. Shishlo AG. Issledovanie processa obessolivaniya dobavochnoj vody blochnoj TES metodom nano- fil'tracii. Izvestiya vuzov. Tekhnicheskie nauki. 2013; 4: 38-41.(In Russ).

5. 5 Fazullin DD, Mavrin GV, Shajhiev IG, Nizameev IR Ul'trafil'traciya vodomaslyanyh emul'sij dinamicheskoj membranoj nejlon–polistirol. Membrany i membrannye tekhnologii, 2019;8(1): 51-58.

6. Roldugin VA. Bazhenov VI, Plisko SD, T.V. Modelirovanie vneshnego massoperenosa v polovolokonnyh mmbrannyh kontaktorah Kirsh Membrany i membrannye tekhnologii 2019; 5(4): 261-268.(In Russ).

7. Jose A.C. Broekaert. Editors .Adolescent pregnancy.2-nd ed. Wiley-VCH: Verlag CmbH & Co. KGaA:,2002.

8. 8. Becker Y. Spektroskopiya. - Moscow: Tehnosphera; 2009. (In Russ).

9. Lazarev SI, Golovin YuM., Lazarev DS, Polikarpov VM. Issledovaniya sostoyaniya vody v acetatcellyuloznoj membrane MGA-95 metodami infrakrasnoj spektrometrii i termogravimetrii. Membrany i membrannye tekhnologii 2019; 5(4):278-281. (In Russ).

10. Pasmore M, Todd P, Smith S, Baker D, Silverstein J, Coons D, Bowman CN. Effects of ultrafiltration membrane surface properties on Pseudomonas aeruginosa biofilm initiation for the purpose of reducing biofouling. J. Membrane Science. 2002;194:, 15-32.

11. Wilf I. New membrane research and development achievements. Desalination and Water Reuse. 2001;10(1): 28-33.