Browsing by Author "Matos, M."
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- Behaviour and fate of metals in urban wastewater treatment plants: a reviewPublication . Cantinho, P.; Matos, M.; Trancoso, Maria Ascensão; Santos, M. M. Correia dosThe concerns on metals in urban wastewater treatment plants (WWTPs) are mainly related to its contents in discharges to environment, namely in the final effluent and in the sludge produced. In the near future, more restrictive limits will be imposed to final effluents, due to the recent guidelines of the European Water Framework Directive (EUWFD). Concerning the sludge, at least seven metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) have been regulated in different countries, four of which were classified by EUWFD as priority substances and two of which were also classified as hazardous substances. Although WWTPs are not designed to remove metals, the study of metals behaviour in these systems is a crucial issue to develop predictive models that can help more effectively the regulation of pre-treatment requirements and contribute to optimize the systems to get more acceptable metal concentrations in its discharges. Relevant data have been published in the literature in recent decades concerning the occurrence/fate/behaviour of metals in WWTPs. However, the information is dispersed and not standardized in terms of parameters for comparing results. This work provides a critical review on this issue through a careful systematization, in tables and graphs, of the results reported in the literature, which allows its comparison and so its analysis, in order to conclude about the state of the art in this field. A summary of the main consensus, divergences and constraints found, as well as some recommendations, is presented as conclusions, aiming to contribute to a more concerted action of future research.
- Design and operation of power systems with large amounts of wind power : Final report, Phase one 2006-08, IEA WIND Task 25Publication . Holttinen, Hannele; Meibom, Peter; Orths, Antje; Van Hulle, Frans; Lange, Bernhard; O'Malley, Mark; Smith, J. Charles; Estanqueiro, Ana; Ricardo, João; Ummels, Bart C.; Gomez, Emilio; Matos, M.; Soder, Lennart; Shakoor, Anser; Strbac, Goran; Tande, John O.; Pierik, Jan; Ela, Erik; Milligan, MichaelThere are already several power systems coping with large amounts of wind power. High penetration of wind power has impacts that have to be managed through proper plant interconnection, integration, transmission planning, and system and market operations. This report is a summary of case studies addressing concerns about the impact of wind power s variability and uncertainty on power system reliability and costs. The case studies summarized in this report are not easy to compare due to different methodology and data used, as well as different assumptions on the interconnection capacity available. Integration costs of wind power need to be compared to something, like the production costs or market value of wind power, or integration cost of other production forms. There is also benefit when adding wind power to power systems: it reduces the total operating costs and emissions as wind replaces fossil fuels. Several issues that impact on the amount of wind power that can be integrated have been identified. Large balancing areas and aggregation benefits of large areas help in reducing the variability and forecast errors of wind power as well as help in pooling more cost effective balancing resources. System operation and working electricity markets at less than day-ahead time scales help reduce forecast errors of wind power. Transmission is the key to aggregation benefits,electricity markets and larger balancing areas. From the investigated studies it follows that at wind penetrations of up to 20 % of gross demand (energy), system operating cost increases arising from wind variability and uncertainty amounted to about 1 4 /MWh. This is 10 % or less of the wholesale value of the wind energy.
- Metal concentrations and removal along the SBR wastewater treatment plant of Torres Vedras, Portugal [Resumo]Publication . Cantinho, P.; Santos, M. M. Correia dos; Trancoso, Maria Ascensão; Cortês, E.; Matos, M.ABSTRACT: The concerns on metals in municipal Wastewater Treatment Plants (WWWTPs) discharges are mainly related with its contents in sludge, witch can prevent its application in land and so the recycling of valuable nutrients, and with the more restrictive limits foreseen for final effluents, due to the recent guidelines introduced by European Water Framework Directive (EUWFD).
- Metal soption and partitioning coefficients in all matrices of the Torres Vedras SBR WWTP, Portugal [Resumo]Publication . Cantinho, P.; Santos, M. M. Correia dos; Trancoso, Maria Ascensão; Cortês, E.; Matos, M.ABSTRACT: The literature review concerning the issue of metals behaviour and fate throughout WWTPs shows that, although relevant data have been published in recent decades, results are not consensual and more studies are needed, particulary from data obtained in full scale WWTPs.