Macrocapsules, composed of a pH-sensitive polymer and phosphate buffer, offer a novel remediation alternative for acidic ground waters. To test their potential effectiveness, laboratory experiments were carried out followed by a field trial within a coal pile runoff (CPR) acidic contaminant plume. Results of traditional limestone and macrocapsule treatments were compared in both laboratory and field experiments. Macrocapsules were more effective than limestone as a passive treatment for raising pH in well water from 2.5 to 6 in both laboratory and field experiments. The limestone treatments had limited impact on pH, only increasing pH as high as 3.3, and armoring by iron was evident in the field trial. Aluminum, iron and sulfate concentrations remained relatively constant throughout the experiments, but phosphate increased (0.15-32 mg/L), indicating macrocapsule release. This research confirmed that macrocapsules may be an effective alternative to limestone to treat highly acidic ground water. Encapsulated phosphate buffer macrocapsules were more effective than limestone for passive treatment of acidic coal pile runoff (CPR) contaminated ground water, increasing pH from 2.5 to 6 in laboratory and field experiments.

The aims of the present study were to optimize and validate methods for esterase activity (EA), total oxidant status (TOS) and total antioxidant capacity (TAC) determination in mussel' gills, and to establish the relationships between these biomarkers and Pb, Cd and Cu pollution, in single form and ternary mixture. Two different buffers for sample homogenization, the need of ultracentrifugation, and analytical validation were evaluated. Coefficients of variation, when buffer without additives and ultracentrifugation were used, were <15%, and recovery were 97%–109% in all cases. The EA response tends to decrease with treatments, TOS decreased significantly in Cd and ternary groups, while TAC tended to increase in treatments with Pb, Cd and ternary groups. In conclusion, the methods for EA, TOS and TAC measurements in gills of mussel were precise and accurate and could be interesting resources in biomonitoring programmes.

The present study describes the impregnation of coffee extract (CE) into bacterial cellulose synthesized from kombucha tea fungus (KBC) of different cellulose content, incubated for different incubation periods (2, 4, and 10 days), to prepare biocomposites having the potential for wound healing applications. Total polyphenols in hydroalcoholic extracts from ground roasted coffee and its release from the prepared biocomposites were determined as gallic acid equivalent. The polyphenols content was found to be 13.66 mg/g and the minimum inhibitory concentration (MIC) of the CE was determined using colony-forming unit (CFU) method against Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus aureus where the growth inhibition was 86 and 97% respectively. Biocomposites (KBC/CE) with the lowest cellulose and CE content showed the highest wet tensile stress (3.35 MPa), absorption of pseudo extracellular fluid (154.32% ± 4.84), and water vapor transmission rate (3184.94 ± 198.07 g/m²/day), whereas it showed the lowest polyphenols’ release (51.85% ± 2.94)when immersed in PBS buffer of pH 7.4. The impregnation of CE into KBC provided biocomposites that can enlarge the range of BC in the biomedical application.

In the present study, a novel synthesized adsorbent material based on 3-mercaptopropyltrimethoxysilane-functionalized multi-walled carbon nanotubes was used to increase the Pb²⁺ adsorption from aqueous solutions in a flow injection solid-phase extraction system coupled to flame atomic absorption spectrometry. Spectroscopic and microscopic techniques (Fourier transform infrared spectroscopy, energy dispersive spectroscopy, and scanning electron microscopy) were employed to confirm the chemical modification of the adsorbent surface. Preconcentration conditions (sample pH, flow rate, buffer solution, and eluent concentrations) were optimized using factorial and Doehlert matrix designs that made it possible to construct a linear graph in the 5.0- to 130.0-μg L⁻¹ range (r = 0.9999) and estimate detection and quantification limits (1.7 and 5.7 μg L⁻¹, respectively). The method precision was found to be 4.20 and 1.97 % for 5.0 and 100.0 μg L⁻¹ Pb²⁺ solutions, respectively. When using the 3-mercaptopropyltrimethoxysilane-functionalized multi-walled carbon nanotubes, the sensitivity for the Pb²⁺ trace determination was improved to 95 % compared with the oxidized multi-walled carbon nanotubes, thus evidencing the significant enhancement of the adsorption capacity. The developed method was successfully applied to the analysis of Pb²⁺ species in different water samples and the PACS-2 marine sediment-certified reference material.

Nitrogen fertilizers used in agriculture often cause nitrate leaching towards shallow groundwater, especially in lowland areas where the flat topography minimize the surface run off. In order to introduce good agricultural practices that reduce the amount of nitrate entering the groundwater system, it is important to quantify the kinetic control on nitrate attenuation capacity. With this aim, a series of anaerobic batch experiments, consisting of loamy soils and nitrate-contaminated groundwater, were carried out using acetate and natural dissolved organic matter as electron donors. Acetate was chosen because it is the main intermediate species in many biodegradation pathways of organic compounds, and it is a suitable carbon source for denitrification. Sorption of acetate was also determined, fitting a Langmuir isotherm in both natural and artificially depleted organic matter soils. Experiments were performed in quadruplicate to account for the spatial variability of soil parameters. The geochemical code PHREEQC (version 2) was used to simulate kinetic denitrification using Monod equation, equilibrium Langmuir sorption of acetate, and equilibrium reactions of gas and mineral phases (calcite). The reactive modeling results highlighted a rapid acetate and nitrate mineralization rate, suggesting that the main pathway of nitrate attenuation is through denitrification while calcite acted as a buffer for pH. However, in the absence of acetate, the natural content of organic matter did not allow to complete the denitrification process leading to nitrite accumulation. Reactive modeling is thought to be an efficient and robust tool to quantify the complex biogeochemical reactions which can take place in underground environments.

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.

Albendazole (ALB) belongs to a group of benzimidazoles - classified as antiparasitic pharmaceuticals. Its widespread application results in the presence of this pharmaceutical in natural environment (water and soil). In this paper a suitable pretreatment method was established including sampling, freeze-drying and extraction. Vicia faba was used as model organism. ALB accumulation by plant tissues was observed in hydroponic culture as well as in soil. The range of pharmaceutical concentrations was 1.7 × 10-5 mol/L (in hydroponic culture) and 1.7 × 10-5 to 1.7 × 10-4 mol/kg air dry soil (in soil). Observations were conducted for 14 days. After this time biological material was freeze-dried and after homogenization, dimethyl sulfoxide (DMSO) extraction was performed. The recovery of ALB for the roots was 93 % while for the shoots 86 %. After cleaning, the samples were subjected to further analysis by HPLC system. Phosphate buffer and acetonitrile (50:50) were used as a mobile phase. Drug retention time was 6.3 min. Results obtained in this experiment indicate higher drug accumulation in roots rather than in the hypocotyl part of the plant, cultivated both in soil and in hydroponic culture. © 2013 The Author(s).

The decolorization and degradation of anionic sulphonated azo dye (Reactive orange 16 (RO16)), which is suspected to be carcinogenic, were investigated using ozone. The decolorization process of the reactive dye was carried out by bubbling ozone at the bottom of a bubble column reactor containing the dye solution. The effect of pH, reaction time, dye concentration, ozone concentration, and decolorization time was studied. Also, degradation products and possible degradation mechanism were investigated. The results showed that ozonation was a highly effective way to remove color from wastewater. The color of a synthetic waste solution containing water-soluble reactive dye was reduced to 69.69 % under the basic condition (pH 12), with complete RO16 degradation occurring in 8 min. Ozone consumption continued for a further 16 min after which time most of the degradation reactions were complete. Kinetic studies showed that direct ozonation of the aqueous dyes represented a pseudo-first-order reaction with respect to the dye. The apparent rate constant increased with both the applied ozone dose and higher pH values and declined logarithmically with the initial dye concentration. Intermediates such as 6-acetylamino-3-aminonaphthalene-2-sulfonic acid, 2-(4-nitrosophenyl) sulfonylethyl hydrogen sulfate, and 6-acetamido-4-hydroxy-3-nitroso naphthalene-2-sulfonic acid were detected by gas chromatograph coupled with mass spectrometry in the absence of pH buffer, while nitrate and sulfate ions and formic, acetic, and oxalic acids were detected by ion chromatography.