Impacts of Cocontaminants on the Performances of Perchlorate and Nitrate Specialty Ion-Exchange Resins

Abstract

The influence of anionic inorganic cocontaminants including nitrate, Cr(VI), Se(VI), and As(V) on the application of nitrate and perchlorate specialty resins in water treatment was investigated. It was found that nitrate can be removed from waters using perchlorate specialty resins, but the resin is poorly regenerated. Perchlorate was not easily removed from either nitrate or perchlorate specialty resins. Simultaneous removal of nitrate and Cr(VI) was optimal when using nitrate specialty resin. Perchlorate/nitrate specialty resins were inefficient in removing As(V), but can exchange Cr(VI) or Se(VI). A major concern is the presence of high levels of Cr(VI), As(V), or Se(VI) in the waste brine, which affects waste brine disposal and cost. Perchlorate specialty resins showed very low run length for Cr(VI), As(V), or Se(VI). Nitrate specialty resins were very efficient in removing Cr(VI), and they can be easily regenerated.

A Bibliometric Analysis of Research on Selenium in Drinking Water during the 1990–2021 Period: Treatment Options for Selenium Removal

“…Low-cost ion exchangers derived from waste biomass [209,210] and inorganic ion exchangers based on silicates [211] have been investigated for selenium removal with successful results and can be considered a valid option to reduce the economic costs of the process. In order to improve the selectivity of the resins for selenium oxyanions and avoid the competition of other anions, innovative ligand and chelating resins [212][213][214] and metal-loaded cationic resins [215] have been proposed. Nevertheless, further research efforts are still required to identify more selective ion exchangers for the removal of selenium from aqueous solutions.…”

Physical–Chemical Processes for Nitrogen Removal

“…Pakzadeh and Batista (2011) conducted interesting research on the performance of conventional and specialty resins for removal of cocontaminants, such as nitrate and perchlorate. The results showed that perchlorate-selective resins can be used to remove nitrate.…”

“…Thus, it is important to emphasize that although the resins were nitrate selective, high concentrations of sulfate and/or chloride decreased the number of BVs until nitrate breakthrough. The perchlorate-selective resins showed the following performance for nitrate removal: influent nitrate 16.4-20.6 mg NO 3 À N l À1 , effluent nitrate less than 10 mg NO 3 À N l À1 , 340-565 BVs until target effluent nitrate concentration was reached, EBCT of 2.5 min (flow rate of 24 BV h À1 ), and influent sulfate concentration of 100 mg l À1 (Pakzadeh and Batista, 2011). The sulfate-selective resins showed the following performance for nitrate removal under low sulfate conditions (32-56 mg SO 4 2-l À1 ): influent nitrate 10.5-20 mg NO 3 À N l À1 , effluent nitrate 7-10 mg NO 3 À N l À1 , 400-610 BVs until target effluent nitrate concentration was reached, and EBCT of 1.5-3 min (Clifford and Liu, 1993;Ghurye et al, 1999).…”

“…The sulfate-selective resins showed the following performance for nitrate removal under low sulfate conditions (32-56 mg SO 4 2-l À1 ): influent nitrate 10.5-20 mg NO 3 À N l À1 , effluent nitrate 7-10 mg NO 3 À N l À1 , 400-610 BVs until target effluent nitrate concentration was reached, and EBCT of 1.5-3 min (Clifford and Liu, 1993;Ghurye et al, 1999). Under high sulfate conditions (100-200 mg SO 4 2-l À1 ), the sulfate-selective resins showed a decreased performance in nitrate removal: influent nitrate 18.2-22.6 mg NO 3 À N l À1 , effluent nitrate 9.9-11.3 mg NO 3 À N l À1 , 175-358 BVs until target effluent nitrate concentration was reached, and EBCT of 1.7-3 min (Hoek et al, 1988;Liu and Clifford, 1996;Matosic et al, 2000;Pakzadeh and Batista, 2011). In summary, based on the results in Table 12, the typical operating conditions and expected performance for an ion exchange column or fixed-bed reactor using nitrate-selective resin is as follows: influent nitrate concentration of 20-30 mg NO 3 À N l À1 , effluent nitrate concentration of less than 10 mg NO 3 À N l À1 , 400-600 BVs until target effluent nitrate concentration is reached, EBCT of 2-3 min (flow rate of 30-20 BV h À1 ), influent sulfate concentration of 50 mg l À1 or less, and influent chloride concentration of 100 mg l À1 or less.…”

Selective removal of nitrate using a novel asymmetric amine based strongly basic anion exchange resin

“…However, groundwater mostly contains not only nitrate but also relatively high concentrations of competing anions such as sulfate, chloride and bicarbonate ions. Particularly, sulfate is a divalent anion which is preferentially adsorbed by conventional strongly basic anion exchangers through an electrostatic interaction, leading to a sharp reduction of the resin sorption capacity for nitrate, as it is a monovalent ion (Pakzadeh and Batista, 2011). The subsequently developed strongly basic anion exchangers are nitrate-specialty resins such as Purolite A 520E (A 520E), Imac HP555, Amberlite IRA 996 and Indion NSSR (Hekmatzadeh et al., 2012).…”