TY - JOUR
T1 - Profiles and removal efficiency of organochlorine pesticides with emphasis on DDTs and HCHs by two different sewage treatment works
AU - Man, Yu Bon
AU - Chow, Ka Lai
AU - Cheng, Zhang
AU - Kang, Yuan
AU - Wong, Ming Hung
N1 - Funding Information:
The authors thank Mr. Raymond Tang and Dr. Frankie Lau of the Drainage Services Department, HKSAR, the research team led by Prof. M.H. Wong at Hong Kong Baptist University and the research team led by Prof. P.K.S. Lam at the State Key Laboratory in Marine Pollution, City University of Hong Kong, for technical assistance. Financial support from the Drainage Service Department, HKSAR ( DEMP 11/04 , 14/03 and 15/01 ), Start-up Research Grant for Newly Recruited Assistant Professors ( RG 55/2016-2017R ), Funding Support to ECS Proposal Rated 3.5 by RGC ( RG 38/2017-2018R ), The Education University of Hong Kong, and the Environment and Conservation Fund (ECF Project 30/2016) is gratefully acknowledged.
PY - 2018/2
Y1 - 2018/2
N2 - The removal efficiencies of nine organochlorine pesticides (OCPs) were investigated in two sewage treatment works (STWs; Stonecutter Island [SCI] and Shatin [ST]). The levels of OCPs in sewage samples collected from SCI (chemically enhanced primary treatment) and ST (secondary treatment) were determined with gas chromatography–mass spectrometry. The crude sewage in the two STWs generally had low levels of total hexachlorocyclohexane (HCHs; total of alpha-, beta- and gamma-HCH; SCI, 19.4 ± 4.62 ng/L; ST, 12.1 ± 4.27 ng/L) and total dichloro-diphenyl-trichloroethane (DDTs; total of p,p’ and o,p’-DDE, -DDD and -DDT; SCI, 6.31 ± 2.83 ng/L; ST, 6.09 ± 1.67 ng/L). High total removal efficiencies for total HCHs (SCI, 79.9 ± 7.03%; ST, 82.5 ± 2.51%) and total DDTs (SCI, 96.1% ± 3.37%; ST, 99 ± 0.501%) were observed. In particular, ST achieved outstanding performance in the removal of heptachlor (100% ± 0.00%), heptachlor epoxide (94.8 ± 3.96%), hexachlorobenzene (99.7 ± 0.387%), gamma-HCH (100 ± 0.00%) and total DDTs (99.2 ± 0.644%). There was no observable correlation between the removal efficiencies and the log Kow values of individual OCPs, which suggests that the removal mechanisms may not be related to sorption by particulate matter. Removal of OCPs seems to rely more on other mechanisms such as volatilisation, advection and biotransformation. This study is the first to investigate the fate and distribution of OCPs throughout the entire sewage treatment process. The results provide valuable reference for potential modification of sewage treatment processes with regard to OCPs.
AB - The removal efficiencies of nine organochlorine pesticides (OCPs) were investigated in two sewage treatment works (STWs; Stonecutter Island [SCI] and Shatin [ST]). The levels of OCPs in sewage samples collected from SCI (chemically enhanced primary treatment) and ST (secondary treatment) were determined with gas chromatography–mass spectrometry. The crude sewage in the two STWs generally had low levels of total hexachlorocyclohexane (HCHs; total of alpha-, beta- and gamma-HCH; SCI, 19.4 ± 4.62 ng/L; ST, 12.1 ± 4.27 ng/L) and total dichloro-diphenyl-trichloroethane (DDTs; total of p,p’ and o,p’-DDE, -DDD and -DDT; SCI, 6.31 ± 2.83 ng/L; ST, 6.09 ± 1.67 ng/L). High total removal efficiencies for total HCHs (SCI, 79.9 ± 7.03%; ST, 82.5 ± 2.51%) and total DDTs (SCI, 96.1% ± 3.37%; ST, 99 ± 0.501%) were observed. In particular, ST achieved outstanding performance in the removal of heptachlor (100% ± 0.00%), heptachlor epoxide (94.8 ± 3.96%), hexachlorobenzene (99.7 ± 0.387%), gamma-HCH (100 ± 0.00%) and total DDTs (99.2 ± 0.644%). There was no observable correlation between the removal efficiencies and the log Kow values of individual OCPs, which suggests that the removal mechanisms may not be related to sorption by particulate matter. Removal of OCPs seems to rely more on other mechanisms such as volatilisation, advection and biotransformation. This study is the first to investigate the fate and distribution of OCPs throughout the entire sewage treatment process. The results provide valuable reference for potential modification of sewage treatment processes with regard to OCPs.
KW - DDT
KW - HCH
KW - OCPs
KW - Removal efficiencies
KW - Sewage sludge
UR - http://www.scopus.com/inward/record.url?scp=85039806315&partnerID=8YFLogxK
U2 - 10.1016/j.eti.2017.12.004
DO - 10.1016/j.eti.2017.12.004
M3 - Journal article
AN - SCOPUS:85039806315
SN - 2352-1864
VL - 9
SP - 220
EP - 231
JO - Environmental Technology and Innovation
JF - Environmental Technology and Innovation
ER -