Development of a Sludge Dewatering Filter and Utilization of Dried Sludge in Brick Making

These A dewatering filter was designed and constructed to dewater sludge collected from Eleyele waterworks using slow sand filtration. Washed sand passing through sieve mesh size of 1.18 mm was used as the filter media. The flow rate of the filtrate was monitored for six (6) days and readings were taken at 30-minute intervals for 6 hours after each sludge loading of 15 L. The dewatered and dried sludge was investigated for use as brick material. The sludge and laterite samples were characterized using Atomic Absorption Spectroscopy. The major chemical components of  the sludge and laterite samples were silicon, aluminium and iron oxides. The laterite soil sample consisted of 60.47% SiO2, 17.77% Al2O3 and 8.18% Fe2O3 while the sludge sample consisted of 52.98% SiO2, 29.46% Al2O3 and 3.63% Fe2O3. Batching method by weight was used in mixing the materials in the ratios of sludge at 0%, 15% and 30% to produce laboratory scale bricks with dimensions of 70 mm by 70 mm by 70 mm and the properties of the bricks were investigated. The average compressive strength of the laterite bricks with dried sludge content of 0%, 15% and 30% were 3.15 N/mm2, 3.08 N/mm2 and 2.64 N/mm2, respectively. The results of this research demonstrated that a locally constructed sludge dewatering filter can be used to thicken waterworks sludge and laterite-sludge can be made from dewatered water works sludge.Keywords—Compressive strength, bricks, filter, media slow sand filtration, waterworks sludg