Pomegranate peel was investigated as biosorbent to remove uranium as well as thorium from aqueous solutions under different experimental conditions (concentration, counter ions, temperature). The material was used in raw and modified form after treatment with acidic and alkaline solutions to increase its sorption capacity. Isotherms were obtained at pH 4 and Cᵢₙᵢₜᵢₐₗ: 5–300 mg L⁻¹ for uranium and at pH 3 and Cᵢₙᵢₜᵢₐₗ: 5–100 mg L⁻¹ for thorium, respectively. The equilibrium data of the sorption study, which were adapted to the Langmuir and Freundlich models, indicated enhanced sorption efficiency (115 and 80 mg g⁻¹ for uranium and thorium). Furthermore, kinetic and thermodynamic data as well as investigation by FTIR, XRD, and SEM revealed the complex sorption mechanism that can be explained by a combination of physical sorption accompanied by surface precipitation.

Innovative titania nanostructures were synthesized via efficient and prolific liquid phase deposition route and efficiently utilized for catalytic degradation of Eosin Y. The as-synthesized TiO₂@ITO nanostructures were subjected to various characterization tactics that confirmed the efficacious fabrication of nanostructures. The minute size of particles around 5–6 nm having anatase crystalline phase and concrete like morphology was greatly revealed by atomic force microscopy, XRD, and SEM, respectively. The resulting nanoconcretes were employed for photocatalytic degradation of Eosin Y dye in aqueous medium. The effects of various experimental parameters such as the reducing agent concentration, sunlight, time, catalytic dose, and microwave power were investigated for the potential photocatalytic degradation. The proposed TiO₂@ITO nanostructures showed potential photocatalytic efficiency then previously reported nanomaterial for degradation of toxic Eosin Y dye; it shows approximately 99.8% dye degraded within 50–60 s using only 100 μg of nanocatalyst under optimized conditions. Owing to minute size, topography and electron–hole pair abilities TiO₂@ITO nanostructures suggest an exceptional icon at the commercial level for successful degradation of toxic pollutants.Graphical abstract

Petrochemical industrial effluent contains industrial wastewater from various manufacturing processes. The mixed treatment of these different petrochemical wastewater effluents may influence the organic removal performance of the anaerobic processes. In this study, three typical petrochemical effluents, including polyester (PE), polyethylene terephthalate, and purified terephthalic acid wastewater, were collected. The effect of the mixed petrochemical wastewater on the organic removal and microbial community structure was investigated in the anaerobic batch assays via spectroscopy and high-throughput sequencing. The organic removal efficiencies were similar (71–85%) in all the batch assays for 90 h acclimation. The mixture of wastewater, especially the addition of PE wastewater, significantly prolonged organic removal process. It was related to the aromatic removal performance and microbial community structure during the mixed wastewater treatment. The microbial community structure in the mixed wastewater batch assay showed high similarity with that in the PE wastewater batch assay. Ignavibacterium, Syntrophus, and Pelotomaculum were crucial to the degradation of aromatic compounds together with Methanosaeta. The mixture of wastewater, especially the addition of PE wastewater, caused the decay of these functional microbes and resulted in the inefficient removal of the aromatic compounds.

Seafood has long been considered a unique source of nutrition. However, increasing trends in consumption of marine products must be considered, especially in potentially polluted environments such as the Persian Gulf. This study was undertaken to analyse the level of heavy metal contamination of nickel (Ni), zinc (Zn), and lead (Pb) in shrimp (Penaeus merguiensis) captured from the northern Persian Gulf. The concentration of heavy metals in the muscle of shrimp followed the order Zn > Ni > Pb. The content of Zn and Ni was higher than recommended standard limits by the FAO/WHO. The combined impact of all metals was lower than the acceptable limit of 1 in shrimp. The carcinogenic risk for Ni was higher than the unacceptable value. In total, our finding indicated no potential health risk from the daily consumption of this species. However, long-term consumption of shrimp can pose a risk of carcinogenic effects of nickel. Continuous monitoring of these trace metals in seafood is necessary to ensure the quality of seafood and food safety.

Green philosophy is gaining popularity worldwide. Recycling materials from building demolitions, reutilizing by-products from industrial facilities and exploring the potential uses of waste during a second life cycle are the objectives of this philosophy. In the present article, bottom ashes from electric power generation plants using biofuel combustion were evaluated to verify their potential use as expansive clay stabilizers. Two objectives are pursued: (1) finding a new use for waste that is typically landfilled despite its great potential arising from its technical properties and (2) improving the mechanical properties and reducing the expansive nature of the expansive clays identified during the construction of a motorway. Based on this framework, the present study demonstrated the potential of biomass bottom ashes to stabilize expansive clays. The optimum dosage to improve the properties of clays was determined based on performance parameters, such as plasticity, free swelling or soil collapse. Afterwards, the contaminating potential of ashes was evaluated, being classified as hazardous waste. However, the stabilized mixtures were classified as inert products, thus guaranteeing the environmental feasibility of their use. Finally, the technical application of the stabilized clays as filling materials for embankments and subgrade for light traffic roads was proved. Graphical abstract

Chromium removal from aqueous solutions has gained attention due to its hazardous impact on life organisms. In the present study, sorption processes were performed to examine the opportunity to apply biochar derived from waste tomato leaves and stems for Cr(III) ion removal. Biochars were produced through pyrolysis in a wide range of temperature (250–800 °C). The obtained biochars were investigated in detail by means of ultimate and proximate analyses, pH point of zero charge, FT–IR, scanning electron microscopy, and mercury porosimetry. Biochars are characterized by high amount of ash varying from 23 to 44% and as a result high pHpzc values of about 13. It was proven that increasing pyrolysis temperature positively affected sorption of Cr(III) ions. Mineral matter in the biochars plays a crucial role in the removal of Cr(III) ions from aqueous solution mainly due to their precipitation. The sorption capacity of biochar produced at 800 °C was 169.5 mg g⁻¹, whereas at 250 °C only 62.2 mg g⁻¹. It was found that biochar can be reused in sorption process after desorption using 0.1 M HCl, while the sorption capacity decreased 4-fold.

It is generally recognized that dispersal mode can affect the relative role of environmental and spatial factors in structuring biotic communities. Disentangling the effects of dispersal mode on metacommunity structuring is essential to understanding the mechanisms of community assembly. Despite high seasonal variation in assemblage structure and phenological features of lotic macroinvertebrates, few studies examined the seasonal changes in the relative contribution of environmental and spatial processes. Here, we used two-season (spring and autumn) investigation data to link dispersal mode with local environmental and spatial factors that regulate macroinvertebrate metacommunity in a Chinese high-mountain stream network. Our aims were (1) to disentangle the relative role of environmental and spatial processes on structuring macroinvertebrate with different dispersal ability (aquatic passive: AqPa, terrestrial passive: TePa, and terrestrial active: TeAc) and (2) to determine seasonal shifts in metacommunity structuring processes. We found that assemblages of TeAc (with highest dispersal capacity) in both seasons were influenced more by environmental filtering than spatial structuring, whereas assemblages of TePa were mainly determined by spatial processes. Unexpectedly, AqPa group showed low spatial control in both seasons, probably due to their underestimated dispersal capacity via animal vector. The relative role of environmental and spatial factors was broadly stable across two seasons for AqPa and TeAc groups, but the TePa showed seasonal differences in the relative role of spatial factors, because of their seasonally changing dispersal capacity. In summary, our study emphasizes the use of dispersal mode for understanding metacommunity structuring mechanisms.

Dissolved humic substances (DHSs) are the major components of organic matter in the aquatic environment. DHSs are well known to considerably affect the speciation, solubility, and toxicity of a wide variety of pollutants in the aquatic environment. In this study, the effects of the toxicity of heavy metals and hydrophobic organic pollutants (HOPs) on Chlamydomonas reinhardtii in the presence of humic acid (HA) were examined by a microscale algal growth inhibition (μ-AGI) test based on spectrophotometric detection. To clarify the relationship between the chemical properties of HAs and the toxicity change of pollutants, eight HAs from different sources were prepared and used. HAs were responsible for mitigating the toxicity of Hg, Cu, pesticides (γ-HCH, 2,4-D, and DDT), and polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap), anthracene (Ant), and benzo[a]pyrene (BaP). In particular, an approximately 100-fold decrease in the toxicity of BaP was observed in the presence of 10 ppm HAs extracted from tropical peat. The results indicated that the carboxylic group content and the HA molecular weight are correlated to the changes in the heavy metal toxicity. For HOPs, the aromaticity and polarity of HAs are crucial for mitigating their toxicity. Furthermore, it was clearly shown that the lake water including a high concentration of DHSs collected from Central Kalimantan, Indonesia, reduced the toxicity of Hg and γ-HCH on Chlamydomonas reinhardtii. Graphical abstract

This article is devoted to the study of physicochemical parameters and the assessment of the accumulation and distribution of metals in peat deposits from the North European part of Russia (Arkhangelsk region). Peat profiles were selected both in the area with a high anthropogenic load and in a bog remote from industrial pollution. The determination of metals was carried out by using the methods X-ray fluorescence analysis and atomic absorption spectroscopy. It was determined that the studied bogs can be attributed to the low ash type, and the recorded pH and mineralisation values make it possible to attribute these deposits to the acid-oxidising facies of oligotrophic peatlands, characteristic of taiga landscapes. Assessment of metal accumulation showed a high content of titanium, chromium, lead, nickel, vanadium, cobalt, aluminium, silicon, and copper in peat, mainly caused by the burning of fossil fuels and industrial production, as well as the burning of urban and industrial waste. The peat profiles are characterised by significant fluctuations in the content of elements in different horizons. Studies have shown the need to monitor the content of metals in peatlands from the Arkhangelsk region to assess atmospheric pollution from industrial emissions, both at the moment and in the past.