The objectives of the survey were to analyse the structure of the mollusc communities in the mining subsidence reservoirs that were created as a result of land subsidence over exploited hard coal seams and to determine the most predictive environmental factors that influence the distribution of mollusc species. The reservoirs are located in urbanised and industrialised areas along the Trans-Regional Highway, which has a high volume of vehicular traffic. They all have the same sources of supply but differ in the physical and chemical parameters of the water. In total, 15 mollusc species were recorded including four bivalve species. Among them Anodonta cygnea is classified as Endangered according to the Polish Red Data Book of Animals and also as Near Threatened according to the European Red List of Non-marine Molluscs. Eleven of the 15 mollusc species are included on the European Red List of Non-marine Molluscs as Least Concern. Conductivity, pH and the concentration of calcium were the parameters most associated with the distribution of mollusc species. Canonical correspondence analysis showed that Potamopyrgus antipodarum, Radix balthica, Physella acuta, Gyraulus crista and Pisidium casertanum were associated with higher conductivity and lower pH values. A. cygnea, Anodonta anatina and Ferrissia fragilis were negatively influenced by these parameters of the water. The results of this survey showed that the mining subsidence reservoirs located in urbanised and industrialised areas provide refuges for rare and legally protected species and that they play an essential role in the dispersal of alien species as well.

The effect of humic acid (HA), on the adsorption and transport of arsenic (As) onto and within a model iron oxide-based adsorbent, iron oxide-coated diatomite (IOCD), is investigated. Experimental results indicate that the adsorption of both As and HA is highly pH-dependent. As uptake was suppressed by HA, with the level of suppression increasing with HA concentration. The suppression is attributed to the partial coverage of the adsorption sites, as confirmed by elemental analysis. Adsorption energy analysis indicates that for As(III), the main interaction with IOCD is physical adsorption, whereas for As(V), it is more likely ion exchange. The presence of HA may alter the adsorption energy and interaction of As with the adsorbent, particularly at higher HA concentrations. Kinetic results indicate that HA did not affect the diffusional transport of As in systems with both As and HA. However, for IOCD preloaded with HA, the adsorption kinetics of As was significantly slower, although the As uptake was similar to the conditions of co-sorption with HA. The slower kinetics and similar equilibrium uptake of As in the HA-preloaded IOCD system may be attributed to the partial blockage of the intraparticular pores within IOCD, which slowed down the diffusion of As.

Natural (AC-N) and electrochemical iron-modified activated carbon (AC-Fe-2.5A) were applied to treat wastewater with organic by-products generated by the manufacture of acrylic resins from methyl methacrylate (MMA) using batch and column systems. MMA wastewater has an extremely complex composition with a chemical oxygen demand concentration of 651.25 g O₂/L, total organic carbon (TOC) concentration of 227.86 g/L, NH₄⁺concentration of 62.74 g/L, and 352,500 PtCo units. Wastewater was distilled to decrease the ammonium concentration with a removal efficiency of ammonium of 52 %. Then, Fenton oxidation was applied in order to promote the partial oxidation of organic matter; the molar dosage of Fe²⁺/H₂O₂was 0.018/5.700 at pH 5.3. After distillation and oxidation processes, batch experiments using natural and iron-modified activated carbon were carried out in order to determinate the adsorption equilibrium time and capacities. The global removal percentages of TOC by oxidation–adsorption treatment were the highest at pH 2, 21.09 and 29.46 % for AC-N and AC-Fe-2.5A, respectively, and for color were most efficient at pH 4, 80.62 and 72.55 % for AC-N and AC-Fe-2.5A, respectively. The results showed that AC-Fe-2.5A was more efficient than AC-N for the removal of TOC. The electrochemical modification improves the adsorption capacities and properties of activated carbon.

Industrial production of manganese/silicon ore has generated a large number of tailing wastes which are difficult to dispose. A new method treating coking wastewater was proposed using the manganese/silicon tailing waste and demonstrated with good performances: the chemical oxygen demand (COD) removal rate was around 60 % without pH and temperature adjustment, with a reasonable reaction time of 2.5 h and tailing dosage of 0.2 g/L; while phenylamine was eliminated with a removal rate as high as 99 and 61.6 % for synthetic and real coking wastewater, respectively. Experimental results indicated that the removal of organic pollutants was mainly realized through chemical adsorption and/or oxidation by oxide components inside the tailing, rather than by physical adsorption. Operational parameters such as tailing dosage, reaction time, and temperature were optimized. Acid conditions were found to be favorable to remove the selected model organic pollutants, i.e., volatile phenols and phenylamine. Fortunately, the optimistic wastewater pH for COD removal was found to be around 7.0, right within the range of influent pH for real coking wastewater. The new method can treat coking wastewater and reuse mining tailing wastes simultaneously.

The bioactivity of three kinds of multi-walled carbon nanotubes (MWCNT) towards the conidia of entomopathogenic fungus Isaria fumosorosea was examined in an in vitro study. Commercial—raw and functionalized—carboxylated MWCNT were applied. A fungal conidia suspension was placed in contact with dispersed MWCNT over different time-periods. After contact with the nanomaterial, the conidia were cultured on dishes and both the linear vegetative mycelium growth and the sporulation and germination of the spores derived from the culture were investigated. Also, the pathogenicity of the conidia after contact with MWCNT was examined in relation to test larvae. No fungistatic activity of MWCNT relative to I. fumosorosea conidia was demonstrated. Conidia contact with MWCNT resulted in the following changes in vital processes in the subsequent culture compared to the control standard culture: (1) raw MWCNT limited mycelium inoculation, but the growth rate observed later in the log-phase was more intense; (2) after 24-h conidia contact with all MWCNT types, the mycelium sporulated the most intensively; longer contact resulted in sporulation process limitation. Germination of conidia after contact with the MWCNT was not significantly modified. Raw MWCNT potentiated conidia pathogenicity towards test insects. It was observed that carboxylation of MWCNT reduces the bioactivity of this nanomaterial towards the investigated conidia.

Arsenic (As) is a ubiquitous metalloid known for its adverse effects to human health. Microorganisms are also impacted by As toxicity, including methanogenic archaea, which can affect the performance of a process in which biological activity is required (i.e., stabilization of activated sludge in wastewater treatment plants). The novel ability of a mixed methanogenic granular sludge consortium to adapt to the inhibitory effect of arsenic As was investigated by exposing the culture to approximately 0.92 mM of arsenite (Asᴵᴵᴵ) for 160 days in an arsenate (Asⱽ)-reducing bioreactor using ethanol as the electron donor. The results of shaken batch bioassays indicated that the original, unexposed sludge was severely inhibited by Asᴵᴵᴵ as evidenced by the low 50 % inhibition concentrations (IC₅₀) determined, i.e., 19 and 90 μM Asᴵᴵᴵ for acetoclastic and hydrogenotrophic methanogenesis, respectively. The tolerance of the acetoclastic and hydrogenotrophic methanogens in the sludge to Asᴵᴵᴵ increased 47-fold (IC₅₀ = 910 μM) and 12-fold (IC₅₀ = 1100 μM), respectively, upon long-term exposure to As. In conclusion, the methanogenic community in the granular sludge demonstrated a considerable ability to adapt to the severe inhibitory effects of As after a prolonged exposure period.

Continuous use of recycled water (treated sewage effluent) over a long period of time may lead to the accumulation of salt in the root zone soil. This is due to the relatively higher levels of salt content in the recycled water compared to surface water. In this study, a laboratory column study was carried out to validate the HYDRUS 1D model under no rain condition. During the validation, the relative error and the % bias between observed and simulated soil water electrical conductivity (ECSW) were found to be low and varied in a range of 5–10 and 5–6 %, respectively. The validated model was then used to predict long-term (5 years) salt accumulation under drought conditions. The analysis of model predicted salt values showed a cyclical pattern of salt accumulation in the root zone, and this related to the variation in rainfall and evapotranspiration. The mean root zone ECSWin the 5th year was found to be within the highest salinity tolerance threshold for pasture (11.2 dS/m); however, the maximum root zone ECSWwas found to be about 63 % more than the threshold. Irrespective of seasons, in 5 years time, ECSWat the depth of 1.0 m increased from 3.0 to 7.0 dS/m, which may pose a salinity risk to the groundwater table if there is a perched water table at a depth <1 m below the field surface. One of the management options to minimise long-term salt accumulation was also examined. By reducing the salt in recycled water by 50 %, it was possible to keep the ECₛwwithin the recommended threshold values. Overall, the methodology developed in this study can be used to identify appropriate management options for sustainable recycled water irrigation.

This article evaluates various extraction techniques’ suitability for soil mercury phytoavailable fraction assessment, including DGT method and extraction with microscopic filamentous fungi metabolites, MgCl₂, rainwater, and EDTA. After mercury extraction from contaminated soils by these techniques, the obtained data were compared to mercury accumulation by shoots of barley (Hordeum vulgare L.). Comparison of these values showed that DGT method is able to separate soil mercury with the best agreement to total mercury concentration in shoots of barley. However, comparing mercury extraction efficiency of selected techniques to extraction efficiency of barley, statistical significance at 0.05 significance level was proved for fungal Cladosporium sp. and Alternaria alternata metabolites. Our results indicate that these extraction techniques are suitable for risk assessment of mercury phytoavailability in contaminated areas.

This paper analyzes the mathematical modeling procedure to describe the decomposition of adsorbed phenanthrene in prototypical and real soil samples (sand and agricultural soil, respectively) by ozone. The modeling scheme considered a set of ordinary differential equations with time varying coefficients. This model used the adsorbed ozone in the soil, the ozone reacting with the contaminant and the phenanthrene concentration in the soil sample. The main parameters involved in the mathematical model included a time varying ozone saturation function (k ₛₐₜ (t)) and reaction constants (k ᵣ). These parameters were calculated using the ozone concentration variation at the reactor output, named as ozonogram, and the measurements of phenanthrene decomposition through ozonation. The model was validated using two series of experiments: (1) soil saturated with ozone in the absence of the contaminant and (2) soil artificially contaminated with phenanthrene. In both cases, the proposed parametric identification method yields to validate the mathematical model. This fact was confirmed by the correspondence between numerical simulations and experimental data. In particular, total decomposition of phenanthrene adsorbed in two different systems (ozone-sand and ozone-agricultural soil) was obtained after 15 and 30 min of reaction, respectively. This difference was obtained as a consequence of soil physicochemical characteristics: specific surface area and pore volume. The ozonation reaction rate constants of phenanthrene in the sand and agricultural soil were calculated using the same parameter identification scheme.

Glyphosate applied in association with atrazine provides the best cost/benefit for weed control for genetically modified corn. Therefore, the aim of this work was to evaluate the effects of applying glyphosate in mixture with atrazine on soil microbial population and on herbicides fate in a representative Oxisol from Brazil. The treatments consisted in applying the recommended field rate of glyphosate in association with 0, 1, and 2 times the recommended field rate of atrazine (and vice versa), plus the control (without herbicides application). The presence of atrazine temporarily (21 days) decreased soil microbial biomass (SMB) and increased soil carbon mineralization (SCₘᵢₙ, up to 13 times) and microbial metabolic quotient (qCO₂) due to the stresses caused by its toxicity. When the mixture was applied independent of the rates, SMB was recovered and the amounts of extractable and non-extractable¹⁴C-residues were the same for both herbicides at 63 days. These results suggest that glyphosate may mitigate atrazine’s temporary impact on soil microbes by supplying them nutrients during their adaptation.