Bittern can be used instead of aluminum-based coagulants in the treatment of wastewater produced during the fabric-dyeing process. The wastewater pH is basic, which is favorable for the use of bittern. After the addition of bittern, precipitated magnesium hydroxide works as the coagulant to collect dye, solids, organic matter, and heavy metals from the wastewater before settling out of solution. The sludge produced from this wastewater treatment is also easier to dispose of than sludge produced by aluminum-based coagulants because there are less restrictions surrounding the disposal of magnesium, and it may be possible to recycle the sludge as fertilizer.
Bittern can also be used as a source of magnesium ions (Mg) for the precipitation of struvite, a useful fertilizer, from wastewater containing nitrogen and phosphorus. One source of useful wastewater is landfill leachate. Bittern is just as good as other sources of magnesium ions at removing phosphorus from wastewater streams, but it lags behind other magnesium ion sources in terms of the removal of ammonia (a nitrogen compound).