# Studying the Impact of Cement-Based and Geopolymer Concrete on the Proliferation of Escherichia coli and Staphylococcus aureus in Water-Related Applications

## TL;DR

This study tests how new geopolymer concrete can inhibit bacteria growth in water environments, showing better performance than traditional cement.

## Contribution

The novelty lies in evaluating geopolymer composites for bacterial inhibition in water-related applications.

## Key findings

- Geopolymer composites showed better antibacterial efficiency than cement for both Gram-positive and Gram-negative bacteria.
- Bacterial growth was inhibited after several days on the tested materials.
- The geopolymer matrix contained significant amounts of SiO2 and quartz.

## Abstract

The main aim of this research was to synthesize the new geopolymer composite and test its antibacterial properties. The new composites are based on a geopolymer matrix, with the addition of carbon fiber, nano-silica and antibacterial nanopowder. The first stage of this research was the synthesis of geopolymer composites containing variable proportions of nano-additives and, as a reference material, cement. The next step was bacterial cultivation. Two different bacterial strains were selected, Gram-positive and Gram-negative (Escherichia coli and Staphylococcus aureus). In this stage, the agar microbiological medium is used for the evaluation of bacterial growth inhibition by cement and geopolymers. In the final stage, the growth of the colony was observed and the pH measurements were taken. The final assessment of efficiency was made by using optical microscopy and a colony counter based on the Petri dish. The test performed showed that the main mineralogical components are quartz, 55.0%, and mullite, with 42.1% of crystalline ingredients. EDS analysis shows that the main oxide component is SiO2, about 50.9%. The obtained results connected with bacteria growth show the growth of both types of bacteria on materials; however, after several days, the growth was inhibited. An assessment of microorganism growth inhibition by cement and geopolymers shows the better efficiency of geopolymer composites in this area for both types of colonies (Gram-positive and Gram-negative). The new element in this research was to plan the research from the point of view of its application in the water environment. The provided research can be useful for the inhibition of biofouling phenomena on marine and inland water infrastructure.