Influence of pH on Removal of Heavy Metallic Cations by Fly Ash in Aqueous Solution

Romanian bentonite and fly ash characterization and their use in heavy metal “in-situ” immobilization in polluted soils

“…The adsorption capacity of 5.31 mg/g for Zn(II) o FA is higher than the values found by other researchers for the adsorption of zinc onto fly ash [20,21], but is very closed to qe = 4.505 mg/g obtained by reference [22]. The adsorption capacity of 19.9 mg/g for Pb(FA) is closed to the value 18.8 mg/g obtained by authors [20]. The adsorption capacity obtained for Pb(B) was 8.96 mg/g at 30 minutes.…”

Metallic ion removal from aqueous solutions by fly ashes: multicomponent studies

“…Another interesting possibility might be to make it a low cost adsorbent for water treatment provided production can match industrial needs. Ricou et al 1,2 have tested the adsorption of individual pollutants in an aqueous solution by using¯y ashes produced by a pulverised coal combustion plant. The results obtained when using these particular¯y ashes are encouraging for the removal of heavy metals from industrial wastewater.…”

Determination of adsorption efficiency based on cation exchange capacity related to red earth, bone meal and pulverised fly ash as ameliorants to lead contaminated soils

“…Interest in the use of fly ash as a soil amendment (or ameliorant) results from (i) the need to develop sustainable uses of this by-product (Adriano et al, 1980;Bilski et al, 1995) and (ii) reports showing improved growth of some crops (El-Mogazi et al, 1988;Rees and Sidrak, 1956), pasture (Hill andLamp, 1980 andSummers et al, 1998), and after turf species Weber, 2001 andPathan et al, 2001), following addition of fly ash to some soils. Therefore the choice of PFA (ameliorant) was based on the potential of its efficacy over a wide range of pH, and with reference to associated phenomena occurring at the oxide/water interface (Stumm, 1992), such as ion exchange, adsorption, surface precipitation and bulk solution precipitation which can be attributed to the effective removal of heavy metals in aqueous solution by fly ash (Ricou et al, 1999). When all the ameliorants were compared, as earlier discussed and shown in Table 9, both Red earth and Bone meal had the highest effect on PbCO 3.…”

“…For example previous studies have shown that the costs associated with phytoremediation are lower than conventional methods (Macek et al, 2000). Phytoextraction technologies have been widely used, but further development is still required before implementation on large-scale remediation (Salt et al, 1998). However limitations associated with the use of plants for remediation of organic and heavy metal pollutants in soil include the climatic and geological conditions of the site to be cleaned, the temperature, altitude, and soil type at the site.…”