Development of nanocomposites and minerals added pervious concretes for water treatment

In recent years, the interest of researchers in previous concrete, which is used in applications such as preventing flooding and draining polluted water, has increased, and studies investigating its applications have accelerated. This study investigated the effects of pervious concrete samples obtained using nanocomposite and mineral admixtures on drinking water treatment and their usability as a water treatment material. Four factors, each with three levels (L9), were determined using the Taguchi experimental design method (25/75%, 50/50%, and 75/25% w/w), bis(2-hydroxyethyl) terephthalate (BHET) (0, 1%, 0.5%, and 1.0%), graphene nanoplatelets (0.1%, 0.5%, and 1.0% w/w in place of cement), and hydroxyapatite microparticles (0.01%, 0.05%, and 0.1% w/w in place of cement). The prepared specimens, including the reference specimen, were subjected to destructive and non-destructive physical tests. It was concluded that the nano- and micro-material additives used did not significantly alter the physical properties of the pervious concrete, as the void ratio of the specimens was very high. In addition, the water treatment performance of the pervious concrete in terms of physical and chemical properties was evaluated by keeping the prepared specimens in raw dam water for 48 hours. According to the main effect plots, hydroxyapatite with functional groups capable of adsorbing heavy metals on its surface was found to be the most effective additive in removing heavy metals from drinking water. The highest removal of Ba, Ca, Co, Cr, Fe, and Mn from drinking water in comparison with raw water was determined as 87.92%, 89.08%, 28.80%, 83.79%, 98.53% and 87.74% respectively. Furthermore, it was concluded that the use of purified water instead of tap water in the curing conditions of permeable concrete improves the treatment performance.