Estimation and Removal of Chromium Ions from Tannery Wastes Using Zeolite-3A

Abstract

The concentration of potentially toxic chromium metal ions in sediments and liquid waste samples from selected tanneries was measured by atomic absorption spectrophotometry after digestion with nitric acid. The data obtained revealed the presence of elevated levels of chromium metal ions in waste samples relative to the NEQS (National Environmental Quality Standards) require-ments. A new process entitled IERECHROM (Ion Exchange REmoval of CHROMium) has been developed for the removal and separation of chromium ions from sediments using zeolite-3A. The factors affecting chromium ion removal include exchanger concentration, pH, shaking time and temperature. The applicability of the Freundlich. Dubinin–Radushkevich and virial isotherm equations to the system has been examined. The thermodynamic parameters °LH0, °LG0 and °LS0 were calculated using the virial isotherm expression. The results suggest that natural aluminosilicates such as zeolite-3A can be utilised as low-cost ion-exchange and sorbent materials because of their selectivities for the removal of chromium ions and various other heavy metals.

Removal of toxic chromium from wastewater using green alga Ulva lactuca and its activated carbon

“…Surface adsorption is found to be an important basis for the treatment of toxic chromium contaminated water [4], where, numerous adsorbents such as clay [5], tires and sawdust [6] and zeolite [7] were used. Biosorption is a potential alternative to traditional treatment processes of metal ions removal [8][9][10].…”

Adsorption of Hexavalent Chromium from Aqueous Solution on Raw and Modified Activated Carbon

“…Adsorption has been found to be an important basis for the treatment of Cr(VI) or Cr(III) contaminated wastewater, where numerous adsorbents such as cellulose (Liu et al, 2001), sawdust (Á lvarez et al, 2007;Karthikeyan et al, 2005), bagasse (Valix et al, 2006), groundnut husk (Dubey and Bopal, 2007), clay (Lazaridis et al, 2001), and zeolite (Tahir et al, 1998) were used. Among the numerous adsorbents that are available, activated carbon has undoubtedly been the most popular and widely used in wastewater treatment worldwide (Han et al, 2000;Khezami and Capart, 2005;Liu et al, 2007;Natale et al, 2007).…”

Determination of levels of fluoride and trace metal ions in drinking waters and remedial measures to purify water

“…As an alternative to Freundlich isotherm, the data were fitted to Dubinin -Raduskevich (D-R) equation (Tahir et al, 1998)] in the linearized form as follows:…”