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1.
Chem Biol Interact ; 344: 109481, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34051209

RESUMO

Decontamination of unprotected skin areas is crucial to prevent excessive penetration of chemical contaminants after criminal or accidental release. A review of literature studies was performed to identify the available decontamination methods adopted to treat skin contamination after chemical, radiological and metal exposures. In this bibliographic review, an overview of the old and recent works on decontamination procedures followed in case of potential hazards substances contaminations with a comparison between these systems are provided. Almost all data from our 95 selected studies conducted in vitro and in vivo revealed that a rapid skin decontamination process is the most efficient way to reduce the risk of intoxication. The commonly-used or recommended conventional procedures are simple rinsing with water only or soapy water. However, this approach has some limitations because an easy removal by flushing may not be sufficient to decontaminate all chemical deposited on the skin, and skin absorption can be enhanced by the wash-in effect. Other liquid solutions or systems as adsorbent powders, mobilizing agents, chelation therapy are also applied as decontaminants, but till nowadays does not exist a decontamination method which can be adopted in all situations. Therefore, there is an urgent need to develop more efficient and successful decontaminating formulations.


Assuntos
Descontaminação/métodos , Substâncias Perigosas/isolamento & purificação , Pele/efeitos dos fármacos , Substâncias para a Guerra Química/isolamento & purificação , Humanos , Nanopartículas Metálicas/química , Metais/isolamento & purificação , Radioisótopos/isolamento & purificação , Absorção Cutânea , Sabões/química , Água/química
2.
PLoS One ; 16(2): e0247327, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33626109

RESUMO

Currently, bee-gathered pollen (bee pollen) is commonly used worldwide as a dietary supplement and is recognized for its curative properties. Floral pollen is also important but is less recognized due to a lack of investigation. This study aims to determine the morphological characteristics and nutritional and phytochemical properties of floral maize pollen. Fresh pollen grains harvested from a farm of maize plants are yellow in colour and spheroid in shape. They change to amber and indented prismatic solid shapes when dehydrated. The main composition of floral maize pollen is carbohydrates (44.30±3.73%), followed by moisture (23.38±5.73%), crude proteins (17.16±3.13%), crude fibres (9.56±0.92%), and ash (4.98±0.11%), while the lowest content is observed for crude fats (0.62±0.06%). The predominant mineral is potassium (768.50±11.40 mg 100 g-1), followed by sodium (695.10±9.70 mg 100 g-1), calcium (147.20±12.60 mg 100 g-1), and magnesium (97.30±2.9 mg 100 g-1). The microelements (with average values) consist of iron (49.50±3.30 mg 100 g-1) and zinc (30.00±3.70 mg 100 g-1). Excellent phytochemical properties add value to floral maize pollen. Maize pollen contains a high total phenolic content (TPC) and total flavonoid content (TFC) of 783.02 mg GAE 100 g-1 and 1706.83 mg QE 100 g-1, respectively, and possesses strong antioxidant activity of 10.54 mg mL-1. Maize floral pollen and derived products can serve as future food resources for human consumption and as a source of functional and bioactive compounds in nutraceutical and pharmaceutical industries.


Assuntos
Antioxidantes/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Zea mays/química , Antioxidantes/química , Carboidratos/química , Carboidratos/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Metais/química , Metais/isolamento & purificação , Fenóis/química , Fenóis/isolamento & purificação , Compostos Fitoquímicos/química , Proteínas de Plantas , Pólen/química
3.
Artigo em Inglês | MEDLINE | ID: mdl-31185604

RESUMO

This study analyzes the leaching behavior of elements from red mud (bauxite residue) at pH values ranging from 2 to 13. The leaching characteristics of metals and contaminated anions in five red mud samples produced by Bayer and combined processes were analyzed using the batch leaching technique following the US Environmental Protection Agency (USEPA) Method 1313. In addition, the geochemical model of MINTEQ 3.1 was used to identify the leaching mechanisms of metals. The results showed that Ca, Mg, and Ba follow the cationic leaching pattern. Al, As, and Cr show an amphoteric leaching pattern. The leaching of Cl- is unaffected by the pH. The maximum leaching concentration of the proprietary elements occurs under extremely acidic conditions (pH = 2), except for As. The leaching concentration of F- reaches 1.4-27.0 mg/L in natural pH conditions (i.e., no acid or base addition). At the same pH level, the leaching concentrations of Pb, As, Cr, and Cu are generally higher from red mud produced by the combined process than that those of red mud from the Bayer process. The leaching concentration of these elements is not strongly related to the total elemental concentration in the red mud. Geochemical modeling analysis indicates that the leaching of metal elements, including Al, Ca, Fe, Cr, Cu, Pb, Mg, Ba, and Mn, in red mud are controlled by solubility. The leaching of these elements depended on the dissolution/precipitation of their (hydr)oxides, carbonate, or sulfate solids.


Assuntos
Óxido de Alumínio/química , Concentração de Íons de Hidrogênio , Metais/isolamento & purificação , Carbonatos , Metais/toxicidade , Oxirredução , Solubilidade
4.
Water Res ; 143: 467-478, 2018 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-29986255

RESUMO

This work is to evaluate pilot-scale Revolving Algal Biofilm (RAB) reactors of two heights (0.9-m and 1.8-m tall) to treat supernatant from sludge sedimentation at Metropolitan Water Reclamation District of Greater Chicago (MWRD) for removing nutrients (N and P) as well as various metals. The RAB reactors demonstrated a superior performance in N and P removal as compared to control raceway ponds. Taller 1.8-m RAB reactors performed better than 0.9-m RAB reactors in terms of total nutrient removal and algal biomass productivity. At 7-day HRT, total P (TP) and Total Kjeldahl N (TKN) removal efficiency reached to 80% and 87%, respectively, while ortho-P and ammonia removal efficiency reached to 100%. Decreasing HRT led to an enhanced TP and TKN removal rate and nutrient removal capacity. At HRT of 1.3-day, the TP removal per footprint of 1.8-m tall RAB reactors was around 7-times higher than the open pond system. The RAB reactors also showed certain capabilities of removing metals from wastewater. The study demonstrated that RAB-based treatment process is an effective method to recover nutrients from municipal wastewater.


Assuntos
Metais/isolamento & purificação , Microalgas , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Amônia/isolamento & purificação , Biofilmes , Biomassa , Reatores Biológicos , Chicago , Desenho de Equipamento , Nitrogênio/metabolismo , Fósforo/metabolismo , Lagoas , Esgotos , Águas Residuárias , Poluentes Químicos da Água/isolamento & purificação
5.
Chemosphere ; 193: 278-287, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29145088

RESUMO

Chemical extraction of phosphorus (P) from incinerated sewage sludge ash (ISSA) is adversely influenced by co-dissolution of metals and metalloids. This study investigated P recovery and leaching of Zn, Cu, Pb, As and Ni from ISSA using inorganic acids (sulphuric acid and nitric acid), organic acids (oxalic acid and citric acid), and chelating agents (ethylenediaminetetraacetic acid (EDTA) and ethylene diamine tetramethylene phosphonate (EDTMP)). The aim of this study was to optimize a leaching process to recover P-leachate with high purity for P fertilizer production. The results show that both organic and inorganic acids extract P-containing phases but organic acids leach more trace elements, particularly Cu, Zn, Pb and As. Sulphuric acid was the most efficient for P recovery and achieved 94% of total extraction under the optimal conditions, which were 2-h reaction with 0.2 mol/L H2SO4 at a liquid-to-solid ratio of 20:1. EDTA extracted only 20% of the available P, but the leachates were contaminated with high levels of trace elements under optimum conditions (3-h reaction with EDTA at 0.02 mol/L, pH 2, and liquid-to-solid ratio of 20:1). Therefore, EDTA was considered an appropriate pre-treatment agent for reducing the total metal/metalloid content in ISSA, which produced negligible changes in the structure of ISSA and reduced contamination during subsequent P extraction using sulphuric acid.


Assuntos
Fósforo/isolamento & purificação , Reciclagem/métodos , Esgotos/química , Oligoelementos/isolamento & purificação , Ácidos não Carboxílicos , Ácidos Carboxílicos , Quelantes , Ácido Edético , Incineração , Metais/isolamento & purificação , Fósforo/química , Oligoelementos/química
6.
Methods Mol Biol ; 1483: 197-216, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27645739

RESUMO

Small inorganic ions are easily separated through capillary electrophoresis because they have a high charge-to-mass ratio and suffer little from some of the undesired phenomenon affecting higher molecular weight species like adsorption to the capillary wall, decomposition, and precipitation. This chapter is focused on the analysis of small ions other than metal ions using capillary electrophoresis. Methods are described for the determination of ions of nitrogen, phosphorus, sulfur, fluorine, chlorine, bromine, and iodine.


Assuntos
Eletroforese Capilar/métodos , Íons/isolamento & purificação , Metais/isolamento & purificação , Cloro/química , Cloro/isolamento & purificação , Flúor/química , Flúor/isolamento & purificação , Íons/química , Metais/química , Nitrogênio/química , Nitrogênio/isolamento & purificação , Fósforo/química , Fósforo/isolamento & purificação , Enxofre/química , Enxofre/isolamento & purificação
7.
Artigo em Inglês | MEDLINE | ID: mdl-26436214

RESUMO

The release of elemental ions from 8 coffee machines and 11 electric kettles into food simulants was investigated. Three different types of coffee machines were tested: portafilter espresso machines, pod machines and capsule machines. All machines were tested subsequently on 3 days before and on 3 days after decalcification. Decalcification of the machines was performed with agents according to procedures as specified in the respective manufacturer's manuals. The electric kettles showed only a low release of the elements analysed. For the coffee machines decreasing concentrations of elements were found from the first to the last sample taken in the course of 1 day. Metal release on consecutive days showed a decreasing trend as well. After decalcification a large increase in the amounts of elements released was encountered. In addition, the different machine types investigated clearly differed in their extent of element release. By far the highest leaching, both quantitatively and qualitatively, was found for the portafilter machines. With these products releases of Pb, Ni, Mn, Cr and Zn were in the range and beyond the release limits as proposed by the Council of Europe. Therefore, a careful rinsing routine, especially after decalcification, is recommended for these machines. The comparably lower extent of release of one particular portafilter machine demonstrates that metal release at levels above the threshold that triggers health concerns are technically avoidable.


Assuntos
Café , Utensílios de Alimentação e Culinária , Metais/análise , Análise de Alimentos , Contaminação de Alimentos/prevenção & controle , Metais/isolamento & purificação
8.
Environ Sci Technol ; 49(14): 8271-6, 2015 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-26107263

RESUMO

Sewage sludge and biosolids production and management are a central component of water and sanitation engineering. The culmination of previous incremental technologies and regulations aimed at solving a current treatment problem, rather than developing the practice for the higher goals of sustainability have resulted in sludge becoming an economic and social liability. Sludge management practice must shift from treatment of a liability toward recovery of the embedded energy and chemical assets, while continuing to protect the environment and human health. This shift will require new research, treatment technologies and infrastructure and must be guided by the application of green engineering principles to ensure economic, social, and environmental sustainability.


Assuntos
Esgotos/química , Humanos , Metais/isolamento & purificação , Fósforo/isolamento & purificação , Poluentes Químicos da Água/análise
9.
J Pharm Biomed Anal ; 106: 153-8, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25454388

RESUMO

The use of medical herbs for the treatment of many human diseases is increasing nowadays due to their mild features and low side effects. Not only for their healing properties, but also for their nutritive value supplementation of diet with various herbs is recommended. Thus also their analysis is of rising importance. While total elemental compositions are published for many common herbs, the origin of toxic as well as beneficial elements is not yet well investigated. Thus different indigenous medicinal plants, namely Croatian spruce (Picea abies), savory (Satureja montana L.), mountain yarrow (Achillea clavennae), showy calamint (Calamintha grandiflora), micromeria (Micromeria croatica), yellow gentian (Gentiana lutea) and fir (Abies alba) together with soil samples were collected in the National Park Northern Velebit. The macro- and trace elements content, after microwave digestion, was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectroscopy (ICP-MS). The study focuses on the one hand on essential elements and on the other hand on non-essential elements which are considered as toxic for humans, covering in total Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn.


Assuntos
Metais/isolamento & purificação , Plantas Medicinais/química , Solo/química , Oligoelementos/isolamento & purificação , Croácia , Humanos , Espectrometria de Massas/métodos , Micro-Ondas , Espectrofotometria Atômica
10.
J Assist Reprod Genet ; 31(12): 1703-11, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25261352

RESUMO

PURPOSE: To determine the composition of commercially available protein supplements for embryo culture media and test if differences in protein supplement composition are biologically relevant in a murine model. METHODS: Amino acid, organic acid, ion and metal content were determined for 6 protein supplements: recombinant human albumin (AlbIX), human serum albumin (HSA and Buminate), and three complex protein supplements (SSS, SPS, LGPS). To determine if differences in the composition of these supplements are biologically relevant, mouse one-cell embryos were collected and cultured for 120 hours in each protein supplement in Global media at 5 and 20 % oxygen in an EmbryoScope time-lapse incubator. The compositions of six protein supplements were analyzed for concentrations of 39 individual amino acids, organic acids, ions and elements. Blastocyst development and cell cycle timings were calculated at 96-hours of culture and the experiments were repeated in triplicate. Blastocyst gene expression was analyzed. RESULTS: Recombinant albumin had the fewest undefined components , the lowest concentration of elements detected, and resulted in high blastocyst development in both 5 and 20 % oxygen. Buminate, LGPS and SPS had high levels of transition metals whereas SSS had high concentrations of amino acids. Pre-compaction mouse embryo development was delayed relative to embryos in AlbIX for all supplements and blastocyst formation was reduced in Buminate, SPS and SSS. CONCLUSIONS: The composition of protein supplements are variable, consisting of previously undescribed components. High concentrations of pro-oxidant transition metals were most notable. Blastocyst development was protein dependent and showed an interaction with oxygen concentration and pro-oxidant supplements.


Assuntos
Meios de Cultura/química , Técnicas de Cultura Embrionária/métodos , Desenvolvimento Embrionário/efeitos dos fármacos , Fertilização in vitro , Aminoácidos/química , Aminoácidos/isolamento & purificação , Animais , Blastocisto/efeitos dos fármacos , Embrião de Mamíferos , Humanos , Íons/química , Íons/isolamento & purificação , Metais/química , Metais/isolamento & purificação , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Albumina Sérica/química , Albumina Sérica/farmacologia
11.
Environ Sci Process Impacts ; 16(8): 2018-27, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24953257

RESUMO

Batch experiments were carried out for 7 days to investigate the simultaneous removal of various organic and inorganic contaminants including total nitrogen (TN), total phosphorus (TP), metals, pharmaceuticals and personal care products (PPCPs), endocrine disrupting chemicals (EDCs), and estrogenic activity in wastewater by four freshwater green microalgae species, Chlamydomonas reinhardtii, Scenedesmus obliquus, Chlorella pyrenoidosa and Chlorella vulgaris. After treatment for 7 days, 76.7-92.3% of TN, and 67.5-82.2% of TP were removed by these four algae species. The removal of metals from wastewater by the four algae species varied among the metal species. These four algae species could remove most of the metals efficiently (>40% removal), but showed low efficiencies in removing Pb, Ni and Co. The four algae species were also found to be efficient in removing most of the selected organic compounds with >50% removal, and the estrogenic activity with removal efficiencies ranging from 46.2 to 81.1% from the wastewater. Therefore, algae could be harnessed to simultaneously remove various contaminants in wastewater.


Assuntos
Microalgas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Biodegradação Ambiental , Disruptores Endócrinos/isolamento & purificação , Disruptores Endócrinos/metabolismo , Metais/isolamento & purificação , Metais/metabolismo , Nitrogênio/isolamento & purificação , Nitrogênio/metabolismo , Compostos Orgânicos/isolamento & purificação , Compostos Orgânicos/metabolismo , Fósforo/isolamento & purificação , Fósforo/metabolismo , Poluentes Químicos da Água/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-24679088

RESUMO

The present work investigated the leaching potential of moderately thermophilic bacteria in the recovery of metals from spent petroleum catalyst of varying particle sizes. The batch bioleaching experiments were conducted by employing a mixed consortium of moderate thermophilic bacteria at 45°C and by using five different particle sizes (from 45 to >2000 µm) of acetone-washed spent catalyst. The elemental mapping by FESEM confirmed the presence of Al, Ni, V and Mo along with sulfur in the spent catalyst. During bioleaching, Ni (92-97%) and V (81-91%) were leached in higher concentrations, whereas leaching yields of Al (23-38%) were found to be lowest in all particle sizes investigated. Decreasing the particle size from >2000 µm to 45-106 µm caused an increase in leaching yields of metals during initial hours. However, the final metals leaching yields were almost independent of particle sizes of catalyst. Leaching kinetics was observed to follow the diffusion-controlled model showing the linearity more close than the chemical control. The results of the present study suggested that bioleaching using moderate thermophilic bacteria was highly effective in removing the metals from spent catalyst. Moreover, bioleaching can be conducted using spent catalyst of higher particle size (>2000 µm), thus saving the grinding cost and making process attractive for larger scale application.


Assuntos
Bactérias/metabolismo , Metais/isolamento & purificação , Tamanho da Partícula , Petróleo/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Acetona , Catálise , Cinética , Metais/metabolismo , Modelos Químicos , Espectroscopia de Infravermelho com Transformada de Fourier , Enxofre/isolamento & purificação , Enxofre/metabolismo , Poluentes Químicos da Água/metabolismo
13.
J Hazard Mater ; 269: 31-7, 2014 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-24360509

RESUMO

In the present study, the bioremoval of arsenic from synthetic acidic wastewater containing arsenate (As(5+)) (0.5-20mg/L), ferrous iron (Fe(2+)) (100-200mg/L) and sulfate (2,000 mg/L) was investigated in an ethanol fed (780-1,560 mg/L chemical oxygen demand (COD)) anaerobic up-flow fixed bed column bioreactor at constant hydraulic retention time (HRT) of 9.6h. Arsenic removal efficiency was low and averaged 8% in case iron was not supplemented to the synthetic wastewater. Neutral to slightly alkaline pH and high sulfide concentration in the bioreactor retarded the precipitation of arsenic. Addition of 100mg/L Fe(2+) increased arsenic removal efficiency to 63%. Further increase of influent Fe(2+) concentration to 200mg/L improved arsenic removal to 85%. Decrease of influent COD concentration to its half, 780 mg/L, resulted in further increase of As removal to 96% when Fe(2+) and As(5+) concentrations remained at 200mg/L and 20mg/L, respectively. As a result of the sulfidogenic activity in the bioreactor the effluent pH and alkalinity concentration averaged 7.4 ± 0.2 and 1,736 ± 239 mg CaCO3/L respectively. Electron flow from ethanol to sulfate averaged 72 ± 10%. X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses were carried out to identify the nature of the precipitate generated by sulfate reducing bacteria (SRB) activity. Precipitation of arsenic in the form of As2S3 (orpiment) and co-precipitation with ferrous sulfide (FeS), pyrite (FeS2) or arsenopyrite (FeAsS) were the main arsenic removal mechanisms.


Assuntos
Arsenicais/isolamento & purificação , Reatores Biológicos , Sulfetos/química , Bactérias Redutoras de Enxofre/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Desulfovibrio/química , Desulfovibrio/genética , Concentração de Íons de Hidrogênio , Ferro/química , Metais/química , Metais/isolamento & purificação , Microscopia Eletrônica de Varredura , Oxirredução , Oxigênio/química , Espectrometria por Raios X , Sulfatos/química , Bactérias Redutoras de Enxofre/química , Bactérias Redutoras de Enxofre/ultraestrutura , Águas Residuárias/análise , Difração de Raios X
14.
J Environ Manage ; 133: 51-8, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24361728

RESUMO

The goal of this work was to assess the selection of the most suitable combination of plant species for the phytomanagement of mine tailings, by comparing among different plant life-forms (grasses, shrubs and trees). A comparison on induced rhizosphere changes generated by four plant species (the grass Piptatherum miliaceum, the shrub Helichrysum decumbens, and the trees, Pinus halepensis and Tetraclinis articulata) and high density vegetation patches (fertility islands) at a mine tailing located at Southeast Spain and the description of their physiological status employing stable isotopes analyses were carried out. The edaphic niches for plant growth were determined by salinity, organic matter and total soil nitrogen while metal(loid)s concentrations played a minor role. Induced changes in plant rhizospheres had a significant impact in soil microbiology. While grasses and shrubs may play an important role in primary ecological succession, trees seem to be the key to the development of fertility islands. The low δ(15)N values (-8.00‰) in P. halepensis needles may reflect higher ectomycorrhizal dependence. Large differences in leaf δ(18)O among the plant species indicated contrasting and complementary water acquisition strategies. Leaf δ(13)C values (-27.6‰) suggested that T. articulata had higher water use efficiency than the rest of species (-29.9‰). The implement of a diverse set of plant species with contrasting life forms for revegetating tailings may result in a more efficient employment of water resources and a higher biodiversity not only in relation to flora but soil microbiology too.


Assuntos
Biodegradação Ambiental , Metais/isolamento & purificação , Mineração , Poaceae/metabolismo , Árvores/metabolismo
15.
Radiats Biol Radioecol ; 54(1): 85-96, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25764850

RESUMO

The site contaminated with uranium-radium production wastes in the Komi Republic was studied. The activity concentration of naturally occurring radionuclides (226Ra, 228Th, 238U, 230Th, 232Th, 210Po, and 210Pb), as well as concentrations of nonradioactive chemically toxic elements (Pb, Zn, Cu, As, V, Mo, Sr, Y, and Ba) in the soil samples from the experimental site is 10-183 times higher than reference levels. A chronic exposure to alpha-emitters and nonradioactive chemically toxic elements causes adverse effects in tufted vetch (Vacia cracca L.) both at the cellular (aberration of chromosomes) and population (decrease in the reproductive ability) levels. Radionuclides are the main contributors to the decrease in the reproductive capacity and an increase in the level of the cytogenetic damage in root tip cells of tufted vetch seedlings. As and Pb significantly influence the reproductive capacity of plants. Sr, Zn, Y and P modify the biological effects caused by exposure to radionuclides. Moreover, P and Zn reduce the adverse effects of radionuclides; however, Sr and Y enhance these effects.


Assuntos
Aberrações Cromossômicas/efeitos da radiação , Radioisótopos/isolamento & purificação , Poluentes Radioativos do Solo/isolamento & purificação , Vicia/efeitos da radiação , Humanos , Metais/química , Metais/isolamento & purificação , Radioisótopos/química , Rádio (Elemento)/química , Rádio (Elemento)/isolamento & purificação , Tório/química , Tório/isolamento & purificação , Urânio/química , Urânio/isolamento & purificação
16.
Water Res ; 47(14): 4833-42, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23871254

RESUMO

This work reports on the recovery of nutrients and metals from anaerobically digested manure sludge using a pilot scale microfiltration membrane system. Soluble nitrogen (N), phosphorous (P) and metals are valuable commodities which exist in high concentration in anaerobically digested manure sludge. The typical disposal of sludge on farmland can cause serious harm to the ecosystem due to eutrophication. The recovery of these materials in clarified solutions represents an added value product and a less contaminated sludge that is environmentally less hazardous. The objective of this study was to investigate the recovery of nutrients and metals using a pilot scale cross-flow membrane filtration system. A ceramic membrane of 0.22 m(2) and 0.2 µm pore size was used to perform solid-liquid separations and soluble materials were recovered in particle and bacteria free solutions. Strategies such as batch diafiltration (DF) and acid pre-treatment were investigated and the fractions collected compared against the initial permeate containing 686.2 mg NH3-N L(-1) and 41.51 mg PO4-P L(-1). Clarified fractions obtained through DF with no acid pre-treatment yielded N:P ratios of around 30 and relatively low levels of P (364.24 mg NH3-N L(-1) and 25.60 mg PO4-P L(-1)) and metals. Acid pre-treatment of the sludge resulted in a two-fold increase of P extracted (271.11 mg NH3-N L(-1) and 71.60 mg PO4-P L(-1)), altering N:P ratios to 8. Depending on the metal species, a 2-9 fold increase in concentration was also observed. Thus it has been demonstrated that different treatment strategies influence the removal and recovery of nutrients and metals from sludge. The best treatment conditions therefore depend on the targeted materials to be recovered. By careful manipulation of the treatment processes the production of specific nutrient compositions in terms of N:P ratios is possible.


Assuntos
Filtração/métodos , Metais/isolamento & purificação , Esgotos , Anaerobiose , Indústria de Laticínios , Filtração/instrumentação , Concentração de Íons de Hidrogênio , Nitrogênio/isolamento & purificação , Tamanho da Partícula , Fósforo/isolamento & purificação , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos
17.
Food Chem ; 138(2-3): 770-5, 2013 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-23411174

RESUMO

The content of elements (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in edible oils (sunflower, hazelnut, canola, corn and olive oils) from Turkey was determined using inductively coupled plasma optical emission spectrometry (ICP-OES) after ultrasonic extraction, wet digestion, and extraction induced by emulsion breaking procedures (EIEB). In order to evaluate the best sample preparation procedure, EIEB procedure was compared by ultrasonic extraction and wet digestion procedures. The results in the samples (minimum-maximum in mgkg(-1)) were : 0.022-0.058, Cr 0.126-7.106, Cu 0.570-4.504, Fe 8.004-12.588, Mn 0.035-0.054, Ni 0.908-2.182, Pb 0.099-0.134 and Zn 2.206-8.982. The EIEB procedure was found to be fast, reliable, simple, and excellent in comparison with the other studied procedures. The recovery test was performed by spiking the samples with known amounts of the metals in the form of organometallic standards and applying the EIEB procedure. The recoveries were in the range of 96-109%.


Assuntos
Métodos Analíticos de Preparação de Amostras/métodos , Metais/análise , Metais/isolamento & purificação , Óleos de Plantas/análise , Oligoelementos/análise , Oligoelementos/isolamento & purificação , Análise Espectral , Turquia , Ultrassom
18.
Water Res ; 47(4): 1512-20, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23305683

RESUMO

The objective of this work was to evaluate the capacity of steel slag filters to treat a gypsum mining leachate containing 11-107 mg P/L ortho-phosphates, 9-37 mg/L fluoride, 0.24-0.83 mg/L manganese, 0.20-3.3 zinc and 1.7-8.2 mg/L aluminum. Column tests fed with reconstituted leachates were conducted for 145-222 days and sampled twice a week. Two types of electric arc furnace (EAF) slags and three filter sequences were tested. The voids hydraulic retention time (HRT(v)) of columns ranged between 4.3 and 19.2 h. Precipitates of contaminants present in columns were sampled and analyzed with X-ray diffraction at the end of tests. The best removal efficiencies over a period of 179 days were obtained with sequential filters that were composed of Fort Smith EAF slag operated at a total HRT(v) of 34 h which removed 99.9% of phosphorus, 85.3% of fluoride, 98.0% of manganese and 99.3% of zinc. Mean concentration at this system's effluent was 0.04 mg P/L ortho-phosphates, 4 mg/L fluoride, 0.02 mg/L manganese, 0.02 zinc and 0.5 mg/L aluminum. Thus, slag filters are promising passive and economical systems for the remediation of mining effluents. Phosphorus was removed by the formation of apatite (hydroxyapatite, Ca(5)(PO(4))(3)OH or fluoroapatite, Ca(5)(PO(4))(3)F) as confirmed by visual and X-ray diffraction analyses. The growth rate of apatite was favored by a high phosphorus concentration. Calcite crystals were present in columns and appeared to be competing for calcium and volume needed for apatite formation. The calcite crystal growth rate was higher than that of apatite crystals. Fluoride was removed by precipitation of fluoroapatite and its removal was favored by a high ratio of phosphorus to fluoride in the wastewater.


Assuntos
Sulfato de Cálcio , Fluoretos/isolamento & purificação , Metais/isolamento & purificação , Mineração , Fósforo/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Apatitas/química , Precipitação Química , Filtração , Resíduos Industriais , Aço/química , Difração de Raios X
19.
Chemosphere ; 89(3): 350-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22583786

RESUMO

This paper reports the removal of ten target metals of environmental concern ((53)Cr, Mn, Co, (60)Ni, (65)Cu, (66)Zn, As, (88)Sr, (95)Mo, and Ba) from oil sands tailings pond water. The organism responsible for removal was found to be an indigenous green micro-alga identified as Parachlorella kessleri by sequencing of the 23S rRNA gene. P. kessleri grew in tailings pond water samples taken from two oil sands operators (Syncrude Canada Ltd. and Albian Sands Energy Inc.), and enriched with low (0.24 mM NO(3)(-) and 0.016 mM PO(4)(-3)) and high (1.98 mM NO(3)(-) and 0.20mM PO(4)(-3)) concentrations of nutrient supplements (the most realistic scenario). The removal of (60)Ni, (65)Cu, As, (88)Sr, (95)Mo, and Ba from Syncrude tailings pond water was significantly enhanced by high concentrations of nitrogen and phosphorus, whereas the high nutrient concentrations adversely affected the removal of Co, (60)Ni, As, (88)Sr, and Mo in samples of Albian tailings pond water. Based on ANOVA two-factor analysis, higher nutrient concentration does not always result in higher metal removal, and TPW source must also be considered.


Assuntos
Clorófitas/metabolismo , Resíduos Industriais/análise , Metais/isolamento & purificação , Campos de Petróleo e Gás/química , Poluentes Químicos da Água/isolamento & purificação , Biodegradação Ambiental , Monitoramento Ambiental , Metais/metabolismo , Óleos , Petróleo/análise , Lagoas , Dióxido de Silício , Poluentes Químicos da Água/análise
20.
J Biotechnol ; 161(2): 126-37, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22484126

RESUMO

Biotechnological downstream processing faces several challenges, such as dilute product streams and contained target products which are sensitive to heat, oxidation, other chemicals, etc. State-of-the-art separation methods, e.g. chromatography, are not always the best option due to variable yield losses and high costs. Foam fractionation appears as a promising alternative unit operation in biotechnological downstream processing. From its applications in metal industry and on fish farms, it was developed further towards the recovery of phytonutrients, metabolites and proteins. However, no large scale applications of foam fractionation in biotechnological downstream processing exist yet. This is due to the complexity of various biotechnological media, which makes a universalized approach for systematic process design of protein separations difficult. Ongoing research in the fields of process engineering, surface chemistry and protein chemistry can help to close this gap. Although many different substances, such as detergents, have been separated or recovered using foam fractionation, this review focuses mainly on biotechnological applications, more specifically on protein separation.


Assuntos
Biotecnologia/métodos , Fracionamento Químico/métodos , Metais/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Proteínas/isolamento & purificação
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