Simultaneous recovery of ammonium sulfate and ice from aqueous solution using eutectic freeze crystallization process
Document Type
Article
Publication Date
1-1-2025
Abstract
This study investigated the feasibility of eutectic freeze crystallization (EFC) process for ammonium sulfate (AS) salt recovery from 41 wt% AS solution. The EFC experiments were conducted using a 1 L double-jacketed crystallizer coupled with a recirculating chiller under varying freezing time, seed mass and seed size. The EFC process demonstrated successful AS salt recovery and water purification with the highest ice purity attained at 96.28 %. The construction of a binary AS-water phase diagram allowed the determination of the eutectic temperature, which was found to be-19.06 degrees C at 40 wt% of AS solution. The results indicated that the increase in freezing time enhanced the AS nucleation rate, growth rate, yield and mean product crystal size. The introduction of seeding not only provided well-controlled crystal nucleation and growth during EFC process, but also promoted the formation of larger, well-structured crystals and reduced agglomeration. Overall, the EFC process is a viable and promising option for recovering AS from wastewater, which offers high potential towards achieving zero liquid discharge goal, i.e. a sustainable and efficient approach in managing industrial effluent rich in ammonium and sulfate contaminants.
Keywords
Eutectic freeze crystallization, Ammonium sulfate recovery, Resource recovery, Freeze desalination, Phase diagram
Divisions
sch_che
Funders
Ministry of Higher Edu-cation, Malaysia under Fundamental Research Grant Scheme (FRGS/1/2022/TK05/UNIMAS/02/1)
Publication Title
Journal of Crystal Growth
Volume
649
Publisher
Elsevier
Publisher Location
RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS