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Sludge, a byproduct of chemical mechanical polishing (CMP) used in integrated-circuit (IC) industries, is composed of hazardous materials such as nano-particles of SiO2, Al2O3, CaF2, and unknown organics. These nano-particles are potentially dangerous if released into the environment. Preliminary studies are carried out on sludge-blended cement concrete (SBCC) formed into specimens of cylindrical concrete with 10 cm diameter and 20 cm height. They are with 10 wt.% cement replaced by CMP sludge powder. Three water/cementitious (W/C) ratios were selected to mold the specimens for setting time, XRD analysis, TCLP analysis and compressive strength and stress–strain tests, respectively. TCLP test results revealed that the concentrations of leached heavy metals were substantially below the regulatory thresholds. The strengths of the SBCC specimens were comparable to those of the ordinary Portland cement concrete (OPCC) specimens with 3-day curing and about 22–38% much higher than those of OPCC cylindrical concrete specimens at 7–91 days of age. These results demonstrate the feasibility of recycling CMP sludge into construction materials, a positive step for sustainable development.

In this study, fly- and scrubber-ash from a municipal solid waste incinerator (MSWI) were mixed uniformly in their production weight proportions; then, the mixture was added to waste glass frit and melted to form a glassy slag. The toxicity characteristic leaching procedure test results for the glassy slag revealed that the amount of leached heavy metals was far below the regulatory threshold. The slag-blended cement concrete (SBCC) specimens were manufactured with 20 wt.% of the cement replaced by slag powder. Three water/cementitious ratios, 0.48, 0.58 and 0.68, were selected to mold the specimens for compressive strength testing. The strengths of the SBCC specimens were close to or higher than those of the ordinary Portland cement concrete (OPCC) specimens at an age of 28 days and were 5–10% higher than those of the OPCC specimens at ages of 56 and 90 days. The experimental results demonstrated the feasibility of recycling MSWI fly- and scrubber-ash with waste glass.