Ecological light pollution occurs when artificial lights disrupt the natural regimes of individual organisms or their ecosystems. Increasing development of shoreline habitats leads to increased light pollution (e.g., from cottages, docks, automobile traffic), which could impact the ecology of littoral zones of lakes and rivers. Smallmouth bass (Micropterus dolomieu) engage in sole paternal care, guarding their nest continually, day and night, to protect their developing offspring. Any alterations to their behaviour—either directly because of the response to light or indirectly due to changes in nest predator activity and associated response of the bass—could lead to increased energetic demands for fish that have a fixed energy budget and ultimately reduce reproductive success. To examine this issue, tri-axial accelerometer biologgers were externally attached to nesting smallmouth bass during the egg stage to determine whether light pollution (i.e., dock lights with low levels of continuous light and spotlights with high intensity irregular light simulating automobile traffic) altered behaviour of nesting males relative to control fish. Our study revealed that both types of light pollution increased overall bass activity level compared with the control group. The intermittent light treatment group had the highest activity and exhibited large fluctuations between night and day activity levels. Fish in the continual light treatment group displayed statistically higher activity than the control fish but showed limited fluctuations between day and night activity levels. Our results suggest that continuous or intermittent light sources, common in shoreline habitats that have been developed, have the potential to alter the behaviour and thus energy use of nest-guarding fish. This study contributes to the growing body of literature on the ecological consequences of light pollution in aquatic ecosystems.

The overall purpose of this work was to evaluate the treatment system performance of sequential hybrid bioreactors, one without aeration and another with intermittent aeration, in the bioremoval of Cr(VI) and total chromium and in the removal of total organic carbon (TOC). The saturation kinetic curves were studied with initial concentrations of Cr(VI) of 80, 120 and 150 mg L⁻¹. A reference test was performed before adding chromium to the system, with the intention of checking the influence of the presence of chromium on the TOC removal. During the bioreactor regeneration, the chromium removal was evaluated, after each kinetic studied. For kinetics with 80 mg L⁻¹ of Cr(VI), the results showed that after 600 h of operation, there was no saturation of bioreactors, yielding 87 % overall removal of Cr(VI) and 62 % chromium total. For initial concentrations of Cr(VI) of 120 and 150 mg L⁻¹, only the non-aerated bioreactor reached saturation after 228 and 216 h of operation, respectively. In regeneration, it was found in all the assays performed that the chromium concentration at the outlet of the bioreactor became almost zero at a maximum of 72 h of operation. In the blank test, the TOC removal achieved was 64 %, while in the three tests in the presence of chromium, this was approximately 55 % (80 mg L⁻¹), 41 % (120 mg L⁻¹) and 31 % (150 mg L⁻¹). After cell lysis by ultrasound, it was found that the chromium concentration retained inside there was lower than the concentrations present in the environment.

Porous asphalt (PA), porous concrete (PC), and permeable inter-locking pavers (PICP) with sub-surface layers consisting of different gravel sizes (63, 40, and 12 mm) commonly used in the bedding, base, and sub-base layers of permeable pavements were investigated for their ability to remove total suspended solids (TSS), total phosphorous (TP), and total nitrogen (TN). The investigation focused on the individual surface and sub-surface layers of the three permeable pavements to “treat” these pollutants and how the physical design of these layers influences their water quality treatment performance. This assessment was conducted with a laboratory study, but performances were also compared to data obtained from a field-scale study of pollutant removal in PA, PC, and PICP. Pollutant removal by a sub-surface layer and the particle size distribution of outflow are dependent on both the thickness of the layer and the gravel size. Superior performance in removing pollutants was found in PC’s surface layer compared to the surface layers of PA and PICP. The lab-scale pavements and the field-scale pavements have similar performance in removing pollutants for TSS (87–95 %) and TP (75–89 %) but not for TN (3–10 % for lab-scale and 2–40 % for field-scale pavements). A simple mathematical model based on these results was developed to provide estimates of performance in the field.

High amounts of antibiotics are introduced in the soil environment by manure amendment, which is the most important spreading route in soil, with a potential ecotoxicological impact on the environment. The objectives of this study were (a) to assess the tetracycline (Tc) bioavailability in a clay and in a sandy soil, and (b) to evaluate the effects of the Tc and cow manure on the structure and function of soil microbial communities. Clay and sandy soils were spiked with Tc at the concentrations of 100 and 500 mg Tc kg⁻¹ soil, and were amended or not with cow manure. The clay soil showed greater Tc sorption capacity and bioavailable Tc was between 0.157 and 4.602 mg kg⁻¹ soil. Tc dose and time-dependent effects on soil microbial communities were investigated by fluorescein diacetate activity, phospholipid fatty acids analysis, as well as by Biolog community level physiological profile and microbial counts at 2, 7 and 60 days after Tc and/or manure addition. The added Tc caused detrimental effect on the microbial activity and structure, particularly in the short term at the highest concentrations. However, the Tc effect was transient‚ it decreased after 7 days and totally disappeared within 60 days. Cow manure shifted the bacterial structure in both soils, increased the microbial activity in clay soil and contributed to recover the microbial structure in Tc-spiked manure treatments.

In this paper, the application of biofiltration is investigated for controlled removal of gas phase chloroform through cometabolic degradation with ethanol. A trickle bed air biofilter (TBAB) operated under acidic pH 4 is subjected to aerobic biodegradation of chloroform and ethanol. The TBAB is composed of pelleted diatomaceous earth filter media inoculated with filamentous fungi species, which served as the principle biodegrading microorganism. The removal efficiencies of 5 ppmᵥ of chloroform mixed with different ratios of ethanol as cometabolite (25, 50, 100, 150, and 200 ppmᵥ) ranged between 69.9 and 80.9%. The removal efficiency, reaction rate kinetics, and the elimination capacity increased proportionately with an increase in the cometabolite concentration. The carbon recovery from the TBAB amounted to 69.6% of the total carbon input. It is postulated that the remaining carbon contributed to excess biomass yield within the system. Biomass control strategies such as starvation and stagnation were employed at different phases of the experiment. The chloroform removal kinetics provided a maximum reaction rate constant of 0.0018 s⁻¹. The highest ratio of chemical oxygen demand (COD)ᵣₑₘₒᵥₐₗ/nitrogenᵤₜᵢₗᵢzₐₜᵢₒₙ was observed at 14.5. This study provides significant evidence that the biodegradation of a highly chlorinated methane can be favored by cometabolism in a fungi-based TBAB.

The Spent Pot Liner (SPL) is a toxic solid waste from the aluminum industry. The genotoxic potential of SPL and its main chemical components (fluoride, cyanide, and aluminum) were evaluated on vegetal (Allium cepa L. system test) and human cells (comet assay) in the present study. Meristematic cells from A. cepa submitted to the treatments presented a reduction in the mitotic index (MI) and an increase in the frequency of chromosome alterations (CA). The SPL treatment reduced MI in 50 % when compared to the negative control. In addition, there were significant reductions in MI on the cyanide and aluminum treatments. All frequencies of chromosome alterations observed to the treatments were statistically different from control, and cyanide was the most cytogenotoxic component. The exposed cells to the treatments also increased the frequency of condensed nuclei. The comet assay on human leukocytes demonstrated that all treatments induced DNA fragmentation. Fluoride and SPL showed similar damages to the positive control (doxorubicin, UA = 259.7) and higher than the negative control (CaCl₂ 0.01 M, UA = 16.5). The aluminum induced intermediary damage, and the cyanide was responsible for minor damage. In conclusion, both SPL and its main components presented genotoxic and mutagenic potential on evaluated cells. Fluoride was the main genotoxic component for human leukocytes while cyanide leads the higher alterations for A. cepa meristematic cells. Thus, the storage and discard of this residue should be regulated and supervised more closely in order to reduce the risk of environmental pollution and its contact with human.

Studied technosols represent a unique system of a 50-year-old environmental burden after dam failure of coal-ash pond. The released ashes rich in arsenic with a thickness of 1–2 m were covered by a 40-cm thick layer of soil. Long-term exposure and selection pressure of elevated concentrations of arsenic (a range of 93–634 μg/g) induced the formation of the specific adapted autochthonous microorganisms. The phylum Proteobacteria was identified as a dominant phylum in the soils and represented only by one class—Gammaproteobacteria with six species. The species of phylum Firmicutes, Bacteroidetes and Actinobacteria were also identified. Thirty-three species of identified autochthonous microscopic fungi belong to 18 genera with the most abundant Mortierella alpina (Zygomycota). The most frequent identified mycobiota belongs to genera Penicillium, Aspergillus, Trichoderma and Alternaria. The isolates of Alternaria triticina, Bionectria ochroleuca, Chrysosporium queenslandicum, Exophiala psychrophila, Metarhizium robertsii, Trichoderma rossicum and Phlebia acerina were identified for the first time in Slovakia. Despite the stimulation of autochthonous community by nutrient medium and augmentation by native species, As leachability was relatively low—on average 5.63 wt.%, 9.23 wt.% and 17.04 wt.% of the total As for inoculated Pseudomonas chlororaphis ZK-1, Pseudomonas putida ZK-5 and Aspergillus niger, respectively. The highest As leachability was achieved through biostimulation of autochthonous microbiota using liquid SAB medium (34.73 wt.% of total As content). Additionally, microbial activity was efficient in the biovolatilization of As from soils (∼70 wt.% of the total As volatilized). It appears that bioremediation using microorganisms represents one of the possible ways of As removal from soils containing coal-combustion ashes with elevated concentrations of As.

Mining activities can cause drastic disturbances in soil properties, which adversely affect the nutrient cycling and soil environment. As a result, many efforts have been made to explore suitable reclamation strategies that can be applied to accelerate ecology restoration. In this study, we reconstructed mine soils with fly ash, gangue, sludge, planted ryegrass, and inoculated arbuscular mycorrhizal fungi (AMF) in Pangzhuang mine of Xuzhou during 2009 to 2015. The soil aggregation process, enzyme activities (i.e., invertase, urease and acid phosphatase activities), soil organic carbon (SOC) as well as other soil nutrients such as nitrogen, phosphorus, and potassium contents of the reconstructed mine soils were monitored during 6-year reclamation. The integrated application of sludge and AMF led to a promising reclamation performance of mining areas, in which soil aggregate stability, enzyme activities, SOC, and ryegrass biomass were effectively enhanced. The micro-aggregates (< 0.25 mm) decreased with the increase of macro-aggregates (> 0.25 mm) during the reclamation, indicating that macro-aggregates were gradually formed from micro-aggregates during the pedogenesis of reconstructed mine soils. The correlation analysis shows that SOC contents in aggregate fraction of 0.25∼0.5 mm were correlated with aggregate distribution and enzyme activities. Enzyme activities, however, were not significantly correlated with aggregate distribution. The outcomes from the present study could enrich our understanding on soil property changes in pedogenesis process of reconstructed mine soils, and meanwhile, the employment of sludge combined with AMF is suggested to be an effective alternative for the mine soil reclamation.

At present, the remediation of heavy-metal-polluted cropland soil is a considerable problem. In this study, in situ immobilization field experiment was conducted by planting rice (Oryza sativa L.) in low Cd-contaminated paddy soil to determine the optimal soil amendment that would reduce the accumulation of Cd in brown rice. GL (main component is alkaline residue), FG (main components are Si and Ca), and SH (main component is lime) were utilized as amendments. The remediation effects of the amendments on the soil and rice were investigated, and the potential mechanisms of reducing Cd availability to rice were analyzed. Amendment application significantly increased the soil pH value, reduced the DTPA-extractable Cd concentrations, and shifted Cd species from the exchangeable Cd fractions to the carbonate-bound, Fe-Mn oxides and residual fractions in paddy soil. For the plant, amendment application apparently increased the concentrations of Ca in rice plants, which could compete with Cd in root uptake. Besides, amendment application also effectively restricted the translocation of Cd from roots to shoots and consequently led to a notable decrease of Cd concentration in brown rice. These results demonstrated that the FG ameliorant could be effective in reducing Cd bioavailability and accumulation in rice grown on low Cd-contaminated paddy soils.

Wastewater (WW) for irrigation and application of biosolids in soil is becoming important as it is going to become very common in the near future. By 2050, the world is going to have four billion people living in water-scarce countries, making it a norm of freshwater for the cities and WW for agriculture. Further, biosolids might still be used as green biofertilizers for soils, if they are improved from an ecological point of view. However, application of biosolids in soil is argued because of the amount of organic pollutants that compromise the dynamic equilibrium of the biological systems. Therefore, information on the concentration, behavior, and cycling of organic pollutants as well as their possible degradation pathways is needed to predict, prevent, and remediate these pollutants from different sources including WW and biosolids. Among the group of organic pollutants, emerging contaminants (ECs) enter into the soil with the irrigation water from treated effluents and fertilization by biosolids. Quantification of ECs from WW and biosolids is of main importance to predict the toxic effects of WW effluents and sludge. Moreover, their incorporation into vegetables through irrigation and their magnification through natural food webs have been proved and must be monitored. This review presents information on the different sources of emerging contaminants and linking with the ecological effects they produced by reacting in the environment during various applications of WW and biosolids in soil. The available methods for analysis and quantification of ECs in different matrices, such as WW and biosolids, are also presented.