Microbially-enhanced chemisorption of Ni2+ ions into biologically-synthesised hydrogen uranyl phosphate (HUP) and selective recovery of concentrated Ni2+ using citrate or chloride ion
Microbially-enhanced chemisorption of Ni2+ ions into biologically-synthesised hydrogen uranyl phosphate (HUP) and selective recovery of concentrated Ni2+ using citrate or chloride ion
复制标题
微生物增强化学吸附 Ni2 离子到生物合成磷酸氢铀酰 (HUP) 中，并使用柠檬酸盐或氯离子选择性回收浓缩 Ni2
作者：
G. Bašnáková;L. Macaskie
磷酸铀酰氢（HUP）酶催化柠檬酸杆菌N14固定在聚丙烯酰胺凝胶去除溶液中的镍离子通过插层离子交换到HUP晶格。使用含有100 mg干重的生物质和100 -250 mg负载铀柱的流通柱，在约20 min后发生Ni 2+的饱和和穿透。600 ml，每根柱上总共装载了约30 mg Ni 2+，对应于约2：1的U：Ni摩尔比，根据先前鉴定的材料Ni（UO 2 PO 4）2的特性。使用100 mM柠檬酸钠-柠檬酸缓冲液在140 ml或500 mM柠檬酸盐缓冲液的短脉冲（5 ml）中选择性地解吸Ni 2+，然后用水洗涤，得到80 ml的总回收体积，后者的洗涤溶液中的总柠檬酸盐浓度为约30 mM。作为不产生残留BOD的替代洗脱剂，NaCl（0.6 M）或海水产生与0.5 M柠檬酸盐脉冲相当的Ni 2+回收率，但Ni 2+回收体积为40-50 ml。Ni 2 +-沉积：解吸的浓度比（体积：体积）对于氯离子比对于100 mM柠檬酸盐好3-4倍。
Hydrogen uranyl phosphate (HUP) deposited enzymatically on Citrobacter N14 immobilized in polyacrylamide gel removed nickel ions from solution via intercalative ion-exchange into the HUP lattice. Using flow-through columns containing 100 mg dry weight of biomass and ∼200–250 mg loaded uranium column saturation and breakthrough of Ni2+ occurred after ca. 600 ml, with a total of ∼30 mg Ni2+ loaded per column, corresponding to a molar ratio of U:Ni of ∼ 2:1, in accordance with the identity of the material as Ni(UO2PO4)2, identified previously. Ni2+ was selectively desorbed using 100 mM sodium citrate-citric acid buffer over 140 ml or a short pulse (5 ml) of 500 mM citrate buffer followed by a water wash, giving a total recovery volume of 80 ml, with a total citrate concentration of ∼30 mM in the wash solution of the latter. As an alternative eluant which gives no residual BOD NaCl (0.6 M) or seawater gave comparable recovery of Ni2+ to the 0.5 M citrate pulse, but with a Ni2+ recovery volume of 40–50 ml. The concentration ratio of Ni2+-deposition:desorption (vol:vol) was 3–4 fold better with chloride ion than with 100 mM citrate.