A Pérez

Publications (3)6.61 Total impact

• Article: Costs estimation of an integrated process for the treatment of heavy-metal loaded aqueous effluents

  J. Llanos, R. Camarillo, A. Pérez, P. Cañizares, M. A. Rodrigo
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  ABSTRACT: This work aims at providing a guide for the calculation of investment and operation costs of a process to treat diluted streams of heavy metal ions. This process is composed of two stages: (1) a metal concentration stage by polymer supported ultrafiltration; (2) a polymer regeneration and metal recovery by electrodeposition. First of all, the most relevant parameters to be used in the process design will be correlated with the key working variables. Next, these parameters will be related with the cost of the main investment of the plant, providing Williams equations based on both literature and suppliers’ budgets. Finally, a detailed costs calculation for the most representative values of the working variables will be presented as example. KeywordsWater treatment–Cost–Williams equation–Metal ions–Ultrafiltration–Electrodeposition
  Journal of Applied Electrochemistry 04/2012; 41(9):1099-1107. · 1.75 Impact Factor
• Article: Characterization of a ceramic ultrafiltration membrane in different operational states after its use in a heavy-metal ion removal process.

  J Llanos, P M Williams, S Cheng, D Rogers, C Wright, A Pérez, P Cañizares
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  ABSTRACT: In the present study, the atomic force microscopy (AFM) technique has been used to characterize a Carbosep M5 ceramic membrane (MWCO=10kDa, TiO(2)-ZrO(2) active layer). This membrane was previously used in a polymer supported ultrafiltration (PSU) process to recover copper, using partially ethoxylated polyethylenimine as the water-soluble polymer. The membrane was characterized in four different operational states: new, new and cleaned, fouled in a PSU stage and cleaned after a PSU process. The influence of the membrane state on pore opening size distribution and roughness was studied, finding a 16% decrease in the former and a 20% increase in the latter due to foulant deposition upon the membrane active layer. Phase angle distribution was also analyzed to indicate the foulant spreading on the membrane surface. These phase angle measurements can be related to pore opening size and roughness, concluding that the cleaning procedure is not totally effective and that foulant presence on the membrane active layer is not remarkable. Finally, AFM was used to measure the influence of pH on adhesion forces between a silica probe and the membrane active layer. These results can be related to the flux evolution vs pH in PSU experiments, finding both lowest adhesion and highest flux at pH 6.
  Water Research 06/2010; 44(11):3522-30. · 4.86 Impact Factor
• Article: Simultaneous recovery of cadmium and lead from aqueous effluents by a semi-continuous laboratory-scale polymer enhanced ultrafiltration process

  P. Cañizares, A. Pérez, R. Camarillo, R. Mazarro
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  ABSTRACT: Performance of a semi-continuous polymer enhanced ultrafiltration (PEUF) process has been investigated for the simultaneous recovery of cadmium and lead from binary mixtures. This method uses poly(acrylic acid) as water-soluble polymer to bind these metals. Experiments have taken place in a laboratory-scale system. Loading ratio (mg total metal ions/g polymer) and pH values for separation of cadmium and lead have been studied by means of preliminary experiments, analyzing their influence on permeate flux, metal rejection coefficients and separation factor.The proposed process includes three different stages: total retention of metal ions, selective separation and polymer regeneration. Operating pH values for total retention of metal ions and polymer regeneration processes are 5 and 2, respectively. Selective separation has been investigated working at an intermediate pH value. In this way, if a stream containing 12.5 ppm of each metal ion (1:1 in weight) is treated in the first stage, two different streams enriched in each metal ion are obtained in the second stage. Permeate stream is enriched in cadmium with a proportion near 5:1 in weight, and retentate is enriched in lead with a similar proportion.Finally, the three stages have been modelled successfully with a mathematical model based on conservation equations and chemical reactions taking place in solution.
  Journal of Membrane Science.