Potential mechanisms for bioregeneration of perchlorate-containing ion-exchange resin

Biosorption and Bioreduction of Perchlorate Using the Nano-Fe3O4-Laden Quaternary-Ammonium Chinese Reed: Considering the Coexisting Nitrate and Nano-Fe3O4

“…The observed perchlorate bioreduction rates for 24, 48, 96, 120, and 240 h were about 0.046, 0.035, 0.022, 0.019, and 0.012 mg p ·mg ss –1 ·day –1 , respectively. As a result, the highest bioreduction rate for laden perchlorate was obtained in the first 24 h. This is in accordance with the results reported by Sharbatmaleki and Batista. , …”

“…The bioreduction rates for laden perchlorate and nitrate at different time intervals are given in Tables and S5, respectively. Considering the large amounts of laden nitrate on the surface of the biosorbent, the bioreduction of laden perchlorate was significantly decreased, but its bioreduction rate was still 0.046 mg p ·mg ss –1 ·day –1 at 24 h, which was similar to or even higher than some reported values. , Venkatesan et al described that perchlorate ions on the outer surface of the resin are more available for bacterial reduction prior to the ions that are located deep inside of the bead. Because of the large surface area in the reed-based biosorbent (45.4 m 2 /g), a few perchlorate ions could be adsorbed in deep in the biosorbent.…”

“…Technologies/methods for perchlorate remediation include adsorption/ion exchange, biological/chemical reduction, membrane treatments, and electrochemical treatment. ,− Currently, ion exchange/adsorption is the optimal method for perchlorate remediation in groundwater or drinking water. However, the spent resins/adsorbents and elevated levels of toxic brine are still considered to be potential pollution sources, which require further treatment before disposal.…”

“…However, the spent resins/adsorbents and elevated levels of toxic brine are still considered to be potential pollution sources, which require further treatment before disposal. It was reported that the bioregeneration of spent adsorbents/resins can be made possible by a downstream biological step. ,, Such integrated ion exchange/biological technologies can prove to be economical alternatives to the conventional methods. ,,− The bioregeneration of spent resins and bioreduction of brine using perchlorate-reducing bacteria (PRB) have been applied by researchers. ,− For example, the perchlorate laden on SBG2 resin was directly decomposed by cultivated perchlorate-reducing microorganisms as ascribed by Wang et al…”

Isolation and characterization of a perchlorate-reducing Acinetobacter bereziniae strain GWF

“…[4] The United States Environmental Protection Agency (EPA) estimates that more than 10 million people live in the United States with detectable levels of perchlorate in their drinking water today. [5] In China, perchlorate exists in milk, crops and vegetables at concentrations up to 9.1 ng/mL, 4.88 ng/g dry weight and 30.5 ng/g wet weight, respectively. [6À8] Therefore, perchlorate has been regarded as a new threat to human beings.…”