Laboratory batch and column experiments were performed to better understand the effects of Ca²⁺, Mg²⁺, and HCO₃ ⁻ on Cr(VI) removal from aqueous systems with pyrite. Batch results show that increasing HCO₃ ⁻ concentration led to an increase in Cr(VI) removal by pyrite due to pH buffering capacity of HCO₃ ⁻. However, while Ca²⁺ and Mg²⁺ individually had no effect on Cr(VI) removal at pH 4, the addition of Ca²⁺ or Mg²⁺ to systems containing HCO₃ ⁻ resulted in a significant decrease in Cr(VI) removal at pH 8 relative to the systems containing HCO₃ ⁻ alone. The XPS data proved that while Ca²⁺ precipitated as CaCO₃₍S₎ onto pyrite surface, Mg²⁺ sorbed and/or accumulated as Mg(OH)₂₍S₎ onto oxidized pyrite surface. The formation of surface precipitates (e.g., CaCO₃) inhibited further Cr(VI) reduction by blocking electron transfer between Cr(VI) and pyritic surface sites. While the precipitation of Ca²⁺ as CaCO₃ led to a significant decrease in effluent pH, the decrease in effluent pH was very low in systems containing Mg²⁺, most probably due to much higher solubility of Mg²⁺ at pH 8. Zeta potential measurements provided further evidence that while Ca²⁺ or Mg²⁺ had no effect on zeta potential of pyrite particles under acidic conditions (e.g., pH < 7), the addition of Ca²⁺ or Mg²⁺ to systems containing Cr(VI) reversed the pyrite surface potential from negative to positive under alkaline pH conditions (e.g., pH > 8) relative to system containing only Cr(VI), suggesting the sorption and/or accumulation of surface precipitates on pyrite surface.

In this study, a cost-effective and easily prepared adsorbent for fluoride removal was synthetized by loading activated aluminum and lanthanum onto hydrothermal palygorskite (HP) (denoted as La-Al-TAP). And the La-Al-TAP was characterized by scanning electron microscope (SEM), x-ray diffraction analysis (XRD), and x-ray photoelectron spectroscopy (XPS). As a result, the optimal condition for La-Al-TAP preparation was proposed as follows: 0.004 mol/L La(III) and 0.125 mol/L Al(OH)₃ colloid was loaded onto the acidulated HP (AP) with volume ratio of AP/La(III)/Al(OH)₃ = 1:6:1, and then La-Al-AP was calcined at 300 °C for 2 h. Results proved that the La-Al-HP adsorbent had a significantly larger surface (95.58 m²/g) than that of raw HP (34.31 m²/g). The amorphous structure provided a favorable site for fluoride adsorption, subsequently improving the adsorption capacity of HP. The results all indicated the formation of oxide La-Al-O composite at the surface of adsorbent. The adsorption of fluoride by adsorbent La-Al-TAP was well fitted to the Langmuir isotherm and the maximum adsorption capacity was up to 1.04 mg/g. It was also found that the adsorbent could be regenerated for such six times with good security performance. In conclusion, the newly prepared La-Al-TAP adsorbent in this study has potential as an excellent adsorbent for fluoride removal in groundwater remediation works.

The uptake of polybrominated diphenyl ethers (PBDEs) by carrot and lettuce was investigated. Degradation of PBDEs in soil in the absence of the plants was discarded. Different carrot (Nantesa and Chantenay) and lettuce (Batavia Golden Spring and Summer Queen) varieties were grown in fortified or contaminated compost-amended soil mixtures under greenhouse conditions. After plant harvesting, roots (core and peel) and leaves were analyzed separately for carrot, while for lettuce, leaves and hearts were analyzed together. The corresponding bioconcentration factors (BCFs) were calculated. In carrots, a concentration gradient of 2,2′,3,4,4′,5′-hexabromodiphenyl ether (BDE-138) became evident that decreased from the root peel via root core to the leaves. For decabromodiphenyl ether (BDE-209) at the low concentration level (7 and 20 ng g⁻¹), the leaves incorporated the highest concentration of the target substance. For lettuce, a decrease in the BCF value (from 0.24 to 0.02) was observed the higher the octanol–water partition coefficient, except in the case of BDE-183 (BCF = 0.51) and BDE-209 (BCF values from 0.41 to 0.74). Significant influence of the soils and crop varieties on the uptake could not be supported. Metabolic debromination, hydroxylation or methylation of the target PBDEs in the soil–plant system was not observed.

The objective of this study was to examine the effect of band gap of photocatalyst on the decolorization of dye new coccine (NC). The concentration of NC in the present of CuO, Fe₂O₃, TiO₂, and ZnO reduced to 50.5, 23.3, 0.1, and 0 mg L⁻¹, respectively, after 5 h solar light irradiation. The concentration of NC in dark condition only decreased to 48.140, 45.079, 35.269, and 31.045 mg L⁻¹ with CuO, Fe₂O₃, TiO₂, and ZnO as photocatalysts, respectively, after 5 h contact time. The absorbance peaks and chemical oxygen demand (COD) concentration of NC in the presence of TiO₂ and ZnO decreased to baseline and zero compared to the CuO and Fe₂O₃. The COD concentration of NC with CuO, Fe₂O₃, TiO₂, and ZnO as photocatalysts reduced to 21, 13, 0, and 0 mg L⁻¹, respectively, after 12 h of solar irradiation. The surface morphology of photocatalysts was examined by scanning electron microscope (SEM), and it was found that the particle size of CuO, Fe₂O₃, TiO₂, and ZnO ranging 250–375, 250–600, 40–100, and 60–500 nm, respectively. In summary, the higher band gap energy level indicated greater photocatalytic degradation and mineralization of NC.

The study was aimed to evaluate the selected improvements of nature restoration in a depleted gravel pit. The study site consisted of four water reservoirs of different shapes and sizes, flooded after the gravel extraction ended. Ecological succession monitoring, conducted by the Warsaw University of Life Sciences students associated in the Student Scientific Association of Animal Sciences Faculty since the completion of mining, have focused on amphibians. A twofold approach upheld amphibian species population dynamics, as well as selected habitat elements. The restoration practices dedicated to habitat conditions enhancing have been proved to be definitely effective and useful for similar sites.

Biochar can potentially reduce fumigant emissions in agriculture. Dimethyl disulfide (DMDS) is an effective soil fumigant for controlling soil-borne pests. However, it is important to reduce DMDS emissions because the compound has an unpleasant and easily perceived sulfur odor. This study therefore aimed to determine the effects of two types of biochar amendments on DMDS bioactivity and emission, using bioassay methods and soil columns. The efficacy of DMDS for controlling root-knot nematode and Fusarium spp. was not reduced when the biochar used in this study was applied at a rate less than 2 and 0.5 % (on a weight basis), respectively. The biochar with high specific surface area (SSA 113 m⁻² g⁻¹) reduced the efficacy of DMDS against soil-borne pests more than the low SSA biochar (14 m⁻² g⁻¹). Increased doses of DMDS were able to offset decreases in the efficacy of DMDS in soils amended with biochars, except for high SSA biochar applied at a rate of 2 %. Biochar amendments applied to the soil surface at shallow depth can significantly reduce DMDS emission to the atmosphere. The results of this study will support decision-making about the practical use of biochar to reduce DMDS emissions.

Metalcasting involves having a molten metal poured in a hollow mould to produce metal objects. These moulds are generally made of sand and are chemically bonded, clay-bonded, or even unbounded. There are many binder systems used. Binders based on furfuryl resins constitute currently the highest fraction in the binders no-bake group. Moulding sand, after knocking out the cast, is partially reclaimed, and the remaining part, known as waste foundry sand is used or stored outside the foundry. In this case, the environment hazardous organic compounds and metals can be leached from the moulding sand, thus causing pollution of water and soil. Also during the casting moulds with molten metal, they emit pyrolysis gases containing many different compounds, often dangerous from the BTEX and PAH group, which has adverse impacts on the environment and workers. The article presents the results of research on the impact of the regenerate addition to the moulding sand matrix on emitted gases and the degree of threat to the environment due to leaching of hazardous components. Therefore, for the total assessment of the moulding sands harmfulness, it is necessary to perform investigations concerning the dangerous substances elution into the environment during their management and storage, as well as investigations concerning emissions of hazardous substances (especially from the BTEX and PAHs group) during moulds pouring, cooling, and casting knocking out. Both kinds of investigations indicated that reclaimed sand additions to moulding sands have significantly negative influence on the environment and working conditions.

The bioaccessibilites of heavy metals in vegetables grown around a waste-incinerator site were estimated using the physiologically based extraction test (PBET) method, to assess potential health risk to the local consumers. The average gastric and intestinal bioaccessibilities of Cd, Cr, Cu, Ni, and Pb in vegetables varied within 3.2–9.4 and 0.8–5.3 %, 1.4–2.3 and 1.1–1.9 %, 25–46 and 13–26 %, 6.6–30 and 2.6–5.3 %, 11–29 and 7.1–23 %, respectively. Strong negative correlations were found between electrochemical potential (ΔE ₀) and bioaccessibility for leaf mustard samples (r ² = 0.857) and leaf lettuce samples (r ² = 0.696). In addition, softness index (σp) and electrochemical potential (ΔE ₀) exhibited a moderate but not significant relationship with bioaccessibilities on the basis of the multiple regression analysis (0.05 < p < 0.1). The total bioaccessible target hazard quotient (TBTHQ) of the five heavy metals was 2.5, with Pb being the major risk contributor. According to the TBTHQs of each group of vegetables, local consumers are experiencing adverse health effects by consuming most of the vegetables around waste-incinerator site.

This paper presents the study of the occurrence of ten endocrine-disrupting compounds in twenty wastewater samples, collected from different sampling points throughout a wastewater treatment plant process. This work was assessed using ultra-performance liquid chromatography with electrospray ionization-tandem mass spectrometry that provides simultaneous quantification and confirmation of the presence of these emerging compounds. All samples were previously cleaned with vacuum filtration and extracted by solid-phase extraction. The compounds studied in this work are 17β-estradiol, ethinylestradiol, estriol, estrone, progesterone, mestranol and diethylstilbestrol, 4-n-nonylphenol, 4-tert-octylphenol and bisphenol A. The analytical limits were calculated for each compound and were used to identify and these target compounds in a wastewater treatment plant. The main conclusions obtained during this study emphasized that wastewater is an important contamination source of these compounds, the most common being bisphenol A and nonylphenol and wastewater treatment plants are not structured to remove endocrine-disrupting compounds. However some removal efficiencies were achieved for estriol (around 98 %) and bisphenol A (around 67 %) along treatment process, indicating that with some preventive approaches it is possible to minimize this problem.

Volatile organic sulfur compounds (VOSCs) are frequently reported in eutrophic lakes during the process of algal blooms’ degradation. The algal-induced so-called black water blooms have been purported to be a big contributor to the production of VOSCs. However, the production mechanism of VOSCs in black water blooms and its influencing factors still remain unclear. In this study, a laboratory sediment/algal slurry experiment was carried out to investigate the formation process of black water blooms and factors such as temperature, microorganisms, and sulfate concentrations on the production of VOSCs in eutrophic lake sediments during the decomposition of algal blooms. The simulation study indicated that black water blooms can only be produced with the participation of sediment and algal together, which could be the result of low redox potential and the continuous release of ferrion irons (Fe²⁺) and hydrogen sulfide (H₂S) into the lake’s ecosystem; however, neither of algal nor sediment can induce the formation of black water blooms. In addition, the sediment + algal treatment can produce more VOSCs than a single sediment or algal treatment. Higher temperature incubation and a higher concentration of sulfate additions can enhance the concentration of H₂S and VOSCs in black water blooms. However, the addition of microbial inhibitors in the algal/sediment slurry indicated that sulfate reducing bacteria (SRB) can stimulate the production of VOSCs, whereas methanogen might consume some concentration of VOSCs and thus lower their concentration in black water blooms.