TY - JOUR

T1 - Environmental monitoring of low-level radioactive waste disposal in electrochemical plant facilities in Zelenogorsk, Russia

AU - Boguslavsky, A. E.

AU - Gaskova, O. L.

AU - Naymushina, O. S.

AU - Popova, N. M.

AU - Safonov, A. V.

N1 - Publisher Copyright: © 2020 Elsevier Ltd Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/8/1

Y1 - 2020/8/1

N2 - The concentrations of radionuclides, especially anions, in water can substantially exceed local background levels in the vicinity of former and currently operating uranium enrichment plants. In this study, we present new data on environmental monitoring near the uranium sludge collector of an electrochemical plant (ECP) in Krasnoyarsk Krai, Russia. We first tracked the complex biogeochemical processes that can affect the fate and transport of U in highly nitrate-polluted ground- and surface water. We described the main mechanisms of U immobilization: (a) biogenic and abiogenic reduction (microbial nitrate reduction caused dramatically Eh decrease), (b) sorption by organic matter in peat and by microbial biofilms on a sandy rock surface, and (c) precipitation with biogenic and abiogenic phases. The intensity of the biogenic and abiogenic factors depended on the dynamics of changes in the oxidation-reduction potential (ORP)-pH conditions as well as organic- and inorganic anion concentrations with distance from the source of pollution. Anammox bacteria were found in areas with high nitrate pollution, and we believe that they played a key role in lithotrophic nitrogen consumption and primary organic production. These data can form the basis for complex groundwater remediations close to U sludge repositories and can be implemented beyond the ECP site itself.

AB - The concentrations of radionuclides, especially anions, in water can substantially exceed local background levels in the vicinity of former and currently operating uranium enrichment plants. In this study, we present new data on environmental monitoring near the uranium sludge collector of an electrochemical plant (ECP) in Krasnoyarsk Krai, Russia. We first tracked the complex biogeochemical processes that can affect the fate and transport of U in highly nitrate-polluted ground- and surface water. We described the main mechanisms of U immobilization: (a) biogenic and abiogenic reduction (microbial nitrate reduction caused dramatically Eh decrease), (b) sorption by organic matter in peat and by microbial biofilms on a sandy rock surface, and (c) precipitation with biogenic and abiogenic phases. The intensity of the biogenic and abiogenic factors depended on the dynamics of changes in the oxidation-reduction potential (ORP)-pH conditions as well as organic- and inorganic anion concentrations with distance from the source of pollution. Anammox bacteria were found in areas with high nitrate pollution, and we believe that they played a key role in lithotrophic nitrogen consumption and primary organic production. These data can form the basis for complex groundwater remediations close to U sludge repositories and can be implemented beyond the ECP site itself.

KW - Groundwater

KW - Microbiological activity

KW - Sorption

KW - Thermodynamic modeling

KW - Uranium

KW - Waste disposal

KW - URANIUM

KW - MIGRATION

KW - U(VI)

KW - ADSORPTION

KW - MICROBIAL REDUCTION

KW - SPECIATION

KW - ACTINIDES

KW - NATURAL-WATERS

KW - BIOGENIC FACTORS

KW - GROUNDWATER

UR - http://www.scopus.com/inward/record.url?scp=85086731922&partnerID=8YFLogxK

U2 - 10.1016/j.apgeochem.2020.104598

DO - 10.1016/j.apgeochem.2020.104598

M3 - Article

AN - SCOPUS:85086731922

VL - 119

JO - Applied Geochemistry

JF - Applied Geochemistry

SN - 0883-2927

M1 - 104598

ER -