Sulphate removal from aqueous solutions: State-of-the-art technologies and future research trends

An Integrated Electrochemical System for Synergistic Cathodic Nitrate Reduction and Anodic Sulfite Oxidation

“…In this system, NO 3 − is converted to NH 4 + at the cathode and SO 3 2− is converted to SO 4 2− at the anode. The final products could be recycled via crystallization and utilized to form valuable compounds such as magnesium ammonia phosphate (struvite precipitate, NH 4 MgPO 4 ·6H 2 O) [ 31 , 32 ], calcium sulfate (CaSO 4 ), barium sulfate (BaSO 4 ), Ettringite (Ca 6 Al 2 (SO 4 ) 3 (OH) 12 ) [ 33 ], etc., thus achieving more effective treatment of nitrate and sulfite in wastewater.…”

Study on the removal of SO42− and Ca2+ from potassium chloride brine via a method combining calcium chloride and carbon dioxide

“…There are a variety of methods for SO 4 2− removal, including the chemical precipitation method, 2–4 freezing method, membrane separation method, 5 and ion exchange method. 6,7 The four mentioned methods have their own advantages and disadvantages. Although the membrane separation process is relatively simple and the separation effect is good, it has the disadvantages of high cost, susceptibility to poisoning, and short service life, thus its practical application is limited.…”