Arsenic adsorption and migration of lanthanum bentonite modified by Acidiphilium cryputum JF-5
A novel bio-lanthanide-modified bentonite was obtained by Acidiphilium cryputum JF-5 to release Fe2+from bentonite minerals through bioreduction and further enhance lanthanide modification.The adsorption effect of bio-lanthanum modified bentonite on As(Ⅴ)was investigated through isothermal adsorption experiments,and its adsorption capacity was compared with the international commercial phosphorus locking agent(Phoslock).The migratory behavior of bio-lanthanum modified bentonite in quartz sand columns was explored through column experiments.The results showed that:(1)JF-5 could enhance the release of Fe2+from bentonite and thus enhance the La3+loading.The preparation of biolanthanide-modified bentonite at a low solid-liquid ratio(1.6 g/mL)had the highest La3+loading quantity(370 mg/g).(2)The adsorption behavior of biolanthanide-modified bentonite on As(Ⅴ)was in accordance with the Freundlich model,and the maximum adsorption amount was 7.58 mg/g,which was substantial increased compared with Phoslock(3.08 mg/g);its adsorption kinetic process of As(Ⅴ)was similar to that of Phoslock,both of them could rapidly remove As(Ⅴ)within 4 h.(3)The mobility of bio-lanthanide-modified bentonite in quartz sand columns could be described by convective diffusion model,at flow rate of 0.38,0.77,1.54 mL/min,the retention capacity of the bio-lanthanum modified bentonite in quartz sand column was 3.68,3.77,2.29 mg,respectively,which could be seen that the solution in the quartz column under the condition of medium flow rate could be more sufficiently contacted with the medium and thus improve the retention capacity.
万方数据
维普
