*Proceeding Paper* **The Influence of the Quality of Brick Firing on Their Calcium Diffusion Capacity and Biodegradation Potential—A Preliminary Study †**

**Klára Kobetiˇcová 1,\* , Jana Náb ˇelková 1, Martin Keppert <sup>1</sup> , Igor Medved' 2, Zbigniew Suchorab 1,3 and Robert Cern ˇ ý <sup>1</sup>**


**Abstract:** The diffusion of calcium ions Ca2+ in aquatic solutions (10 g/l) was measured for two brick samples from a region in Bohemia (Vysoké Mýto, Holešov-Žopy). The experiment was performed under laboratory conditions at the ambient temperature of 20 ± 2 ◦C for a period of 240 h. The bricks were cut into three depth layers. The calcium concentrations were analyzed chelatometrically. The biodegradation potential of the individual layers was also studied. The results indicated that the depth and quality of firing are of importance regarding the transport of calcium, and they affect the success of bio-colonization.

**Keywords:** calcium; diffusion; brick; biodegradation; biofilm; porosity

**Citation:** Kobetiˇcová, K.; Nábˇelková, J.; Keppert, M.; Medved', I.; Suchorab, Z.; Cerný, R. The Influence of the ˇ Quality of Brick Firing on Their Calcium Diffusion Capacity and Biodegradation Potential—A Preliminary Study. *Mater. Proc.* **2023**, *13*, 6. https://doi.org/10.3390/ materproc2023013006

Academic Editors: Katarzyna Mróz, Tomasz Tracz, Tomasz Zdeb and Izabela Hager

Published: 13 February 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).
