TY - JOUR
T1 - Pretreatment strategies for ion exchange to control brominated disinfection byproducts in potable reuse
AU - Ersan, Mahmut S.
AU - Dickenson, Eric R.V.
N1 - Funding Information:
The authors would like to thank SNWA staff for help on analytical assistance: Brett Vanderford, Janie Zeigler, Douglas Mawhinney, Steven George, Josephine Chu, Parviz Eivazi, Lena Wright, Jennifer McCarville, and Matthew Desautel. We are grateful to Dr. Christopher Bellona and Carolyn Coffey at the Colorado School of Mines for providing raw water samples from their pilot unit. We also thank Dr. Stephanie Riley for her assistance during sample collections from the pilot O3/BAC/GAC unit at Clark County Water Reclamation District. Last, but not least, we would like to gratefully acknowledge Purolite Ltd. for providing resin samples.
Publisher Copyright:
© 2022
PY - 2022/6
Y1 - 2022/6
N2 - The application of ion exchange (IX) resins to remove disinfection byproduct (DBP) precursors in wastewater effluents is challenging due to relatively high concentrations of competing anions. This study examined various pretreatment strategies to target competing ions to improve IX removal of DBP precursors, bromide and dissolved organic matter (DOM), measured as trihalomethane and haloacetic acid formation potentials (THMFP and HAAFP). IX batch experiments were performed with four commercial anion exchange (AIX) resins selective for bromide (BrP), DOM (A860), sulfate (MTA) and PFOA/PFOS (PFA), and one cation exchange (CIX) resin selective for iodide (CT). For single AIX treatments the bromide removal ranking was the following: PFA (58%) > MTA (51%) > BrP (43%) > A860 (16%), which corresponded with decreasing brominated THMFP removals and increasing bromine incorporation factors. For dual AIX combinations (PFA and BrP, MTA and BrP), either simultaneous or sequential treatments had the highest bromide (PFA + BrP [69%], MTA + BrP [67%], (PFA→BrP [77%], MTA→BrP [74%]) and Br-THMFP (THMFP [∼80%]) and Br-HAAFP (HAAFP [∼77%]) removals, and therefore the lowest fractions of brominated DBPs (Br-DBPs). Despite ozone (O3), biological active carbon (BAC), and granular activated carbon (GAC) pretreatments reducing the overall DOM concentration (33%), these pretreatment steps did not improve the bromide removals of the resins, although it did increase the Br-THMFP and Br-HAAFP removals by 2–38% and 13–20%, respectively. Nanofiltration (NF) pretreatment significantly removed sulfate (97%) resulting in an increased bromide removal of 19% by the AIX resins, which led to increased removal of Br-THMFP and Br-HAAFP by 93% and 96%, respectively. Among all the IX resins the CT resin had the highest bromide removal (83%) and lowest fraction of Br-DBPs. The results reveal pretreatment with existing technologies including AIX, O3/BAC/GAC, or NF can potentially enhance the removal of brominated DBP precursors by IX resins during potable reuse applications.
AB - The application of ion exchange (IX) resins to remove disinfection byproduct (DBP) precursors in wastewater effluents is challenging due to relatively high concentrations of competing anions. This study examined various pretreatment strategies to target competing ions to improve IX removal of DBP precursors, bromide and dissolved organic matter (DOM), measured as trihalomethane and haloacetic acid formation potentials (THMFP and HAAFP). IX batch experiments were performed with four commercial anion exchange (AIX) resins selective for bromide (BrP), DOM (A860), sulfate (MTA) and PFOA/PFOS (PFA), and one cation exchange (CIX) resin selective for iodide (CT). For single AIX treatments the bromide removal ranking was the following: PFA (58%) > MTA (51%) > BrP (43%) > A860 (16%), which corresponded with decreasing brominated THMFP removals and increasing bromine incorporation factors. For dual AIX combinations (PFA and BrP, MTA and BrP), either simultaneous or sequential treatments had the highest bromide (PFA + BrP [69%], MTA + BrP [67%], (PFA→BrP [77%], MTA→BrP [74%]) and Br-THMFP (THMFP [∼80%]) and Br-HAAFP (HAAFP [∼77%]) removals, and therefore the lowest fractions of brominated DBPs (Br-DBPs). Despite ozone (O3), biological active carbon (BAC), and granular activated carbon (GAC) pretreatments reducing the overall DOM concentration (33%), these pretreatment steps did not improve the bromide removals of the resins, although it did increase the Br-THMFP and Br-HAAFP removals by 2–38% and 13–20%, respectively. Nanofiltration (NF) pretreatment significantly removed sulfate (97%) resulting in an increased bromide removal of 19% by the AIX resins, which led to increased removal of Br-THMFP and Br-HAAFP by 93% and 96%, respectively. Among all the IX resins the CT resin had the highest bromide removal (83%) and lowest fraction of Br-DBPs. The results reveal pretreatment with existing technologies including AIX, O3/BAC/GAC, or NF can potentially enhance the removal of brominated DBP precursors by IX resins during potable reuse applications.
KW - Anion and cation exchange
KW - Bromide
KW - Disinfection byproduct precursors
KW - Haloacetic acids
KW - Potable reuse
KW - Trihalomethanes
UR - http://www.scopus.com/inward/record.url?scp=85126067126&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85126067126&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2022.134068
DO - 10.1016/j.chemosphere.2022.134068
M3 - Article
C2 - 35202669
AN - SCOPUS:85126067126
SN - 0045-6535
VL - 296
JO - Chemosphere
JF - Chemosphere
M1 - 134068
ER -