A Case Study of Landfill Leachate Using Coal Bottom Ash for the Removal of Cd2+, Zn2+ and Ni2+

Abstract

Abstract:The removal of Cd 2+ , Zn 2+ and Ni 2+ by coal bottom ash has been investigated. In single metal system, metal uptake was studied in batch adsorption experiments as a function of pH (2-3), contact time (5-180 min), initial metal concentration (50-400 mg/L), adsorbent concentration (5-40 g/L), particle size, and ionic strength (0-1 M NaCl). Removal percentages of metals ions increased with increasing pH and dosage. Removal efficiency at lower concentrations was greater than at higher values. The maximum amount of metal ion adsorbed in milligrams per gram was 35.4, 35.1 and 34.6 mg/g for Zn 2+ , Cd 2+ and Ni 2+ , respectively, starting out from an initial solution at pH 3. Simultaneous removal of Zn 2+ , Cd 2+ and Ni 2+ ions from ternary systems was also investigated and compared with that from single systems. Cd 2+ uptake was significantly affected by the presence of competing ions at pH 2. The results obtained in the tests with landfill leachate showed that bottom ash is effective in simultaneously removing several heavy metals such as Ni, Zn, Cd, As, Mn, Cu, Co, Se, Hg, Ag, and Pb.

Statistical comparison of leaching behavior of incineration bottom ash using seawater and deionized water: Significant findings based on several leaching methods

“…Noteworthy that, such changes are both ion specific and mineral specific, for example, a large concentration of Cl may decrease the net charge of the hydroxide surface [31]. Base on the current leaching test results, the interpretation of the multi-leaching behaviors (whereby Cu, Pb and Zn leached more while Hg, Sb and Tl leached less) may be a function of one or all of the following parameters: ionic strength, electronegativity, system pH and the adsorption surfaces [37]. However, leaching performance of different IBA samples varied for the six elements, which could be caused by the differences in IBA chemical properties.…”

Study on the Possibilities of Natural Use of Ash Granulate Obtained from the Combustion of Pellets from Plant Biomass

“…By the addition of bentonite these indices decreased to: Cd (48.4%), Pb (46.8%), Na (54.6%), Al (35.7%) and K (32.1%) (Figure 3). In the literature, it is possible to find much information on the low solubility of a number of components in water, mainly from the group of heavy metals (Cd, Cu, Ni, Zn), due to the alkalinity of bottom ash [46].…”

Comparative Study on the Treatment of Leachate from a Mine Waste Dump with Two Agricultural Biowastes

“…Figure 4 shows how the amount of adsorbed metal (mg•g −1 ) decreases progressively with increasing adsorbent concentration. The explanation for this is that metal adsorption is subject to the "particle concentration effect" because of flocculation of the solid phase, with a consequent decrease in the available surface area (Ayala & Fernandez 2016;Petrovič & Simonič, 2016;Karimi-Jashni & Saadat, 2014).…”