Preparation and of PVA-based compositions with embedded silver, copper and zinc oxide nanoparticles and assessment of their antibacterial properties.

A series of poly(vinyl alcohol) (PVA) based liquid compositions with addition of zinc oxide, silver and copper nanoparticles has been prepared. The compositions also contained other consistency-forming organic components. The physico-chemical properties of the products have been determined. Their pH and density have been assessed. Also, the size of nanoparticles has been defined with using a dynamic light scattering technique. The compositions were subjected to XRD, FT-IR and microscopic analysis as well. Thanks to the incorporation of both metal oxide and metallic nanoparticles, it was possible to enrich the products with antibacterial properties. Their inhibiting properties in the growth of microorganisms have been confirmed against both Gram-negative and Gram-positive strains such as E. coli, S. aureus and P. aeruginosa. Thanks to the ability for solidification, the compositions may be applied on a bacterially contaminated surface, and after destroying the microorganisms and its solidification, it may be peeled off along with the dead bacterial film.

Efficacy of a novel biofilter in hatchery sanitation: II. Removal of odorogenous pollutants.

The present research assessed the treatment efficiency of odorogenous pollutants in air from a hatchery hall vented on organic and organic-mineral beds of an enclosed-container biofilter. In this study, the following media were used: organic medium containing compost and peat (OM); organic-mineral medium containing bentonite, compost and peat (BM); organic-mineral medium containing halloysite, compost and peat (HM). The concentration of odorogenous gaseous pollutants (sulfur compounds and amines) in the hatching room air and in the air after biotreatment were determined by gas chromatography. In the hatchery hall among the typical odorogenous pollutants, there were determined 2 amines: 2-butanamine and 2-pentanamine, hydrogen sulfide, sulfur dioxide, carbon disulfide, sulfides and mercaptans. Ethyl mercaptan showed the highest levels as its mean concentration in the hatchery hall air exceeded 60 microg/m3 and in single samples even 800 microg/m3. A mean concentration of 2-butanamine and sulfur dioxide in the examined air also appeared to be relatively high--21.405 microg/m3 and 15.279 microg/m3, respectively. In each filter material, the air treatment process ran in a different mode. As the comparison reveals, the mean reduction of odorogenous contaminants recorded in the hall and subjected to biotreatment was satisfying as it surpassed 60% for most established pollutants. These high removal values were confirmed statistically only for single compounds. However, a low removal level was reported for hydrogen sulfide and sulfur dioxide. No reduction was recorded in the bentonite supplemented medium (BM) for sulfur dioxide and methyl mercaptan. In the organic medium (OM) no concentration fall was noted for dipropyl sulfide either. In all the media investigated, the highest removal rate (100%), not confirmed statistically, was observed for carbon disulfide. Very good results were obtained in the medium with a bentonite additive (BM) for both identified amines, whose mean elimination rate exceeded 60% (p

Microbial contamination level of air in animal waste utilization plants.

OBJECTIVE: The aim of this research was evaluation of microbial contamination of air within and in the vicinity of animal waste disposal plants. MATERIALS AND METHOD: Air samples were analyzed to determine total bacterial and fungal counts as well as microbial species composition. Measurements of climate conditions (temperature, humidity, air motion) and total dust concentration were also performed. RESULTS: Total numbers of bacteria and fungi surpassed the threshold limit values for production halls. The most abundant bacteria detected were those consisting of physiological microflora of animal dermis and mucosa. Fungal species composition proved to be most differentiated in the air beyond the plant area. Aspergillus versicolor, a pathogenic and allergenic filamentous fungus, was isolated only inside the rendering plant processing hall. CONCLUSIONS: The measurement results showed a low sanitary-hygienic state of air in the plant processing halls and substantial air pollution in its immediate vicinity.