TY - JOUR
T1 - Ecological risks of heavy metals/metalloid discharged from two sewage treatment works to Mai Po Ramsar site, South China
AU - Man, Yu Bon
AU - Lei, Kim Man
AU - Chow, Ka Lai
AU - Leung, Anna Oi Wah
AU - Mo, Wing Yin
AU - Wong, Ming Hung
N1 - Funding Information:
Financial support from the Drainage Service Department, The Government of the Hong Kong SAR (DEMP 14/03) and the Environment and Conservation Fund, The Government of the Hong Kong SAR (ECF Project 30/2016) is gratefully acknowledged.
PY - 2020/6/1
Y1 - 2020/6/1
N2 - The concentrations of six heavy metal/metalloids (HMs) cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), and arsenic (As) were determined in the influent, effluent, and dewatered sludge of two sewage treatment works (Yuen Long Sewage Treatment Work (YLSTW) and Shek Wu Hui Sewage Treatment Work (SWHSTW)) and river waters and sediment (Shan Pui River and Ng Tung River) within the Mai Po Ramsar site in Hong Kong SAR, China. In both STWs, Pb had the highest removal efficiencies (YLSTW 86.5 ± 19.0% to 97.3 ± 3.04%; SWHSTW 87.4 ± 12.8% to 100 ± 0.0800%). In the whole effluent toxicity test, both STWs were effective in lowering the toxicity of the effluent to zebrafish and cherry shrimp. The environmental risk assessments of these HMs on three local aquatic organisms, three species of fish, two species of crustaceans, and three species of algae, were calculated based on measured HMs concentrations in river water and sewage samples, and the predicted no-effect concentrations. Results showed that Zn concentrations in all collected samples posed potential risks to all studied aquatic organisms (average risk quotient = 445). The concentrations of Cu in the rivers posed potential risks (average risk quotient = 5.42) to all fish species. It was concluded that Zn and Hg derived from the STWs might pose potential risks to the living organisms inhabiting the Ramsar site, and Cu, Cd, Pb, and As in the rivers were originated from the two rivers and possibly other tributaries.
AB - The concentrations of six heavy metal/metalloids (HMs) cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), and arsenic (As) were determined in the influent, effluent, and dewatered sludge of two sewage treatment works (Yuen Long Sewage Treatment Work (YLSTW) and Shek Wu Hui Sewage Treatment Work (SWHSTW)) and river waters and sediment (Shan Pui River and Ng Tung River) within the Mai Po Ramsar site in Hong Kong SAR, China. In both STWs, Pb had the highest removal efficiencies (YLSTW 86.5 ± 19.0% to 97.3 ± 3.04%; SWHSTW 87.4 ± 12.8% to 100 ± 0.0800%). In the whole effluent toxicity test, both STWs were effective in lowering the toxicity of the effluent to zebrafish and cherry shrimp. The environmental risk assessments of these HMs on three local aquatic organisms, three species of fish, two species of crustaceans, and three species of algae, were calculated based on measured HMs concentrations in river water and sewage samples, and the predicted no-effect concentrations. Results showed that Zn concentrations in all collected samples posed potential risks to all studied aquatic organisms (average risk quotient = 445). The concentrations of Cu in the rivers posed potential risks (average risk quotient = 5.42) to all fish species. It was concluded that Zn and Hg derived from the STWs might pose potential risks to the living organisms inhabiting the Ramsar site, and Cu, Cd, Pb, and As in the rivers were originated from the two rivers and possibly other tributaries.
KW - Environmental risk assessment
KW - Removal efficiency
KW - Secondary treatment
KW - Water quality parameters
KW - Whole effluent toxicity test
UR - http://www.scopus.com/inward/record.url?scp=85086995725&partnerID=8YFLogxK
U2 - 10.1007/s10661-020-08397-w
DO - 10.1007/s10661-020-08397-w
M3 - Journal article
C2 - 32602080
AN - SCOPUS:85086995725
SN - 0167-6369
VL - 192
JO - Environmental Monitoring and Assessment
JF - Environmental Monitoring and Assessment
IS - 7
M1 - 466
ER -
