Reuse of Treated Wastewater in the Manufacture of Concrete: Major Challenge of Environmental Preservation

Abstract

This work concerns the reuse of treated wastewater from Er-Rachidia wastewater treatment plant (WWTP) in the mixing of ordinary B25 concrete, in order to reduce the overexploitation of groundwater, avoid its discharge into watercourses and reduce the risk of environmental pollution due to its mineral and organic matter load. In this respect, Tree types of mixing water were used in this study: Drinking Water (DW), Groundwater (GW) and Treated Wastewater (TW). The results recorded for each type of mixing water, in the fresh and hardened state of concretes, are then compared with the requirements of the standards. The obtained results show that the treated wastewater does not have any adverse effect upon the quality of the concrete; it has shown an improvement of the mechanical resistance from the first stage, a similar density, setting time and porosity and a slight decrease of the workability compared with the control concrete. A One-way analysis of variance (ANOVA) at the 5% significance level indicated no significant difference between concrete samples produced and cured with treated wastewater and control samples at ages 7, 14, 28 and 90 days. Throughout this study the substitution of drinking water by treated wastewater will help to minimize the need for its use. Additionally, it saves drinking water for consumption and makes wastewater treatment plants more economically attractive, together with other similar goals for sustainable development.