Filamentous fungus Aspergillus niger is commonly found on decaying vegetation or in indoor environment and has a number of uses, including application in bioremediation. Hence, the basic interactions of this common mould with selenite were studied, including biovolatilization, bioaccumulation and toxicity effects of selenite on fungal growth. The fungal strain, originally isolated from noncontaminated soil, was cultivated under aerobic conditions on liquid cultivation media with concentration of Se(IV) 19 or 27 mg.l-1 during 25 days. The fungal growth in the presence of selenite was not inhibited when compared to control, only the sporulation was reduced. The concentration of Se(IV) in liquid medium decreased rapidly within first ten days to 1 mg.l-1. However, according to results from the 25th day of cultivation, the concentration of total selenium in medium did not change significantly and only negligible amount of selenium (less then 1%) was bioaccumulated. That indicates some biotransformation of selenite into other selenium species. During the cultivation, up to 21% of total amount of selenium was transformed into volatile derivatives (biovolatilization) by filamentous fungus A. niger.

This article evaluates the impact of pH (4.0-8.5) on the sorption capacity of bentonite for humic acids. The sorption capacity of bentonite was higher in an acidic solution. The maximum sorption efficiency was observed at pH 5. Pseudo-first and pseudo-second order kinetic models, as well as the Freundlich isotherm were applied to fit the experimental results at pH 7.5, which was compared to sorption efficiency at pH 5.5. The equilibrium was achieved after 49 and 32 hours for pH 5.5 and 7.5, respectively. Within the experimental concentration scale of humic acid, the sorption capacity expressed by the values of Freundlich constants at pH 5.5 (0.377 mg.g(-1)) and at pH 7.5 (0.142 mg.g(-1)) indicates a high affinity of humic acids for bentonite in diluted aqueous solutions.

The aim of the presented study was to assess the potential of Thymus serpyllum biomass to remove antimony(111) from contaminated waters and to identify optimal conditions for the sorption process. Sb(III) removal was highest in the range 3.3-4.6, although the effect of pH was rather small. The optimal agitation speed was 140 rpm and optimal biomass dosage was 16 g.L(-1). The values of free energy, ethalpy (75.7 J.K(-1).mol(-1)) and entropy change (21.6 kJ.mol(-1)) have been calculated from the equilibrium data. These indicate, that the sorption process was endothermic and spontaneous. The value of activation energy (18.0 kJ.mol(-1)) suggests, that the process involved is chemisorption. was strongly bound to the biomass and the desorption yields using inorganic acids, hydroxides and salts were low. However, the biomass showed a good potential for use in multiple sorption cycles with Sb(III) removal being more than 90 % over five cycles. This, together with maximum sorption capacity (8.77 mg.g(-1)), which is comparable or better than a big part of (bio)sorbents previously assessed for Sb(III) removal indicates sufficient potential of Thymus sopyllum biomass for treatment of contaminated waters.

Arsenic removal from aqueous solutions by biomass of two fungal strains, Aspergillus niger and Neosartorya fischeri, was assessed. The biosorption capacity of fungal biomass was studied within the As(V) concentration range of approximately 0.2 to 5.0 mg L(-1) at two different pH values (pH 5 and 7). With increasing initial arsenic concentration, the biosorption capacity of both fungal strains increased almost linearly and achieved the sorption capacity of 0.317 and 0.124 mg g(-1) for biomass of N. fischeri and A. niger, respectively. The effect of biomass treatment with FeCl3 and HCI on As(III) and As(V) uptake was also studied. The optimum biosorption pH as well as the effect ofbiomass treatment was found to be dependent on the fungal strain used. Treatment with FeCl3 and HCl did not result in any significant increase in arsenic uptake. To the contrary, treatment with ferric oxyhydroxide was found to be very effective and virtually 100% of the arsenic was removed from the samples of contaminated natural water.

This paper evaluates the immobilization of humic acids extracted from soils on the surface of natural zeolite clinoptilolite from aqueous solutions and the influence of humic acid coverage on the arsenate immobilization. The kinetics of humic acids sorption onto two different fractions of zeolite was evaluated and Freundlich isotherm was applied for finer fraction (below 0.1 mm). Freundlich constant was 0.002 mg.g(-1) which indicates low affinity of humic acids towards the inorganic material in diluted solutions. The amount of sorbed humic acids slightly decreased the affinity of sorbent for arsenate at pH 7. The sorption capacity for iAs(V) decreased from 10.97 mg.g(-1) to 7.57 mg.g(-1).

Little is known about thallium behavior in the environment, especially its interactions with microorganisms such as fungi. This article evaluates basic interactions (bioaccumulation, biosorption and growth inhibition) between thallium and the common heat-resistant fungal species Neosartorya fischeri. The results suggest that the N. fischeri strain is relatively resistant to elevated concentrations of thallium in cultivation media up to 1 mg·l -1 . However, the toxic effect of thallium on fungal growth depends on the time of cultivation, and after 30-day cultivation growth inhibition was reduced. The bioaccumulation of thallium after 30-day cultivation by fungal strain was 35.74 mg·kg -1 and 432.91 mg·kg -1 for initial concentration 1.012 and 4.861 mg·l -1

Production of volatile derivatives of arsenic was studied using pure cultures of different fungal strains under laboratory conditions. Arsenic was used in its trivalent and pentavalent forms to evaluate the effect of arsenic valency on its biovolatilization. The average amount of volatilized arsenic for all fungal strains ranged from 0.026mg to 0.257mg and 0.024mg to 0.191mg of trivalent and pentavalent arsenic, respectively. These results show that approximately 23% of arsenic was volatilized from all culture media originally enriched with approximately 4 and 17mgL−1 of arsenic in trivalent form. The average amount of biovolatilized arsenic from culture media originally enriched with 4 and 17mgL−1 of arsenic in pentavalent form was 24% and 16%, respectively. The order of ability of arsenic biovolatilization is Neosartorya fischeri > Aspergillus clavatus > Aspergillus niger. Toxicity and fungal resistance to trivalent and pentavalent arsenic were also evaluated based on radial growth and biomass weight.

The quantification of arsenic biovolatilization by microscopic filamentous fungi Aspergillus clavatus, A. niger, Trichoderma viride and Penicillium glabrum under laboratory conditions is discussed in this article. The fungi were cultivated on a liquid medium enriched with inorganic arsenic in pentavalent form (H3AsO4). Filamentous fungi volatilized 0.010 mg to 0.067 mg and 0.093 mg to 0.262 mg of arsenic from cultivation systems enriched with 0.25 mg (5 mg.l−1 of arsenic in culture media) and 1.00 mg of arsenic (20 mg.l−1 of arsenic in culture media), respectively. These results represent the loss of arsenic after a 30-day cultivation from cultivation systems. The production of volatile arsenic derivatives by the A. niger and A. clavatus strains was also determined by hourly sorption using the sorbent Anasorb (CSC) on the 29th day of cultivation.

The aim of this work is to show the ability of several fungal species, isolated from arsenic polluted soils, to biosorb and volatilize arsenic from a liquid medium under laboratory conditions. Mechanisms of biosorption and biovolatilization play an important role in the biogeochemical cycle of arsenic in the environment. The quantification of production of volatile arsenicals is discussed in this article.

The biosorption of cadmium and arsenic from aqueous solutions onto the unmodified compact biomass of microscopic filamentous fungus Aspergillus clavatus DESM. was studied in the concentration range of 0.25 - 100 mg.l(-1). The experimental biosorption results for arsenic and cadmium followed well the Freundlich equilibrium sorption model.

In a hypogean Jewish cemetery in Bratislava containing cemetery soil and tombstones, the types of fungi on various calcite mineral substrates in dark, cold and constantly moist chambers without direct ventilation and lighting were investigated. The mineral substrates included monomineral limestone, and limestone containing quartz, magnesite, gypsum, micas, feldspar, illite and smectite. The characteristics of the mineral substrates were examined by pH and X-ray-diphractographic analyses. The pH of the substrates in water ranged from 9.71 to 10.33. Structural changes in the substrates were revealed by scanning electron microscope photos. The samples yielded 36 different microfungi. The most common contaminants of the substrates analysed were Acremonium strictum, Alternaria alternata, Aspergillus versicolor, Aureobasidium pullulans, Cladosporium sp., Fusarium sp., Penicillium sp., P. chrysogenum, P. viridicatum, and Trichoderma sp. The investigation has shown that these hard, highly alkaline mineral substrates are susceptible to the growth of microscopic fungi, sporulation and subsequent degradation of the materials.