TY - JOUR
T1 - Elimination of microcystin-LR and residual Mn species using permanganate and powdered activated carbon
T2 - Oxidation products and pathways
AU - Jeong, Boyoung
AU - Oh, Min Seok
AU - Park, Hyun Mee
AU - Park, Chanhyuk
AU - Kim, Eun Ju
AU - Hong, Seok Won
AU - Kim, Eun Ju
N1 - Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017
Y1 - 2017
N2 - The oxidation of microcystin-LR (MC-LR) in deionized water (DI) and river water using potassium permanganate (KMnO4) at a neutral pH and at 23 ± 2 °C was investigated. These two aqueous systems (i.e., DI and river water) gave comparable second-order rate constants (289.9 and 285.5 M−1s−1(r2 > 0.99), respectively), which confirmed the effectiveness of this oxidation process for the treatment of natural surface water. The presence of either humic or fulvic acid reduced the removal efficiency of MC-LR, with the latter exhibiting a greater inhibitory effect. Monitoring of MC-LR and residual Mn2+levels with adding KMnO4(1 mg/L) and powdered activated carbon (PAC, 5–20 mg L-1) before and during coagulation, respectively, revealed that 60 min of permanganate pre-oxidation followed by coagulant addition with PAC was the most effective approach for reducing both levels below limits stated by WHO guidelines. The MC-LR degradation products were the result of oxidation occurring at the diene and aromatic moieties of the Adda (3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid) side-chain, in addition to amine bond hydrolysis of the Mdha (N-methyldehydroalanine) moiety. Several toxic by-products with an intact Adda chain were observed during the reaction, but completely disappeared after 60 min. This further supports the conclusion that sufficient contact time with permanganate (i.e., >60 min) is essential to reducing the residual toxicity and maximizing the efficiency of MC-LR oxidation when treating raw water.
AB - The oxidation of microcystin-LR (MC-LR) in deionized water (DI) and river water using potassium permanganate (KMnO4) at a neutral pH and at 23 ± 2 °C was investigated. These two aqueous systems (i.e., DI and river water) gave comparable second-order rate constants (289.9 and 285.5 M−1s−1(r2 > 0.99), respectively), which confirmed the effectiveness of this oxidation process for the treatment of natural surface water. The presence of either humic or fulvic acid reduced the removal efficiency of MC-LR, with the latter exhibiting a greater inhibitory effect. Monitoring of MC-LR and residual Mn2+levels with adding KMnO4(1 mg/L) and powdered activated carbon (PAC, 5–20 mg L-1) before and during coagulation, respectively, revealed that 60 min of permanganate pre-oxidation followed by coagulant addition with PAC was the most effective approach for reducing both levels below limits stated by WHO guidelines. The MC-LR degradation products were the result of oxidation occurring at the diene and aromatic moieties of the Adda (3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid) side-chain, in addition to amine bond hydrolysis of the Mdha (N-methyldehydroalanine) moiety. Several toxic by-products with an intact Adda chain were observed during the reaction, but completely disappeared after 60 min. This further supports the conclusion that sufficient contact time with permanganate (i.e., >60 min) is essential to reducing the residual toxicity and maximizing the efficiency of MC-LR oxidation when treating raw water.
KW - Microcystin-LR
KW - Natural organic matter
KW - Oxidation by-product
KW - Oxidation pathway
KW - Potassium permanganate
KW - Powdered activated carbon
UR - http://www.scopus.com/inward/record.url?scp=85013997565&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2017.02.043
DO - 10.1016/j.watres.2017.02.043
M3 - Article
C2 - 28249210
AN - SCOPUS:85013997565
SN - 0043-1354
VL - 114
SP - 189
EP - 199
JO - Water Research
JF - Water Research
ER -