Adsorptive Properties of Fish Scales of Oreochromis Niloticus (Mojarra Tilapia) for Metallic Ion Removal from Waste Water

Abstract

The present work presents the experimental study of the adsorptive properties for the removal of Cu 2+ , Pb 2+ , Co 2+ , and Ni 2+ metallic ions from water of thermally pretreated fish scales from a very common and abundant source in Mexico, the Oreachromis Niloticus fish, known as "Mojarra Tilapia". To determine the influence and importance that the two main fractions (the organic or protein fraction and the inorganic fraction mainly composed of hydroxyapatite) of this material play in this adsorptive capacity, the original pretreated fish scales are subjected to an acid demineralization and a basic deproteinization treatment to modify the organic/ inorganic matter ratios present, and their materials are characterized in terms of their adsorption ability, especially in the removal of the Cu 2+ ion. The adsorption isotherms for the thermally pretreated fish scales show that they have a maximum Cu 2+ adsorption capacity of 58 mg of Cu 2+ /g of adsorbent with an ion selectivity removal in the order Cu 2+ > Pb 2+ > Co 2+ > Ni 2+ . When the pure organic and inorganic parts of the fish scales are used in the adsorption experiments, the inorganic part has a 75% higher removal capacity than the organic fraction. The adsorption experiments using fish scales with different organic or inorganic fractions show a nonadditive, synergistic effect on the equilibrium amount of metallic ion adsorbed, which is independent of the inorganic content between 30 and 90 wt % of this inorganic fraction. Lowvacuum scanning electron microscopy and elemental analysis reveal that the ion-exchange reaction is the main mechanism for the metallic ion adsorption by fish scales.

Biomass characterisation and adsorption mechanism of Cu (II) biosorption onto fish (Catla catla) scales

“…Magnesium was no longer present in the loaded copper sample. This verifies the ion exchange mechanism ions as mentioned by Villanueva-Espinosa et al (2001). Figure 3 shows FTIR spectra of the biomass before and after loading of metal ions.…”

“…Scales were then washed repeatedly with deionised distil water, dried overnight in a laboratory oven at 50°C. The dried scales were stored in a refrigerator for the prevention of microbial contamination (Villanueva-Espinosa et al, 2001).…”

“…Villanueva-Espinosa et al (2001) studied the adsorption of copper, lead and cobalt onto scales of Mojarra tilapia fish. Nadeem et al (2008) and Rahaman et al (2008) investigated removal of lead and arsenic by scales of Labeo rohita and Atlantic cod respectively.…”

“…Villanueva-Espinosa et al (2001) found that the power law model can be used to predict the uptake rate for the various metal ions. The pseudo second order kinetic model gave good fit to the biosorption system studied by Nadeem et al (2008) and Srividya and Mohanty (2009).…”

Removal of Brilliant Red from Aqueous Solutions by Adsorption on Fish Scales

“…The experimental study of the adsorptive properties for the removal of copper, lead, cobalt, and nickel ions from water by thermally pretreated fish scales from Oreachromis niloticus (Mojarra Tilapia) was reported 15 . A study on the application of Atlantic code scales in removing the heavy metals such as lead, arsenic and chromium from energy-produced waste streams was also reported 16 .…”