Utilisation of a hydrogen uranyl phosphate-based ion exchanger supported on a biofilm for the removal of cobalt, strontium and caesium from aqueous solutions

Accumulation of zirconium phosphate by a Serratia sp.: a benign system for the removal of radionuclides from aqueous flows

“…and 137 Cs ? , for which application of the HUP-based methodology to real nuclear waste was shown previously (Paterson-Beedle and Macaskie 2006). The potential for this biogenic approach compared to some commercial materials is shown in Table 1.…”

“…The steady state specific activity was *3,800 units (nmol p-nitrophenol released from p-nitrophenyl phosphate per min per Capacity (bed volumes, BV) d 6 9 10 4 -2.4 9 10 5 1.2 9 10 5 -4.0 9 10 5 2 9 10 4 -4.0 9 10 4 3 9 10 7 -3 9 10 10 (Cs) e 5 9 10 7 -3 9 10 10 (Sr) e *8 9 10 8 (Co) e Capacity (l/kg) 1 9 10 5 -4.0 9 10 5 1.5 9 10 5 -5 9 10 5 2.5 9 10 4 -5 9 10 4 7.5 9 10 8 -7.1 9 10 11 (dw) f 1.6 9 10 8 -1.6 9 10 11 (ww) f,c 8.0 9 10 9 -7.6 9 10 12 (dw) g 1.8 9 10 9 -1.7 9 10 12 (ww) g,c pH 1-13 [10 4-8 Full range not tested a Source: http://www.fortum.com. b Calculations based on maximum HUP loadings (16.6 g/g biomass) on biofilm immobilized onto polyurethane foam (cubes) packed in reactors as described in Paterson-Beedle et al (2006). c Estimated using 78% moisture content.…”

Phosphate-Mediated Remediation of Metals and Radionuclides

“…Additionally, biofilms of Serratia sp. NCIMB 40259 that promoted the precipitation of H 2 (UO 2 ) 2 (PO 4 ) 2 (chernikovite) further removed 85% and 97% of cooccurring 60 Co and 137 Cs, respectively, via substitution of H + within chernikovite [147]. Prior to investigations into a possible bioremediation role for nonspecific acid phosphatases (NSAP), this class of enzymes had been examined for their role in microbial physiology and contributions to virulence [116,148].…”

“…Therefore, contaminated subsurface environments with changing hydrobiogeochemical conditions (typical for most sites) will likely influence speciation chemistry and thus require an alternative strategy. Active remediation strategies that promote metal-and/or radionuclide-phosphate formation can take advantage of in situ hydrobiogeochemical parameters (Figure 4) that support contaminant sequestration through the formation of (1) low solubility minerals that are unaffected by changes in redox, (2) mineral stability across a wide pH range, and (3) reactive mineral surfaces that can support sequestration of other cooccurring metals through adsorption, substitution, and precipitation reactions [60,83,109,147,154,188]. Innovative bioremediation approaches that neutralize low pH groundwater and maintain sufficient phosphate concentrations to complex soluble contaminants can enhance strategies that rely solely on abiotic approaches.…”

Biorecycling of Precious Metals and Rare Earth Elements

“…originally isolated from metal polluted soil (Macaskie & Dean, 1982) for the recovery of heavy metals such as uranyl ion, lead, copper, cadmium, www.intechopen.com lanthanum, strontium, manganese, thorium, americium and plutonium (Macaskie & Dean, 1984;Macaskie & Dean, 1985;Tolley et al, 1991;Macaskie, 1992;Macaskie et al, 1994;Yong et al, 1998;Forster & Wase, 2003;. In the case of uranium the deposited material can be used as nanocrystalline ion exchanger for the removal of radionuclides from nuclear wastes (Paterson-Beedle et al, 2006), while a similar function can be achieved via biogenic hydroxyapatite (calcium phosphate) (Handley-Sidhu et al, 2011) which has a crystallite size much smaller than that of commercial HA, and hence a much higher surface area for interaction with the 'target' metallic species. The metal-accumulating Serratia strain (NCIMB 40259) atypically overproduces a PhoN acid type phosphatase.…”