Electromembrane recycling of highly mineralized alkaline blowdown water from evaporative water treatment plants at thermal power stations
- Authors: Chichirova N.D.1, Chichirov A.A.1, Lyapin A.I.1, Minibaev A.I.1, Silov I.Y.2, Tolmachev L.I.3
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Affiliations:
- VPO Kazan State Power University
- JSC TGK-16 Branch—Kazan Cogeneration Power Station TETs-3
- JSC Membranines Technologijos LT
- Issue: Vol 63, No 14 (2016)
- Pages: 1046-1050
- Section: Article
- URL: https://journals.rcsi.science/0040-6015/article/view/172541
- DOI: https://doi.org/10.1134/S0040601516140044
- ID: 172541
Cite item
Abstract
Thermal power stations (TPS) are the main source of highly mineralized effluents affecting the environment. An analysis of their water systems demonstrates that alkaline effluents prevail at TPSs. Extraction of an alkali from highly mineralized effluents can make the recycling of effluents economically feasible. A method is proposed of electromembrane recycling of liquid alkaline highly mineralized wastes from TPSs. The process includes electromembrane apparatuses of two types, namely, a diffusion dialysis extractor (DDE) intended for extraction of the alkali from a highly mineralized solution having a complex composition and an electrodialysis concentrator for increasing the concentration of the extracted solution to a value suitable for use in water treatment plants at TPSs. For implementation of the first process (i.e. the extraction of alkali from alkaline-salt solution) various membranes from various manufacturers were studied: CM-PAD and AM-PAD (Ralex, Czechia), MK-40, MA-40, MA-41, MA-414, and MB-2 (OOO OKhK “Shchekinoazot”, Russia), AR103-QDF and СR61-CMP (Ionies Inc., USA). The experiments demonstrate that the acceptable degree of separation of the alkali and the salt is achieved in a pair of cation-exchange membranes with the efficiency of separation being higher without an electric field. The highest efficiency was attained with Russian-made membranes (MK-40, OOO OKhK “Shchekinoazot”). A full scale experiment on recycling of highly-mineralized blowdown water from the evaporating water treatment system at the Kazan cogeneration power station No. 3 (TETs-3) was performed in a pilot unit consisting of two electromembrane apparatuses made by UAB “Membraninės Technologijos LT”. In the experiments every ton of blowdown water yielded 0.1 t of concentrated alkaline solution with an alkali content of up to 4 wt % and 0.9 t of the softened salt solution suitable for the reuse in the TPS cycle. The power rate is 6 kWh / ton of blowdown water.
About the authors
N. D. Chichirova
VPO Kazan State Power University
Author for correspondence.
Email: ndchichirova@mail.ru
Russian Federation, Kazan, 420066
A. A. Chichirov
VPO Kazan State Power University
Email: ndchichirova@mail.ru
Russian Federation, Kazan, 420066
A. I. Lyapin
VPO Kazan State Power University
Email: ndchichirova@mail.ru
Russian Federation, Kazan, 420066
A. I. Minibaev
VPO Kazan State Power University
Email: ndchichirova@mail.ru
Russian Federation, Kazan, 420066
I. Yu. Silov
JSC TGK-16 Branch—Kazan Cogeneration Power Station TETs-3
Email: ndchichirova@mail.ru
Russian Federation, Kazan, 420051
L. I. Tolmachev
JSC Membranines Technologijos LT
Email: ndchichirova@mail.ru
Lithuania, Klaipeda, LT-94101