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Thesis Analysis Of THESIS ANALYSIS OF OCTAMETHYLCYCLOTETRASILOXANE AND DECAMETHYLCYCLOPENTASILOXANE IN WASTEWATER, SLUDGE AND RIVER SAMPLES BY HEADSPACE GAS CHROMATOGRAPHY/MASS SPECTROMETRY Submitted by Yu Zhang Department of Civil and Environmental Engineering In partial fulfillment of the requirements For the Degree of Master of Science Colorado State University Fort Collins, Colorado Summer 2014 Master’s Committee: Advisor: Pinar Ömür-Özbek Kenneth Carlson Gregory Dooley Copyright by Yu Zhang 2014 All Rights Reserved ABSTRACT ANALYSIS OF OCTAMETHYLCYCLOTETRASILOXANE AND DECAMETHYLCYCLOPENTASILOXANE IN WASTEWATER, SLUDGE AND RIVER SAMPLES BY HEADSPACE GAS CHROMATOGRAPHY/MASS SPECTROMETRY Siloxanes are commonly used in cosmetic and personal care products, healthcare products and many industrial applications. Because siloxanes are persistent, they end up in the wastewater and go untreated through the wastewater treatment units, which lead to contamination of the surface waters through effluent discharge. Siloxanes tend to be adsorbed onto or absorbed by the activated sludge in the wastewater treatment process. In the digesters, the siloxanes volatilize and accumulate in the biogas, which leads to mechanical problems due to scaling. The two most common siloxanes detected in wastewaters and sludge are: octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5). For this study, the D4 and D5 in wastewater and sludge samples were monitored using headspace gas chromatography/mass spectrometry. Samples were collected from the City of Loveland Wastewater Treatment Plant (WWTP), Loveland, CO and the Drake Wastewater Reclamation Facilities (WWRF), Fort Collins, CO. The levels of D4 were in the range of 0.7-11.3 ng·mL-1 in wastewater and 0.3-1.8 µg·g-1 dry solid in the sludge from Drake WWRF; 1.0-6.7 ng·mL-1 in wastewater and 0.3-1.7 µg·g-1 dry solid in the sludge from Loveland WWTP. D5 levels were determined in the range of 0.4-10.4 ng·mL-1 in wastewater and 3.2-31.4 µg·g-1 dry solid in the sludge from Drake WWRF; 0.5-14.0 ng·mL-1 in wastewater and 2.5-18.9 µg·g-1 dry solid in the sludge from Loveland WWTP. The concentrations of D4 and D5 were higher in this study compared to other researches in other countries and the concentrations in waste activated sludge ii were in a comparable range. The concentrations of D4 and D5 in the receiving water body near the discharging points were below the limit of detection. The average mass loadings in the influent were 53.1 and 159.9 g·d-1 of D4 and 155.3 and 225.3 g·d-1 of D5 respectively in two plants. iii ACKNOWLEDGEMENT There are many people to thank for helping me during the research work and completion of this thesis. First, I would like to thank my advisor Dr. Pinar Ömür-Özbek for her guidance, encouragement, support and patience to make this research come true and completed. I would like to thank Dr. Greg Dooley for helping me set up the equipment and teaching the operation system. I am also grateful for Dr. Ken Carlson, who taught me the chemistry in environmental engineering. I also would like to express my thank and gratitude to John McGee from City of Loveland Wastewater Treatment Plant, who taught me the wastewater treatment plant operation, provided the opportunity to work with you and gave big support to this research. I would like thank Brian Cranmer for helping setting up the equipment and explaining the operation of the equipment. I also express my gratitude to my colleague Harshad Vijay Kulkarni, who trained me to use the lab, explained the research process and led my passion towards to this research field. I would like to thank Keerthivasan Venkatapathi, who was also one of my colleagues and shared the same lab with me. I also thank my friends who encourage and support me during studying in the US. I would like to express the most special gratitude to my parents and my family who provide support and encouragement for me to study and work, without which none of this would have been possible. iv TABLE OF CONTENTS ABSTRACT .................................................................................................................................... ii ACKNOWLEDGEMENT ............................................................................................................. iv LIST OF TABLES ........................................................................................................................ vii LIST OF FIGURES ....................................................................................................................... xi Chapter 1. Introduction ................................................................................................................... 1 Chapter 2. Literature Review .......................................................................................................... 3 2.1 Siloxanes .......................................................................................................................... 3 2.2 Siloxanes in the Environment .......................................................................................... 8 2.3 Impacts of Siloxanes of Environment ............................................................................ 10 2.4 Impacts of Siloxanes on Wastewater Treatment Utilities .............................................. 12 2.5 Treatment/Romoval of Siloxanes ................................................................................... 14 2.6 Detection and Analysis of Siloxanes .............................................................................. 15 Chapter 3. Problem Statement ...................................................................................................... 19 3.1 General Statement ......................................................................................................... 19 3.2 Goal of This Study ........................................................................................................ 21 Chapter 4. Analysis of Octamethylcyclotetrasiloxane and Decamethylcyclopentasiloxane in Wastewater, Sludge and River Samples by Headspace Gas Chromatography/Mass spectrometry ....................................................................................................................................................... 22 4.1 Introduction ................................................................................................................... 22 4.2 Materials and Methods ................................................................................................... 23 4.2.1 Chemicals and glassware ........................................................................................ 23 4.2.2 Stock Solutions and Calibrations Curves ................................................................ 24 4.2.3 Sample Collection and Preparation ......................................................................... 25 4.2.4 Method Validation .................................................................................................. 26 4.2.5 HS-GC/MS Analysis ............................................................................................... 27 4.2.6 Total Solids Analysis .............................................................................................. 28 4.3 Results and Discussions ................................................................................................. 28 4.3.1 Method validation ................................................................................................... 28 4.3.2 Method Comparison................................................................................................ 37 v 4.3.3 Results of Total Solids of Sludge............................................................................ 38 4.3.4 Results of Drake Wastewater Reclamation Facility, Fort Collins, CO................... 40 4.3.5 Results of City of Loveland Wastewater Treatment Plant, Loveland, CO ............. 42 4.3.6 Concentration Comparison ..................................................................................... 46 4.4 Conclusions .................................................................................................................... 48 References ..................................................................................................................................... 49 Appendix ....................................................................................................................................... 55 A. Raw Data – D4 ................................................................................................................... 55 B. Raw Data – D5 ................................................................................................................... 74 C. Raw Data – M4Q ............................................................................................................... 93 D. Total Solids Analysis ....................................................................................................... 110 E. Awareness Survey ............................................................................................................ 113 F. Sludge Picture .................................................................................................................. 116 vi LIST OF TABLES Table 2-1: Common Uses of Siloxanes and Silicones (Dewil et al., 2006) .................................... 4 Table 2-2: Physical Properties of Common Siloxanes (Mcbean, 2008) ........................................
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