정수처리과정에서 의약품 및 내분비계 교란 물질의 발생 및 제거

학위논문 (박사)-- 서울대학교 보건대학원 : 보건학과, 2015. 2. 조경덕.Micropollutants have been discharged to surface waters by the untreated effluents in sewage treatment plants (STPs) and wastewater treatment plants (WWTPs). The contaminated waters are naturally utilized as a source of drinking water in water treatment plants (WTPs). Many micropollutants resist conventional WTP systems and survive in tap water. In particular, pharmaceuticals and endocrine disruptors (ECDs) are examples of frequently detected micropollutants in drinking water. Although chronic exposure to micropollutants in drinking water has unclear adverse effects for humans, peer reviews have argued that the continuous accumulation of these substances in water environments and inappropriate removal of them in WTP systems may potentially affect human health, in future. Therefore, WTP monitoring and effective elimination process studies for pharmaceuticals and ECDs are required to control micropollutant contamination in drinking water. In this study, 14 micropollutants, which are frequently used in daily life and whose detection in domestic surface waters have been reported, were selected as the target compounds: acetaminophen, caffeine, carbamazepine, diclofenac, metoprolol, naproxen, ibuprofen, sulfamethoxzole, sulfamethazine, atrazine, 2,4-dichlophenoxyacetic acid, bisphenol A, nonylphenol, and triclocarban. The main objectives of this study were to visualize the fate and removal of the selected micropollutants in WTP systems and to contribute to efficient elimination of the pollutants by modification of the WTPs. The specific aims of this study were to (1) investigate the occurrence and behavior of the selected micropollutants in a WTP, and the dominant removal mechanisms in a conventional system, using liquid chromatography tandem mass spectrometer (LC-MS/MS) (Study 1)(2) elucidate the effects of natural contents (dissolved organic matters (DOM), water temperature, and pH) and operational conditions (adsorbent dosage and contact time) of the adsorption for the selected micropollutants, and estimate their sorption coefficients based on the hydrophobicity using Freundlich isotherm and linear isotherm (Study 2)(3) evaluate the removal efficiencies for metoprolol in chlorination (Cl2), ultraviolet (UV-C) radiation, and a Cl2/UV system, obtain the optimal conditions using two-level factorial design of experiments for metoprolol, and identify its byproducts in the suggested process (Study 3)and (4) evaluate the suitability of micropollution indicators for use in the monitoring of river water and various drinking waters, analyze the correlations of their co-occurrences with each other, and estimate their persistence in conventional water treatments (coagulation, adsorption, and chlorination) and some advanced treatments (O3, UV, UV/peroxide (UV/H2O2), and Cl2/UV) (Study 4). Study 1 monitored the presence and behavior of the micropollutants in a WTP system. The levels of 14 micropollutants were measured in a water treatment plant in Seoul, Korea with LC-MS/MS. Among the measured micropollutants, 12 (all except atrazine and triclocarban) were found in the influent and effluent from the WTP, at levels ranging from 2 ng/L to 482 ng/L. Concentrations of acetaminophen, metoprolol, ibuprofen, and naproxen were higher in winter, while levels of the herbicide 2,4-dichloro-phenoxyacetic acid (2,4-D) were higher in summer. Only a small amount of metoprolol was removed in the water treatment process. The average removal efficiencies of the detected micropollutants in the WTP diversely ranged from 6% to 100%. The laboratory experiment showed that micropollutants with log Kow higher than 2.5 (especially bisphenol-A, 2,4-D, carbamazepine, triclocarban, and nonylphenol) were effectively removed by the coagulation process. Sunlight photodegradation also effectively removed sulfamethoxazole, sulfamethazine, caffeine, diclofenac, ibuprofen, and acetaminophen. This study implied that the micropollutants were mainly removed during the coagulation stage in the WTP by the combination of several mechanisms, such as adsorption to the particles and sunlight photodegradation. Study 2 investigated the effect of carbon dosage, contact time, sorption coefficients, pH, DOM, and temperature on the removal of nine micropollutants (acetaminophen, caffeine, diclofenac, naproxen, sulfamethoxazole, sulfamethazine, atrazine, 2,4-D, and triclocarban) by adsorption with activated carbon (AC). Increasing the carbon dosage and the contact time enhanced the removal of the micropollutants. The sorption coefficients of the hydrophilic compounds (caffeine, acetaminophen, sulfamethoxazole, and sulfamethazine) fit a linear isotherm, and the hydrophobic compounds (naproxen, diclofenac, 2, 4-D, triclocarban, and atrazine) fit a Freundlich isotherm. The removal of the hydrophobic pollutants and the caffeine were independent of pH changes, but acetaminophen, sulfamethazine, and sulfamethoxazole were adsorbed by mainly electrostatic interaction with ACtherefore, they were affected by pH. The decrease in adsorption removal in the surface water samples was observed and this decrease was significant for the hydrophobic compounds. The decline in the adsorption capacity in the surface water samples is caused by the competitive inhibition of DOM with micropollutants onto activated carbon. Low temperature (5C) also decreased the adsorption removal of the micropollutants, and that affected the hydrophobic compounds more than the hydrophilic compounds. The results obtained in this study could be applied to optimize the adsorption capacities of micropollutants using AC in the water treatment process. Study 3 assessed the degradation of metoprolol based on the type of treatment system, using Cl2, UV-C (λ=254 nm) and Cl2/UV, in order to investigate whether the disinfection for metoprolol removal was effective, and to predict the disinfection application at different conditions of UV light intensity (1.1-4.4 mW/cm2), chlorine dose (1-5 mg/L as Cl2), pH (2-9), and DOM (1-4 mgC/L), using a two-level factorial design for the experiments. The results showed that, among the three treatment options, the Cl2/UV process was the most effective for metoprolol removal. For the optimization of metoprolol removal during Cl2/UV treatment, 16 experiments, combining the four factors, were conducted to investigate the amount of metoprolol in distilled water after 1 hour of Cl2/UV treatment. Among the factors assessed, DOM inhibition of the OH radical was the most dominant in the terms of metoprolol degradation. The established model fitted well with the actual results in the experiments using surface water and tap water. The optimized conditions (UV-C = 4.4 mW/cm2[Cl2] = 5 mg/L, pH = 7, and [DOM] = 0.8-1.1 mgC/L) of the model transformed more than 78.9% of the metoprolol in the Cl2/UV process. Five byproducts of metoprolol (molecular weights: 171, 211, 309, 313, and 341) were identified with LC-MS/MS during the Cl2/UV process. The major degradation mechanisms of metoprolol were constructed, and these results may provide valuable information concerning advanced oxidation processes. metoprolol was effectively degraded in the Cl2/UV system, and the optimal conditions and unidentified byproducts were elucidated during the treatment process. Study 4 estimated the suitability of caffeine, metoprolol, sulfamethoxazole, and carbamazepine as indicator micropollutants of with detection in various types of water, such as river water, spring water, tap water, and bottled water. Moreover, the lab-scale experiments of coagulation, adsorption, chlorination, O3, UV, UV/H2O2, and Cl2/UV were conducted to confirm the persistence of the four nominated pollutants in the WTPs. All indicator candidates were detected > 80% in the river sample, and caffeine had the highest concentration (158.6 ng/L) and a positive correlation in the co-occurrences. However, the tap water contained a higher level of metoprolol (14.2-40.4 ng/L) than caffeine, and metoprolol showed the lowest removal (10-18%) in the conventional treatments. Considering the detection and resistance in drinking water, metoprolol was recommended as an indicator micropollutant. Among the advanced oxidation processes, the Cl2/UV process was the most effective for removing the selected contaminants (90-100%). In conclusion, this thesis determined the fate and dominant removal mechanisms for micropollutants in WTPs, the effects of the control factors and the adsorption coefficients of the micropollutants in adsorption with AC, the optimized operational conditions of the Cl2/UV process for metoprolol as a recalcitrant micropollutant, and whether metoprolol could be a micropollution indicator in drinking water. According to the results of this thesis, many kinds of micropollutants can exist in WTPs at the level of parts-per-trillion (ppt) and parts-per-billion (ppb), and various technologies and related research are needed to examine the degradation of persistent micropollutants in order to supply the population with healthy drinking water.Contents Abstract i List of Tables xiii List of Figures xvi List of Abbreviations xxii Chapter 1. Introduction 1.1. Backgrounds 1 1.2. Micropollutants in environment 7 1.3. Occurrences and removals in water treatment 34 1.4. Removal mechanisms in water treatment 50 1.4.1. Coagulation / sedimentation 50 1.4.2. Adsorption 57 1.4.3. Disinfection 66 1.5. Objectives and hypotheses 75 1.6. Dissertation structure 78 Chapter 2. Occurrence and removal of selected micropollutants in a WTP 2.1. Introduction 81 2.2. Materials and methods 83 2.2.1. Materials 83 2.2.2. Sampling 84 2.2.3. Analytical methods 88 2.2.4. Laboratory experiments 94 2.3. Results and discussion 96 2.3.1. The occurrence of selected micropollutants in source water 96 2.3.2. Removal of micropollutants and their fate during the water treatment process 100 2.3.3. Levels in the final effluent in WTP 116 Chapter 3. Adsorption removals of micropollutants in water using activated carbon 3.1. Introduction 119 3.2. Materials and methods 121 3.2.1. Chemicals 121 3.2.2. Water sample 123 3.2.3. Adsorption experiment 125 3.2.4. Analytical methods 133 3.3. Results and discussion 135 3.3.1. Role of dosage and contact time in adsorption removal 135 3.3.2. Sorption potentials of the selected micropollutants 139 3.3.3. Effect of pH on the sorption 146 3.3.4. Effect of dissolved organic matter 150 3.3.5. Temperature effects 154 Chapter 4. Optimization of Metoprolol degradation in disinfection processes and identification of byproducts 4.1. Introduction 158 4.2. Materials and methods 161 4.2.1. Chemicals 161 4.2.2. Water samples 163 4.2.3. Laboratory experiments 165 4.2.4. Analytical methods 168 4.2.5. Statistical analysis for control factors 170 4.3. Results and discussion 173 4.3.1. Kinetics using the Cl2, UV-C, Cl2/UV processes 173 4.3.2. Optimal conditions 182 4.3.3. Identification of byproducts during Cl2/UV 190 Chapter 5. Determination of indicator micropollutant in WTP 5.1. Introduction 196 5.2. Materials and methods 200 5.2.1. Chemicals 200 5.2.2. Water samples 202 5.2.3. Laboratory experiments 205 5.2.4. Analytical methods 209 5.2.5. Statistical analysis 211 5.3. Results and discussion 212 5.3.1. Occurrences in drinking water 212 5.3.2. Persistence in water treatments 218 5.3.3. Removals in the suggested AOPs 224 Chapter 6. Conclusions 6.1. Conclusions 232 6.2. Suggestions for future study 237 References 240 국문초록 274Docto

(An) experimental study on growth of the face and jaws in guinea pigs

치의학과/박사[한글]두개골의 성장과정에서 봉합부의 성장은 주위골 성장이나 연부조직의 영향을 받아서 두골사이에 있는 봉합성 결합조직의 증식으로 신생골이 첨가되어 지는 것이고, 비중격의 역할은 비상악 복합체의 일차전위에 관여하며, 안면 및 악골의 성장에 중요한 부위로 알려져 있다. 저자는 이에 관련하여 성장중인 Guinea pig에서 전두비골봉합을 절제한 예와 비중격을 제거한 예에서 안면 및 악골의 성장관계를 관찰하기 위하여 생후 25일된 체중250gmn내외의 Guinea Pig 32두를 사용하여 일측전두비골봉합의 절제군에 8두, 양측전두비골봉합의 절제군에 8두, 비중격의 제거군에 8두, 그리고 정상군에 8두씩 각각 배당하였다. 전두비골봉합의 절제군은 Dental Bur를 사용하여 전두골과 비골의 절제량이 같도록 일측전두비골봉합과 양측전두비골봉합을 각각 8두씩 절제하였다. 각군의 봉합절제 및 비중격제거 수술후 생존기간은 5개월로 하였으며. 동물을 희생시킨후 10% Formalin에 7일간 고정시킨 후 potassium hydroxide 용액에 끓여서 깨끗이 한 후 건조두개골을 얻어 관찰하여 다음과 같은 결과를 얻었다. 1. 일측전두비골봉합을 절제한 군에서는 비골이 단소하였고 전악골, 상악골 및 하악골의 성장에는 아무런 영향을 주지 않았다. 2. 양측전두비골봉합을 절제한 군에서는 일측전두비골봉합을 절제한 군과 마찬가지로 비골이 단소하였고 상안면부의 성장에는 아무런 영향을 주지 않았다. 3. 비중격을 제거한 군에서는 상안면부가 단소하였고 비강과 비공은 작으며 전악골과 상악골은 단소하였다. 상안면부의 성장부족으로 상악절치는 하악절치의 설측과 교합 (반대교합)하고 비골은 전하방으로 경사하였다. [영문]Thirty two growing guinea pigs, 25 days of age and weighing approximately 250 grams were used. The animals were divided into four groups ; group of animals with unilateral extirpation of frontonasal suture, group of animals with bilateral extirpation of frontonasal suture , group of animals with resection of nasal septum, and group for normal animals. A dental bur, mounted in a handpiece, was used to extirpate the frontonasal suture either unilaterally in 8 animals or bilaterally in 8 animals. The extirpation channel was cut equally out of the frontal and nasal bones. In the group of animals for resection of nasal septum, transverse incision was made through the mucosa between the upper incisors and the lip. The tissues ware elevated from the premaxilla ,entrance was gained into the nasal cavity and nasal septum was resected by means of a grasping forceps. The postoperative survival was five months. The animals were killed by means of ether. Immediately after death, the head was separated from trunk. The heads were then fixed in 10% Formalin far 7 days and cleaned by boiling in a solution of potassium hydroxide. The purpose of this study was to undertaken the growth of the face and jaws after extirpation of frontonasal suture and resection of nasal septum in growing guinea pigs. The results were as follows; 1. In the group of animals with unilateral extirpation of the frontonasal suture, the nasal bones were shorter than that of the control. The growth of the upper facial region, on the other hand, was not affected by unilateral extirpation of the frontonasal suture. 2. Findings of animals with bilateral extirpation of the frontonasal suture were similar to group of animals with unilateral extirpation. 3. In the group of animals with resection of the nasal septum, the upper facial region was shorter and smaller with a severe relative mandibular prognathism. The nasal cavity and piriform aperture were smaller than in the normal animals. The premaxilla and maxilla were smaller. As a result of the shorter upper facial region the upper incisors were lingual to the lower incisors. This was the reverse of the normal findings. A marked downward and forward deflection of the nasal bones was noted.restrictio

하수처리 공정에서 질소제거향상을 위한 SBCOD(Slowly biodegradable chemical oxygen demand) 효과 연구

학위논문(석사) --서울대학교 대학원 :건설환경공학부,2008.2.Maste