Micrometer-size poly(vinyl phosphonic acid) (p(VPA)) hydrogel was synthesized by employing UV irradiation of an emulsion containing vinyl phosphonic acid (VPA) and crosslinker, prepared using lecithin as surfactant and gasoline as solvent. The p(VPA) microgels were employed in absorption of UO₂²⁺ions from aqueous environments and have very high and fast absorption capacity. In about 20 min, 670 mg UO₂²⁺ions were absorbed per gram of p(VPA) microgel from the prepared UO₂²⁺ion solution, and the absorption capacity increased up to 900 mg at pH 6. Various parameters affecting UO₂²⁺absorption characteristics of p(VPA) were investigated. It was found that the Langmuir isotherm fitted the absorption characteristics of p(VPA) better than the Freundlich isotherm. Moreover, magnetic ferrite can be prepared within p(VPA) and used as a magnetically responsive p(VPA) microgel composite for externally controlled absorption of UO₂²⁺ions with little decrease in the absorption capacity of the p(VPA) microgel.

The remediation of dye-contaminated soil using silent discharge plasma in dielectric barrier discharge (DBD) reactor was reported in this study. Acid scarlet GR was selected as the representative of azo dye pollutants. Effects of applied voltage, discharge frequency, and gas flow rate on Acid scarlet GR treatment effect which were characterized by degradation efficiency and the change of chemical oxygen demand (COD) during the degradation were investigated. The decolorization rate of Acid scarlet GR in the soil increased with the applied voltage and discharge frequency, and the optimal gas flow rate was obtained at 1.0 L min⁻¹. The energy efficiency was clearly enhanced by way of increasing the amount of contaminated soil in the DBD reactor finitely. The degradation efficiency of Acid scarlet GR and the removal of COD value were achieved 93 % and 74 % after 25-min discharge treatment, respectively. The results indicated that the DBD remediation system was able to degrade Acid scarlet GR in the soil quickly and efficiently. This study is expected to provide a possible pathway of Acid scarlet GR degradation in soil.

This work presents an evaluation of the remediation efficiency and of the environmental impact of a zero-valent iron commercial substrate used for the removal of heavy metals from groundwater in different conditions. A specific feature of the substrate is the presence of zero-valent iron (ZVI), organic carbon, and sulfate. The authors analyzed its composition and performances by means of batch tests in different boundary conditions. In detail, the efficacy was evaluated for metals (Cu, Cr, Pb, and Zn) and for nitrates and sulfates. Neutral and acidic pH values, imputable to dangerous waste landfill leachate or to acid mine drainage, were considered. The environmental impact of the substrate was also assessed for the investigated pHs. The product showed a high efficiency in the removal of metals (mainly described by a pseudo-second-order kinetic model), with a noticeable variability according to the pH of the polluted phase. Nitrate ion removal was inhibited by sulfates at all the considered pH values. Characterization and batch studies revealed that the substrate was a source of Mn, Cr, Pb, Cu, and sulfate ions, besides Fe. This study shows that the employment of an optimized amount of reagent, while achieving good performances, is essential to contain the leaching of undesirable substances into aqueous environment.

The proposed and validated method for determination of ⁹⁰Sr content in environmental samples (water, soil and plant) is based on the radiochemical analytical separation of ⁹⁰Y from the sample and measuring its activity after the establishment of radioactive equilibrium with ⁹⁰Sr. Validation is the confirmation by examination and provision of objective evidence that they meet the individual requirements stipulated for a specific use. Validation of method was done based on the blank samples for water by adding ⁹⁰Sr known activity and using reference materials of soil (IAEA-326) and plant (IAEA-330). Content of ⁹⁰Sr in environmental samples was determined by α/β low level proportional counter. The accuracy and the precision of the applied method are confirmed and the method is validated and can be used for determination of ⁹⁰Sr in environmental samples. On the other hand, participations in interlaboratory comparisons are confirmed that the adequacy of the validated method is ensured.

The contamination of hazardous metal(loid) is one of the serious environmental and human health risks. This study isolated a total of 40 cadmium (Cd)- and arsenic (As)-resistant bacterial isolates from coastal sediments by pour plate technique using tryptic soy agar supplemented with Cd or As (50 mg l⁻¹) for use as metal(loid) bioremediation agents. Out of 40, 4 isolates, RCd3, RCd6, RAs7, and RAs10, showed a relatively higher growth rate in Cd- or As-supplemented culture media which were selected for further study. The selected isolates showed a high minimum inhibitory concentration (60–400 mg l⁻¹for Cd and 400–2200 mg l⁻¹for As), which demonstrated their remarkable Cd and As resistance capabilities. The metal(loid) removal efficiencies (0.032–0.268 μg Cd h⁻¹ mg⁻¹and 0.0003–0.0172 μg As h⁻¹ mg⁻¹[wet weight cell]) of selected isolates indicated their greater magnitude in absorbing Cd compared to As from water. Phylogenetic analysis of the 16S rDNA sequences revealed that isolates RCd3, RCd6, RAs7, and RAs10 were closely related to Acinetobacter brisouii, Pseudomonas abietaniphila, Exiguobacterium aestuarii, and Planococcus rifietoensis, respectively. Because of high Cd and As resistance and removal efficiency, the selected isolates can survive in a high metal(loid)-contaminated environment and could be a potential tool for bioremediation of high metal(loid)-contaminated effluents to protect the aquatic environment.

The agricultural destination of sewage sludge promotes the return of organic matter and nutrients to the soil, prevents contamination and degradation of hydric resources, and contributes to food and fiber production. In Brazil, the Resolution of the National Environment Council (Conama 375/06) and in the State of Paraná the Resolution of the State Environment Cabinet (Sema 021/09) established criteria and procedures for agricultural use of sewage sludge seeking to avoid risk to public health and the environment. This case study attempts to present the results of the destination of the sludge generated in the Sludge Management Units (SMU) in Curitiba Metropolitan Region (CMR), State of Paraná, Brazil from 2007 to 2010. Data analysis of agronomic parameters and inorganic substances (metals) of 99 batches of sewage sludge destined for agricultural use, based on 239 agronomic projects, was performed. The comparison of the characteristics of the batches generated in anaerobic and aerobic SMUs of CMR was also conducted. During the study, 88,166 t of sludge (33,404 dry tons) were destined for 2,288 ha of agricultural areas. The sludge provided 88 % of the lime, 74 % of N, 73 % of P₂O₅, and 35 % of K₂O for fertilizing the corn, soybean, bean, oat, wheat, green manure, and in the implementation and postharvest of stone fruit trees. The 80 benefited farmers reduced expenses with fertilizers and limestone, saving an average of US$813.45 per ha.

Phosphorus (P) management in agriculture is crucial for both environmental health and future availability of P resource. Application of P as fertilisers (organic or inorganic) often results in either P accumulation in soil or loss to water bodies, rendering them unavailable to crops. In this study, the mobility of inorganic (KH₂PO₄(PP)) and organic (poultry manure (PM)) P sources, as affected by coal combustion products (CCPs: fly ash (FA) and fluidised bed combustion ash (FBC)) application to soils, was evaluated using column leaching experiments. The incubated samples were also characterised using X-ray diffraction (XRD) and scanning electron microscopy (SEM) to understand their surface properties in relation to P adsorption and leaching. The results showed differential effects of CCPs to P treatments—in the case of PP, the CCPs decreased P leaching by 12.11 % (FA) and 20.56 % (FBC), whereas in the case of PM treatment, both CCPs increased P in leachates by 35.53 % (FA) and 18.44 % (FBC). The decrease in P leaching for PP-treated soil as affected by CCPs was attributed to high pH and Ca concentration. There was a negative relationship between the increase in CCP-induced pH and P leaching demonstrating that pH plays a crucial role in P immobilisation, transformation and leaching. The increase in P leaching for CCP-incubated–PM-treated soils was because of the mineralisation of organic P from PM. The surface chemistry from XRD and SEM results showed an increased surface area for CCPs-incubated soil compared to the control and also showed the presence of Ca-rich minerals in CCPs such as ettringite, wollastonite and merwinite.

Soil pollution with trace elements is a growing problem with serious environmental impacts and developing strategies to reduce those impacts is a high priority. The objectives of this study were to assess the role of sulfur (S) in reducing the phytotoxic effects of copper (Cu) and the appearance of oxidative stress due to excess Cu in the growth medium and to assess the potential of guinea grass for Cu phytoremediation. The experiment was carried out in a greenhouse, where the forage grass Panicum maximum cv. Tanzânia was grown with a nutrient solution containing combinations of three S concentrations (0.1, 2, and 4 mmol L⁻¹) and four Cu concentrations (0.3, 100, 500, and 1,000 μmol L⁻¹) using a 3 × 4 factorial design in complete randomized blocks with four replicates. The following variables were measured: shoot and root dry mass production, leaf and tiller number, S and Cu concentrations in diagnostic leaves and roots, H₂O₂, lipid peroxidation, and proline levels in the diagnostic leaves. Very high Cu availability (1,000 μmol L⁻¹) that resulted in Cu concentration higher than 60 mg kg⁻¹in diagnostic leaves caused more than 50 % reduction in shoot and root dry mass production about 30–40 % in the number of leaves and tillers around 20 % increase in lipid peroxidation and more than 10 times increase in proline production. Plants properly fed with S showed mitigation to Cu toxicity. Guinea grass showed promise as an agent in the phytoremediation of Cu-polluted areas.

Anthropogenic CO₂ emission is identified as the major cause of climate change. The use of fossil fuels has to be accommodated, possibly with a CO₂ capture process. Sequestration of captured CO₂ at high pressure is proposed as a feasible option for future mitigation of climate change, though using fossil fuels. However, this needs significant energy input and carries the potential threat of a possible future catastrophe. Capture of CO₂ with possible recycling is a long-term sustainable option. In this paper, a process involving a chain of reactions using solid sodium to capture both CO₂ and SO₂ from a flue gas is described. A significantly detailed description of both chemical reactions and physical processes is discussed. Recycling of captured CO₂ and SO₂ in the form of solid graphite and elemental sulphur (as the by-products) is the special feature of this process. However, critical selection of intermediate process liquids and equipment in this process needs further study for real-life implementation of this scheme.