Edible muscle tissues of Solea solea, Mullus barbatus, and Sardina pilchardus marketed in Mersin were analyzed for their Cr (total), Mn, Fe, Ni, Cu, Zn, As (total), Cd, Sn, and Pb levels. Metal levels of the tissues were determined using inductively coupled plasma-mass spectrophotometric (ICP-MS) methods. Muscle levels of Cr, Mn, Fe, Ni, Cu, Zn, As, Sn, and Pb were determined as 0.19–2.80, 0.08–3.88, 0.93–25.76, 0.03–0.63, 0.01–1.96, 1.28–45.95, 0.49–25.26, 0.14–4.03, and 0.02–1.37 mg kg⁻¹ w.w., respectively. Cadmium levels were below detection limits in all the muscle samples taken. Mean metal levels of the tissues were compared with the provisional tolerable daily (PTDs) and weekly (PTWIs) intake limits. Mean metal levels taken by the consumption of analyzed tissues were below PTDs and PTWIs; hence, the fish species studied do not pose any risk for human consumption from the point of heavy metals.

Spherical biochar derived from saccharides (glucose, sucrose, and xylose) was prepared through two steps: pre-hydrothermal carbonization at 190 °C and calcination at low temperatures (200–325 °C). The spherical biochar was characterized by Brunauer–Emmett–Teller (BET) surface area analysis, Fourier transform infrared spectroscopy, zeta potential, scanning and transmission electron microscopies, and X-ray diffraction. The result indicated that the spherical biochar exhibited low S BET (15–22 m²/g), but abundant superficial active oxygen-containing functional groups. The spherical biochar possessed a negatively charged surface within solution pH 2.0–11. The adsorption process of Pb²⁺, Cu²⁺, and methylene green 5 (MG5) was strongly dependent on the solution pH and reached fast equilibrium at approximately 60 min. The maximum Langmuir adsorption capacity (Q°ₘₐₓ) exhibited the following order: glucose-biochar > sucrose-biochar > xylose-biochar prepared at 300 °C. The selective adsorption order of glucose-biochar was Cu²⁺ (0.894 mmol/g) > Pb²⁺ (0.848 mmol/g) > MG5 (0.334 mmol/g). The electrostatic attraction played a determining role in the adsorption mechanism of pollutant cations. The adsorption of anionic dye (acid red 1) on the spherical biochar was negligible because of electrostatic repulsion. The spherical biochar can serve as a newer and promising adsorbent to remove toxic pollutant cations from water media.

Basil (Ocimum basilicum L.) is extensively cultivated as either an important spice and food additive or a source of essential oil crucial for the production of natural phenylpropanoids and terpenoids. It is frequently attacked by fungal diseases. The aim of the study was to estimate the impact of thiuram contact time on the uptake of manganese, cobalt, nickel, copper, zinc, cadmium, and lead by Ocimum basilicum L. The relevant plant physiological parameters were also investigated. Two farmland soils typical for the Polish rural environment were used. Studies involved soil analyses, bioavailable, and total forms for all investigated metals, chlorophyll content, and gas exchange. Atomic absorption spectrometry was used to determine concentration of all elements. Analysis of variance proved hypothesis that thiuram treatment of basil significantly influences metal transfer from soil and their concentration in roots and aboveground parts. This effect is mostly visible on the 14th day after the fungicide administration. Thiuram modifies mycoflora in the rhizosphere zone and subsequently affects either metal uptake from the soil environment or their further migration within the basil plant. Notable, those changes are more evident for basil planted in mineral soil as compared to organic soil with higher buffering capacity.

The inhibitory effect of seven different metals on the specific anammox activity of granular biomass, collected from a single stage partial nitritation/anammox reactor, was evaluated. The concentration of each metal that led to a 50% inhibition concentration (IC₅₀) was 19.3 mg Cu⁺²/L, 26.9 mg Cr⁺²/L, 45.6 mg Pb⁺²/L, 59.1 mg Zn⁺²/L, 69.2 mg Ni⁺²/L, 174.6 mg Cd⁺²/L, and 175.8 mg Mn⁺²/L. In experiments performed with granules mechanically disintegrated (flocculent-like sludge), the IC₅₀ for Cd⁺² corresponded to a concentration of 93.1 mg Cd⁺²/L. These results indicate that the granular structure might act as a physical barrier to protect anammox bacteria from toxics. Furthermore, the presence of an external layer of ammonia oxidizing bacteria seems to mitigate the inhibitory effect of the metals, as the values of IC₅₀ obtained in this study for anammox activity were higher than those previously reported for anammox granules. Additionally, the results obtained confirmed that copper is one of the most inhibitory metals for anammox activity and revealed that chromium, scarcely studied yet, has a similar potential inhibitory effect.

A strengthened constructed rapid infiltration (SCRI) system is a sewage treatment system derived from a constructed rapid infiltration (CRI) system. The SCRI tank structure primarily includes saturated and non-saturated layers. The degradation of the chemical oxygen demand (COD) and the conversion of ammonia nitrogen (NH₄⁺-N) are primarily performed in a non-saturated layer. To study the COD and NH₄⁺-N removal process in a non-saturated layer, two organic glass columns with a radius of 2.5 cm and a height of 70 cm were loaded with layers of soil from the Shunyi district of Beijing. The primary goal of this research is to quantify the removal effect factors and the relationship of the COD and NH₄⁺-N in the non-saturated layer. The SCRI system functioned successfully under a wetting-drying ratio of 1:5 with hydraulic loading at 1.0 m³/ (m²·d) for over 2 months. Our results show that the removal rate of NH₄⁺-N is approximately 69.11%, and the removal efficiency of COD is approximately 90.46%. The removal of COD is only slightly affected by pH, while the removal of NH₄⁺-N is greatly influenced by pH.

In today’s world, remediation of the environmental pollutants including soil contaminations is among the main issues and concerns considered by environmental scientists. Vapor extraction method is an in situ method to clean up volatile and semi-volatile contaminants of soil especially in unsaturated areas. Thermal enhancement to extract vapors includes different technologies. Its purpose is to transfer heat to the subsurface of the soil to increase the vapor pressure of volatile organic compounds and, consequently, to increase the amount of extracted VOCs. In this study, modeling was done by using laboratory data after screening. Validation was also done with the help of an artificial neural network using the response surface methodology. After training and evaluating the model, it was found that this model determines the amount of contaminant removal rate according to available data and different temperatures by good measures. The correlation coefficient square was equal to 0.95 in the validation section by the neural network. This coefficient was equal to 0.99 in the original model. At the end, a contaminant removal formula for sandy soils has been presented. As a result, due to the proximity of the correlation coefficient to 1, this model can be used to predict the removal rate of thermal enhancement in the relevant circumstances with a slight error.

Polycyclic aromatic hydrocarbons (PAHs) are scavenged from the atmosphere during snowfall, stored in the seasonal snowpack, and exchanged with PAHs in atmosphere. Thus, the PAHs in fresh snow and snowpack could reflect the PAH levels in atmosphere. This study investigated the concentrations and compositions of 16 priority-controlled PAHs in fresh snow and seasonal snowpack, as well as PAH levels in underlying soils before and after snow melting. The total concentrations of PAHs in fresh snow and snowpack ranged from 26.6 ± 4.2 to 36.9 ± 1.7 μg L⁻¹ and from 40.3 ± 4.4 to 105.9 ± 6.9 μg L⁻¹, respectively. The higher concentrations of PAHs in fresh snow compared with other areas indicated a high PAH level in atmosphere in Changchun city, presenting a potential risk to human health. Higher concentrations of total PAHs in snowpack than those in fresh snow indicated the prominent deposition of PAHs from atmosphere to snowpack in winter. In contrast, a specific reduction of five- to six-ring PAHs in the snowpack suggested that strong photolysis of five- to six-ring PAHs occurred in snowpack. The variation of PAHs in different snowpacks suggested that the deposition may be largely affected by local environment. The results of diagnostic ratios and principal component analysis (PCA) suggested that the PAHs in fresh snow and snowpack are both from a mixed source of coal combustion and from vehicle emissions. However, nonmetric multidimensional scaling (NMDS) divided fresh snow and snowpack into two groups, indicating the different contributions of coal combustion and vehicle emissions to PAHs in fresh snow and snowpack. After snowpack melting, three- to four-ring PAH levels in underlying soils showed no change, indicating that the three- to four-ring PAHs were volatilized to the atmosphere. This study indicated a risk of atmospheric PAHs in Changchun city in winter and in the beginning of spring.

Effect of harvesting and hydraulic retention time (HRT) on the performance of a sequencing batch reactor (SBR), growing a green alga Botoryococcus braunii, was investigated. In this continuous tertiary treatment, relieving limitations of light, inorganic carbon, nitrogen, and phosphorous can make photoautotrophy active through the rapid fixation of the building blocks into microalgal biomass together with heterotrophy promoted by organics and self-shading effect. Analysis of the results reveals that the control over CO₂ supply and the extension of solid retention time (SRT) are the keys to maintaining higher biomass productivity and better treatability in the mixotrophic SBR. Among HRTs tested, the shortest HRT of 2 days could demonstrate the best removal efficiencies of ammonia (98.8%) and total phosphorus (96.2%) while keeping the highest specific growth rate of 0.23 day⁻¹. Those results provide understanding on the impact of settling sequence, which extends SRT to 5~7 days and prevents significant limitations of light and essential building blocks. With the interplay between photoautotrophic and heterotrophic metabolisms of microalgae, this study identifies how the mixotrophic SBR perform resource recovery during tertiary treatment of livestock wastewater, and how limitation is associated with the effluent quality in the SBR.

In the present research, the distribution and subcellular localization of cadmium in the roots, shoots, and leaves of Monochoria hastata were evaluated to understand structural and ultrastructural changes caused by the metal. Several visual toxic symptoms such as withering, chlorosis, and falling of leaves appeared in M. hastata, especially at 15 mg L⁻¹ Cd concentration. Analysis of Cd concentration by ICP-OES showed that Cd concentrations in the root were significantly higher than those in the shoot and found to be in the following order: root > stem > leaf. Bioconcentration factor (BCF) and translocation factor (TF) were used to evaluate accumulation and transfer of metals from the root to aerial parts. TF of Cd in M. hastata was <1 in all three Cd concentrations. But it has quite considerable extent of BCF value suggesting that M. hastata is a moderate accumulator. SEM has provided a strong evidence of closing of stomata due to Cd-induced stress. The results of TEM showed the deposition of electron-dense material in vacuoles, cell wall, chloroplasts, and mitochondria. Besides, significant ultrastructural changes such as changes of the shapes of the chloroplasts, reduction of the number of cristae, high vacuolization in the cytoplasm, decrease in the intercellular spaces, shrinkage of vascular bundle, and loss of cell shape were observed in the TEM micrograph study. FTIR analysis revealed the presence of different functional groups which are responsible for binding of Cd ions in the biomass. From the above study, it is clear that M. hastata can potentially be useful for the removal of Cd from Cd-containing wastewater.

Modification of a catalyst with polyethylene glycol (PEG) created a dramatic increase in the catalytic activity for the degradation of phenol wastewater. The Fe/PEG-modified γ-Al₂O₃ catalyst was prepared by an impregnation method. The as-prepared catalyst was characterized by X-ray photoelectron spectroscopy, wide- and small-angle X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and N₂ adsorption-desorption experiments, and the results showed that the Fe species were highly dispersed on the surface of the PEG-modified support. At the same time, the PEG modification resulted in an increase in the Brunauer-Emmett-Teller surface area and pore volume. The catalytic activity test showed that the Fe/PEG-modified γ-Al₂O₃ catalyst exhibited a superior performance for the degradation of phenol wastewater in this study, and the phenol and COD removal values reached 94.1 and 88.9%, respectively, within 60 min. The results clearly show that PEG modification is a promising methodology for the preparation of a catalyst with good dispersal of the active component on the support.