Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 20
Filter
Add more filters










Publication year range
1.
Environ Technol ; 39(12): 1586-1596, 2018 Jun.
Article in English | MEDLINE | ID: mdl-28532345

ABSTRACT

High quantities of industrial wastewaters containing a wide range of organic and inorganic pollutants are being directly discharged into the environment, sometimes without proper treatment. Nanotechnology has a tremendous potential improving the existing treatments or even develop new treatment solutions. In this study, nano-TiO2 or nano-Fe2O3 was used for the photocatalytic treatment of kraft pulp mill effluent and mining effluent. The experiments with the organic effluent lead to reduction percentages of 93.3%, 68.4% and 89.8%, for colour, aromatic compounds and chemical oxygen demand, respectively, when treated with nano-TiO2/H2O2/UV and nano-Fe2O3/H2O2/UV, at pH 3.0. Significant removal of metals from the mining effluent was recorded but only for Zn, Al and Cd, the highest removal attained with 1.0 g L-1 of nano-TiO2/UV and nano-Fe2O3/UV. Regarding the toxicity of the organic effluent to Vibrio fischeri, it was reduced with the treatments combining the oxidant and the catalyst. However, for the inorganic effluent, the best reduction was achieved using 1.0 g L-1 of catalyst. In fact, the increase in dose of the catalyst, especially for nano-TiO2, enhanced toxicity reduction. Our results have shown that the use of these NMs seemed to be more effective in the organic effluent than in metal-rich effluent.


Subject(s)
Nanoparticles , Titanium , Waste Disposal, Fluid , Catalysis , Ferric Compounds , Hydrogen Peroxide , Industrial Waste , Paper , Photochemical Processes , Wastewater , Water Pollutants, Chemical
2.
Environ Pollut ; 231(Pt 2): 1633-1641, 2017 Dec.
Article in English | MEDLINE | ID: mdl-28964607

ABSTRACT

Soil salinization, as the combination of primary and secondary events, can adversely affect organisms inhabiting this compartment. In the present study, the effects of increased salinity were assessed in four species of terrestrial fungi: Lentinus sajor caju, Phanerochaete chrysosporium, Rhizopus oryzae and Trametes versicolor. The mycelial growth and biochemical composition of the four fungi were determined under three exposure scenarios: 1) exposure to serial dilutions of natural seawater (SW), 2) exposure to serial concentrations of NaCl (potential surrogate of SW); and 3) exposure to serial concentrations of NaCl after a period of pre-exposure to low levels of NaCl. The toxicity of NaCl was slightly higher than that of SW, for all fungi species: the conductivities causing 50% of growth inhibition (EC50) were within 14.9 and 22.0 mScm-1 for NaCl and within 20.2 and 34.1 mScm-1 for SW. Phanerochaete chrysosporium showed to be the less sensitive species, both for NaCl and SW. Exposure to NaCl caused changes in the biochemical composition of fungi, mainly increasing the production of polysaccharides. When fungi were exposed to SW this pattern of biochemical response was not observed. Fungi pre-exposed to low levels of salinity presented higher EC50 than fungi non-pre-exposed, though 95% confidence limits overlapped, with the exception of P. chrysosporium. Pre-exposure to low levels of NaCl also induced changes in the biochemical composition of the mycelia of L. sajor caju and R. oryzae, relatively to the respective control. These results suggest that some terrestrial fungi may acquire an increased tolerance to NaCl after being pre-exposed to low levels of this salt, thus, suggesting their capacity to persist in environments that will undergo salinization. Furthermore, NaCl could be used as a protective surrogate of SW to derive safe salinity levels for soils, since it induced toxicity similar or higher than that of SW.


Subject(s)
Basidiomycota/drug effects , Mycelium/drug effects , Rhizopus/drug effects , Soil Microbiology/standards , Soil/chemistry , Basidiomycota/growth & development , Mycelium/growth & development , Rhizopus/growth & development , Salinity , Salt Tolerance/drug effects , Seawater/chemistry , Sodium Chloride/toxicity
3.
Environ Pollut ; 220(Pt A): 495-503, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27745914

ABSTRACT

The ocean has been assumed as the main sink of microplastics (MPs), however, soils may also receive MPs from different sources and through different pathways, which may affect the biota and their role in soil functions. To the best of our knowledge, only one study, until now, reported the effects of MPs on the survival and fitness of soil organisms (Lumbricus terrestris). In our study, epigeic earthworms, of the species E. andrei, were exposed to different concentrations of MPs (0, 62.5, 125, 250, 500 and 1000 mg/kg soildw) in an OECD artificial soil and tested for reproduction, survival and growth of adults, following a standard protocol. The size of the polyethylene MPs to which earthworms were exposed ranged between 250 and 1000 µm. No significant effects were recorded on survival, number of juveniles and, in the final weight of adult earthworms after 28d of exposure, to the different concentrations of MPs. Nevertheless, FTIR-ATR of earthworms and histopathological analysis of the gut provided evidences of damages and immune system responses to MPs.


Subject(s)
Gastrointestinal Tract/drug effects , Immune System/drug effects , Oligochaeta/drug effects , Particle Size , Polyethylene/adverse effects , Soil Pollutants/adverse effects , Soil/chemistry , Animals , Environmental Exposure/adverse effects , Oligochaeta/metabolism , Plastics/adverse effects , Reproduction/drug effects
4.
Aquat Toxicol ; 179: 1-7, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27541481

ABSTRACT

Risk assessment of pesticides has been based on direct toxic effects on aquatic organisms. Indirect effects data are taken into account but with limitations, as it is frequently difficult to predict their real impacts in the ecosystems. In this context the main aim of this work was to assess how the exposure to the herbicide pendimethalin (Prowl(®)), under environmentally relevant concentrations, may compromise the nutritional composition of food for a relevant group of primary consumers of freshwater food webs-the daphnids, thus affecting their reproduction performance and subsequently the long-term sustainability of active populations of this grazer. Therefore, Daphnia magna individuals were chronically exposed in a clean medium to a control diet (NCF - i.e., non-contaminated green algae Raphidocelis subcapitata) and to a contaminated diet (CF - i.e., the same monoalgal culture grown in a medium enriched with pendimethalin in a concentration equivalent to the EC20 for growth inhibition of algae), during which reproductive endpoints were assessed. The algae were analysed for protein, carbohydrate and fatty acid content. The chemical composition of R. subcapitata in the CF revealed a slight decrease on total fatty acid levels, with a particular decrease of essential ω9 monounsaturated fatty acids. In contrast, the protein content was high in the CF. D. magna exposed to CF experienced a 16% reduction in reproduction, measured as the total number of offspring produced per female. Additionally, an internal pendimethalin body burden of 4.226µgg(-1) was accumulated by daphnids fed with CF. Hence, although it is difficult to discriminate the contribution of the pesticide (as a toxic agent transferred through the food web) from that of the food with a poor quality-compromised by the same pesticide, there are no doubts that, under environmentally relevant concentrations of pesticides, both pathways may compromise the populations of freshwater grazers in the long term, with consequences in the control of the primary productivity of these systems.


Subject(s)
Daphnia/drug effects , Herbicides/toxicity , Reproduction/drug effects , Water Pollutants, Chemical/toxicity , Aniline Compounds/analysis , Animals , Biomass , Chlorophyta/drug effects , Chlorophyta/growth & development , Chlorophyta/metabolism , Daphnia/physiology , Diet , Fatty Acids, Unsaturated/analysis , Female , Herbicides/metabolism , Nutritive Value
5.
Aquat Toxicol ; 176: 197-207, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27162069

ABSTRACT

Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same aggregation behaviour after sunlight exposure was observed for bare QDs. These results further emphasize that the shell of QDs seems to make them less harmful to aquatic biota, both under standard environmental conditions and after the exposure to a relevant abiotic factor like sunlight.


Subject(s)
Cadmium Compounds/toxicity , Quantum Dots/toxicity , Sulfides/toxicity , Sunlight , Water Pollutants, Chemical/toxicity , Aliivibrio fischeri/drug effects , Animals , Cadmium Compounds/radiation effects , Chlorophyta/drug effects , Daphnia/drug effects , Quantum Dots/radiation effects , Sulfides/radiation effects , Zinc Compounds/toxicity
6.
Sci Total Environ ; 547: 413-421, 2016 Mar 15.
Article in English | MEDLINE | ID: mdl-26795542

ABSTRACT

Aiming at contributing new insights into the effects of nanomaterials (NMs) in the terrestrial ecosystem, this study evaluated the impacts of organic nano-vesicles of sodium dodecyl sulphate/didodecyl dimethylammonium bromide (SDS/DDAB) on the emergence and growth of plant seeds, and on the avoidance and reproduction of soil invertebrates. For this purpose several ecotoxicological assays were performed with different test species (terrestrial plants: Zea mays, Avena sativa, Brassica oleracea and Lycopersicon esculentum; soil invertebrates: Eisenia andrei and Folsomia candida). A wide range of SDS/DDAB concentrations were tested, following standard protocols, and using the standard OECD soil as a test substrate (5% of organic matter). The aqueous suspensions of SDS/DDAB, used to spike the soils, were characterised by light scattering techniques for hydrodynamic size of the vesicles, aggregation index, polydispersity index, zeta potential and surface charge. The SDS/DDAB concentrations in the test soil were analysed by HPLC-UV at the end of the assays. Invertebrate species were revealed to be sensitive to nano-SDS/DDAB upon immediate exposure to freshly spiked soils. However, the degradation of SDS/DDAB nano-vesicles in the soil with time prevented the occurrence of significant reproduction effects on soil invertebrates. Plants were not particularly sensitive to SDS/DDAB, except B. oleracea (at concentrations above 375 mg kg(-1)dw). The results gathered in this study allowed a preliminary determination of a risk limit to nano-SDS/DDAB. The low toxicity of SDS/DDAB nano-vesicles could be explained by its high and fast degradation in the soil. The soil microbial community could have an important role in the fate of this NM, thus it is of remarkable importance to improve this risk limit by taking into account specific data addressing this community.


Subject(s)
Nanostructures/toxicity , Quaternary Ammonium Compounds/toxicity , Sodium Dodecyl Sulfate/toxicity , Soil Pollutants/toxicity , Animals , Biological Assay , Ecotoxicology , Oligochaeta , Plants , Soil
7.
Environ Sci Pollut Res Int ; 22(17): 13212-24, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25940480

ABSTRACT

The rapid development of nanotechnology and the increasing use of nanomaterials (NMs) raise concern about their fate and potential effects in the environment, especially for those that could be used for remediation purposes and that will be intentionally released to the environment. Despite the remarkable emerging literature addressing the biological effects of NMs to aquatic organisms, the existing information is still scarce and contradictory. Therefore, aimed at selecting NMs for the treatment of organic and inorganic effluents, we assessed the potential toxicity of NiO (100 and 10-20 nm), Fe2O3 (≈85 × 425 nm), and TiO2 (<25 nm), to a battery of aquatic organisms: Vibrio fischeri, Raphidocelis subcapitata, Lemna minor, Daphnia magna, Brachionus plicatilis, and Artemia salina. Also a mutagenic test was performed with two Salmonella typhimurium strains. Suspensions of each NM, prepared with the different test media, were characterized by dynamic light scattering (DLS) and eletrophoretic light scattering (ELS). For the assays with marine species, no toxicity was observed for all the compounds. In opposite, statistically significant effects were produced on all freshwater species, being D. magna the most sensitive organism. Based on the results of this study, the tested NMs can be classified in a decreasing order of toxicity NiO (100 nm) > NiO (10-20 nm) > TiO2 (<25 nm) > Fe2O3, allowing to infer that apparently Fe2O3 NMs seems to be the one with less risks for receiving aquatic systems.


Subject(s)
Ecotoxicology , Metals/chemistry , Oxides/chemistry , Oxides/toxicity , Waste Management , Wastewater/chemistry , Animals , Aquatic Organisms/drug effects , Aquatic Organisms/genetics , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/toxicity
8.
Ecotoxicol Environ Saf ; 115: 234-42, 2015 May.
Article in English | MEDLINE | ID: mdl-25723133

ABSTRACT

Olive mill wastewater (OMW) still is a major environmental problem due to its high chemical oxygen demand (COD) and total phenolic content (TPC), contributing for the high toxicity and recalcitrant nature. Several attempts have been made for developing more efficient treatment processes, but no chemical or biological approaches were found to be totally effective, especially in terms of toxicity reduction. In this context, the main purpose of this study was to investigate the treatability of OMW by the combination of photocatalytic oxidation, using two nanomaterials as catalysts (TiO2 and Fe2O3), with biological degradation by fungi (Pleurotus sajor caju and Phanerochaete chrysosporium). Photocatalytic oxidation was carried out using different systems, nano-TiO2/UV, nano-Fe2O3/UV, nano-TiO2/H2O2/UV and nano-Fe2O3/H2O2/UV. The effectiveness of the treatment was assessed through color (465nm), aromatics (270nm), COD and TPC reductions, as well as by the decrease in toxicity using the bacterium Vibrio fischeri. The chemical treatment with the system nano-TiO2/H2O2/UV promoted 43%, 14%, 38% and 31% reductions in color, aromatics content, COD and TPC, respectively. However no toxicity reduction was observed. The combination with a biological treatment increased the reduction of COD and TPC as well as a reduction in toxicity. The treatment with P. chrysosporium promoted the highest reduction in toxicity, but P. sajor caju was responsible for the best reduction in COD and TPC. However, the biological treatment was more effective when no hydrogen peroxide was used in the pre-treatment.


Subject(s)
Fungi/metabolism , Industrial Waste , Nanostructures/chemistry , Plant Oils , Waste Management/methods , Wastewater , Catalysis , Ferric Compounds/chemistry , Hydrogen Peroxide/chemistry , Industrial Waste/analysis , Olive Oil , Oxidation-Reduction , Phanerochaete/metabolism , Phenols/analysis , Photolysis , Plant Oils/chemistry , Pleurotus/metabolism , Titanium/chemistry , Wastewater/chemistry
9.
Curr Med Chem ; 20(36): 4575-94, 2013.
Article in English | MEDLINE | ID: mdl-23834185

ABSTRACT

In recent years, much attention has been given to dietary antioxidants, especially polyphenols. Several peptides derived from protein molecules have also been found to show antioxidant capacity along with other biological properties and thus there is an increasing interest in these compounds as health promoters. This review summarizes and discusses the main sources of antioxidative peptides with focus on food-derived peptides (animal, plant and marine sources), methods of preparation, antioxidant capacity evaluation as well as their proposed mechanisms of action. A discussion of the potential health effects and comments on the different applications for these antioxidants and their potential research interest are also subject of this review.


Subject(s)
Antioxidants/administration & dosage , Antioxidants/chemistry , Food , Peptides/administration & dosage , Peptides/chemistry , Animals , Humans
10.
Environ Monit Assess ; 185(1): 279-94, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22350347

ABSTRACT

Soil quality in urban areas is affected by anthropogenic activities, posing a risk to human health and ecosystems. Since the pseudo-total concentrations of potentially toxic elements may not reflect their potential risks, the study of element mobility is very important on a risk assessment basis. This study aims at characterising the distribution and major sources of 34 elements in two Portuguese urban areas (Lisbon and Viseu), with different geological characteristics, industrial and urban development processes. Furthermore, the potential availability of As, Co, Cr, Cu, Ni, Pb and Zn was assessed, by measuring the fraction easily mobilised. Lisbon is enriched in elements of geogenic and anthropogenic origin, whereas in the smaller city, the high levels observed are mainly related to a geogenic origin. Background values can be more relevant than the dimension of the city, even when anthropogenic components may be present, and this parameter should be considered when comparing results from different cities. Regarding the potential available fraction, a high variability of results was observed for elements and for sampling sites with an influence of the soil's general characteristics. Elements showing very high concentrations due to geological reasons presented, in general, a low mobility and it was not dependent on the degree of contamination. For elements with major anthropogenic origin, only Zn was dependent on the pseudo-total content. Yet, the highest available fractions of some elements, both with major geogenic and anthropogenic origin, were observed in specific contaminated samples. Therefore, a site-specific evaluation in urban soils is important due to the high spatial variability and heterogeneity.


Subject(s)
Environmental Monitoring , Soil Pollutants/analysis , Cities , Environmental Pollution/statistics & numerical data , Hazardous Substances/analysis , Humans , Soil/chemistry , Soil Pollutants/toxicity
11.
Sci Total Environ ; 430: 184-92, 2012 Jul 15.
Article in English | MEDLINE | ID: mdl-22652008

ABSTRACT

Urban soil quality may be severely affected by PAH and PCB contamination, impairing environmental and human health. A comprehensive study was conducted in two contrasting Portuguese urban areas (Lisbon and Viseu) in order to assess the levels of these contaminants and potential risks to human health, to identify sources and study their behavior in soils. The concentrations of PAHs and PCBs were related to the size of the city. The concentrations found in the larger city (Lisbon) were similar to other urban areas. Differences between profiles of the two urban areas were observed for both groups of contaminants, which could be attributed to differences of sources or climate. Lisbon seems to be affected by nearby sources (traffic, industry and incineration processes) whereas in the smaller city atmospheric transport may be playing an important role. Cluster analysis revealed that PAHs and PCBs were associated with anthropogenic toxic elements (Cu, Pb, Zn and Hg in Lisbon; Pb and Hg in Viseu), therefore reflecting common sources. It was also found that organic carbon was an important factor for PAHs and high chlorinated PCB retention in soils. The incremental probability of developing cancer over lifetime, based on a reasonable maximum exposure to PAHs present in Lisbon residential soils, was 9.0 × 10(-6) and 2.4 × 10(-6) for an occupational exposure, both slightly higher than the target risk of 1 × 10(-6). Similarly, the mutagenic risk of PAHs in Lisbon was 3.3 × 10(-5) for residential soils and 1.8 × 10(-6) in recreational areas.


Subject(s)
Carcinogens, Environmental/analysis , Environmental Exposure , Mutagens/analysis , Polychlorinated Biphenyls/analysis , Polycyclic Aromatic Hydrocarbons/analysis , Soil Pollutants/analysis , Cities , Cluster Analysis , Environmental Monitoring , Gas Chromatography-Mass Spectrometry , Humans , Metals, Heavy/analysis , Portugal , Risk Assessment , Soil/chemistry
12.
Ecotoxicology ; 21(3): 637-48, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22314390

ABSTRACT

The present work aimed at evaluating the toxicity and genotoxicity of two organic (vesicles composed of sodium dodecyl sulphate/didodecyl dimethylammonium bromide-SDS/DDAB and of monoolein and sodium oelate-Mo/NaO) and four inorganic (titanium oxide-TiO2, silicon titanium-TiSiO4, Lumidot-CdSe/ZnS, and gold nanorods) nanoparticles (NP), suspended in two aqueous media (Milli Q water and American Society for Testing and Materials (ASTM) hardwater), to the bacteria Vibrio fischeri (Microtox test) and Salmonella typhimurium-his⁻ (Ames test with strains TA98 and TA100). Aiming a better understanding of these biological responses physical and chemical characterization of the studied NP suspensions was carried out. Results denoted a high aggregation state of the NP in the aqueous suspensions, with the exception of SDS/DDAB and Mo/NaO vesicles, and of nanogold suspended in Milli Q water. This higher aggregation was consistent with the low values of zeta potential, revealing the instability of the suspensions. Regarding toxicity data, except for nano TiO2, the tested NP significantly inhibited bioluminescence of V. fischeri. Genotoxic effects were only induced by SDS/DDAB and TiO2 for the strain TA98. A wide range of toxicity responses was observed for the six tested NP, differing by more than 5 orders of magnitude, and suggesting different modes of action of the tested NP.


Subject(s)
Aliivibrio fischeri/drug effects , Inorganic Chemicals/toxicity , Metal Nanoparticles/toxicity , Mutagens/toxicity , Organic Chemicals/toxicity , Salmonella typhimurium/drug effects , Aliivibrio fischeri/genetics , Diffusion , Electrochemistry/methods , Glycerides/toxicity , Inorganic Chemicals/classification , Luminescence , Luminescent Measurements , Metal Nanoparticles/classification , Mutagenicity Tests , Mutagens/classification , Oleic Acid/toxicity , Organic Chemicals/classification , Quaternary Ammonium Compounds/toxicity , Salmonella typhimurium/genetics , Sodium Dodecyl Sulfate/toxicity , Surface-Active Agents/toxicity
13.
J Hazard Mater ; 194: 345-54, 2011 Oct 30.
Article in English | MEDLINE | ID: mdl-21871729

ABSTRACT

This study aimed to evaluate the toxicity and genotoxicity of soils, and corresponding elutriates, contaminated with aqueous suspensions of two organic (vesicles of sodium dodecyl sulphate/didodecyl dimethylammonium bromide and of monoolein and sodium oleate) and five inorganic nanoparticles (NPs) (TiO(2), TiSiO(4), CdSe/ZnS quantum dots, Fe/Co magnetic fluid and gold nanorods) to Vibrio fischeri and Salmonella typhimurium (TA98 and TA100 strains). Soil samples were tested 2h and 30 days after contamination. Suspensions of NPs were characterized by Dynamic Light Scattering. Soils were highly toxic to V. fischeri, especially after 2h. After 30 days toxicity was maintained only for soils spiked with suspensions of more stable NPs (zeta potential>30 mV or <-30 mV). Elutriates were particularly toxic after 2h, except for soil spiked with Fe/Co magnetic fluid, suggesting that ageing may have contributed for degrading the organic shell of these NPs, increasing the mobility of core elements and the toxicity of elutriates. TA98 was the most sensitive strain to the mutagenic potential of soil elutriates. Only elutriates from soils spiked with gold nanorods, quantum dots (QDs) and TiSiO(4) induced mutations in both strains of S. typhimurium, suggesting more diversified mechanisms of genotoxicity.


Subject(s)
Mutagens/toxicity , Nanoparticles , Soil Pollutants/toxicity , Aliivibrio fischeri/drug effects , Aliivibrio fischeri/genetics , Salmonella typhimurium/drug effects , Salmonella typhimurium/genetics
14.
Article in English | MEDLINE | ID: mdl-20954041

ABSTRACT

The aim of the present study was to assess the toxic effects of a secondary treated effluent from a modern pulp mill processing Eucalyptus globulus on both sexes of goldfish. The effects in the exposed fish were investigated by measuring biomarkers which have been used to assess the effects of BKME on aquatic biota, with particular emphasis in fish. However, few studies have been focused on effluents from pulp mill plants processing eucalyptus. The relative proportion of cytochrome P450 (CYP1A) and vitellogenin (VTG) induction were analyzed in the livers of males and females goldfish, exposed to different concentrations of a bleached Kraft pulp mill (BKPM) effluent. Somatic indices such as HSI (hepatosomatic index) and GSI (gonadosomatic index) were calculated and a significant reduction was found in males GSI. A significant increase of HSI was recorded for both sexes exposed to 50% BKPM effluent. Exposure to BKPM effluent induced CYP1A synthesis in both sexes and decreased VTG synthesis in females according to the different effluent concentrations suggesting that the secondary treated effluent contained compounds that affect fish negatively. The results suggest that BKPM effluent can cause sex-related biochemical changes in xenobiotic metabolism.


Subject(s)
Environmental Monitoring/methods , Goldfish/growth & development , Paper , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/toxicity , Water Purification/methods , Animals , Biological Assay , Biomarkers/analysis , Biomarkers/blood , Biomarkers/metabolism , Enzyme-Linked Immunosorbent Assay , Eucalyptus/chemistry , Female , Goldfish/blood , Goldfish/metabolism , Gonads/drug effects , Gonads/enzymology , Liver/drug effects , Liver/enzymology , Male , Portugal , Sex Characteristics
15.
Ecotoxicology ; 18(8): 1011-7, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19621256

ABSTRACT

The toxicity of bleached Kraft pulp mill effluents (BKME) is usually attributed to chemical compounds which are produced and released throughout various stages of pulp and paper production. The main objective of the present work was to detect sub-lethal responses of goldfish (Carassius auratus) to secondary treated BKME which was treated with Rhizopus oryzae. A total of 96 carps (C. auratus; 11 +/- 3 g) were exposed to different concentrations of the post-treated effluent (0, 1, 10, 25, 50, and 100%), in 28 days semi-static tests. Several biomarkers were then evaluated to assess the toxicological effects: induction of CYP1A (metabolic processes of organic compounds in liver), change in steroid profiles (11-Ketotestosterone, 17beta-estradiol), histopathology of liver and gonads and somatic indices (GSI, HSI) for endocrine disruption and other physiological disturbances. The most significant results show an induction of CYP1A in both sexes and a decrease of 17beta-estradiol concentrations in females. Histopathological changes such as liver tissue degeneration were observed in fish exposed to 50 and 100% of the BKME. Although the BKME was biologically treated there are some chemical compounds in the effluent that are capable to affect fish physiology, however, a clear evidence for endocrine disruption was not found.


Subject(s)
Industrial Waste/adverse effects , Liver/drug effects , Rhizopus/metabolism , Water Pollutants, Chemical/toxicity , Animals , Biomarkers , Cytochrome P-450 CYP1A1/drug effects , Cytochrome P-450 CYP1A1/metabolism , Enzyme Induction/drug effects , Female , Goldfish/metabolism , Gonadal Steroid Hormones/metabolism , Liver/metabolism , Male , Paper
16.
Water Res ; 43(9): 2471-80, 2009 May.
Article in English | MEDLINE | ID: mdl-19345976

ABSTRACT

Huge efforts have been made both in adopting more environmental-friendly bleaching processes, and in developing advanced oxidation processes and more effective biological treatments for the reduction of deleterious impacts of paper mill effluents. Even so, the success of such treatments is frequently reported in terms of chemical parameters without a proper evaluation of the effluent's toxicity mitigation. This is the first study reporting an exhaustive evaluation of the toxicity of a secondary bleached kraft pulp mill effluent, after either tertiary treatment with the soft-rot fungi Rhizopus oryzae or with a photo-Fenton oxidation, using a battery of freshwater species. As it has been reported the photo-Fenton/UV treatment has proved to be the most effective in reducing the colour and the COD (chemical oxygen demand) of the effluent. Nevertheless, extremely low EC(50) values were reported for almost all species, after this tertiary treatment. The treatment with R. oryzae was less effective in terms of colour removal and COD reduction, but proved to be the most promising in reducing toxicity.


Subject(s)
Biodegradation, Environmental , Industrial Waste/adverse effects , Rhizopus/metabolism , Waste Disposal, Fluid/methods , Animals , Bioreactors , Color , Daphnia/drug effects , Eukaryota/drug effects , Oxidation-Reduction , Paper , Vibrio/drug effects
17.
Sci Total Environ ; 407(10): 3282-9, 2009 May 01.
Article in English | MEDLINE | ID: mdl-19269018

ABSTRACT

Three white-rot fungi (Pleurotus sajor caju, Trametes versicolor and Phanerochaete chrysosporium) and one soft-rot fungi (Rhizopus oryzae) species confirmed their potential for future applications in the biological treatment of effluents derived from the secondary treatment of a bleached kraft pulp mill processing Eucalyptus globulus. Among the four species P. sajor caju and R. oryzae were the most effective in the biodegradation of organic compounds present in the effluent, being responsible for the reduction of relative absorbance (25-46% at 250 nm and 72-74% at 465 nm) and of chemical oxygen demand levels (74 to 81%) after 10 days of incubation. Laccase (Lac), lignin (Lip) and manganese peroxidases (MnP) expression varied among fungal species, where Lac and LiP activities were correlated with the degradation of organic compounds in the effluent treated with P. sajor caju. The first two axes of a principal component analysis explained 88.9% of the total variation among sub-samples treated with the four fungus species, after different incubation periods. All the variables measured contributed positively to the first component except for the MnP enzyme activity which was the only variable contributing negatively to the first component. Absorbances at 465 nm, LiP and Lac enzyme activities were the variables with more weight on the second component. P. sajor caju revealed to be the only species able to perform the biological treatment without promoting an increment in the toxicity of the effluent to the Vibrio fischeri, as it was assessed by the Microtox assay. The opposite was recorded for the treatments with the other three species of fungus. EC(50-5 min) values ranging between 28 and 57% (effluent concentrations) were recorded even after 10 to 13 days of treatment with P. chrysosporium, R. oryzae or with T. versicolor.


Subject(s)
Industrial Waste , Polyporaceae/metabolism , Rhizopus/metabolism , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/metabolism , Biodegradation, Environmental , Fermentation , Paper , Principal Component Analysis , Water Pollutants, Chemical/analysis , Wood
18.
Talanta ; 54(2): 383-8, 2001 Apr 12.
Article in English | MEDLINE | ID: mdl-18968262

ABSTRACT

A new method based on separation with gas chromatography and detection with a quartz crystal microbalance was used for quantification of nitrobenzene, 2-, 3- and 4-nitrotoluene in landfill gas. The analytical error, the analysis time and general analytical performance were identical for gas chromatography-mass spectrometry (GC-MS) and gas chromatography-quartz crystal microbalance (GC-QCM). GC-QCM constitutes a very inexpensive alternative to GC-MS for monitoring nitroaromatic compounds in landfill gas.

19.
J Environ Monit ; 2(3): 277-9, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11256713

ABSTRACT

A new method, based on separation with gas chromatography and detection with a quartz crystal microbalance, was used for the quantification of ethane-1-thiol, propane-1-thiol, ethyl methyl sulfide, propane-2-thiol, butane-2-thiol and butane-1-thiol. The analytical error, the analysis time and the general analytical performance are identical for gas chromatography-mass spectrometry (GC-MS) and gas chromatography-quartz crystal microbalance (GC-QCM). However, the GC-QCM method constitutes a low cost alternative to GC-MS for monitoring individual sulfur compounds in landfill gas. It is an easily assembled apparatus made with an injection device, a furnace, a column, a crystal cell and a quartz crystal.


Subject(s)
Air Pollutants/analysis , Environmental Monitoring/methods , Sulfur Compounds/analysis , Chromatography, Gas/methods , Crystallization , Gases/chemistry , Quartz , Refuse Disposal
20.
Talanta ; 51(6): 1149-53, 2000 May 05.
Article in English | MEDLINE | ID: mdl-18967945

ABSTRACT

A new sensor based on oxidative combustion of nitroaromatics to NO(2) and its detection with a quartz crystal microbalance (QCM) coated with copper phthalocyanine (CuPc) was developed for determination of nitroaromatics in landfill gas. An alternative method based on gas chromatography-mass spectrometry (GC-MS) was also used in order to assess the performance of the proposed method. The results show that the analytical apparatus based on the QCM is less expensive than the GC-MS, and that the analytical error is 0.8% for both methods.

SELECTION OF CITATIONS
SEARCH DETAIL
...