Potential impact of engineered nanomaterials release into environment

Engineered nanomaterials (ENMs) are defined as a materials with at least one dimension between 1 nm to 100 nm. They have large surface area and specific electronic, optoelectronic, thermal and catalytic properties in comparison to their bulk counterparts, which make them particularly useful. ENMs that are found in different products (paints, cosmetics, medicines, food, sun tan lotions, remediation treatments, etc.) are usually designed to achieve desired properties. Those materials can be released into the environment throughout their entire life cycle and their extensive usage nowdays could led to their accumulation into environment. Over the last twenty years, ENMs have significantly increased in quantity produced, thus their presence in environment could have significant impact. However, understanding the effects that engineered nanomaterials (ENMs) have on environment through these applications is still limited. The aim of this paper is to point out issues releated to release of ENMs into the environment

The combined electrocoagulation/flotation and adsorption processes for organic substances regeneration of waste printing developer

This paper investigates the possibility of reducing the content of organic substances in waste printing developer using a combination of electrocoagulation/flotation (ECF) and adsorption (AD) processes. The content of organic substances in waste printing developer was monitored by analysis of total organic carbon (TOC), chemical oxygen demand (COD) and biological oxygen demand (BOD5) before and after the ECF and AD processes, respectively. When combining the two processes, a removal of 99.4, 92.9 and 96.0% of the TOC, COD and BOD5 was achieved, respectively. Obtained results confirm the improvement in the printing industrial effluent quality and height removal of organic substances by the combined ECF and AD treatments

Germination energy and seed germination - valid parameters of heavy metal presence in water

The use of water polluted with heavy metals for irrigation can cause phytotoxic effects and affect crop production. An important step in mitigating possible negative effects is certainly a continuous monitoring of water quality, assessment of risk for crops by biotests, right choice of test plant and selection of parameters that reliably indicate the changes in the environment. The aim of this study was to assess indicators potential of germination energy (GE) and seed germination (G) of five cultivated plants (sorghum, cabbage, sunflower, beans and buckwheat) in detection of metal (Cr, Pb and Cd) presence in water. A filter paper method according to ISTA was used. Metals were applied in series of concentrations including maxmium allowable concentrations (MAC’s). Chromium significantly inhibited G and GE of sunflower seeds in treatments with 2000 µg/l, while lead caused such effects of GE and G of sorghum and sunflower in amounts exceeding 50 µg/l (two times less than MAC), and of cabbage and buckwheat at 200µg/l. Cadmium significantly inhibited GE and G of beans at 0.1 µg/l (100 fold less than MAC).The overall results suggest that GE and G can be considered as valid parameters for the detection of certain metal presence in water, in amounts exceeding MAC such as Pb (sorghum and sunflower seeds) and Cd (beans seeds)

The immobilization of copper from waste printing developer sludge

The electrocoagulation (EC) treatment of the waste printing developer in laboratory conditions was produced the sludge with a high amount of copper. The solidification/stabilization (S/S) treatment of electrocoagulation sludge (ECS) has been conducted with four immobilization agents: Portland cement, calx, bentonite, and local clay. The efficiency of the S/S treatment was monitored by applying standard German (DIN 38414-4) leaching test. The characterization of ECS in terms of its toxicity was evaluated by comparing the copper concentration levels in the leaching solution with maximum allowed concentrations according to current regulations

Sorption-desorption behaviour of hydrophobic organic compounds on Danube sediment

The sorption-desorption hysteresis of naphthalene and phenanthrene onto Danube sediment was investigated. Hysteresis indices (HI) are calculated for three equilibrium concentration (Ce=1%, 5% i 50% of the solubility in water). The results of sorption-desorption hysteresis indicated that it exists for both investigated sorbates on the Danube sediment. For more hydrophobic compound, phenanthrene (logKOW< 4.55) hysteresis is less pronounced in comparison with naphthalene (logKOW< 3.36). In the case of naphthalene, the existence of hysteresis may be due to irreversible pore deformation of the sorbent which causes the formation of meta-stable states in the sorbate mesopores

Salivary Factors that Maintain the Normal Oral Commensal Microflora

Root of Gentiana lutea commercially available as gentian root, a natural antidote for different types of poisons, possess antioxidative, immunomodulatory, cytoprotective and anti-inflammatory, and adverse, genotoxic and mutagenic effects. It has monoterpenes loganic acid, swertiamarin, gentiopicroside and sweroside as most abundant constituents. In this study, we assessed the toxicity of monoterpenes’ reactive molecular fragments using in silico prediction by VEGA-QSAR platform. Further, we compared the data obtained with in vitro geno- and cyto- toxicity testing of the above monoterpenes and the G. lutea root extract (GE), on human primary unstimulated and mitogen-stimulated peripheral blood mononuclear cells (PBMCs). Viability was assessed by TB and XTT tests after 48 h treatmen. DNA damage was evaluated by alkaline comet assay on unstimulated cells, whereas cytokinesis-block micronucleus assay was employed on mitogen-stimulated PBMCs. Stability of compounds throughout treatment was monitored by UPLC. The observed in vitro results had highest compliance with in silico IRFMN/ISSCAN-CGX prediction model. Compounds showed high stability during experiment while treatment with single compounds reduced number of viable cells and increased DNA damage. GE treatment had toxic impact on unstimulated PBMCs but no significant genotoxic influence on mitogen-stimulated PBMCs. In summary, the mild GE effect suggests that the complexity of crude GE extract chemical composition may attenuate the toxicity of the tested monoterpenes loganic acid, swertiamarin, gentiopicroside and sweroside

Pentachlorobenzene sorption onto sediment organic matter

Sorption behaviour of pentachlorobenzene on four humic acids (HAs) and two humins extracted from a take sediment was studied. The objective was to provide a better understanding of the sorption mechanism of pentachlorobenzene onto sediment organic matter. Ten HAs were obtained by progressive sequential extraction of a sediment sample, while the residue after extraction was separated into two humin fractions on the basis of organic carbon content. The structural heterogeneity of the HAs and humins was characterized using elemental analysis and diffuse reflectance Fourier transform infrared spectroscopy. All sorption isotherms, fitted to a Freundlich equation, were nonlinear. For the HAs, isotherm linearity increased from 0.902 for the first extracted HA to 0.945 for the tenth HA, showing increase in the nonlinearity of the associated sorption isotherms with increasing HA aromaticity. On the other hand, a positive correlation between sorption coefficient and aliphaticity of the HAs supports the hypothesis that the non-polar aliphatic domains in sediment organic matter strongly affect the sorption of hydrophobic organic compounds. Both humin samples showed greater nonlinearity than the HAs, with the greatest degree of nonlinearity (0.827) for the humin with lower organic carbon content, while humin with higher organic carbon content showed the greatest pentachlorobenzene sorption affinity. It has been suggested that sorption processes may be strongly affected by the physical conformation of, and accessibility to, organic matter, as demonstrated by the high K-oc and low n of humin samples. (c) 2007 Elsevier Ltd. All rights reserved

Pentachlorobenzene sorption onto sediment organic matter

Sorption behaviour of pentachlorobenzene on four humic acids (HAs) and two humins extracted from a take sediment was studied. The objective was to provide a better understanding of the sorption mechanism of pentachlorobenzene onto sediment organic matter. Ten HAs were obtained by progressive sequential extraction of a sediment sample, while the residue after extraction was separated into two humin fractions on the basis of organic carbon content. The structural heterogeneity of the HAs and humins was characterized using elemental analysis and diffuse reflectance Fourier transform infrared spectroscopy. All sorption isotherms, fitted to a Freundlich equation, were nonlinear. For the HAs, isotherm linearity increased from 0.902 for the first extracted HA to 0.945 for the tenth HA, showing increase in the nonlinearity of the associated sorption isotherms with increasing HA aromaticity. On the other hand, a positive correlation between sorption coefficient and aliphaticity of the HAs supports the hypothesis that the non-polar aliphatic domains in sediment organic matter strongly affect the sorption of hydrophobic organic compounds. Both humin samples showed greater nonlinearity than the HAs, with the greatest degree of nonlinearity (0.827) for the humin with lower organic carbon content, while humin with higher organic carbon content showed the greatest pentachlorobenzene sorption affinity. It has been suggested that sorption processes may be strongly affected by the physical conformation of, and accessibility to, organic matter, as demonstrated by the high K-oc and low n of humin samples. (c) 2007 Elsevier Ltd. All rights reserved