Clavulanic Acid Adsorption Studies in Zeolites

Abstract

Zeolites are crystalline inorganic solids containing aluminium, silicon and oxygen arranged in a highly regular structure, and they are usually used in separation processes. In this study, zeolites have been shown to act as adsorbents for clavulanic acid. Ion exchange with different compensating cations (Na ϩ , K ϩ , Ca 2ϩ , Ba 2ϩ , Mg 2ϩ , Sr 2ϩ ) was used to modify the natural zeolite (NZ) and the synthetic faujasite (13X). Kinetic analysis of the adsorption of clavulanic acid indicated that the 13X-Na zeolite was the most appropriate for this purpose. Under equilibrium conditions, the retention by this zeolite was about 17.4% (C * /C 0 ϭ 0.826), with the amount of clavulanic acid adsorbed relative to the amount of zeolite employed (q * ) being ca. 0.5 mg/g. The 13X-Na zeolite was characterized in terms of its Si/Al ratio (1.5), density (d z ϭ 2.248 g/cm 3 ), superficial area (S BET ϭ 444.860 m 2 /g), total pore volume (V pore ϭ 0.308 cm 3 /g), micropore volume (V micro ϭ 0.203 cm 3 /g) and particle porosity (ε p ϭ 0.69). Adsorption isotherms at 10, 15 and 20 ЊC were constructed using 13X-Na zeolite and solutions of pure clavulanic acid; these demonstrated that the lower the temperature, the higher the amount of clavulanic acid adsorbed.

Comparative studies on parametric sensitivity analyses using conventional and factorial design methodologies: mathematical modelling of clavulanic acid adsorption on zeolites

“…The simulations were carried out using data from previous work,11, 12 dealing with CA adsorption on synthetic faujasite zeolite 13X‐Na, which was selected as an alternative adsorbent for the clavulanic acid adsorption process. As reference data, the following hydrodynamic parameters were taken from the cited previous work: R s /l = 6.0%, C 0 = 250 mg L −1 and d p = 0.106 mm.…”

“…The proposed model is based on ideal surfaces and predicts that the adsorption surface is energetically ideal. Thus, at equilibrium the adsorption could be described by the Langmuir model (Equation (2)) 12 where q* is the equilibrium concentration of CA in the solid phase, q m is the maximum adsorption capacity of the zeolite, C * is the corresponding equilibrium concentration of CA in the liquid‐phase and k D is the dissociation constant ( = k 2 / k 1 ).…”

Clavulanic Acid Production by Streptomyces clavuligerus: Insights from Systems Biology, Strain Engineering, and Downstream Processing

“…Forte et al [ 178 , 179 ] studied the CA recovery from aqueous solutions by using natural and synthetic zeolites, namely, faujasite-type NaX zeolite (13X) and clinoptilolite–mordenite zeolite (NZ) and their modified cationic forms (K + , Na + , Ca 2+ , Ba 2+ , Mg 2+ , Sr 2+ ), with aperture diameters ranging 0.062 and 0.150 mm. The 13X­-Na zeolite showed the best CA retention (17.4%) in the equilibrium at a zeolite/liquid ratio of 0.5 mg.g −1 [ 178 ]. Higher retention levels have been obtained in separations with quaternary ammonium anionic exchange resins, such as Amberlite IRA 400 and Q Sepharose XL.…”

“…This technique allows the biomolecules to be selectively adsorbed in solid materials while minimizing the degradation of the product. Forte et al [178,179] studied the CA recovery from aqueous solutions by using natural and synthetic zeolites, namely, faujasite-type NaX zeolite (13X) and clinoptilolite-mordenite zeolite (NZ) and their modified cationic forms (K + , Na + , Ca 2+ , Ba 2+ , Mg 2+ , Sr 2+ ), with aperture diameters ranging 0.062 and 0.150 mm. The 13X-Na zeolite showed the best CA retention (17.4%) in the equilibrium at a zeolite/liquid ratio of 0.5 mg.g −1 [178].…”

Evaluation of kinetic and mass transfer parameters for adsorption of clavulanic acid into natural and synthetic zeolites

“…Amongst the low-cost alternative adsorbents, zeolites are attractive due to their characteristically crystalline and microporous structure, along with suitable chemical properties [7]. Such materials therefore possess a well-defined bimodal pore size distribution with the intracrystalline micropores (~0.3 ~ 1.0 nm) linked together through a network of macropores having a diameter of the same order as the crystal size (~1 ~ 5 µm).…”