TY - JOUR
T1 - Household cooking with seaweed salts and chloraminated tap water produce harmful iodinated disinfection by-products
AU - Cao, Zhongqi
AU - Ding, Shunke
AU - Deng, Yang
AU - Luan, Xinmiao
AU - Chu, Wenhai
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (Nos. 51822808 and 51778445), Science and Technology Innovation Action Plan of Shanghai Science and Technology Commission (No. 21DZ1202203), Program of Shanghai Academic Research Leader (No. 21XD1424000), International Cooperation Project of Shanghai Science and Technology Commission (No. 20230714100), Shanghai Soft Science Project (No. 20692113900), and Tongji University Youth 100 Program.
Publisher Copyright:
© 2021
PY - 2022/3/1
Y1 - 2022/3/1
N2 - Among the harmful halogenated disinfection by-products (DBPs) produced from water disinfection, iodinated DBPs (I-DBPs) are of the highest toxicity. Here we reported for the first time that daily household cooking using seaweed salts and tap water with chloramine residual could produce high concentrations of I-DBPs. At a typical household cooking setting (1-hr heating at 80 °C), the reactions of chloramines (1.0 mg/L as Cl2) with 10 g/L seaweed salt in ultrapure water generated 96.8 ± 3.2 μg/L of iodo-containing trihalomethanes (I-THMs) and 385.3 ± 10.9 μg/L of total organic iodine (TOI). The yields are 1 ∼ 3 orders of magnitude greater than their typical occurrence levels in drinking water. At the unintended scenario, chloramines reacted with iodine and trace dissolved organic matter, both of which derived from seaweed salts containing iodide and organic iodine species. When chloraminated tap water was used at the identical conditions, aliphatic I-DBPs (i.e. I-THMs and iodo-containing haloacetic acids) significantly increased up to 163.5 ± 3.9 μg/L as a result of more natural organic matter, which could serve as DBP precursors, present in the tap water. Speciation and concentrations of different I-DBPs generated relied heavily on temperature, heating duration, chloramine concentration, and salt dose. Following a simulated household cooking in the presence of seaweed salts, the toxicity of tap water to luminescent bacteria (Vibrio qinghaiensis sp.-Q67) increased by 4.6 ∼ 8.7 times on the basis of EC50. These findings spotlight the potential risks of I-DBPs generated from daily household cooking with seaweed salts, because salt consumption contributes to more than half of daily iodine intake.
AB - Among the harmful halogenated disinfection by-products (DBPs) produced from water disinfection, iodinated DBPs (I-DBPs) are of the highest toxicity. Here we reported for the first time that daily household cooking using seaweed salts and tap water with chloramine residual could produce high concentrations of I-DBPs. At a typical household cooking setting (1-hr heating at 80 °C), the reactions of chloramines (1.0 mg/L as Cl2) with 10 g/L seaweed salt in ultrapure water generated 96.8 ± 3.2 μg/L of iodo-containing trihalomethanes (I-THMs) and 385.3 ± 10.9 μg/L of total organic iodine (TOI). The yields are 1 ∼ 3 orders of magnitude greater than their typical occurrence levels in drinking water. At the unintended scenario, chloramines reacted with iodine and trace dissolved organic matter, both of which derived from seaweed salts containing iodide and organic iodine species. When chloraminated tap water was used at the identical conditions, aliphatic I-DBPs (i.e. I-THMs and iodo-containing haloacetic acids) significantly increased up to 163.5 ± 3.9 μg/L as a result of more natural organic matter, which could serve as DBP precursors, present in the tap water. Speciation and concentrations of different I-DBPs generated relied heavily on temperature, heating duration, chloramine concentration, and salt dose. Following a simulated household cooking in the presence of seaweed salts, the toxicity of tap water to luminescent bacteria (Vibrio qinghaiensis sp.-Q67) increased by 4.6 ∼ 8.7 times on the basis of EC50. These findings spotlight the potential risks of I-DBPs generated from daily household cooking with seaweed salts, because salt consumption contributes to more than half of daily iodine intake.
KW - Iodinated disinfection by-products
KW - Precursor
KW - Seaweed iodine salt
KW - Simulated household cooking
KW - Tap water
UR - http://www.scopus.com/inward/record.url?scp=85118978661&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2021.133471
DO - 10.1016/j.cej.2021.133471
M3 - Article
AN - SCOPUS:85118978661
SN - 1385-8947
VL - 431
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 133471
ER -