A full-scale study of nanofiltration: Separation and recovery of NaCl and Na2SO4 from coal chemical industry wastewater

Ionic liquid‐induced deep grafting of polyelectrolyte to reform polyamide layer for antifouling nanofiltration membrane

“…Nanofiltration (NF), a low-energy separation process, has shown excellent separation of water/salt or water/ organics in water treatment processes and shows great promise in water purification and resource recovery. [3][4][5][6][7] However, severe membrane fouling often occurs during operation, which leads to increased transmembrane resistance, decreased permeate flux and changes in separation selectivity (deteriorating product water quality). [8][9][10] Moreover, frequent chemical cleaning is prone to serious secondary fouling and shortens membrane life.…”

“…The increasing prevalence of water scarcity and pollution seriously impedes the sustainable development of industrial and social activities. Nanofiltration (NF), a low‐energy separation process, has shown excellent separation of water/salt or water/organics in water treatment processes and shows great promise in water purification and resource recovery 3–7 . However, severe membrane fouling often occurs during operation, which leads to increased transmembrane resistance, decreased permeate flux and changes in separation selectivity (deteriorating product water quality) 8–10 .…”

Selective Separation of Sulfate and Chloride Ions from Industrial Wastewater by In Situ Generation of CaFe-Layered Double Hydroxides and the Related Resource Utilization

“…Sulfate (SO 4 2– ) is a common nontoxic component in natural wastewater and industrial wastewater, and it is often found in high concentrations in mining, metallurgy, textile, fertilizer, and coal chemical wastewater. , The discharge of wastewater with high SO 4 2– content results in water mineralization that produces toxic and corrosive H 2 S and poses the health hazard to mammals. − There is a large amount of sewage discharge in the production process of the coal chemical industry, which contains a large number of salts, mainly including Na 2 SO 4 , NaCl and other salts. , At present, SO 4 2– removal technologies in wastewater mainly include the biological method, membrane separation, ion exchange technology, electrodialysis, adsorption , and chemical precipitation. , Because microbial growth requirements are relatively strict, the efficiency of biological treatment is more likely to be affected by the environmental conditions. Traditional chemical precipitation method usually uses barium and calcium salts to achieve SO 4 2– precipitation .…”

“…2−5 There is a large amount of sewage discharge in the production process of the coal chemical industry, which contains a large number of salts, mainly including Na 2 SO 4 , NaCl and other salts. 6,7 At present, SO 4 2− removal technologies in wastewater mainly include the biological method, 8 membrane separation, 9 ion exchange technology, 10 electrodialysis, 11 adsorption 12,13 and chemical precipitation. 2,12 Because microbial growth requirements are relatively strict, the efficiency of biological treatment is more likely to be affected by the environmental conditions.…”

Pilot-Scale Selective Electrodialysis for the Separation of Chloride and Sulphate from High-Salinity Wastewater

“…In response to the high energy consumption of conventional crystallization processes, a process that uses organic solvents to reduce the solubility of salts and precipitate the salts to achieve low energy consumption for salt removal has been applied on a large scale [7][8][9]. However, the products of the above treatment methods are often mixtures that are difficult to treat and their generation and storage can result in significant environmental risks [10]. Nanofiltration (NF) and monovalent selective electrodialysis (MSED) are widely used for the separation of mono-polyvalent ions from high-salinity wastewater to achieve product recovery.…”