Micropollutants: The Singapore Experience Siao Yun CHANG Water - PowerPoint PPT Presentation

Micropollutants: The Singapore Experience Siao Yun CHANG Water Quality Department 5 Nov 2019

2 Country Information Singapore 724.2 km 2 (279.6 mi 2 ) Land Area: Population: 5.7million Average Annual Rainfall: 2,330mm (92 inches) Average Water Demand: 430 m i gd (516.4 mgd / 1585 acre-foot/day)

We Are PUB, We Are Water “To ensure a clean sustainable environment, and supply of water and safe food for Singapore.” “To ensure a clean and “To ensure and secure a “Supply Good Water. sustainable environment for supply of safe food.” Reclaim Used Water. Tame Singapore, together with our Storm Water.” v Safe Food partners and the community” v Clean Water v Public Health v Clean Land A Statutory Board constituted under the Public v Clean Air Utilities Act 2001 to provide integrated water supply, sewerage and drainage services

PUB manages the complete water cycle

Presentation Outline • Research findings on micropollutants in water reclamation plant in Singapore • PUB’s approach on micropollutants management

Occurrence & Removal of Emerging Contaminants by Conventional Activated Sludge (CAS) and Membrane Bioreactor (MBR) Systems PI: A/P Karina Gin Researchers: Dr Tran Ngoc Han, Dr You Luhua Department of Civil & Environmental Engineering E2S2-CREATE NUS Environmental Research Institute (NERI)

Objectives • Investigate the occurrence of ECs in raw wastewater and treated effluent. • Evaluate the removal of ECs in a full-scale biological wastewater treatment plant using different treatment systems, i.e. conventional activated sludge (CAS) and membrane bioreactor (MBR).

Target Emerging Contaminants The selection of target ECs was based on at least one of the following criteria: § High consumption in the world. § Widespread occurrence in urban wastewater/ treated effluent all over the world as reported in the literature. § Potential risk to human health and aquatic ecosystems. § The analytical capability of the laboratory.

Target Emerging Contaminants Antibiotics & Antimicrobials Class Target ECs Abbr. Class Target ECs Abb b -lactams 1 Ceftazidime CFZ 12 Sulfonamides Sulfamethazine SMZ 2 Meropenem MER 13 Reductase Trimethoprim TMP inhibitor 3 Amoxicillin AMX 14 Tetracycline Tetracycline TET family 4 Quinolones Ciprofloxacin CIPX 15 Minocycline MIN 5 Lincosamides Lincomycin LIN 16 Chlortetracycline CTC 6 Clindamycin CLI 17 Oxytetracycline OXY 7 Macrolides Erythromycin ERYC 18 Antiseptics Triclosan TCS 8 Azithromycin AZT 19 Triclocarban TCC 9 Clarithromycin CLAR 20 Glycopeptide Vancomycin VCM 10 Tylosin TYL 21 Amphenicol Chloramphenicol CAP 11 Sulfonamides Sulfamethox- SMX azole

Other ECs No Class Target ECs Abbr. Class Target ECs Abbr. Acetaminophen ACT Hormones Estrone E1 22 NSAIDs 36 Ibuprofen IBP Estriol E3 23 37 Naproxen NPX Cortisone C2 24 38 Ketoprofen KEP Corticosterone C1 25 15 39 Fenoprofen FEP UV-filters 4-MBC 4-MBC 26 40 Indomethacin IDM Octocrylene OCT 27 41 Salicylic acid SA Oxybenzone OXB 28 42 Anti-itching Diclofenac DCF 29 Crotamiton CTMT Lipid Clofibric acid CA 30 43 Repellent Diethyltoluamide DEET regulator Gemfibrozil GFZ Artificial Acesulfame ACE 31 44 sweetener Anti- Carbamazepine CBZ 32 45 Sucralose SUC convulsant Gabapentin GBP 33 46 Cyclamate CYC 34 Anti-psychotic Sulpiride SUL 47 Saccharin SAC b -blockers Atenolol ATN 35 48 Iohexol IOH 49 X-ray contrast agents Iopromidol IOP 50 Bisphenol A BPA 51 Plasticizer

Schematic diagram of Water Reclamation Plant

Methods Addition of ILIS Method 1: Direct injection Filtered samples Method 2: SPE ILIS: isotopically labeled internal standards

Occurrence of Emerging Contaminants in Raw Wastewater

Antibiotics/Antimicrobials in Raw Influent 1 0 7 D e te ctio n fre q u e n c y 1 0 0 % C o n ce n tra tio n (n g / L ) 1 0 0 % 1 0 0 % 1 0 6 1 0 0 % 1 0 0 % 1 0 5 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % 1 0 4 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % 1 0 3 1 0 0 % 1 0 0 % 1 0 0 % 1 0 2 1 0 0 % 1 0 0 % 1 0 0 % 0 % 0 % 1 0 0 % 1 0 1 1 0 0 C L I S M Z T E T T Y L T C S A M X A Z T C A P C F Z C IP X C L A R C T C E R Y -H 2 O E R Y L IN M E R M IN O X Y S M X T M P V C M T C C • High variability in antibiotics • All antibiotics, except CFZ and TYL, were detected in raw influent • β-lactams, macrolides, sulfonamides, fluoroquinolone, and tetracyclines, were detected in raw influent > 1000 ng/L.

PPCPs, ASs and EDCs in Raw Influent 1 0 7 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % C o n ce n tra tio n (n g / L ) 1 0 6 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % 1 0 5 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % 1 0 4 1 0 0 % 1 0 0 % 1 0 0 % 1 0 3 1 0 0 % 1 0 0 % 1 0 0 % 1 0 0 % 1 0 2 1 0 0 % 1 0 0 % 1 0 1 1 0 0 E T N A Z F T C F T P P Z P P X A C C L M H B C C F C C B Y E E B B O P S A U U T P M X O D D G I A A C C E F G I N S S B O S A I T I D C All target PPCPs, EDCs, and ASs (except hormones: E1, E3, C1, C2 and OCT) were present in • raw influent Concentrations of PPCPs, EDCs, and ASs varied substantially, from several tens to upper • hundred thousands ng/L, depending upon compound and sampling date NSAIDs, X-ray contrast media (IOH and IOP), β-blocker (ATN), ASs (ACE, CYC, SAC, and SUC) • were the most abundant compounds and caffeine (CF)

Occurrence of Emerging Contaminants in Treated Wastewater

C o n cen tra tio n (n g /L ) 1 0 0 1 0 1 1 0 2 1 0 3 1 0 4 1 0 5 A M X A Z T C A P C F Z C IP X C L A R Antibiotics/antimicrobials In fluent C L I C T C E R Y -H 2 O E R Y L IN M L E M E R M IN O X Y S M X S S T S M Z T E T T M P M B R T Y L V C M T C C T C S

C o n cen tra tio n (n g /L ) 1 0 -1 1 0 0 1 0 1 1 0 2 1 0 3 1 0 4 1 0 5 1 0 6 A C E A C T A T PPCPs, ASs and EDCs N B P A C B Z C C F T M T C Y C D C In fluent F D E E T F E P G B P G F Z M L E I B P I D M I O H I O S S T P N P X O X B S M B R A S A C S U C S U L

Removal of Antibiotics by CAS & MBR Systems Target ECs % Removal by CAS system (n = 4) % Removal by MBR system (n = 4) Range Median Mean ± SD Range (%) Median Mean ± SD (%) (%) (%) (%) (%) MER 80.7–92.6 84.4 85.5 ± 5.0 81–92.3 84.5 85.6 ± 4.9 AMX 99.3–99.7 99.5 99.5 ± 0.2 69.9–99.7 99.5 92.1 ± 14.8 CIPX 76.6–92.4 87.8 86.2 ± 6.8 84.9–99.9 88.6 90.5 ± 6.8 LIN 8.1–56.1 42.1 37.1 ± 21 -8.1–79.3 62.1 48.8 ± 38.8 CLI 83.6–85.7 83.9 84.3 ± 1.0 85.8–88.9 87.5 87.4 ± 1.3 ERY 31.4–77.7 63.8 59.2 ± 19.7 26.6–74.9 54.8 52.3 ± 19.8 ERY-H 2 O 35–64.7 49.3 49.6 ± 13.8 49.9–67.7 64.8 60.6 ± 10.5 AZT 48.8–80.9 78.0 71.4 ± 15.3 88.6–96.8 91.4 90.1 ± 3.4 CLAR 51.3–73.8 67.0 64.8 ± 10.1 57.8–89.3 71.3 72.4 ± 13.8 SMX 62.8–77.7 66.6 68.4 ± 4.5 54–74.9 69.0 66.8 ± 8.9 SMZ 52.2–96 80.3 76.9 ± 19 78.4–96.2 88.1 87.7 ± 9.6 TMP 23.8–42.2 33.1 33.0 ± 7.8 67.7–73.3 69.1 69.8 ± 2.4 TET 44.3–87.6 67.1 66.5 ± 23.4 83.3–95.5 92.4 90.9 ± 5.6 MIN 44.8–86.9 70.2 68.1 ± 20.8 70.1–86.9 84.7 81.6 ± 7.8 CTC 31.4–88 58.8 59.2 ± 31.6 84–97.8 87.9 89.4 ± 6.1 OXY 54.6–93.9 80.3 77.3 ± 16.8 89.3–96.3 93.4 93.1 ± 3.5 TCS 87.4–94.2 91.1 90.9 ± 3.6 83.8–97.6 96.4 93.5 ± 6.6 TCC 51.1–84.7 69.9 68.9 ± 14.9 67.9–93.5 80.4 86.6 ± 12.3 VCM 96.6–99.9 99.9 99.1 ± 1.7 97.2–99.9 99.9 99.3 ± 1.4 CAP 98.4–98.8 98.6 98.6 ± 0.2 98.4–98.8 98.6 98.6 ± 0.2

Removal of PPCPs & EDCs by CAS & MBR Systems Removal by CAS system ( n = 4) Removal by MBR system ( n = 4) Removal range Median Mean ± SD Removal range Mean ± SD Target ECs (%) (%) (%) (%) Median (%) (%) 98.9 ± 0.4 98.0 ± 0.7 ACT 98.3–99.2 98.9 97.4–98.9 97.9 93.6 ± 3.3 89.8 ± 4.5 ATN 88.9–96 94.8 83.7–94.6 90.5 86.2 ± 4.0 91.4 ± 4.4 BPA 81.9–90.6 86.2 88.3–97.9 89.7 7.3 ± 8.9 4.3 ± 2.9 CBZ -0.2–19.1 5.2 1.9–7.7 3.9 CF 100 100 100 100 100 100 9.4 ± 13.1 14.4 ± 6.9 CTMT 0.4–28.8 4.3 6.8–22.1 14.4 4.7 ± 19.7 19.4 ± 22.3 DCF -16.9–28.5 3.6 -4.7–44.4 19.0 92.6 ± 3.2 87.3 ± 3.5 DEET 88–95 93.7 82.1–90.1 88.5 99.1 ± 0.4 FEP 98.6–99.6 99.1 100 100 100 50.2 ± 46.7 82.4 ± 9.0 GBP -8.3–91.3 58.9 76.2–95.6 78.8 77.3 ± 3.5 87.7 ± 7.1 GFZ 74.9–82.5 76 78.5–95.5 88.3 97.3 ± 0.6 97.4 ± 0.8 IBP 96.9–98.2 97 96.7–98.1 97.4 98.6 ± 03 98.6 ± 03 IDM 98.3–99 98.6 98.3–99 98.6 40.8 ± 29.8 72.2 ± 6.2 IOH 7.3–70.3 40.4 65.9–79.2 71.9 -10.2 ± 45.4 12.4 ± 63 IOP -53.7–44.8 -16 -80.7–53.4 38.5 59.0 ± 15.1 63.8 ± 10.8 NPX 36.5–68.9 65.3 48.3–72.2 67.3 94.7 ± 1.5 96.9 ± 0.9 OXB 92.5–95.7 95.3 95.6–97.5 97.2 61.47 ± 34.6 72.1 ± 22.1 SA 12.9–95.1 68.9 42.2–95.4 75.3 37.0 ± 31.5 35.2 ± 18.5 SUL 9.5–73.5 32.4 20.6–59.3 30.4