Radiological waste disposal and accidents from radionuclide production over several decades have resulted in widespread radioactive contamination of surface water systems in South Ural. Natural attenuation of radioactive contamination of freshwater can be considered as an alternative to manage radioactive materials released into the environment. A management alternative takes advantage of natural remediation processes, especially the binding of radionuclides and their compounds to water body solids via humic substances. The formation of radionuclide complexes with humic acids removes and converts radionuclides to a less hazardous form and is followed by a decrease in radionuclide bioavailability to freshwater biota, especially fish and benthos. Here, we present an investigation and quantification of natural remediation of highly contaminated surface water systems located in South Ural via humic substances. Based on a large set of experimental data, we state that in the surface water systems, humic acids promote the immobilization of radionuclides and thus decrease their bioavailability for fish in the investigated water bodies. We examine the influence of humic substance on the chemical and biological interactions between radionuclides and the environment that has experienced increasing interest concerning the remedial uses of humic materials.

The effects of alkaline dust emitted from a cement plant for over 40 years on the anatomy of needles of Scots pine and lignin accumulation were analysed. Comparative analytical studies were conducted in stands similar as to their silvicultural indicators, climate and age in alkalised and in a relatively unpolluted area. Cross-section of needles were stained, photographed under microscope and measured. It was found that, due to the alkalisation of the environment, the total area of the needle cross-section, needle width and thickness and the area of mesophyll had decreased. At the same time, the vascular bundles and epidermis had increased. The greatest anatomical and biochemical differences between the needles from trees growing under optimum conditions and in the alkalised area were observed in the oldest needles. Visual analysis of cross-sections and biochemical analysis showed accumulation of lignin in older needles but more intensively in alkalised areas than in control.

Ground-level dynamics of O₃, NO x and benzene, toluene, ethylbenzene and xylenes were characterised at rural sites in the medium Ebro River Basin (Northern Spain) from April to September (2003-2007) and by means of automated and passive monitoring. The study registered high O₃ levels within the area, which were influenced by traffic emissions, and a monthly evolution of these levels consistent with the occurrence of a broad summer maximum, typical of polluted areas. The mean ozone concentration registered in the studied area by means of passive sampling was 87 ± 12 μg m⁻³. The 2008/50/EC objective value for the protection of vegetation was widely exceeded during this study (AOT40 = 57,147 ± 14,114 μg m⁻³ h), suggesting that current ambient levels may pose a risk for crops and vegetation in this important agroindustrial region.

In order to find out a new effective accumulator of polycyclic aromatic hydrocarbons (PAHs) useful for monitoring studies on a large scale and low costs, the accumulation capacity of both biological and artificial matrixes (mosses and polyester fibers, respectively) has been tested. For this purposes, Hypnum cupressiforme and dacron® were exposed to pollution airborne in two sites located nearby an active iron industry and in center of the town of Trieste, where high PAH pollution spots, due to vehicular traffic, are usually detected. The samplers were exposed in six sampling sessions for 21 days. The results obtained were compared with data collected by active PAH samplers, usually employed for official widespread monitoring. The level of correlation between the data sets was calculated. Furthermore, a repeatability study of data was performed. According to the results, both matrixes are good PAH accumulators, though they show different skills.

Global demand for carbon nanotubes (CNTs) is increasing dramatically. As CNTs become commonplace, the range of uses is expected to expand as will the potential for release into ecosystems. Recent research suggests that CNTs display increased suspension in water in the presence of natural organic matter (NOM), thus increasing their ability for transport and dispersion. However, it remains unclear how CNT size will affect the suspension of CNTs in natural waters. Here we examine the effect of CNT diameter (10-500 nm) and CNT length (1-40 μm) in the presence of 1% sodium docecyl sulfate (SDS), and two different freshwater NOM extracts on suspension of CNTs in water. Absorbance spectrometry (UV-VIS) was used to determine CNT concentration in solutions over a 68 h period in the dark. Seventy to ninety-five percent of the CNTs settled out of the 1% SDS solution as compared to 23-54% in each of the NOM solutions. The half-life of suspension in solution increased with decreasing CNT diameter (from 13.9 to 138.8 h⁻¹ for solutions containing NOM). These results demonstrate that settling rates are strongly determined by NOM presence in solution as well as CNT size.

The degradation of diethyl phthalate (DEP) in aqueous solution by titanium dioxide (TiO2) photocatalysis has been investigated in our research. DEP was completely removed in the solution by 50-min irradiation. Results show that DEP degradation rate was affected by initial DEP concentration, photocatalyst amount, light intensity, and pH. Photocatalytic degradation intermediates were identified by gas chromatography-mass spectrometry intermediates were identified by gas chromatography-mass spectrometry. The major intermediates are methyl benzoate, ethyl benzoate, and carboxylic derivatives. The photocatalytic degradation process was found to obey first-order reaction. Consequently, the result of photocatalytic degradation could be an efficient method of DEP removal from wastewater.

Amphibians, particularly frogs, are increasingly used as bioindicators of contaminant accumulation in pollution studies. Their use for field scientific purposes is limited because most frog species are endangered and protected in most countries; killing of specimens are not allowed. The aim of our study was to work out and assess a method by which the elemental contents of frog bones could be estimated effectively based on the toe bones. For this purpose, Rana esculenta L. individuals were collected from an urban pond in Debrecen city (Hungary). The following large bones were also analysed: skull, spinal, femur, tibia-fibula, tarsal bones, metatarsus, humerus and digits from front and hind limbs. In the bones, P, Ca, Mg, Mn, Na, S and Zn elements were measured. The elemental contents of large bones were significantly correlated with bones weight in the case of each element. The elemental contents of phalanges were also estimated based on the large bones. The measured and the estimated elemental contents of phalanges were not different significantly based on the tibia-fibula, metatarsalis bones, front and hind limb digits. Elemental analysis based on phalanges adds a further way of use of phalanges. Frogs using their phalanges could be useful indicators in the assessment of environmental contamination.

Peroxidase from fenugreek (Trigonella foenum-graecum) seeds was highly effective in the decolorization of textile effluent. Effluent was recalcitrant to the action of fenugreek seeds peroxidase (FSP). However, in order to effectively decolorize effluent by peroxidase, the role of six redox mediators has been investigated. The maximum decolorization of textile effluent was observed in the presence of 1.0 mM 1-hydroxybenzotrizole, 0.7 mM H₂O₂, and 0.4 U ml⁻¹ of FSP in the buffer of pH 5.0 at 40°C in 2.5 h. The decolorization of textile effluent in a batch process by peroxidase was 85% in 5 h, whereas the complete decolorization of textile effluent by membrane-entrapped FSP was observed within 11 h of its operation. The absorption spectra of treated effluent exhibited a marked diminution in the absorbance at different wavelengths compared to untreated effluent.

It is well known that mass transfer of a solid compound into a liquid phase is characterized by mutual properties of both sides. Solubilization capacity of the liquid phase is primary affected by its composition in inorganic species inducing salting in/out effect evaluated by Setschenow constant, generally defined at 298.15 K. On the other hand, the equilibrium process is highly influenced by polar compatibility issue. Therefore, the study of such transfer is essential in order to set the role of each party participating in the solid-liquid equilibrium. Thus, a comparison of transfer magnitude and feasibility of carbaryl from pure water, to seawater, and lab-made seawater was held. To do so, solubility of the compound was experimented at different temperature in multiple media. Solubility determination is based on the saturation of a specific heated fluid passing through a saturation cell. The solute transported is subsequently trapped in a specific extraction column. Back flashing method is then applied to dissolve the compound. After validation, aqueous solubility of carbaryl was studied as function of temperature ranging from (273.15 to 318.15 K) at atmospheric pressure. In addition, solubility was determined in pure, seawater, and corresponding lab-made water, thus solubility values ranged from 3.57E-06 to 3.49E-05 in pure water, from 3.04E-06 to 2.53E-05 in seawater and from 6.51E-06 to 3.61E-05 in lab-made water. As a result, thermophysical properties of transfer and usage of lab-made water on the mass transfer properties divergence was spotted. The Salting out phenomenon observed for carbaryl was interpreted by the internal pressure theory that suggests the reduction of internal cavities in the presence of salt, making solubilization process more difficult to achieve. Thus, showing an overall endogenic process with a positive Gibbs free energy of transfer that is highly affected by the magnitude of salting out effect and the temperature. The molar entropy of transfer increases versus temperature caused by the disorder of solvent molecules due to the dissolution process.

Present research has delineated the biosorption potential of three different nonliving biomasses namely eucalyptus bark saw dust, mango bark saw dust, and pineapple fruit peel with respect to Zn (II) ion removal from liquid phase through batch experiments. The efficacy of Zn (II) ion biosorption onto surface of biosorbents was judged and correlated with biosorbent particle size, surface chemistry, and surface texture. Maximum metal ion uptake capacity, percentage removal, and minimum equilibrium concentration as 1.688 mg/g, 84.4%, and 1.56 mg/l, respectively, was obtained using eucalyptus bark saw dust mediated biosorption followed by mango bark saw dust as 1.028 mg/g, 51.4%, and 4.867 mg/l and pineapple fruit peel as 0.45 mg/g, 22.9%, and 7.71 mg/l, respectively, at a particle size of 0.5 mm. Additionally, present investigation also proved that biosorption efficiency and metal ion interaction with adsorbent surface also depends upon presence of functional groups involved in metal ion adsorption and surface porosity.