Removal and transformation of benzotriazole in manganese-oxide biofilters with Mn(II) feeding.

The aim of this study was to evaluate the treatment of organic-carbon-deficient wastewater containing benzotriazole (BTA) in lab-scale aerated biofilters filled with natural manganese oxide ore, sand coated with synthetic manganese oxides and sand (as a control material) in terms of BTA removal efficiency, its transformation products and ecotoxicological impact of the treated wastewater. Additionally, the effect of Mn(II) feeding was tested. The removal of BTA in all the biofilters was ≥97%.

Initial stage of the biofilm formation on the NiTi and Ti6Al4V surface by the sulphur-oxidizing bacteria and sulphate-reducing bacteria.

The susceptibility to the fouling of the NiTi and Ti6Al4V alloys due to the adhesion of microorganisms and the biofilm formation is very significant, especially in the context of an inflammatory state induced by implants contaminated by bacteria, and the implants corrosion stimulated by bacteria. The aim of this work was to examine the differences between the sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) strains in their affinity for NiTi and Ti6Al4V alloys. The biofilms formed on alloy surfaces by the cells of five bacterial strains (aerobic SOB Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans, and anaerobic SRB Desulfovibrio desulfuricans-3 strains) were studied using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM).