During the last decade, the growing load of sludge from textile industries, the top foreign exchange earning sector of Bangladesh, is a common nuisance to environmental system and community health. The present study was aimed to minimize the environmental impact from the disposal of Electrocoagulated Metal Hydroxide Sludge (EMHS) by using it as a partial substitute of clay in the manufacturing of construction material like building blocks (BBs). Different batches of normal and pressurized building blocks (NBBs and PBBs, resp.) were prepared using up to 50% EMHS with clay and then fired at a particular temperature. EMHS proportion in the mixture and firing temperature were two key factors determining the quality of BB. BB did not show any deformation or uneven surfaces at any of the examined firing temperature. At higher firing temperature and EMHS proportion, more weight loss and shrinkage of BB were noticed. Higher compressive strength and lower water adsorption were found at lower EMHS content and higher firing temperature. It was explored that NBB and PBB with 20 and 30% EMHS in clay, respectively, and fired at 1050？°C would be usable for nonloading applications; namely, ornamental bricks, decoration purposes, and fence of garden. 1. Introduction Degradation of environmental quality due to unrestricted and objectionable discharges of sludge from industrial unit is a common practice in developing countries like Bangladesh where little or no treatment of waste residue is carried out before disposals in landfill site haphazardly or openly. Although textile and dyeing sector is a vital part of economic development, speedy and unplanned progress may result in a wide impact on natural resources and human being living within the close vicinity of the sludge disposal locations [1–3]. Electrocoagulated Metal Hydroxide Sludge (EMHS) produces during the treatment of waste effluent of the industry by electrocoagulation (EC) technique [4], where sacrificial anodes made of aluminum or iron corrode to release active coagulant precursors [5–7]. Coagulant produces insoluble metallic hydroxide flocs which can remove pollutants by surface complexation or electrostatic attraction [8, 9]. Coagulants are in the form of both monomeric hydroxide ions and highly charged polymeric metal hydroxyl species, namely, , Fe(H2O)5(OH)2+, Fe(H2O)4(OH)2+, Fe2(H2O)8(OH)24+, , and so forth for anodes made of iron [10]. These species neutralize the electrostatic charges on the suspended solids and facilitate agglomeration resulting in separation from the aqueous phase by producing EMHS.
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