Engineering Term of the Month ALUM
Alum ( aluminum sulfate ) is a white crystalline solid used as a flocculant to remove small , suspended solids and organic matter from water . Alum is commonly used in water treatment to remove particulates . The alum causes suspended particles in the water to clump together so they can settle . Alum is effective at binding together suspended particles because the alum has a positive electrical charge , whereas the suspended solids have negative charges . The negatively charged suspended solids are attracted to the positively charged alum , causing the alum and particulates to clump together . By causing the suspended particles to settle , the concentration of solids in the effluent water is reduced , resulting in cleaner water for supplemental treatment processes . Alum is non-toxic and aluminum is not typically needed to be removed from the water after treatment . If necessary , the alum-treated water after settling can be treated for aluminum using reverse osmosis or distillation .
Sources : https :// www . purewaterproducts . com / water-problems / alum-aluminum-sulfate https :// www . waterform . com . au / news-bulletin / using-alum-aluminium-sulfate-to-improve-settling-in-abattoir-wastewaterlagoons https :// www . ninemilecreek . org / wp-content / uploads / Alum-Education _ 2019 . pdf https :// advancedchemsys . com / coagulant-and-flocculant-in-wastewater-treatment /