Simultaneous Removal of Heavy Metals (Cu, Cd, Cr, Ni, Zn and Pb) from Aqueous Solutions Using Thermally Treated Romanian Zeolitic Volcanic Tuff

Abstract

Increased concentrations of heavy metals in the environment are of public health concern, their removal from waters receiving considerable interest. The aim of this paper was to study the simultaneous adsorption of heavy metals (Cu, Cd, Cr, Ni, Zn and Pb) from aqueous solutions using the zeolitic volcanic tuffs as adsorbents. The effect of thermal treatment temperature, particle size and initial metal concentrations on the metal ions sorption was investigated. The selectivity of used zeolite for the adsorption of studied heavy metals followed the order: Pb > Cr > Cu > Zn > Cd > Ni. The removal efficiency of the heavy metals was strongly influenced by the particle sizes, the samples with smaller particle size (0–0.05 mm) being more efficient in heavy metals removal than those with larger particle size (1–3 mm). Generally, no relevant changes were observed in heavy metals removal efficiency for the treatment temperatures of 200 °C and 350 °C. Moreover, at a higher temperature (550 °C), a decrease in the removal efficiencies was observed. The Cd, Zn, Cu, Cr, Zn and Ni sorption was best described by Langmuir model according to the high values of correlation coefficient. The pseudo-first-order kinetic model presented the best correlation of the experimental data.

Modification of natural zeolites and their applications for heavy metal removal from polluted environments: Challenges, recent advances, and perspectives

“…Generally, an activation temperature of 200–350 °C and small particle size (<1 mm) were reported as sufficient to improve the adsorption capacity of zeolite for heavy metals, while, higher temperatures, which means higher energy consumption, do not significantly improve it [ 126 ]. On the contrary, at high temperatures (>550 °C) under ambient conditions, the natural zeolites lose their adsorptive capacity [94,95].…”

Heavy Metals Removal from Water and Wastewater

“…Depending on their nature, IX can be: (i) inorganic-natural (zeolites, clinoptilolite) or synthetic (layered double hydroxides) [50][51][52][53][54][55][56]; (ii) organic-natural (cellulose, alginic acid, chitin), or synthetic (polycondensation ion exchangers; polymerization ion exchangers) [48,[57][58][59][60][61][62][63]. Depending on the type of mobile ion they can exchange, IX are classified as cationic, anionic, or amphoteric.…”

Enhanced Removal of As(V) and Pb(II) from Drinking and Irrigating Water Effluents Using Hydrothermally Synthesized Zeolite 5A

“…A similar behavior was observed by Joseph et al [68], who investigated the simultaneous removal of Cd(II), Co(II), Cu(II), Pb(II), and Zn(II). Studies [69][70][71][72] show that there is a great affinity of zeolite for Pb. It is assumed that competitive adsorption is the main reason for the adsorption results in an acidic medium.…”