Simultaneous nitrate and perchlorate reduction using sulfur-based autotrophic and heterotrophic denitrifying processes

Abstract

BACKGROUND This study aims at comparing the performances of sulfur‐based autotrophic and methanol‐based heterotrophic denitrification processes for simultaneous removal of perchlorate and nitrate. Influent nitrate concentration was kept at 25 mg L−1 NO3−‐N throughout the study and perchlorate concentration was varied between 50 and 1000 µg L−1. RESULTS The heterotrophic process reduced nitrate and perchlorate completely in all tested conditions (i.e. various nitrate and perchlorate loadings). As for the autotrophic process, although high perchlorate removals were attained, perchlorate was always detected in the effluent with varying concentrations from 21.88–85 µg L−1 depending on the perchlorate and nitrate loadings. Perchlorate was reduced from 1000 µg L−1 to 53 ± 21.36 µg L−1, corresponding to around 95% reduction in the autotrophic process at HRT of 2 h. The presence of perchlorate did not adversely affect the denitrification performance of autotrophic and heterotrophic processes under the conditions studied. The presence of nitrate inhibited autotrophic perchlorate reduction and prevented complete perchlorate reduction. CONCLUSION An autotrophic process may be preferred over a heterotrophic one due to the elimination of organic supplementation and the risk of effluent contamination with organic substrate, but further polishing steps may also be required. © 2015 Society of Chemical Industry

An Overview of Electron Acceptors in Microbial Fuel Cells

“…Among the treatment alternatives, biological reduction is a cost effective method (Ucar et al, 2015a,b, 2016). Reduction of ${\text{CIO}}_4^{-}$ is shown as illustrated in Equation (25) (Ye et al, 2012).…”

“…Perchlorate is a drinking water contamination of interest due to its high mobility and inhibitory effect on thyroid functions (Cetin et al, 2015 ; Ucar et al, 2017 ). Among the treatment alternatives, biological reduction is a cost effective method (Ucar et al, 2015a , b , 2016 ). Reduction of is shown as illustrated in Equation (25) (Ye et al, 2012 ).…”

“…Inorganic electron donors also have their own disadvantages, for example, when sulfur is used, sulfate and acidity can occur in the effluent. However, in recent studies, the use of the advantages of both systems in the removal of nitrate and perchlorate from drinking and underground waters and the elimination of disadvantages are becoming increasingly widespread (Ucar et al, 2015b , 2017 ).…”

Biological Reduction of Acid Red 14 by Elemental Sulfur and Methanol-Based Reactors

“…Sulfur has been used as an electron donor in many biochemical reduction processes [9], [12], [20]. The most important advantages of sulfur are the low cost, ease of operation and its utilization as reactor filling material [10].…”

“…thiosulfate) in the feed as well as in the granular form as the reactor filling material. Sulfur used in the reactor also forms a surface area for microorganisms [10]. Hence, there is no need for continuous supply of dissolved or gaseous electron sources to the reactor.…”