Various inorganic and organic pollutants in industrial soils may adversely affect soil microorganisms and terrestrial ecosystem functioning. The aim of the study was to explore the relationship between the microbial activity, microbial biomass, and functional diversity of soil bacteria and the metals and total petroleum hydrocarbons (TPHs) in the Upper Silesian Industrial Region (Poland). We collected soil samples in pine-dominated forest stands and analyzed them according to a range of soil physicochemical properties, including metal content (cadmium, lead, and zinc) and TPH content. Metal concentrations were normalized to their toxicity to soil microorganisms and integrated in a toxicity index (TI). Soil microbial activity measured as soil respiration rate, microbial biomass measured as substrate-induced respiration rate, and the bacterial catabolic activity (area under the curve, AUC) assessed using Biolog® ECO plates were negatively related to TPH pollution as shown in multiple regressions. The canonical correspondence analysis (CCA) showed that both TPH and TI affected the community-level physiological profiles (CLPPs) of soil bacteria and the pollutants’ effects were much stronger than the effects of other soil properties, including nutrient content.

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.

The present study reports the synthesis and characterization of metallic nanoparticles (NPs) of Pd and bimetallic alloys of PdCu NPs for their application as catalysts to achieve the microbial reduction of p-nitrophenol (PNP). Addition of bimetallic alloys of PdCu NPs to methanogenic sludge incubations increased up to threefold the rate of reduction of PNP. Moreover, their presence promoted a more efficient and selective reduction of PNP to the desired product (p-aminophenol) with negligible accumulation of toxic intermediates (p-nitroso-phenol and p-hydroxylamine-phenol), which prevailed in sludge incubations lacking nanocatalysts. PdCu NPs synthesized by adding precursors H₂PdCl₄ and H₂CuCl₄ independently and simultaneously to the synthesis vessel showed superior catalytic properties as compared to those produced by mixing the same precursors prior addition to the synthesis vessel. The enhanced catalytic properties of bimetallic NPs could be explained by higher physical stability and interfacial arrangement within PdCu alloys promoting a more efficient transfer of reducing equivalents derived from lactate/ethanol fermentation towards the target nitro group in PNP. A wastewater treatment technology, combining the microbial activity of methanogenic consortia and the catalytic activity of bimetallic NPs, is proposed as an alternative for the removal of recalcitrant pollutants from wastewaters.

This work investigates the behavior of atrazine (AT) and its degradation products deethylatrazine (DEA) and deisopropylatrazine (DIA) in oxisol samples. The study was carried out at different depths of maize culture soil under no-till management for up to 180 days. Additionally, controlled laboratory experiments were performed in open flasks in the absence of sunlight or in closed flasks at 4 °C. Higher AT dissipation occurred in the in the field as compared with the samples evaluated under controlled conditions, which indicated that environmental conditions might degrade AT. Interestingly, DEA and DIA levels were low, which suggested that leaching and runoff processes, formation of other degradation products, or even AT mineralization took place. Residual AT, DEA, and DIA were detected in the oxisol samples after 180 days depending on the initial amount of AT in the soil. This study has shown that straw plays a relevant role in AT retention and significantly contributes to DEA and DIA formation. At 180 days, straw samples contained AT concentrations near 100 μg kg⁻¹ and concentrations of the more leachable DEA and DIA close to 50 μg kg⁻¹ even under the influence of sunlight and rainfall. A preliminary analysis of natural water samples near the investigated region showed that DEA and DIA were absent and that AT concentrations were high, which pointed to the need for more detailed evaluation.

The Tagus Estuary is one of the most Hg-contaminated estuaries in SW Europe. Sediment cores were sampled at two low Hg-contaminated sites inside the natural park, Alcochete (ALC) and Vale Frades (VF), and analyzed for mercury and methylmercury. Concentrations of Hg and MeHg in sediments were below 1 μg g⁻¹ and 4.4 ng g⁻¹, respectively. While in summer organic matter and/or excess SO₄ ²⁻ promotes Hg methylation, in winter, Hg availability is the sole driver for methylation. Diffusive fluxes in the sediment/water interface show a sink of Hg species in the ALC site (ca. 170 mg year⁻¹ of Hg and 60 mg year⁻¹ of MeHg), while in the VF area, a sink of MeHg (ca. 1900 mg year⁻¹) as well as a source of Hg (ca. 2000 mg year⁻¹) is observed. The morphology and hydrodynamic regime of the Tagus Estuary seem to influence Hg dynamics even in areas with low levels of Hg contamination.

In this paper, Zn(0)-catalyzed ozonation degradation of acid orange 7 (AO7) and its impact factors including solution pH, Zn loading, and AO7 initial concentration were investigated through a series of bath experiments. The results demonstrated that Zn could markedly accelerate the degradation of AO7 by ozone (O₃) and the degradation efficiency of AO7 increased by 77 and 71 % within 30 min as compared with those in the systems of O₃ alone and Zn/air, respectively. The reuse of Zn resulted in a slight decline in AO7 degradation, suggesting that a coating of ZnO on the surface of Zn particles weakened Zn catalytic activity. The optimal removal of AO7 was achieved in a wide pH range of 4 to 10, and a lower or higher pH was not conducive to the degradation of AO7. In addition, the degradation efficiency of AO7 increased with Zn loading but decreased with AO7 initial concentration. The introduction of free radical scavengers into the system of AO7/Zn/O₃ confirmed that O₂ •⁻, rather than •OH, was the main free radicals responsible for the rapid removal of AO7. The degradation of AO7 by O₃ assisted with Zn could be well expressed with pseudo-first-order kinetic model.

Indoor air pollution significantly influences personal exposure to air pollution and increases health risks. Nitrogen dioxide (NO₂) is one of the major air pollutants, and therefore it is important to properly determine indoor concentration of this pollutant considering the fact that people spend most of their time inside. The aim of this study was to assess indoor and outdoor concentration of NO₂ during each season; for this purpose, passive sampling was applied. We analyzed homes with gas and electric stoves to determine and compare the concentrations of NO₂ in kitchen, living room, and bedroom microenvironments (MEs). The accuracy of passive sampling was evaluated by comparing the sampling results with the data from air quality monitoring stations. The highest indoor concentration of NO₂ was observed in kitchen ME during the winter period, the median concentration being 28.4 μg m⁻³. Indoor NO₂ levels in homes with gas stoves were higher than outdoor levels during all seasons. The concentration of NO₂ was by 2.5 times higher in kitchen MEs with gas stoves than with electric stoves. This study showed that the concentration of NO₂ in indoor MEs mainly depended on the stove type used in the kitchen. Homes with gas stoves had significantly higher levels of NO₂ in all indoor MEs compared with homes where electric stoves were used.

In this paper, we report on the development of a simple, fast, and environment-friendly UV/O₃-based method as an improved alternative to the conventional chemical methods using dichromate or permanganate for determining chemical oxygen demand (COD) in water. In the method through the continuous monitoring of O₃ and CO₂ (concentration and flow rate) before and after reaction, COD can be accurately determined. During the experiment, sample solutions with known COD concentration of 25, 12.5, 5, 2.5, and 1 ppm were first used to validate the feasibility of this new technique. These samples were treated under ambient temperature and pressure for 15 min before the complete digestion time for each sample was measured by analyzing the produced CO₂ concentration. After digestion, residual O₃ dissolved in solution was quantified by the indigo method. A linear relationship between the O₃ consumption and COD value was observed, and the slope of calibration curve was determined to be 0.34 with a R ² of 0.991. Detection limit of the current experimental setup is 0.81 ppm with a measurement range of 1–25 ppm. The precision of the COD measurement is within 5% of the actual concentration. This developed UV/O₃ method demonstrates viability in being applied to fast, reliable, and accurate COD monitoring.

This manuscript reports on a study of new biocatalysts for the biodegradation of pyrethroid pesticides, such as esfenvalerate. Experiments of esfenvalerate biodegradation by bacteria isolated from Brazilian savannah (Curtobacterium sp. CBMAI 1834, Bacillus sp. 2B, Lysinibacillus sp. CBMAI 1837, and Bacillus sp. 4T), sea (Kocuria sp. CBMAI 135, Kocuria sp. CBMAI 136, Kocuria marina CBMAI 141, and Kocuria sp. CBMAI 145), and a tropical peat usually known as “turfa” soil (Bacillus sp. P5CBNB, Kosakonia sp. CBMAI 1836, Bacillus sp. CBMAI 1833, and Kosakonia sp. CBMAI 1835) were performed. A biodegradation pathway was proposed for a better understanding of the environmental fate of the above mentioned insecticide. Esfenvalerate (S,S-fenvalerate) and its metabolites [3-phenoxybenzaldehyde (PBAld), 3-phenoxybenzoic acid (PBAc), 3-phenoxybenzyl alcohol, and 2-(4-chlorophenyl)-3-methylbutyric acid) (CLAc)] were quantitatively analyzed in triplicate experiments by a validated method. Initially, 100 mg L⁻¹ esfenvalerate (Sumidan 150SC) was added for each experiment. The residual esfenvalerate (104.7–41.6 mg L⁻¹) and formation of PBAc (0.1–8.1 mg L⁻¹), ClAc (1.5–11.0 mg L⁻¹), PBAlc (0.9 mg L⁻¹), and PBAld (completely biotransformed) were quantified. The 12 bacterial strains accelerated (with different efficiencies) the esfenvalerate degradation and increased the metabolites concentrations. A new and more complete biodegradation pathway based on HPLC-time of flight (ToF) and gas chromatography-mass spectrometry (GC-MS) analyses (in which thermal instability products were detected) was proposed. The detected metabolites are smaller and more polar compounds that may be carried by water and contaminate the environment.

The present study aimed to minimize the environmental impact from the disposal of electrocoagulated metal hydroxide sludge (EMHS) generated during an electrocoagulation process using aluminum electrode by reusing it as an effective adsorbent for simultaneous removal of fluoride ion (F⁻) and arsenic (As) from aqueous solutions. The adsorbent was characterized by using coupled plasma optical emission spectroscopy (ICP-OES), surface areas and porosity properties, point of zero charge, and X-Ray diffractometry techniques. The surface morphology of adsorbent was studied by scanning electron microscopy (SEM). The dissolution of the adsorbent in function of pH was analyzed in batch experiments. Batch adsorption tests were employed to evaluate the removal and adsorption capacity of adsorbent, under conditions of contact time and adsorbate concentration. In order to determine maximum adsorption capacity of adsorbent and to understand the nature of reaction on their surface, the Langmuir and Freundlich isotherm were calculated. Preferable fitting of the Langmuir isotherm over Freundlich isotherm suggests monolayer coverage of adsorbate at the surface of the adsorbent. Data obtained were also applied to pseudo-first-order and pseudo-second-order equations. The rates of adsorption were found to conform to pseudo-second-order kinetics. The findings of this study revealed that the reuse of EMHS is a promising and efficient adsorbent in order to diminish the fluoride and arsenic pollution from drinking water.