A1 Journal article (refereed), original research

Impurity separation efficiency of multi-component wastewater in a pilot-scale freeze crystallizer

Open Access publication

Publication Details
Authors: John Miia, Choudhury Tuhin, Filimonov Roman, Kurvinen Emil, Saeed Muhammad, Mikkola Aki, Mänttäri Mika, Louhi-Kultanen Marjatta
Publisher: Elsevier
Publication year: 2020
Language: English
Related Journal or Series Information: Separation and Purification Technology
Volume number: 236
ISSN: 1383-5866
eISSN: 1873-3794
JUFO-Level of this publication: 2
Open Access: Open Access publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe2019121949067


New directions in
wastewater treatment consider not only the adequate purification efficiencies
but also water and material recovery for recycling and reuse. Freeze
crystallization offers the potential for the simultaneous separation of water
(ice) and material (i.e., salts and nutrients) from wastewater using a single
wastewater purification process. However, the impurity-separation performance
of freeze crystallization applied to multi-component wastewaters is still
unclear, particularly for industrial or municipal scales.

In this study, a
prototype was developed to demonstrate the application of freeze crystallization
to wastewater purification on the industrial scale. This freeze crystallizer, a
120 liter jacketed vessel equipped with stirring and ice scraping mechanisms,
produced relatively large (500 µm) ice crystals, primarily in water suspension.
To evaluate the purification efficiencies of the prototype system, a
comprehensive number of water-quality indicators were measured following the
purification of highly concentrated landfill leachates. The prototype system
achieved a >95% average impurity removal efficiency for both organic and
inorganic matter, including heavy metals. This excellent separation ability,
given the variety of impurities present in the leachates, shows the
non-selective nature of freeze separation for wastewater treatment. These
outcomes represent an important step forward in scaling up and developing the
full scale freeze purification process for wastewaters.

Last updated on 2020-30-11 at 12:02

Share link