Multicomponent biosorption in fixed beds

Abstract

AbstractÐThe biosorption of Cu, Zn, Cd and Fe from multicomponent mixtures was studied in a¯ow-through column packed with Sargassum algal biosorbent in the Ca-form. The eects of competitive ion exchange such as the elution order of toxic metals from the column, and the concentration overshoots in column euent were investigated both experimentally and by means of an ion exchange equilibrium column model (ECM

Biosorption of Metals: State of the Art, General Features, and Potential Applications for Environmental and Technological Processes

“…The conventional methods (Table 2) involve or capital and operational high costs, or they are inefficient at low metal concentration (1-100 ppm), or they can be associated to production of secondary residues that present treatment problems (Aksu, 2001;Ahluwalia & Goyal, 2007). The initial incentives of biosorption development for industrial process are: (a) low cost of biosorbents, (b) great efficiency for metal removal at low concentration, (c) potential for biosorbent regeneration and metal valorization, (d) high velocity of sorption and desorption, (e) limited generation of secondary residues, and (f) more environmental friendly life cycle of the material (easy to eliminate compared to conventional resins, for example) (Crini, 2005;Kratochvil & Volesky, 2000;Volesky & Naja, 2005). Therefore the use of dead biomasses is generally preferred since it limits the toxicity effects of heavy metals (which may accumulate at the surface of cell walls and/or in the cytoplasm) and the necessity to provide nutrients (Modak & Natarajan, 1995;Sheng et al, 2004; The mechanisms involved in metal accumulation on biosorption sites are numerous and their interpretation is made difficult because the complexity of the biologic systems (presence of various reactive groups, interactions between the compounds, etc.)…”

“…These models (Table 4) differ in the amount of adsorbed layers, the interaction between the binding sites and the metal (adsorbent-adsorbate, adsorbate-adsorbate, and adsorbentadsorbent), and the possibility to apply equilibrium constants equations between the liquid and solid phases. Obviously, these considerations for biosorption systems do not explain the mechanisms of metal uptake due to the complexity of the biologic systems, but it supplies parameters that are utilized to evaluate the biosorption performance, such as the maximum metal uptake and the affinity of the active sites by metallic ions (Kratochvil & Volesky, 2000;Palmieri, 2001). Biosorption of metals in the mostly cases of equilibrium isotherms is modeled according to non-linear functions that are described by Brunauer-Emmet-Teller (BET) type-I isotherms with hyperbolic shape (Guiochon et al, 2006).…”

“…There is broad literature that describes the effects of operational parameters to augment and to improve the biosorption in fixed-bed columns (Chu, 2004;Hashim & Chu, 2004;Kratochvil & Volesky, 2000;Naddafi et al, 2007;Oliveira, 2007;Oliveira, 2001;Valdman et al, 2001;Vieira et al, 2008;Vijayaraghavan et al, 2005;Vijayaraghavan et al, 2008;Vijayaraghavan & Prabu, 2006;Volesky et al, 2003). These parameters modified mainly related are: flow rate, feeding concentration, height of packed-bed column, porosity, mass of biomass, etc.…”

Continuous removal of malathion by immobilised biomass of Bacillus species S14 using a packed bed column reactor

“…The stages in the separation protocol can be automated and high degree of purification can often be achieved in a single-step process (Maiti et al, 2009). Many mathematical models have also been used to study packed bed system and its dynamic behaviour has been well described (Kratochvil et al, 2000, Volesky et al, 1994, Figueira et al, 2000, Hatzikioseyian et al, 2001.…”

Estudio del Mecanismo de Remoción de Hierro y Cobre presentes en Aceites Lubricantes Usados Mediante Bioadsorción

“…El proceso de bioadsorción de los metales pesados por algas marinas pretratadas es una excelente opción para la descontaminación de distintos efluentes acuosos (Figueira et al, 2004;Kratochvil y Volesky, 2000;Schmitt et al, 2001), debido a esto se decidió estudiar el proceso en un medio orgánico con la finalidad de remover algunos metales pesados presentes en los aceites lubricantes usados. Esta aplicación es una innovación tecnológica, ya que en la literatura son solamente encontrados estudios aplicados para sistemas acuosos.…”