Yazarlar

  • MakaleAçık Erişim2017Scopus SJRQ2
    Exploring thermodynamics and kinetic parameters of immobilized catalase enzyme via adsorption on krill clay

    Nas, Mehmet Salih; Gür, Aycan; Gür, Tugba; Yönten, Vahap

    The thermodynamic parameters and immobilization kinetics of catalase enzyme via adsorption onto krill clay were performed in aqueous solution in batch system. The adsorbent was characterized by X-ray fluorescence, scanning electron microscope and Brunauer-Emmett-Teller N-2 adsorption measurements. The effect of some parameters to the adsorption process such as contact time, stirring speed, initial enzyme concentration, initial ionic strength, temperature and pH were analyzed. Maximum adsorption capacity (q(m)) showed a great dependence on pH and initial enzyme concentration. It was found at pH 5.5, and initial enzyme concentration, 0.0075 g L-1 values. Pseudo-first-order, pseudo-second-order and intraparticle diffusion were used to fit the kinetics data on kinetic models. Furthermore, thermodynamic activation parameters such as enthalpy, entropy, Gibbs free energy and activation energy (Delta H degrees, Delta S degrees, Delta G degrees and E-a) which reveal that catalase enzyme adsorption occur spontaneously and in endothermic nature were determined. The obtained results confirmed that the applicability of krill clay is an efficient immobilizing supporter for catalase enzyme and krill clay material can be used as a very effective adsorbent in immobilization of this enzyme from aqueous solutions.

    AtıfWoS9OpenAlex13
    Web of Scienceİncele
  • MakaleYalnız künye2013Scopus SJRQ3
    EFFECT OF THE PRESENCE OF PHOSPHATE BASED FERTILIZER ON METAL REMOVAL CAPACITY OF NATIVE BIORETENTION MATERIALS

    Demir, Veysel; Bin-Shafique, Sazzad

    Batch tests were conducted on several Texas native bioretention media to estimate the removal capacity of lead and copper from contaminated water and to understand the effect of the presence of phosphate (due to application of phosphate based fertilizers in the watershed) on metal removal. The results show that the 77% of lead and 58% of copper precipitated as the phosphate added to the contaminated water even before adding any media. Cedar mulch and hardwood mulch performed best and removed 99.2% of lead and 97.5% of copper from aqueous solution. When phosphate was added, removal increased to 97.8% for copper and 100% for lead (under detection limits). The removal capacity of metals was with the order of cedar mulch > hardwood mulch > pine mulch > sawdust > loam soil > silica sand. The leaching of metals from the media was much lower than the original solution and decreased when phosphate was added.

    AtıfWoS2
    Web of Scienceİncele