Performance and environmental assessment of concrete made with treated industrial wastewater

Abstract

Concrete production consumes significant quantities of potable water. This demand places increasing pressure on freshwater resources, particularly in water-scarce regions. This study investigates the feasibility of using treated industrial wastewater (TIWW) as an alternative to potable water in concrete and mortar production, while also assessing potential environmental and health risks associated with contaminant leaching. Two real TIWW sources were examined, collected from textile and food industries, alongside laboratory-prepared synthetic wastewater containing controlled concentrations of copper and zinc to isolate heavy metal effects. The experimental program was conducted in three phases. Phase I involved chemical characterization of the wastewater and comparison with code-based limits of ASTM, BS & Egyptian code of practice. Phase II evaluated the influence of TIWW on fresh, mechanical, and durability-related properties of concrete, including workability, compressive, flexural, and splitting tensile strengths, sorptivity, rapid chloride penetration, and hydration products using X-ray diffraction (XRD). Phase III focused on cement paste and mortar properties, including water consistency, setting time, compressive strength, and accelerated leaching behavior. Results indicate that using TIWW led to slight reductions in compressive strength (≤ 10%) and minor decreases in tensile and flexural strengths (< 5%), while workability was largely unaffected. Sorpitivity decreased when TIWW was used, attributed to pore-blocking effects of organic matter, whereas rapid chloride penetration increased due to higher ionic conductivity within the pore solution. Setting time retardation was limited for real TIWW but became significant when heavy metal concentrations exceeded 0.5 g/L. Accelerated leaching tests demonstrated minimal heavy metal release, confirming effective immobilization within the cementitious matrix.In conclusion, the findings confirm that TIWW can be safely used in structural concrete under controlled conditions.