Removal of Perchlorate in Ground Water with a Flow‐Through Bioreactor

Abstract

The bacterium, perc1ace, has been shown to reduce perchlorate to less than the detection limit of 0.004 mg L−1 when grown on acetate under anaerobic conditions. In batch studies, the presence of nitrate does not significantly hinder the reduction of perchlorate. The ability of perclace to remove nitrate and perchlorate from ground water in a flow‐through system is described in this study. Celite‐packed columns of 300 ml were used to demonstrate the removal of perchlorate from ground water. At a flow rate of 1 ml min−1, perchlorate was removed from 0.738 mg L−1 to less than detectable levels and when the flow rate was 2 ml min−1 92 to 95% of the perchlorate was removed. Analysis of bacterial biomass at the completion of the study revealed that most of the bacterial growth was concentrated in the inlet area of the column. A circulating pump was added, with the idea that passing the ground water multiple times through the bacterially active zone might increase the efficiency of the column. In this experiment, perchlorate in ground water was reduced from 0.550 mg L−1 to nondetectable levels at a flow rate of 1 ml min−1. When the flow rate was increased to 2 ml min−1, 98% of perchlorate was removed and when the flow rate was 3 ml min −1 95% of perchlorate was removed. Rapid removal of perchlorate by perc1ace immobilized in a bioreactor may provide an efficient, cost‐effective technology for ground water remediation.

Perchlorate Behavior in a Municipal Lake Following Fireworks Displays

“…Isotopic data show the effects of evaporation in that the meteoric water trend is not observed; rather data follow along a trajectory below the meteoric water trend having a slope of about 5 instead of 8. Ratios of 18 O/ 16 O and 2 H/ 1 H are more variable in the summer, because of greater precipitation and generally more intense evaporation compared to the late fall and winter. Considering the limited rainfall that occurred over the period that perchlorate concentrations were decreasing in Wintersmith Lake (Figure 3) and the overall evaporitic trend indicated by the isotopic data (Figure 4), dilution is not expected to be an important factor in lowering perchlorate levels in this system.…”

“…Perchlorate-reducing organisms can use a variety of organic carbon substrates as electron donors, such as glucose, acetate, vegetable oils, and natural organic carbon compounds present in soils and sediments (6,8,14,15). Biological transformation of perchlorate has been successfully utilized for drinking water treatment (16)(17) and for in situ groundwater remediation (18)(19)(20)(21).…”

Environmental Transport and Fate Process Descriptors for Propellant Compounds

“…Typically, a carbon source (electron donor) is required to facilitate perchlorate reduction, either as soil organic carbon (Tipton et al 2003), carbon dioxide (Zheng et al 2002), a carboxylic acid (e.g., acetate; Herman and Frankenberger 1999;Giblin et al 2000;Logan et al 2001;Kim and Logan 2001), or even the co-contaminant nitroglycerin (Attaway 1994). Perchlorate reduction requires molybdenum in some microbe strains (Chaudhuri et al 2002).…”

“…Perchlorate reduction requires molybdenum in some microbe strains (Chaudhuri et al 2002). Many studies report sequential or simultaneous reduction of nitrate and perchlorate under anaerobic conditions by different microbe strains or communities (Herman and Frankenberger 1999;Giblin et al 2000;Okeke et al 2002;Chaudhuri et al 2002;Tipton et al 2003). Anaerobic perchlorate reduction is inhibited by nitrite, which appears as a nitroglycerin transformation product during propellant manufacture (Attaway 1994).…”

Effect of backwashing on perchlorate removal in fixed bed biofilm reactors

“…Several studies have shown that biological treatment is an effective technology to remove perchlorate from drinking water (Brown et al, 2002;Giblin et al, 2000;Herman and Frankenberger, 1999;Min et al, 2004). For example, for a typical groundwater concentration of 50 μg/L, biologically active carbon (BAC) fixed bed reactors consistently removed perchlorate to below 2 μg/L (Brown et al, 2002(Brown et al, , 2005.…”