Before and after an intense wildfire in a forested area of Colorado in June 2012, river water and sediment samples were collected to study temporal and spatial trends related to the event. Water quality and soil properties were disturbed by the fire, but the magnitude was relatively small without precipitation. After precipitation, in-stream total nitrogen and total phosphorus (TP) concentrations significantly increased in the upstream section located within 10 km of the burned area. Large amounts of particulate P associated with highly correlated total suspended solids were introduced to the upstream section. Along with significantly increased in-stream concentrations of soluble reactive P (SRP) and dissolved organic P (DOP) after rain events, SRP dominated dissolved P in the river replacing DOP that was the main dissolved species before the fire event. In the riverbank, TP load increased significantly after the fire, and silt-clay and organic matter mass concentrations increased after precipitation. Riverbed TP mass concentrations decreased due to a reduced sorption capacity leading to a considerable P release from the sediments. The results indicate that fire-released P species will impact the downstream area of the watershed for a considerable time period as the bank erosion-sorption-desorption cycles in the watershed adjust to the fire-related loading.

This study investigates the removal of Cu(II) from aqueous solutions by biosorption-flotation as a function of several parameters, such as collector type, pH, molar ratio, air pressure, time, and initial metal concentration. Dissolved air flotation was applied as a polishing technique for the additional purification of the effluent resulted after biosorption. The obtained results were supported by the physicochemical characteristics of the surfactants used as flotation reagents and suggested that cetylpyridinium bromide (CPB) was the optimum collector for Cu(II) ion removal. Cu(II) removal efficiency exhibited a maximum of 97.09 % in the following operating conditions: biosorption pH 4.5, Cu(II) initial concentration 250 mg/L, biosorbent dosage 0.5 % w/v, agitation rate 200 rpm, temperature 20 °C, biosorption time 30 min, flotation pH 9, air pressure 4.5 × 10⁵ Pa, dilution ratio 3:1, flotation time 10 min, collector CPB 0.01 M, and molar ratio collector/Cu(II) 5 × 10⁻¹:1. The experimental data confirmed that the flotation stage contributed to the optimization of the overall separation process.

The potential of agricultural waste materials for the removal bisphenol A (BPA) from aqueous solution was investigated. BPA is an endocrine-disrupting compound (EDC) used mainly in the plastic manufacturing industry. It may be hazardous to humans and animals because of its estrogenic activity. Agricultural wastes are sustainable adsorbents because of their low cost and availability. Hence, this study investigated the removal of BPA from water by adsorption onto treated coir pith, coconut shell and durian peel. The adsorption of BPA from water onto adsorbent was evaluated using field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET). The effects of morphology, functional groups, and surface area on adsorption before and after pretreatment with sulfuric acid and reaction were investigated, and it was found that the treated adsorbent were able to remove BPA. Carbonyl and hydroxyl groups had appear in large number in FTIR analysis. The present study indicates that coir pith had removed 72 % of BPA with adsorption capacity of 4.308 mg/g for 24 h, followed by durian peel (70 %, 4.178 mg/g) and coconut shell (69 %, 4.159 mg/g). The results proved that these modified phyto-waste were promising materials as alternative adsorbent for the removal of BPA from aqueous solution.

Nikola Tesla B power plant (TENT-B), located on the Sava River in Obrenovac, 52 km west from the Serbian’s capital, Belgrade, is the second largest coal-fired power plant in the country, consisting of two blocks of 620 MW each. Samples of fresh coal ash obtained by coal combustion in TENT-B, as well as coal ash samples from the surface and 1-m depth of active, currently filled, and passive, previously filled and not currently used, cassettes, were taken from the coal ash dump. Ultrasonic extracts of the samples were analyzed using gas chromatography with mass selective detection (GC/MSD) in order to identify and quantify 16 priority polycyclic aromatic hydrocarbons (PAHs). Two PAH extraction mechanisms during coal ash dumping and storage processes are discussed and significant differences between them were established. PAH concentrations in the ash samples were compared statistically. Correlations between samples and sampling points were established, and leaching potential of samples was examined. Concentrations of PAHs can be reduced in coal ash sediments by environmental influences only after long time periods, and PAHs with two six-membered rings pose danger to underground waters, while PAHs with three rings pose danger to soil sediments.

The model of contaminant transport between the abiotic components of the lake water-sediment system is presented. The implementation of the model, which uses radioactive material as a contaminant, and the evaluation of parameter values are discussed in the work. A semi-analytical solution of the simulation of the dynamics of contaminant transport in the lake water and one-dimensional sediment solute transport including non-equilibrium processes is presented. The model includes a concept of dynamics of the contaminant sorption in lake water and sediment compartments, considering the specific porous structure of sediments, the contaminant material exchange between the liquid and solid phases of sediments. The key processes included in the model are sedimentation, resuspension, diffusive exchange of solute at the lake water-sediment interface and advection-diffusion in sediment solute. Modelling of the contaminant transport in both spheres (lake water and bottom sediments) is influenced by non-equilibrium and transformation reactions. Special attention was paid to the contamination balance between the two spheres in the interface area. The ranges of boundary and initial conditions were extended, and final results were obtained using an accurate and robust numerical inversion calculation based on the De Hoog algorithm. Therefore, the model can be used in experimental measurements interpreting the contaminant profile in lake sediments as well as a part associated with the comprehensive determination of the volumetric activity, in the estimation of irradiation doses due to radionuclides released into the lake water.

Three commercial electrodes, Ta-Ir/TiO₂, Rh-Ir/TiO₂, and PbO₂/TiO₂, were used as electrochemical anodes, and their performance was evaluated by the electrochemical oxidation of ammonia at neutral pH in a continuous electrochemical quadrangular reactor. Based on the cyclic voltammetry scans and volt-ampere relation analysis, in direct oxidation, the oxygen evolution from H₂O₂decomposition was completely inhibited, and more•OH radicals could be then generated over PbO₂/TiO₂and in the presence of powder activated carbon (PAC). PbO₂/TiO₂can be indicated as an appropriate for the direct electrooxidation of ammonia in an unpacked bed reactor. While the efficiency for direct oxidation of ammonia was similar for the three anodes in a PAC packed reactor due to the presence of PAC could avoid short circuit and enhance electric efficiency. In indirect oxidation mediated by active free chlorine, Rh-Ir/TiO₂was the most effective in ammonia removal when chloride was present in the reaction system, and the disappeared ammonia was mainly transferred to N₂, and only a small part was converted into nitrate (there was no nitrite detected during the reaction). The results indicated that Rh-Ir/TiO₂had the highest oxidation capability for ammonia compared with Ta-Ir/TiO₂and PbO₂/TiO₂. Hence, Rh-Ir/TiO₂based on a PAC packed bed reactor provides an alternative for the treatment of ammonia wastewater with high chloride concentration.

Mesostructured CuMnCeO ₓ catalysts were prepared and tested in chlorobenzene destruction. Mn and Cu phases enter CeO₂matrix with a fluorite-like structure to form Cu–Mn–O–Ce solid solution. Both synthesis protocol and metal-doping content affect the metal state, reducibility, and oxygen distribution of composites. The c₀.₁₅c₀.₁₅c₀.₇sample exhibits the highest activity with 90 % of chlorobenzene oxidized at around 250 °C. Enhanced oxygen concentration and mobility, and abundant oxygen vacancy promote the desorption of adsorbed Cl, which guarantees the superior stability of CuMnCeO ₓ . Incorporation of CuO and MnO ₓ effectively inhibits the formation of organic byproducts, such as phenolates, maleates, and o-benzoquinone, especially at elevated temperatures.

The contents of As, Cu, Cd, Pb, Mn, along with the Pb isotopic ratios ²⁰⁶Pb/²⁰⁷Pb and ²⁰⁸Pb/²⁰⁶Pb were studied in both soils and tree rings of the marula tree (Sclerocarya birrea) in the vicinity of the Tsumeb deposit (Namibia). Amounts of all the studied metals and As are higher in the immediate vicinity of the Tsumeb Cu-Pb smelter in the soil. The tree rings also have their maximum content of all the studied substances in the vicinity of the smelter (with the exception of Pb). At a more distant site, the maximum concentration of Pb in the soils was 29.8 mg/kg, while the content in the soil in the vicinity of the smelter was as much as 8,174 mg/kg. In the vicinity of the smelter, the maximum Pb content in the tree rings reaches a value of 5.7 mg/kg, compared to a more distant site, where the contents are as high as 9.2 mg/kg. The lower Pb content in the trees on contaminated soil indicates that the composition of the xylem determines the above-ground uptake, rather than the root uptake. Similarly, the above-ground uptake is documented by the isotopic composition of Pb at the distant location, where the tree rings have different contents of Pb isotopes compared to in the soil. The As, Cd, Cu, Pb, and Zn contents are highest in the tree rings from the 1950s (and older), along with those from the 1990s, while the Mn contents were highest in those from the 1960s and 1990s. The contaminant peaks in the 1950s and 1960s could be associated with the roasting of sulfidic ores, while the peak values in the 1990s could have been caused by the start of Cu slag reprocessing in the late 1980s, and culmination of works at the smelter prior to the closing of the mine. The tree rings of the marula tree were found to be a suitable archive for above-ground pollution close to Cu and Pb smelters.

We highlighted some of the key problems associated with the use of beneficial microorganisms for improving adaptation of plants to soils, polluted with heavy metals (HMs), especially Cd. Inoculation of pea line SGE and its Cd-tolerant mutant SGECdᵗ with nodule bacteria Rhizobium leguminosarum bv. viciae demonstrated that nodulation process may be disturbed at Cd concentrations below threshold toxicity levels for each partner and the plant genotype plays a major role in nodulation under Cd stress. A comparative mathematical analysis of available information about Cd tolerance, accumulation of HMs (Cd, Cr, Cu, Ni, Pb, Sr and Zn), response to mycorrhizal fungus Glomus sp. and 15 phenotypic traits of 99 pea varieties revealed that (1) the Cd-sensitive varieties were more efficient in exploring the protective potential of symbiosis to compensate their deficit in Cd tolerance and (2) correlations between the studied traits exist and can be helpful for selection of plant-microbe systems adapted to polluted soils. In pot experiment with 11 varieties of Indian mustard, the plant growth-promoting effect of rhizobacterium Variovorax paradoxus 5C-2 negatively correlated with Cd tolerance and shoot Cd concentration of the plants grown in Cd-supplemented soil. In an outdoor pot experiment, inoculation of willow with the ectomycorrhizal fungus Pisolithus tinctorius and a cocktail of rhizobacteria stimulated root exudation, decreased soil pH and increased Cd mobilization in soil and Cd uptake by plants, but decreased plant growth at a moderate contamination level (25 mg Cd kg⁻¹). Opposite effects were observed in highly contaminated soil (77 mg Cd kg⁻¹). We propose a preliminary systematic framework of interactions between these factors that determine the success of microbial inoculation aimed at improving crop performance on HM-polluted soils or enhancing phytoremediation.