removing Cr from industrial waste water by using modified green concrete by bentonite for

Today, Concrete is one of the main materials used in the industry. Today, the recycling of construction waste and the construction of concretes with the environment has found many fans. Heavy metal chromium is one of the most important environmental pollutants. In this study, glass and bricks recycled from building demolition are used to build concrete (green mixing concrete). This concrete has non-structural standard concrete properties, which was added by adding bentonite adsorbent to remove chromium from industrial wastewater. Various samples were made with different absorbent percentages . Concrete samples were mixed with various concentrations of chromium mg / L, different pH at different contact times Solution 6, was tested and compared in vitro. The results showed that maximum adsorption in the concentration of sewage was 25 mg / L, contact time 8 hours, absorbent dose of 8% and pH, 6 in laboratory (25 ° C). Maximum adsorption in optimal conditions was 95.65% and the absorption capacity was 123.3 mg / g. Experiment with optimal parameters obtained on the actual sample of industrial wastewater was repeated and the rate of adsorption was 97.29%. Absorption of chromium from a quasi-second-order model and absorption isotherm follows the Freundlich model. 28-day resistance of concrete specimens with optimum mixing plan before contact with chromium metal at 114 kg / cm2, after contact with chromium-containing solution with optimal laboratory parameters of 101.1 kg / cm2 and after contact with the actual sample of sewage containing chromium 4 / 127 kg per square centimeter.