@article {3708, title = {Characterization of chars produced in the co-pyrolysis of different wastes: decontamination study}, journal = {Journal of Hazardous Materials}, volume = {207-208}, year = {2012}, pages = {28-35}, abstract = {

The present work is devoted to the study of the decontamination of chars obtained in the co-pyrolysis of plastics, biomass and tyre wastes. The chars were extracted with several organic solvents of different polarities either individually or in sequence. The ability of each selected extractant to remove toxic pollutants was evaluated by comparing the extraction yields and by characterizing the crude extracts with a combination of chemical analysis and toxicity bioassays. Also, the mineral composition of the treated and non-treated chars was assessed. The results obtained in this study indicate that hexane is the more efficient extraction solvent to be used in the organic decontamination of chars obtained in the co-pyrolysis of plastics, tyres and biomass. A sequential extraction with solvents of increasing polarity can provide a better decontamination of the raw pyrolysis char than any individual extraction. The compounds removed from the char during the decontamination process are mainly aliphatic hydrocarbons and aromatic hydrocarbons, therefore a material that may be upgraded to be used as a fuel and/or as raw material for the organic chemical industry.

}, url = {http://www.sciencedirect.com/science/article/pii/S0304389411009964}, author = {M. Bernardo and M. Gon{\c c}alves and Lapa, N. and Barbosa, R. and Mendes, B. and F. Pinto} } @article {3705, title = {Physico-chemical properties of chars obtained in the co-pyrolysis of waste mixtures}, journal = {Journal of Hazardous Materials}, volume = {219-220}, year = {2012}, pages = {196-202}, abstract = {

The present work aims to perform a multistep upgrading of chars obtained in the co-pyrolysis of PE, PP and PS plastic wastes, pine biomass and used tires. The quality of the upgraded chars was evaluated by measuring some of their physico-chemical properties in order to assess their valorisation as adsorbents{\textquoteright} precursors. The crude chars were submitted to a sequential solvent extraction with organic solvents of increasing polarity (hexane, mixture 1:1 v/v hexane:acetone and acetone) followed by an acidic demineralization procedure with 1 M HCl solution. The results obtained showed that the upgrading treatment allow the recovery of 63{\textendash}81\% of the pyrolysis oils trapped in the crude chars and a reduction in the char{\textquoteright}s ash content in the range of 64{\textendash}86\%. The textural and adsorption properties of the upgraded chars were evaluated and the results indicate that the chars are mainly mesoporous and macroporous materials, with adsorption capacities in the range of 3.59{\textendash}22.2 mg/g for the methylene blue dye. The upgrading treatment allowed to obtain carbonaceous materials with quality to be reused as adsorbents or as precursors for activated carbon.

}, url = {http://www.sciencedirect.com/science/article/pii/S030438941200372X}, author = {M. Bernardo and Lapa, N. and M. Gon{\c c}alves and Mendes, B. and F. Pinto and I. Fonseca and Lopes, H} } @article {3703, title = {Study of the organic extraction and acid leaching of chars obtained in the pyrolysis of plastics, tire rubber and forestry biomass wastes}, journal = {Procedia Engineering}, volume = {42}, year = {2012}, pages = {1909-1916}, abstract = {

The present work aims to perform a characterization of chars obtained in the co-pyrolysis of waste mixtures composed by plastics, tires and pine biomass, to provide knowledge about the composition, leaching behavior and risk assessment of these materials in order to define strategies for their possible valorization or safe disposal. The chars were submitted to sequential solvent extractions with organic solvents of increasing polarity that allow the recovery of significant amounts of the pyrolysis oils trapped in the crude chars improving the yield of the pyrolysis liquids. An acidic demineralization procedure was successfully applied to the chars and high efficiency removals of the majority of the heavy metals were achieved. The demineralization study also demonstrated that hazardous heavy metals such as chromium, nickel and cadmium are significantly immobilized in the char matrix, and other heavy metals of concern such as zinc and lead will not represent a leaching problem if acidic conditions were not used. The obtained chars present sufficient quality and characteristics to be used as fuel or alternatively, to be used as adsorbents or precursors of activated carbon.

}, url = {http://www.sciencedirect.com/science/article/pii/S1877705812029748}, author = {M. Bernardo and Lapa, N. and M. Gon{\c c}alves and Mendes, B. and F. Pinto} } @article {3714, title = {Toxicity of char residues produced in the co-pyrolysis of different wastes}, journal = {Waste Management}, volume = {30}, year = {2010}, pages = {628-635}, abstract = {

Char residues produced in the co-pyrolysis of different wastes (plastics, pine biomass and used tyres) were characterized using chemical and toxicity assays. One part of the solid chars was submitted to extraction with dichloromethane (DCM) in order to reduce the toxicity of the char residues by removing organic contaminants. The different volatility fractions present in the extracted char (Char A) and in the raw char (Char B) were determined by progressive weight loss combustion. A selected group of heavy metals (Cd, Pb, Zn, Cu, Hg and As) was determined in both chars.

The chars were subjected to the leaching test ISO/TS 21268 {\textendash} 2, 2007 and the resulting eluates were further characterized by determining a group of inorganic parameters (pH, conductivity, Cd, Pb, Zn, Cu, Hg and As contents) and the concentrations of several organic contaminants (volatile aromatic hydrocarbons and alkyl phenols). An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri.

The chemical and ecotoxicological results were analyzed according to the Council Decision 2003/33/CE and the criteria on the evaluation methods of waste ecotoxicity (CEMWE).

The results obtained in this work indicated that the extraction with DCM is an effective method for the removal of organic contaminants of high to medium volatility from pyrolysis solid residues, thus decreasing their toxicity potential. Zn can be leached from the chars even after the DCM extraction treatment and can contribute to the ecotoxicity of the eluates obtained from chars.

Both chars (treated and non treated with DCM) were classified as hazardous and ecotoxic wastes.

}, url = {http://www.sciencedirect.com/science/article/pii/S0956053X09004632}, author = {M. Bernardo and Lapa, N. and M. Gon{\c c}alves and Barbosa, R. and Mendes, B. and F. Pinto and I. Gulyurtlu} } @article {3717, title = {Chemical and ecotoxicological characterization of solid residues produced during the co-pyrolysis of plastics and pine biomass}, journal = {Journal of Hazardous Materials}, volume = {166}, year = {2009}, pages = {309-317}, abstract = {

A mixture of 70\% (w/w) pine biomass and 30\% (w/w) plastics (mixture of polypropylene, polyethylene, and polystyrene) was subjected to pyrolysis at 400 {\textdegree}C, for 15 min, with an initial pressure of 40 MPa. Part of the solid residue produced was subjected to extraction with dichloromethane (DCM). The extracted residue (residue A) and raw residue (residue B) were analyzed by weight loss combustion and submitted to the leaching test ISO/TS 21268-2 using two different leachants: DCM (0.2\%, v/v) and calcium chloride (0.001 mol/L). The concentrations of the heavy metals Cd, Cr, Ni, Zn, Pb and Cu were determined in the eluates and in the two residues. The eluates were further characterized by determining their pH and the concentrations of benzene, toluene, ethylbenzene and xylenes (BTEX). The presence of other organic contaminants in the eluates was qualitatively evaluated by gas chromatography, coupled with mass spectrometry. An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Ecotoxicity (CEMWE). Residue A was not considered to be ecotoxic by the ecotoxicological criterion (EC50 (30 min) >=10\%), but it was considered to be ecotoxic by the chemical criterion (Ni >= 0.5 mg/L). Residue B was considered to be ecotoxic by the ecotoxicological criterion: EC50 (30 min) <= 10\%. Besides that, residue B was considered to be hazardous according the European legislation (BTEX concentrations higher than 100 ppb). The results indicate that volatile organic contaminants can be present in sufficient amounts in these residues and their eluates to induce ecotoxicity levels. The extraction of the pyrolysis residue with DCM was an efficient method for removing lighter organic contaminants.

}, url = {http://www.sciencedirect.com/science/article/pii/S0304389408016932}, author = {M. Bernardo and Lapa, N. and Barbosa, R. and M. Gon{\c c}alves and Mendes, B. and F. Pinto and I. Gulyurtlu} } @article {3715, title = {Determination of aromatic compunds in leachates from pyrolysis solid residues using HS-GC-MS and DLLME-GC-MS}, journal = {Talanta}, volume = {80}, year = {2009}, pages = {104-108}, abstract = {

A method for the determination of 15 aromatic hydrocarbons in eluates from solid residues produced during the co-pyrolysis of plastics and pine biomass was developed. In a first step, several sampling techniques (headspace solid phase microextraction (HS-SPME), static headspace sampling (HS), and dispersive liquid{\textendash}liquid microextraction (DLLME) were compared in order to evaluate their sensitivity towards these analytes. HS-SPME and HS sampling had the better performance, but DLLME was itself as a technique able to extract volatiles with a significant enrichment factor.

HS sampling coupled with GC{\textendash}MS was chosen for method validation for the analytes tested. Calibration curves were constructed for each analyte with correlation coefficients higher than 0.999. The limits of detection were in the range of 0.66{\textendash}37.85 ng/L. The precision of the HS method was evaluated and good repeatability was achieved with relative standard deviations of 4.8{\textendash}13.2\%. The recoveries of the analytes were evaluated by analysing fortified real eluate samples and were in the range of 60.6{\textendash}113.9\%.

The validated method was applied in real eluate samples. Benzene, toluene, ethylbenzene and xylenes (BTEX) were the compounds in higher concentrations.

The DLLME technique coupled with GC{\textendash}MS was used to investigate the presence of less volatile contaminants in eluate samples. This analysis revealed the presence of significant amounts of alkyl phenols and other aromatic compounds with appreciable water solubility.

}, url = {http://www.sciencedirect.com/science/article/pii/S003991400900455X}, author = {M. Bernardo and M. Gon{\c c}alves and Lapa, N. and Barbosa, R. and Mendes, B. and F. Pinto and I. Gulyurtlu} } @article {3718, title = {Study of the co-pyrolysis of biomass and plastic wastes}, journal = {Clean Technologies and Environmental Policy}, volume = {11}, year = {2009}, pages = {115-122}, abstract = {

This work aimed to study the recovery of two types of waste by the process of pyrolysis. The obtained results show that the adding of a plastic mix improves the overall efficiency of the slow pyrolysis of pine. Therefore, it was possible to achieve higher liquid yields and less solid product than in the classic slow pyrolysis carbonization of biomass. The obtained liquids showed heating values similar to that of heating fuel oil. The gas products had energetic contents superior to that of producer gas, and the obtained solid fractions showed heating values higher than some coals. There were also identified some typical products of fast biomass pyrolysis used as raw material in several industries. The effects of experimental conditions in product yield and composition were also studied. The parameters that showed higher influence were (with its increase): reaction time on gas product composition (increase of the alkane content) and on liquid composition (increase in aromatics content); reaction temperature on product yield (decrease of liquid yield with increase of solids and gases) and on gas product composition (increase in alkane content); initial pressure on liquid composition (increase in the aromatics content) and mainly the pine content of the initial mixture on products yield (increase of gas and solid yield with a decrease in liquids) and on the gas product composition (favouring CO and CO2 formation).

}, url = {http://link.springer.com/article/10.1007/s10098-008-0176-1}, author = {Paradela, F. and F. Pinto and I. Gulyurtlu and Cabrita, I. and Lapa, N.} } @inbook {3693, title = {Industrial liquid effluents in the pulp and paper industry}, booktitle = {Industrial Liquid Effluents - A Guide Book on the Treatment of Effluents from the Mining/Metallurgy, Paper, Plating and Textile Industries}, year = {2006}, pages = {33-73}, publisher = {INASMET-Tecnalia and European Commission}, organization = {INASMET-Tecnalia and European Commission}, address = {Donostia - San Sebasti{\'a}n}, author = {Mahiout, A. and Damann, R. and Pera, J. and Luonsi, A. and Kolari, M. and Siivinen, J. and Santos Oliveira, J. F. and Lapa, N. and Pourcelly, G. and Aslan, F.}, editor = {Cox, M. and N{\'e}gr{\'e}, P. and Yurramendi, L.} } @article {3729, title = {Efficiency of removal in stabilization ponds. I - Influence of climate}, journal = {Water Science and Technology}, volume = {31}, year = {1995}, pages = {219-229}, abstract = {

Owing to the existing or predictable water deficiencies in the South of Portugal, it is necessary to carry out the appropriate management of water resources, by reducing and/or minimizing the negative impacts of untreated/treated domestic effluents in the aquatic environment. As Portugal has a great diversity of ecoclimatic areas, five different stabilization pond systems were chosen to carry out a control study during one year (from March 1991 to March 1992). According to Pina Manique \& Albuquerque the ecological classification of these stations is different, varying from Ibero-mediterranean (continental) up to mediterranean (maritime). The physical and chemical parameters studied were: temperature, pH, dissolved oxygen, conductivity, BOD, COD, nitrates, nitrites, ammonia and total nitrogen, total suspended and volatile solids, total phosphorus and orthophosphates. The microbiological parameters studied were: total and faecal coliforms, faecal Streptococci, Clostridium perfringens and Pseudomonas aeruginosa. The correlations between climatic parameters and the efficiency of the removal of organic matter were analysed.

}, url = {http://www.sciencedirect.com/science/article/pii/027312239500509L}, author = {Mendes, B. S. and Nascimento, M. J. and Pereira, M. I. and Bailey, G. and Lapa, N. and Morais, J and Santos Oliveira, J. F.} } @article {3728, title = {Efficiency of removal in stabilization ponds. II - Statistical analysis of K values}, journal = {Water Science and Technology}, volume = {31}, year = {1995}, pages = {231-238}, abstract = {

The analytical values obtained from five WSP systems located in different ecoclimatic zones in the centre and South of Portugal, were subjected to a statistical analysis of K and K20 values (as used in the van Hoff-Arrhenius equation) utilizing an analysis of variance and a vectorial analysis of principal components. Significant differences between K and K20 values in facultative, maturation ponds and in the whole system were verified. The projection of the first principal components of eigenvectors made possible the classification of the stations, showing the existence of similarities and discrepancies in their removal BOD kinetics behaviour. The K20 value must be estimated and taken into account for the design of waste stabilization ponds.

}, url = {http://www.sciencedirect.com/science/article/pii/027312239500510T}, author = {Mendes, B. S. and Nascimento, M. J. and Pereira, M. I. and Bailey, G. and Lapa, N. and Morais, J and Santos Oliveira, J. F.} } @article {3730, title = {Ecoclimatic influence on waste stabilization ponds (WSP) efficiencies: the case study of the Sesimbra system}, journal = {Water Science and Technology}, volume = {30}, year = {1994}, pages = {269-279}, abstract = {

Portugal has a great diversity of ecoclimatic areas and Sesimbra was chosen to carry out a study on WSP efficiencies over five years (1989 to 1993). According to Pina Manique \& Albuquerque (1954), the climate is classified as Atlantic Mediterranean (AM). Some environmental and climatic parameters have been studied in order to define the area. The treatment system at Sesimbra has three ponds: anaerobic, facultative and maturation. The physical and chemical parameters studied in the WSP system were: Temperature, pH, Dissolved Oxygen, Conductivity, BOD5, COD, nitrates, nitrites, ammonia and total nitrogen, total and volatile suspended solids, total phosphorus and orthophosphates. Algal populations and the following microbiological parameters were studied: total and fecal coliforms, fecal Streptococci, Clostridium perfringens, Pseudomonas aeruginosa and some Enterobacteriaceae. The K and K20 kinetic parameters were studied and derived for the three ponds utilizing the seasonal regional characteristics from the surrounding area. These values were then correlated with temperature and the subsequent removal efficiencies for each pond deduced. The data obtained indicate a necessity to determine the seasonal fluctuations of the K and K20 kinetic parameters for the WSP systems.

}, url = {http://www.iwaponline.com/wst/03008/wst030080269.htm}, author = {Mendes, B. S. and Nascimento, M. J. and Pereira, M. I. and Bailey, G. and Lapa, N. and Morais, J and Santos Oliveira, J. F.} }