Sewage can make Portland cement: a new technology for ultimate reuse of sewage sludge

From the viewpoint of environmental and energy problems, it is desirable th at the organic and inorganic components of sewage sludge can be reused cost -effectively. A process is described which can meet this need. The process was investigated in a large-scale industrial trial, involving the pelletizi ng-drying of sewage sludge, combined with burning in a Portland cement kiln . Special attention was paid to product quality; plant safety; simple opera tion and maintenance; ability to process different sludge and water content s; and low consumption of energy. There were no odour and dust emissions; T he study demonstrated that dried sewage sludge pellets could gainfully he u sed by Portland cement manufacturer.