OCCURRENCE AND FATE OF ENDOCRINE DISRUPTING ANTIMICROBIAL TRICLOCARBAN IN MUNICIPAL SLUDGE DURING ADVANCED ANAEROBIC DIGESTION USING MICROWAVE PRETREATMENT Gokce Kor-Bicakci 1 , Timothy Abbott 2 , Emine Ubay-Cokgor 3 , Cigdem Eskicio 1 Ph.D., Environmental Engineering Department, Istanbul T echnical University (ITU), Istanbul, Turkey 2 Ph.D. candidate, University of British Columbia Okanagan Campus (UBCO), Kelowna, British Columbia, Canada 3 Professor, Environmental Engineering Department, ITU, Istanbul, T urkey 4 Professor, Leader of UBC Bioreactor T echnology Group, UBCO, Kelowna, British Columbia, HERAKLION 2019, 26-29 June 2019, Heraklion, Crete Island, Greece Canada
Emerging Concern in Biosolids PRIMARY SLUDGE WASTE ACTIVATED SLUDGE Fermented primary Thickened WAS sludge BIOGAS Electricity and Waste Cogeneration MIXED SLUDGE heat Class A or Class B Dewatering PRETREATMENT LAND LAND BIOSOLIDS APPLICATION APPLICATION ADVANCED ANAEROBIC DIGESTION EMERGING CONTAMINANTS (e.g. Pharmaceuticals and Personal Care Produc 2
Municipal Sludge Pretreatment Technologies THERMA L Ozonation Chemica Acidic & Alkaline l Peroxidation Conventional heating High pressure (~160°C, 30 min) homogenization Mechani Ultrasonication cal Microwave irradiation (2,450 Pulsed electric fjeld <<<<< Stirred ball mills MHz) Biologic Enzymatic Dual-stage anaerobic al digestion Radio frequency (13.56 MHz) This research Hosseini Koupaie et al., 2017. Water Res ., 118: 70-81. T yagi, V. And Lo, S.L., 2011. Rev Environ Sci Biotechnol ., 10(3), 215-242. 3
Why Triclocarban (TCC)? used as an ingredient in commonly used in many consumer products TCC Halden, R.U., 2014. Environmental Science & T echnology , 48, 3603−3611. Yee, A.L. and Gilbert, J.A., 2016. Science , 353, 6297 4
Triclocarban Table. Selected physico-chemical properties of triclocarban. Property Triclocarban (TCC) Chemical structure 1-(4-chlorophenyl)-3-(3,4- IUPAC name dichlorophenyl)urea C 13 H 9 Cl 3 N 2 O Molecular formula 315.578 Molecular weight (g/mol) 36.7 Chlorine content (weight %) Log K ow (at 25°C, pH 7) 4.9 Log K oc (at 25°C, pH 7) 4.5 pK a (at 20°C) 12.7 Water solubility (mg/L at 0.65 - 1.55 25°C) Vapour pressure (mm Hg at 3.61 x 10 -9 25°C) Antiseptic and disinfectant Use 1) Halden and Paull, 2005. Environ Sci T echnol , 39(6), 1420-6. 2) Heidler and Halden, 2008. Environ Sci T echnol , 5 42(17), 6324-6332. 3) Wu et al., 2009. Journal of Agricultural and Food Chemistry , 57(11), 4900- 4905. 4) Ying et al., 2007. Environmental Pollution , 150(3), 300-305.
Target Compounds Parent Transformation Compound products 1) Dichlorocarbanilide (DCC) Triclocarba 2) Monochlorocarbanilide (MCC) n 3) Carbanilide (NCC) (TCC) 4) 3,3',4,4'-tetrachlorocarbanilide (4-Cl-TCC) 5) Monochloroanilines Motivation: The efgects of microwave (MW) pretreatment on the fate of TCC/by-products 6) 4-chlorocatechol are unknown in municipal waste sludge streams. 6
Research Objectives MAIN OBJECTIVE: T o investigate how MW pretreatment along with advanced anaerobic digestion can afgect the environmental concentrations (NO SPIKING) of TCC and its transformation products in digester infmuent/effmuents streams Pretreatment intensity: MW Temp. [ 80 and 160°C ] and Holding time [ 1 and 30 min ] Digester temperature: Thermophilic [ 55 ± 1°C ] and Variable Mesophilic [ 35 ± 1°C ] s Digester sludge retention times (SRTs): 20, 12, and 6 days 7
METHODOLOGY 8
Wastewater Treatment Plant Selected Westside Regional Wastewater Treatment Plant (West Kelowna Canada) serves population of 44,500 people and average daily fmow capacity of 16,800m 3 /day 9
Microwave Pretreatment Scenarios Thickened WAS (TWAS) ( ˷ 4% Dewatered TWAS ( ˷ 11% TS w/w) centrifugation after polymer solution TS w/w) addition Mixed + Fig. Heating & cooling profjles of dewatered TWAS at Sludge 2.25°C/min . ( ˷ 3.5 % TS Fermented Primary Sludge (3- 10 5% TS w/w) w/w)
Anaerobic Digestion Studies Operation/monitorin 1 st acclimation 2 nd acclimation g stage stage of 10 digesters (acclimated to (acclimated to MW at SRTs of 20, 12, 6 irradiated mixed sludge) mixed sludge) days Total operation time: approx. 9 months Fig. T en bench-scale anaerobic digesters semi-continuously fed mode (once a day, 11 7 days/week).
Parameters Monitered Table. Characterization of digester performance. Sample Parameter • T Digester infmuent/effmuent otal/volatile solids streams • T otal/soluble chemical oxygen demand, biopolymers • pH, alkalinity, ammonia • T otal VFAs (acetic, propionic and butyric acids) • Target TCC parent/transformation compounds • Dewaterability, fecal coliforms, heavy metals Statistical Analysis using Analysis of Variance (ANOVA) using “ Minitab™ • Biogas volume 17 statistical software ” Digester headspace Conventional performance data: G. Kor-Bicakci, E. Ubay-Cokgor, C. Eskicioglu, 2019 12 • Biogas composition (CH 4 , CO 2 , N 2 , O 2 ) Energy , 168, 782−795.
Method development for target compound 13
Quantifjcation of TCC and its Transformation Products in Sludge T otal phase Ultrasound Centrifugation Acid extracts Vorte samples sonication (supernatants) x HLB Loading of samples Filtration Rotary evaporator cartridges N 2 blowdown UHPLC-ESI-MS/MS 14 Elution with MeOH by gravity Extracts in vials
RESEARCH FINDINGS 15
Environmental Occurrence of TCC in Mixed Sludge Transformation products 4-Cl-TCC MCC monochloroanilines 4-chlorocatechol below the limit of detection (LOD) DCC and NCC below the limit Fig. Seasonal fmuctuation in occurrence of triclocarban in difgerent sample collection periods together with weather averages. of quantifjcation between 300 and 1,800 ng/g dw (LOQ) average concentration of TCC 1,030 ± 470 16 ng/g dw
Efgect of MW Pretreatment on Fate of TCC in Mixed Sludge 64 ± 5% 62 ± 6% MW fjnal 30 ± 4% temperature 29 ± 6% MW holding time Fig. Efgect of MW pretreatment on reduction of triclocarban concentrations in pretreated over the un-pretreated mixed sludge (control). below the 4-Cl-TCC, MCC, monochloroanilines, 4- LOD chlorocatechol below the DCC and 17 LOQ NCC
Fate of TCC and its Metabolites during Conventional AD TCC: 1,765 – 1,900 ng/g dw SRT NCC: 505 – 255 ng/g dw SRT NCC concentration the fjrst study TCC DCC MCC NCC via complete reductive Fig. Average concentrations of TCC and NCC of the TH dechlorination and MH digesters’ effmuents at SRT s of 20, 12, and 6 18 days (n = 4).
Fate of TCC during Advanced AD the lowest 45% TCC reduction 65% at 80°C reduction TCC reduction < 10% holding time the lowest 35% at 160°C TCC reduction 47% holding time reduction 30 min > 1 min at SRT s 12 & 6 days TH >> MH Fig. Average concentrations of TCC in total phase of the TH and MH digesters’ effmuents (n = 4). 19
Conclusions • Compared to the control AD, advanced AD using MW pretreatment was found to be efgective in decreasing TCC levels in digester infmuent/effmuent streams (biosolids), • Most intensive MW pretreatment (160°C/30 min) showed the highest impact on TCC removal from mixed sludge at SRT of 12 days, • Seasonal changes had an impact on removal of TCC during wastewater treatment process at the WWTP , • Higher TCC transformation to NCC occurred at thermophilic temperature via potential dechlorination 20 mechanism compared to mesophilic temperature.
Acknowledgements International Research Fellowship Program, Turkey (2214/ Collaborative Research and Development Grant, Canada (CRDP J462765-13) Westside Regional Wastewater Treatment Plant Stafg 21
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Why Triclocarban Selected? High-production volume chemical (the worldwide annual production: ~1,500 ton) Being priority chemical candidates Abundant existence in municipal treatment sludge and biosolids (detected >1000 µg/ kg dry solids) - physico-chemical properties - possible threats to the food chain through land application of among the top 10 compounds detected in biosolids which were biosolids taken from WWTPs in U.S. (in the 231 chemicals assayed) among the top 10 contaminants of American rivers in U.S. Geological Survey (in the 95 contaminants from a 139 streams across 30 states) Venkatesan, A.K., and Halden, R.U., 2014. Nature, Scientifjc Reports, 4, 3731. Halden et al., 2017. Environmental Health Perspectives , 125(6), 064501. 23 Kolpin et al., 2002. Environ. Sci. T echnol. 2002, 36, 1202-1211.
Biogas Production All digesters ~ STABLE Specifjc biogas production 500 - 550 mL biogas/ g VS fed CH 4 content of biogas : 65 - 72% OLRs 1.45 - 5.20 g VS/L of digester/d Improvements: 2-19% over G. Kor-Bicakci, E. Ubay-Cokgor, C. Eskicioglu, 2019. Energy , 168, 782−795. 24 controls
Fate of NCC during Advanced AD TH >> MH shorter exposure temperature duration (1 min) SRT NCC concentration further research required ! 160°C >> 80°C 25 Fig. Average concentrations of NCC in total phase of the TH and MH digesters’ effmuents (n = 4).
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