The contamination of soil with heavy metals is a serious agricultural issue. The presence of foods contaminated with heavy metals in the human diet can cause health damages. Metal phytoextraction processes remove soil contaminants through plant absorption; however, plants display different responses to the metal contamination of the soil. Thus, the purposes of this paper were to determine cadmium (Cd), chromium (Cr), and lead (Pb) immobilization in soil mixed with different amounts of stabilized vermicompost (obtained by earthworm composting) and verify if this vermicompost helps in the removal of heavy metal through the phytoextraction technique with black oat (Avena strigosa Schreb cv IAPAR 61) plants. The addition of a high quantity of vermicompost (50, 75, and 100%) to the soil presents similar results to the immobilization of Cd, Cr, and Pb, and a similar trend was observed in lower quantities (0 and 25%) of vermicompost. The addition of vermicompost improves the growth of black oat plants, but only the treatment with 25% of vermicompost showed promising results in the absorption of Cr and Pb, and the treatment with 50% in the absorption of Cd. Finally, we suggest that “IAPAR 61” black oat cultivar is efficient Cd, Cr, and Pb accumulators. However, heavy metal remained mostly in the root, indicating that root-to-shoot translocation was not efficient, hindering its application for phytoremediation strategies.

Sediment samples from a salt marsh habitat in the vicinity of Linden Chemical Plant (LCP) Superfund site in Brunswick Georgia, USA, were analyzed for the composition of total solvent extracts and sources of lipid compounds. Stable isotope analysis of carbon and nitrogen and gas chromatography-mass spectrometry analysis infer past multiple sources of organic matter (OM) from aquatic and terrestrial origin, e.g., phytoplankton, bacteria, and land plants, as well as anthropogenic contamination. The n-alkane and n-alkanol distributions in the sediment samples were dominated by long-chain homologues maximizing at C₂₅–C₂₇ for alkanes (carbon preference index (CPI) ∼1) and C₃₂ for n-alkanols indicating inputs from higher plants, but also microbial and petroleum-related sources. Fatty acid distribution was characterized by short-chain (< C₁₈) and branched homologues indicative of bacterial origin. The high abundance of dehydroabietic acid and anthropogenic contaminants, including alkylphenols, are indicative of the effects of past industrial activities in the LCP marsh area in Brunswick, Georgia.

By using the activated carbon obtained from Citrullus lanatus rind by zinc chloride activation, methylene blue (MB) removal from aqueous solutions was studied, and the adsorption mechanism was solved through Weber-Morris intraparticle diffusion model, Bangham model, Boyd model, Fourier transform infrared spectra, and scanning electron microscopy. The effects of adsorption parameters (adsorbent concentration, temperature, initial dye concentration, and pH) were investigated. The equilibrium data of MB adsorption were described by applying the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models. The obtained results from adsorption isotherms indicated that Langmuir model is the best-fitted model with the maximum adsorption capacities of 231.48, 243.90, 244.50, and 259.74 mg/g at 25, 35, 45, and 55 °C, respectively. The analysis of the kinetic data by pseudo-first-order, pseudo-second-order, and Elovich models displayed that MB adsorption followed pseudo-second-order model. Also, the date obtained from intraparticle diffusion model, Bangham model, and Boyd model presented that intraparticle diffusion, pore diffusion, and film diffusion played significant role in MB adsorption. The thermodynamic studies demonstrated that MB adsorption onto the activated carbon obtained from C. lanatus rind was physical, spontaneous, feasible, and endothermic. Thus, the activated carbon prepared from C. lanatus rind has been an efficient adsorbent for MB removal from an aqueous solution. Graphical Abstract ᅟ

The bioconcentration potential of fluoxetine (FLX) and its biological effects were investigated in juvenile Pacific oyster exposed for 28 days to environmentally relevant concentrations of FLX (1 ng L⁻¹, 100 ng L⁻¹ and up to 10 μg L⁻¹). FLX bioaccumulated in oyster flesh resulting in 28-day bioconcentration factors greater than 2,000 and 10,000 by referring to wet and dry weights, respectively. Nevertheless, FLX did not induce oyster mortality, delayed gametogenesis, or lead to adverse histopathological alterations. At the two highest concentrations, despite non-optimal trophic conditions, FLX stimulated shell growth but only in a transient manner, suggesting a role of serotonin in the regulation of feeding and metabolism in bivalves. Those high concentrations seemed to drive bell-shaped responses of catalase and glutathione S-transferase activities throughout the exposure period, which may indicate the activation of antioxidant enzyme synthesis and then an enhanced catabolic rate or direct inhibition of those enzymes. However, no clear oxidative stress was detected because no strong differences in thiobarbituric acid-reactive substance (TBARS) content (i.e. lipid peroxidation) were observed between oyster groups, suggesting that cellular defence mechanisms were effective. These results demonstrate the importance of considering additional biomarkers of oxidative stress to obtain a comprehensive overview of the FLX-induced changes in marine bivalves exposed under realistic conditions. Considering the battery of biomarkers used, FLX appears to induce little or no effects on oyster physiology even at a concentration of 10 μg L⁻¹. These results do not confirm the lowest observed effect concentration (LOEC) values reported by some authors in other mollusc species.

The influence of manure and composts on the leaching of heavy metals from soil was evaluated in a model lysimeter experiment under controlled conditions. Soil samples were collected from experimental fields, from 0- to 90-cm layers retaining the layout of the soil profile layers, after the second crop rotation cycle with the following plant species: potatoes, spring barley, winter rapeseed, and winter wheat. During the field experiment, 20 t DM/ha of manure, municipal sewage sludge composted with straw (SSCS), composted sewage sludge (SSC), dried granular sewage sludge (DGSS), “Dano” compost made from non-segregated municipal waste (CMMW), and compost made from municipal green waste (CUGW) was applied, i.e., 10 t DM/ha per crop rotation cycle. The concentrations (μg/dm³) of heavy metals in the leachate were as follows: Cd (3.6–11.5) < Mn (4.8–15.4) < Cu (13.4–35.5) < Zn (27.5–48.0) < Cr (36.7–96.5) < Ni (24.4–165.8) < Pb (113.8–187.7). Soil fertilization with organic waste materials did not contaminate the percolating water with manganese or zinc, whereas the concentrations of the other metals increased to the levels characteristic of unsatisfactory water quality and poor water quality classes. The copper and nickel content of percolating water depended on the concentration of those metals introduced into the soil with organic waste materials. The concentrations of Cd in the leachate increased, whereas the concentrations of Cu and Ni decreased with increasing organic C content of organic fertilizers. The widening of the C/N ratio contributed to Mn leaching. The concentrations of Pb, Cr, and Mn in the percolating water were positively correlated with the organic C content of soil.

Water and sediment samples were collected from up to 17 sites in waterways entering the Corner Inlet Marine National Park monthly between November 2009 and April 2010, with the Chemcatcher passive sampler system deployed at these sites in November 2009 and March 2010. Trace metal concentrations were low, with none occurring at concentrations with the potential for adverse ecological effects. The agrochemical residues data showed the presence of a small number of pesticides at very low concentration (ng/L) in the surface waters of streams entering the Corner Inlet, and as widespread, but still limited contamination of sediments. Concentrations of pesticides detected were relatively low and several orders of magnitude below reported ecotoxicological effect and hazardous concentration values. The low levels of pesticides detected in this study indicate that agricultural industries were responsible agrochemical users. This research project is a rarity in aligning both agrochemical usage data obtained from chemical resellers in the target catchment with residue analysis of environmental samples. Based on frequency of detection and concentrations, prometryn is the priority chemical of concern for both the water and sediments studied, but this chemical was not listed in reseller data. Consequently, the risks may be greater than the field data would suggest, and priorities for monitoring different since some commonly used herbicides (such as glyphosate, phenoxy acid herbicides, and sulfonyl urea herbicides) were not screened. Therefore, researchers, academia, industry, and government need to identify ways to achieve a more coordinated land use approach for obtaining information on the use of chemicals in a catchment, their presence in waterways, and the longer term performance of chemicals, particularly where they are used multiple times in a year.

Mn-Fe/TiO₂ catalysts synthesized by sol-gel and co-precipitation methods were used for the selective catalytic reduction (SCR) of NO with NH₃. The catalysts were characterized by N₂ physisorption, XRD, NH₃/NOₓ-TPD, and H₂-TPR. The catalytic activities for SCR and NH₃/NO oxidation were investigated in the absence and presence of water. In this study, Mn-Fe/TiO₂(S) catalyst exhibited better catalytic activity at low temperature below 175 °C in the absence of H₂O. However, more by-product of N₂O was observed in this case in contrast with Mn-Fe/TiO₂(C). The similar phenomenon was observed during the process of NH₃ catalytic oxidation. The excellent redox capability and abundant active adsorbed species on the catalyst surface accounted for higher NOₓ conversion and more N₂O formation for Mn-Fe/TiO₂(S). It was found that water vapor hindered the activation of NH₃ and adsorption-oxidation of NO, and thus, impeded catalytic activity of Mn-Fe/TiO₂ during standard SCR process at low temperature, even though it reduced the formation of N₂O. The inhibition for over dehydrogenation of amide adsorbed species and the deceleration for decomposition of ammonium nitrate species might be two reasons accounting for the decrease of N₂O concentration in the presence of H₂O. The different catalysts exhibited the different poisoning resistance to SO₂ and the SO₂ resistance of manganese-based catalyst at low temperature still needed the further improvement.

Pilot scale thin film plate reactors (TFPR) were fabricated to study the solar photocatalytic treatment of wastewater obtained from the secondary treatment plant of a sugar refinery. Silver-impregnated titanium dioxide (TiO₂) was prepared by a facile chemical reduction method, characterized, and immobilized onto the surface of ceramic tiles used in the pilot scale reactors. On 8 h of solar irradiation, percentage reduction of chemical oxygen demand (COD) of the wastewater by Ag/TiO₂, pure TiO₂, and control (without catalyst) TFPR was about 95, 86, and 22 % respectively. The effects of operational parameters such as, flow rate, pH, and addition of hydrogen peroxide (H₂O₂) were optimized as they influence the rate of COD reduction. Under 3 h of solar irradiation, 99 % COD reduction was observed at an optimum flow rate of 15 L h⁻¹, initial pH of 2, and addition of 5 mM of H₂O₂. The results show that Ag/TiO₂ TFPR could be effectively used for the tertiary treatment of sugar refinery effluent using sunlight as the energy source. The treated water could be reused for industrial purposes, thus reducing the water footprint of the industry. Graphical Abstract Sugar refinery effluent treatment by solar photocatalytic TFPR

The present study examines the efficiency of soil amendments regarding the retention of chromate ions, from water and cultivated soil with wheat (Triticum durum). The minerals and iron oxides that have been used were zeolite, bentonite, goethite, and zeolite modified with goethite I and II. Each adsorbent was added to different Cr solutions, either Cr(NO₃)₃·9H₂O or CrO₃ in a proportion of 1/100 g adsorbent mL⁻¹ solution. Moreover, greenhouse experiments were also conducted using the above materials as soil amendments. Two doses of chromate ions, i.e., 50 mg Cr(III) L⁻¹ in the form of Cr(NO₃)₃·9H₂O and 1 mg Cr(VI) L⁻¹ in the form of CrO₃, were added to plant pots cultivated with wheat. According to the results, the uptake of chromate ions from aqueous solutions onto different adsorbents has shown that modified zeolites (Z-G I and II) adsorb the highest amount of chromate ions, compared to all the other adsorbents. The statistical analysis of the greenhouse experimental data has shown that the increase of the dry weight in soils with amendments follows the order: Z-G II > G > Z-G I > B > Z for pots where Cr(NO₃)₃·9H₂O solutions were added and Z-G II > G > Z > Z-G I > B for pots where CrO₃ solutions were added, respectively. Moreover, all the used soil amendments reduced the total Cr concentration in plants, especially Z-G II. Consequently, such modified zeolites can be used for the remediation of polluted soils with chromium and the production of high-quality food products.

Industrial synthesis processes produce high concentration of hazardous organic pollutants into water body, which must be removed before being discharged. Advanced oxidation processes (AOPs) using heterogeneous catalysts has been widely utilized for wastewater treatment. Here, RuO₂-based catalyst was synthesized by a general impregnation method and used to oxidize phenol by peroxymonosulfate (PMS) as an oxidant in aqueous solution. The properties of this supported catalyst were characterized by SEM (scanning electron microscopy), XRD (powder X-ray diffraction), and nitrogen adsorption-desorption. The mesoporous Al₂O₃ support had large surface area and high thermal stability. It is found that ruthenium oxide-based catalyst is highly effective to activate PMS to related sulfate radicals. The effects of catalyst loading, phenol concentration, PMS concentration, reaction temperature, and reusability of the as-prepared catalyst on phenol degradation have been investigated. Overall, our findings demonstrate that in RuO₂/Al₂O₃ mesoporous catalyst, Oxone (PMS) is effectively activated, and 100% phenol degradation occurs in 60 min. To regenerate the deactivated catalyst and improve its catalytic properties, three different methods involving annealing in air, washing with water, and applying ultrasonics were used. The catalyst was recovered thoroughly by heating treatment.