Accurate determination of tetravalent uranium reduced by microorganisms via a potentiometric titration procedure
Author:
Chen Shunzhang1, Cheng Yanxia1, Zeng Qian1, Zhu Ting1, Li Feize1, Lan Tu1, Yang Yuanyou1, Yang Jijun1, Liao Jiali1, Liu Ning1
Affiliation:
1. Key Laboratory of Radiation Physics and Technology of the Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University , Chengdu 610064 , P.R. China
Abstract
Abstract
Although bioreduction induced by microorganisms has been considered to play an important role in the chemical and migration behaviors of uranium in nature, the accurate determination of tetravalent uranium reduced by microorganisms is still difficult to achieve. In this work, potentiometric titration via K2Cr2O7 was used to quantitatively determine the microorganism reduced tetravalent uranium (U(IV)) for the first time. By evaluating the influence of microorganism substance content on the titration of U(IV), the appropriate determination range of U(IV) and biomass was confirmed, and U(IV) induced by bioreduction in three microorganisms was determined. With this method, U(IV) of more than 0.12 mg in microorganisms can be quantitatively measured with an accuracy of 2.2% and a precision of 1.3%, which has been established with the premise that the pretreatment biomass and quantity of U(IV) are in an appropriate range. Compared with the estimated values via the changes in hexavalent uranium (U(VI)) concentration in the bioreduction system, the results obtained by this method can more accurately reflect the quantity of U(IV) in microorganisms. This work can help us to better understand the bioreduction behavior of uranium in the environment.
Funder
National Natural Science Foundation of China Key Research and Development Program of Sichuan Province
Publisher
Walter de Gruyter GmbH
Subject
Physical and Theoretical Chemistry
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