Current design practices based on descriptive approaches to concrete specification may not be appropriate for the management of aggressive environments. In this study, the durability of cement-based materials with and without the addition of silica fume, subjected to conditions that leach calcium and silicon, were investigated. Chemical corrosion was simulated by employing various H₂SO₄ and MgSO₄ solutions, and biological corrosion was simulated using Acidithiobacillus sp. bacterial inoculation, leading to disrupted and damaged surfaces; the samples’ mass changes were studied following both chemical and biological attacks. Different leaching trends were observed via X-ray fluorescence when comparing chemical with biological leaching. Lower leaching rates were found for concrete samples fortified with silica fume than those without silica fume. X-ray diffraction and scanning electron microscopy confirmed a massive sulfate precipitate formation on the concrete surface due to bacterial exposure.

Antibiotic and metal resistance can occur together in the environment and can be linked by the same detoxication mechanism (cross-resistance). The understanding of this linkage may be a key to further study of the spread of antibiotic resistance in the non-hospital environment worldwide. In our study, we examined the overproduction of efflux pumps as a possible mechanism of the cross-resistance of isolates originating from industrial and mine tailings. Resistance to metals (Cu, Ni, Zn and Pb) and antibiotics (ampicillin, chloramphenicol, tetracycline and kanamycin) was observed at all the sampling sites and ranged from 16 to 75%. Multiresistance (MAR index > 0.38) was recorded in 26% of the isolates and was associated with the metal selective pressure duration. Overproduction of efflux pumps has mainly been observed in multiresistant isolates. Our results may indicate that the overproduction of efflux pumps could be the mechanism of cross-resistance between metals and therefore related to metal and antibiotic multiresistance. The results also show that the importance of sustainably storing metal-containing waste lies not only in its environmental impact but also in human health via antibiotic resistance proliferation.

External sulfate attack is detected on concrete construction exposed to soils, groundwater, seawater, or wastewater, and leads to serious damage to concrete elements. This paper describes an investigation of acidic corrosion caused by artificial sulphuric acid and biogenic sulphuric acid. The concrete prisms prepared from concrete-containing sulfate-resisting cement were exposed to an acid environment of different origin over a period of 3 months. The concentration of basic chemical elements such as calcium, silicon, iron, and aluminium were measured in liquid phases. Correlation analysis was used to evaluate dependencies and trends of leached-out amounts in these concentrations. Based on correlation coefficient, the intensity of dependency of the leaching trend was determined. A higher aggressiveness of sulfuric acid produced by sulfur-oxidizing bacteria was confirmed in terms of main concrete components’ leaching.

Despite the growing prevalence of using living organisms in industry, the control of biotechnological processes remains highly complex and constitutes one of the foremost challenges in these applications. The usage of electromagnetic fields offers a great opportunity to control various biotechnological processes by alternating growth and cell metabolism without influencing the characteristics of the cultivation medium or the products of the biotechnological process. The investigation of electromagnetic field applications across various industries, including food production, medicine, and pollutant mitigation, has yielded substantial insights. We used the scientific databases PubMed and ScienceDirect to select 103 experimental and theoretical articles that included original results suitable for further investigation. This type of search was repeated with every new relevant article iteratively until no new articles could be detected. Notably, even weak, low-frequency magnetic fields can accelerate the growth of certain organisms, further stabilize the bacterial community in activated sludge within wastewater treatment plants, enhance the fermentation capabilities of both yeast and bacteria, enhance metal bioleaching by the activation of bacterial metabolism, or improve the metal tolerance of plants during the phytoremediation process. Moreover, magnetic fields exhibit a promising sustainable possibility for the better control of biotechnological processes, thus making these processes more competitive compared with the currently used long-term unsustainable extraction of metals. Although with these interesting results, these examples represent highly exceptional applications. Despite these examples, the overall application potential of magnetic fields remains largely unexplored and unknown.

The loss of mass of concrete matrix and subsequent corrosion of concrete has been reported very often. Aggressive liquids such acids, bases, solutions of salts or aggressive gases as well as microorganisms penetrate the concrete and cause deterioration and biodeterioration, respectively. Presented paper is aimed at investigation of concrete corrosion (chemical as well as biologically induced) activated by influence of different aggressive media. Concrete cylinder samples of a 32 mm diameter and 15 mm height were formed as a drilled core from prepared concrete cubes. Concrete samples were exposed to different aggressive media under laboratory conditions (acid mine drainage, cultivation media for different bacteria species, sulphuric acid, aluminium sulphate) as well as in situ (waste water of sewage system in Kosice city) for 3 months. Influence of aggressive media and sulphur-oxidising and sulphate-reducing bacteria on concrete samples has been determined in terms of weight and surface changes of investigated concrete samples and leaching of the selected ions. The weight changes varied in the range 0.04–3.7 %. The visual changes of samples surface were observed. Content of Ca, Si and Fe ions in leachates were measured by X-ray fluorescence methods. Higher percentage of calcium ions released has been measured comparing to silicon ions in all media except for distilled water. The results of elements releasing correspond to results of weight changes of investigated concrete samples.

Wastewater structures, such as treatment plants or sewers can be easily affected by bio-corrosion influenced by microorganisms living in waste water. The activity of these microbes results in deterioration and can cause the reduction in structural performance of such structures. In order to improve the durability of mortar and concrete, different admixtures are being used and the best impact is observed in cement based materials combined with blast furnace slag. In this study, mortar samples with blast furnace slag were exposed to bacterial sulphate attack for 90 and 180 days. The leaching of calcium ions from the cement matrix and equivalent damaged depths of studied mortar samples were evaluated. The results showed more significant leaching of samples placed in bacterial environment, compared to the samples placed in non-bacterial environment. Similarly, the equivalent damaged depths of mortars were much higher for the bacteria-influenced samples. The slag-based cement mortars did not clearly show improved resistance in bacterial medium in terms of calcium leaching.