title: Effects of using arsenic-iron sludge wastes in brick making.
abstract: The arsenic-iron sludge generated in most of the treatment systems around the world is discharged into the nearest watercourse, which leads to accumulative rise of arsenic and iron concentrations in water. In this study, attempts were made to use the arsenic-iron sludge in making bricks and to analyze the corresponding effects on brick properties. The water treatment plant sludge is extremely close to brick clay in chemical composition. So, the sludge could be a potential substitute for brick clay. This study involved the addition of sludge with ratios 3%, 6%, 9% and 12% of the total weight of sludge-clay mixture. The physical and chemical properties of the produced bricks were then determined and evaluated and compared to control brick made entirely from clay. Results of different tests indicated that the sludge proportion and firing temperature were the two key factors in determining the quality of bricks. The compressive strength of 3%, 6%, 9% and 12% sludge containing brick samples were found to be 14.1 MPa, 15.1 MPa, 9.4 MPa and 7.1 MPa, respectively. These results indicate that the compressive strength of prepared bricks initially increased and then decreased with the increase of sludge proportion. Leaching characteristics of burnt bricks were determined with the variation of pH at a constant temperature. The optimum amount of sludge that could be mixed with clay to produce good bonding of clay-sludge bricks was found to be 6% (safely maximum) by weight.
authors.affiliation: Department of Civil Engineering, Khulna University of Engineering and Technology, Khulna 9203, Bangladesh. Electronic address: khmhassan@yahoo.com.
authors.forename: Khondoker Mahbub
authors.initials: KM
authors.lastname: Hassan
authors.affiliation: Integrated Research System for Sustainability Science (IR3S), The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8654, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Fukushi
authors.affiliation: Department of Civil Engineering, Khulna University of Engineering and Technology, Khulna 9203, Bangladesh.
authors.forename: Kazi
authors.initials: K
authors.lastname: Turikuzzaman
authors.affiliation: Department of Civil Engineering, Khulna University of Engineering and Technology, Khulna 9203, Bangladesh.
authors.forename: S M
authors.initials: SM
authors.lastname: Moniruzzaman
mesh_terms: D001151:Arsenic / Q000737:chemistry*; D001459:Bangladesh; D019245:Compressive Strength; D003247:Conservation of Natural Resources; D003252:Construction Materials / Q000032:analysis*; D007501:Iron / Q000737:chemistry*; D012722:Sewage / Q000032:analysis*; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage; D007501:Iron; D001151:Arsenic
keywords: Arsenic–iron sludge; Brick making; Leaching potentials; Waste recycling