Enhancing the efficiency of coagulation method for sewage treatment by adding sludge.

Summary: Cleaning dirty water just got faster! Scientists tested a special tank that cleans sewage. They found that adding a little bit of old sludge back into the dirty water actually helps the gross stuff clump together and sink much faster. They tested different mixes and found the perfect recipe of chemicals, sludge, and stirring time. With this perfect mix, the water gets super clear in just 30 minutes!