Abstract—From a concern regarding the environmental impacts caused by the disposal of residues generated in Water Treatment Plants (WTP's), alternatives ways have been studied to use these residues as raw material for manufacture of building materials, avoiding their discharge on water streams, disposal on sanitary landfills or incineration. This paper aims to present the results of a research work, which is using WTR for replacing the soil content in the manufacturing of soil-cement floor with proportions of 0, 5, 10 and 15%. The samples tests showed a reduction mechanical strength in so far as has increased the amount of waste. The water absorption was below the maximum of 6% required by the standard. The application of WTR contributes to the reduction of the environmental damage in the water treatment industry. Keywords—Residue, soil-cement floor, sustainable, WTP. I. INTRODUCTION URRENTLY, the water treatment process requires the use of many chemicals, due to the increasing pollution of water sources, producing a large amount of waste. The role of WTP's is to treat the water collected in the water sources and make it available for distribution in urban centers. During such processing, oxidation processes are used, coagulation, flocculation, sedimentation, filtration, disinfection, fluoridation and pH stabilization. After oxidation processes coagulant is added to form impurity flakes that are decanted and filtered, retaining impurities not removed in previous steps. These impurities, mainly removed from filters and decanters are called WTP residues or WTR’s. These residues vary in their composition depending on the condition of the raw water, the source and process chemicals used, as well as the way to clean the filters and decanters. The disposal of industrial waste are global agenda on the grounds of improper disposal and pollution generated. The WTR’s raise concerns regarding its disposal, the necessity to seek other alternatives, so as not to pollute the environment. Flavio Araujo is with the Saneago-Sanitation Company of Goias, Av. Fued Jose Sebba, N°1245, Goiania, GO, 74805-100 Brazil (phone: +5562-3243- 3546; fax: +5562-3243-3300; e-mail: fcaraujo40@gmail.com). Paulo Scalize with the Federal University of Goiás, Av. Universitária, 1488, Goiânia, GO, 74605-220 Brazil (e-mail: pscalize.ufg@gmail.com). Julio Lima is with the Saneago-Sanitation Company of Goias, Av. Fued Jose Sebba, N°1245, Goiania, GO, 74805-100 Brazil (e-mail: augusto059_1@hotmail.com). Natalia Vieira with the Pontifical University of Goias, Av, Universitária 1.440, Goiânia, GO, 74605-010 Brazil (e-mail: nataliacarvieira@gmail.com). Antonio Albuquerque with the University of Beira Interior, Edificio 2 das Engenharias, Covilhã, 6201-001 Portugal (e-mail: albuquerqueubi@gmail.com). Isabela Santos is with State University of Goias, Br 153, Nº3105 Fazenda Barreiro do Meio-Campus Henrique Santillo, Anápolis, GO, 75132-400, Brazil (e-mail: isapains@gmail.com). The fate of these residues was the watercourses near the stations. However, the current laws restrict this practice. WTR’s in accordance with Brazilian technical standard NBR 10.004 / 2004 should be minimized, reused or recycled. According Richter (2001) [1], the WTR's are composed of water, suspended solids from raw water and chemicals added during the treatment process. Grandin et al. (1993) [2] points out that WTR’s are composed of organic and inorganic matter such as algae, bacteria, viruses, colloids, sands, clays, calcium, manganese, iron and others. The geological nature of the watershed and the external interference such as pollution of water sources by various sources, such as industrial waste, may differentiate the physical and chemical characteristics of the WTR between regions. Therefore, metals such as zinc, nickel, copper and especially aluminum, make up the WTR in varying proportions, depending on the region where the water is collected. May present positive or negative effects in treatment techniques and reuse of wastes. There are several studies to reuse of these residues in construction. This practice may help to reduce environmental impact and decrease the quantity of natural aggregate taken from nature. Currently, construction industry consumes 14- 50% of all natural resources of the planet. Paixao et al. (2008) [3] have reported the effects of the incorporation of the residue in clayey ceramic, having observed that the use of up to 10% of WTR does not change the mechanical strength of bricks, but reduces bending resistance of dried bodies. WTR was also used for the production of concrete (between 4% and 8% of the total moisture) [4], and the results have shown mechanical compressive strength greater than 27 MPa. Up to 10% of alum WTR and up to 20% of ferric WTR have been used by [5] for the production of structural ceramics materials and the results have shown good compressive strength for all the samples. Sales et al. (2011) [6] have used 13% of residue for producing concrete for non-structural application and have obtained compressive strength of 11 MPa. This article aims to evaluate the use of WTR in the production of soil-cement interlocking flooring, making the compressive strength tests and water absorption required by the standard and study its technical feasibility. II. METHODS The WTR was collected at the drying lagoon of the WTP of Goiânia (Brazil). The water treatment uses only aluminium sulphate as coagulant. The residue was milled to obtain particle size compatible with fine aggregate, which was Soil-Cement Floor Produced with Alum Water Treatment Residues Flavio Araujo, Paulo Scalize, Julio Lima, Natalia Vieira, Antonio Albuquerque, Isabela Santos C World Academy of Science, Engineering and Technology International Journal of Civil and Environmental Engineering Vol:9, No:3, 2015 377 International Scholarly and Scientific Research & Innovation 9(3) 2015 scholar.waset.org/1307-6892/10005228 International Science Index, Civil and Environmental Engineering Vol:9, No:3, 2015 waset.org/Publication/10005228