Seeded membrane distillation crystallization for hypersaline brine treatment

Abstract

Brine evaporation and crystallization are energy- and equipment-intensive technologies commonly used in industries. Alternatively, membrane distillation (MD) has shown ability for concentrating different saline solutions. However, there is a limited understanding of the impact of these solutions on the scaling and wetting behavior. To address this knowledge gap and reduce costs and energy consumption, we investigated a novel method called ‘seeded near-zero liquid discharge membrane crystallization’ (NZLDMC). This approach combines MD and crystallization in a single apparatus, reducing capital and operating costs while improving sustainability. Our study focused on applying seeding processes at NZLDMC for concentrating synthetic mono- and multi-salt solutions with a salinity of 300 g/L and a real salt solution. We investigated the effects of salt crystals and seeds on membrane performance under different operating conditions. Our findings indicate that seeding crystal technology leads to high yield and long-term stability, thereby offering the potential in industries and municipal water treatment to fractionate salt in multi-salt solutions and obtain purified water simultaneously. HIGHLIGHTS The seeded membrane distillation crystallization process allows the treatment of highly concentrated salt solutions.; The absence of membrane scaling is a benefit of seed crystals for long-term stability.; Using a membrane distillation and crystallization process in a single unit reduces capital and operating costs while improving sustainability.;

Keywords

• membrane crystallization
• membrane distillation crystallization
• near-zero liquid discharge
• seeding technology