Perchlorate is one of the major emerging contaminants of concern and has been found in soil and water systems throughout the United States. Human exposures to perchlorate could occur by ingestion of contaminated water and food as well as by skin contact. Studies show that perchlorate blocks the sodium iodide symporter (NIS) protein in human body, which results in several diseases. It has been demonstrated that perchlorate can be removed by Advanced Reduction Processes (ARPs) that combine chemical reductants (e.g. sulfite) with activating methods (e.g. UV light) in order to produce highly reactive reducing free radicals that are capable of rapid and effective perchlorate reduction. However, other compounds in a real system might inhibit or promote this reduction process. Natural organic matter (NOM) widely exists in the environment and it can absorb UV light, so it has the potential to influence the process of perchlorate reduction by ARPs that use UV light as the activating method. Therefore, batch experiments were conducted to obtain data on the impacts of natural organic matter and light intensity on destruction of perchlorate by the ARPs that use sulfite activated by ultraviolet light produced by low-pressure mercury lamps or KrCl excimer lamps. The results indicate that NOM strongly inhibits perchlorate removal by either the sulfite/UV-KrCl or the sulfite/UV-L ARP, because NOM competes with sulfite for UV light and can possibly scavenge sulfite radicals. Even though the absorbance of sulfite is much higher at UV wavelength of 222 nm than that at 254 nm, the results indicate that a higher portion of perchlorate was removed with the UV-L lamp than with the UV-KrCl lamp. The results of this study will help to develop the proper way to apply the ARPs in a real wastewater treatment plant.

Natural organic matter (NOM) is described as an intricate mixture of organic compounds that occurs universally in ground and surface waters. After treatment for potable use, there is NOM remaining in the water that reacts with the chlorine used for disinfection to form disinfection by-products (DBPs). Some of the DBPs, trihalomethanes (THMs) are regulated. Several water treatment works (WTWs) in the Yorkshire Water and United Utilities (previously North West Water) region in England have recently experienced difficulty in meeting THM limits (100 µg L-1) in their finished drinking water at certain times of the year. An investigation into how NOM changes seasonally, pragmatic methods of NOM analysis and its reactivity with chlorine was undertaken. By separating the NOM using adsorbent resins into fractions, it was possible to gain an insight into the seasonality of NOM. It was observed that a particular, difficult to remove fraction was always more reactive with respect to THM formation in autumn. Some of the methods proposed in the literature were used here with varying successes. It was found that High Performance Size Exclusion Chromatographic methods were most useful to the WTW operators for optimising treatment processes. It is known that the formation of DBPs is very complex. An attempt was made to predict the reactivity of a raw water in terms of THM-FP by looking at the NOM makeup. However, it was found that the fluorescence spectra combined with the fluorescence index of raw water and chlorinated samples gave more insight into the reactivity of the raw water at a particular time than knowing the fraction distribution. The use of fluorescence as a tool for understanding chlorine-NOM reactions is promising.

The treatment of potable water in Vars, ON is accomplished by filtering the colored, iron-laden groundwater through granular activated carbon (GAC) filters. When first installed, these filters unexpectedly experienced chromatographic displacements of iron into the produced water which resulted in orange-brown water at consumers’ taps. The treatment plant was later modified by adding potassium permanganate oxidation and a greensand filter prior to the GAC adsorption columns. Consequently, iron was almost completely removed and no longer caused operational problems. The main objective of this dissertation is to study the interactions between natural organic matter (NOM) and iron that caused the observed chromatographic effect. This study was divided into three main stages: a) characterization study on Vars groundwater and its treatment system; b) study of the competitive adsorption of iron with NOM in Vars groundwater; and c) evaluation of the rapid small-scale column test (RSSCT) for predicting the full-scale GAC column breakthroughs. The characterization of Vars groundwater showed that ferrous iron was found to be the dominant iron species, representing 90% of the total iron, and that 15 - 35% of the iron was complexed with NOM. It was hypothesized that the chromatographic displacement of iron from the GAC columns was caused by NOM-iron complexes; however, field mini-column experiments showed this was not the case. Thus, competitive adsorption between iron and NOM was seen as the more likely cause of the chromatographic effect. The adsorption capacity of ferrous iron in Vars raw water was less than that in organic-free water by a factor of 7 due to the competition with NOM over the GAC adsorbing sites. However, the NOM adsorption capacity was not reduced due to the presence of ferrous iron. It was hypothesized that ideal adsorption solution theory (IAST) models, which have been successful in describing competitive adsorption between target organic compounds and NOM, could model the competition between an inorganic compound such as ferrous iron and NOM. The hypothesis was proved to be correct, and the adsorption isotherm of iron in competition with NOM in Vars groundwater was simulated very well by several versions of the IAST model. However, none of the models were capable of simulating the competitive adsorption of NOM and ferrous iron simultaneously. Since the presence of iron did not significantly reduce the adsorption capacity of NOM, a simplified approach of using the single-solute NOM isotherm to represent the competitive NOM isotherm was recommended. The performance of the rapid small-scale column test (RSSCT) was evaluated in order to simulate the iron chromatographic effect observed at Vars’ full-scale GAC column. The RSSCT was not capable of predicting the iron phenomenon and the test proved to be problematic due to the oxidation and precipitation of iron within the small voids between the small-scale column’s GAC particles. The RSSCT, using constant and linear diffusivities, were applied to simulate the NOM adsorption after greensand treatment. Integrating both diffusivities, the tests predicted the onset and slope of the NOM breakthrough up to 10-L water treated/g GAC, which is equivalent to 250 days of operation time for the full-scale column. However, the NOM breakthroughs deviated beyond that point and the RSSCT using constant diffusivity underestimated the column performance greatly. On the other hand, the linear diffusivity RSSCT underestimated the performance to a lesser degree and its NOM breakthrough was quite parallel to the full-scale performance with lower NOM removals of 15%. The higher long-term NOM removal in the full-scale system may be explained by biodegradation, a phenomenon that was not considered by the short duration of RSSCT.

<P> Natural organic matter (NOM) on the surface of resuspended particles influences the partition of metal ions between free dissolved organic matter (DOM), and the particulate species. It also affects the size distribution of floes under agitation. Equilibrium between dissolved organic and particulate organic matter should, therefore, be an important indicator for predicting metal ion exchange. </p> <p> We examined the exchange of cadmium along a pH edge and compared aqueous, organic, and particulate forms of the metal ion in reactors containing either settled or resuspended sediments. A pH edge profile between 3 and 8 shows two regions of speciation: above and below pH 6.2, which corresponds to a 1 : 1, H : Cd exchange. At low pH, cadmium remains in the free form when sediments are settled, but, upon resuspension, about half of it transfers to the dissolved organic and particulate forms. On the other hand, at high pH, all cadmium is particulate in both cases. In both cases there is also a release of DOM centred at pH 6.2, followed by readsorption at higher pH values. </p> <p> The interesting finding is that cadmium binding on particles appears independent of the surge in DOM, as though cadmium is weakly bound to DOM and strongly bound to particles. We can assume that two types of organic matter exist, one dissolved, one particulate. </p> <p> To fix size distribution, the sediment/metal ion mixture was put in a Couette flocculator and subjected to a uniform shear stress. Then, the partitioning of the metal ions between the solution and sediment phases was determined. A distribution coefficient, KD was calculated for each metal ion. A correlation between log KD and log K (hydrolysis constant) was apparent, and our data was consistent with the reported metal ion binding to both sediments and artificial surfaces. We envision that organic matter accumulating on the particle creates a polyelectrolyte domain responsible for greater binding capacity. We propose that an increase in metal ion binding with increasing particle size is due to this polyelectrolyte effect, where binding is governed by particle volume, and not surface area. </p> / Thesis / Master of Science (MSc)

In recent years, stringent world-wide regulation of copper in drinking water, wastewater discharge and sludge has prompted utilities to carefully evaluate copper sources and sinks, benefits and detriments, and mitigation. This work compiled the individual efforts of researchers and utilities to provide a basis for holistic decision-making. Mass balances suggest that between 14-61% of copper in wastewater originates from home plumbing. Dosing of pure copper sulfate "root killer" by consumers, which is of unlikely value, accounted for up to 27% of copper inputs. Removal of copper in wastewater treatment ranged from 24-90%, suggesting a potential for optimization of these processes if desired. Finally, though utilities are pressured to reduce copper inputs at all stages of the urban water cycle, substantial benefits including human and wastewater bacteria micro-nutrition, water disinfection and algae control should not be overshadowed. To better understand copper inputs from corrosion in soft waters, a 12 month study was executed. Free chlorine (0.7 mg/L) was determined to have minimally adverse effects on copper release at pH 9.5 but no significant effect at pH 7.0, and higher temperatures usually increased copper release. Organic matter including soluble and particulate NOM, sodium alginate, and gum xanthan, tended to worsen copper release. Their direct effects included complexation and mobilization of pre-existing copper scale as particulates. Indirect effects were also discovered, including a propensity of gum xanthan and alginate to decrease pH, increasing copper release, and also to produce a microbiologically unstable water, decreasing the dissolved oxygen necessary for fueling corrosion reactions. The range of organic matter effects could be placed within a unified conceptual framework. / Master of Science

Texte remanié de: Thèse--Histoire contemporaine--Paris 4, 2004. Titre de soutenance : Naissance et vie d'une congrégation religieuse entre 1800 et 1950, le Saint-Nom de Jésus. / Contient un choix de documents. Bibliogr. p. 507-523.

Fluoride naturally occurs in some ground and surface waters at high concentrations all around the world. Due to increasing health concerns about over-exposure to fluoride in drinking water, the United States Environmental Protection Agency (USEPA) has begun to review fluoride as a drinking water contaminant. Should the USEPA decide to lower the fluoride maximum contaminant limit (MCL), many water systems in addition to those already struggling to meet the fluoride MCL will require defluoridation as part of their drinking water treatment process. Alum coagulation was investigated as a defluoridation treatment strategy in this research project. Surface and blended (ground/surface) drinking water sources with high fluoride concentrations pose a unique challenge to defluoridation by alum coagulation because of the presence of both natural organic matter (NOM) and fluoride. Defluoridation of synthetic and natural waters using jar tests elucidated interactions of fluoride, NOM, and aluminum during alum coagulation. Alum coagulation was able to remove 80% of fluoride from natural waters with a 500 mg/L alum dose; however, 50% fluoride removal was observed to be possible with an alum dose of 150-170 mg/L. The optimum pH for fluoride removal in synthetic and natural waters was observed to be approximately 6.5 and was found to be an important factor in determining the overall performance of alum coagulation. The presence of fluoride during alum coagulation was found to reduce the removal of three low molecular weight (LMW) organics, acting as surrogates for NOM, to different extents depending on their functionality. The presence of LMW organic acids in synthetic waters did not impact the removal of fluoride; however, increasing NOM concentrations in the natural waters likely accounted for decreasing fluoride removals observed in the natural waters. Additional jar tests with natural waters revealed that pH adjustment was unnecessary for defluoridation of high pH and high alkalinity waters and that an enhanced precipitation effect occurred at low alum doses when no pH adjustment was made during alum coagulation. The enhanced precipitation effect caused comparable or enhanced removals of fluoride and NOM to be observed despite system pH values being higher than the optimal defluoridation pH of 6.5. Lower aluminum residuals were also observed as part of the enhanced precipitation effect, suggesting that when precipitation begins under high pH conditions, fluoride interference does not occur and therefore promotes more precipitate formation with greater available surface area for adsorption. However, as precipitation occurs, pH drops, and fluoride increasingly interacts with the aluminum precipitate resulting in greater overall fluoride removals. / text

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

La politique de ce travail de thèse est la démonstration d'une conception structurale (Autre dans l'Un) et borroméenne (Un dans l'Autre) des psychoses selon deux axes : La barrière épistémo-somatique de la psychiatrie : abstraction psychologique de la pensée consciente et manifestation naturaliste du corps propre. Le sujet cartésien est appréhendé en fonction d'un manque-à-être et d'un manque-à-avoir. Cette dichotomie Imaginaire, cette méconnaissance narcissique a été exploitée afin de distinguer les psychoses selon la signification (paranoïa classique et schizophrénie) et celles selon l'incorporation (sadomasochisme et paraphrénie). Considérer la continuité de la jouissance, de l'Un, et mesurer comment la discontinuité de l'Autre opère pour en réguler le flot. Cette régulation est spécifique à la psychose, la névrose ou la perversion. Les éléments structuraux distingués des éléments Imaginaires permettent d'accéder à une clinique orientée par les formules de la sexuation.Le matériel clinique classique des paranoïas et des mélancolies, selon la signification et l'incorporation, a donc été exploité selon ces deux axes et envisagé à la lumière du matériel psychanalytique de Freud et Lacan. Les concepts cruciaux de forclusion du Nom-du-Père, celle du sens, et surtout l'objet a. Il se présente comme extrait mais non-séparé (a) pour les psychoses schizoparaphréniques ou non-extrait (ao) pour les psychoses paranoïaques.La thèse débouchera sur la pertinence de la clinique borroméenne et du sinthome plus engagé vers l'Un. C'est toute une clinique du nouage et de la contingence qui reste à envisager. Une appréhension de la singularité clinique et pratique du sujet psychotique en dépend. / The policy of this thesis work is demonstrating a structural design and borromeenne of the psychoses according to two dimensions : The epistemo-somatic barrier of psychiatry : psychological abstraction of conscious thought and naturalistic expression of the own body. The Cartesian subject is apprehended as a function of a lack-to-be and a lack-to-have. This imaginary dichotomy, this narcissistic ignorance has been exploited in order to distinguish the psychosis according the meaning (classic paranoia and schizophrenia) and those according to the incorporation (sadomasochism and paraphrenia). Consider the continuity of the enjoyment of the One, and measure how the discontinuity of the other operates to regulate the flow. This regulation is specific to psychosis, neurosis or perversion. The structural elements distinguished from imaginary elements allow you to access to a clinic guided by the formulas of sexuation. The classic clinical material of paranoias and melancholies, depending on the meaning and incorporation, has therefore developed according to these two issues and considered in the light of the psychoanalytic material of Freud and Lacan. The crucial concepts of foreclosure du Nom-du-Père, that of the meaning, and especially the object has. It looks like extracted but non-separated for psychosis schizoparaphreniques or unextracted for paranoid psychosis. This thesis work will lead to the relevance of the borromeenne clinic and the sinthome more committed towards the One. It is a clinic of the knot and the contingency which remains to consider. Apprehension of the singularity clinical and practical of the psychotic subject depends on it.

Ce mémoire porte sur le problème de la catégorisation des éléments linguistiques en langue des signes québécoise (LSQ), plus particulièrement sur la distinction entre le nom et le verbe par l'entremise de paires composées d'un nom et d'un verbe dont le sens et la forme sont reliés. Deux types de paires nom/verbe ont été décrits: le premier est constitué d'éléments dont la forme se distingue par deux caractéristiques temporelles du mouvement: la longueur et la répétition. La distinction présente dans le mouvement de ces paires tend toutefois à se perdre en contexte. Cela a pour effet que les noms et les verbes sont susceptibles d'avoir la même forme phonologique en contexte sans que la valeur nominale ou verbale de l'élément ne soit affectée. Le deuxième type de paire est constitué d'éléments dont la forme est identique en forme de citation et en contexte. L'objectif de ce mémoire vise à décrire le mouvement des noms et des verbes de la LSQ, ainsi que le contexte dans lequel ils se trouvent afin de proposer une série de caractéristiques permettant de distinguer le nom du verbe en contexte en LSQ dans le but de déterminer quel type de propriétés (formelles ou morphosyntaxiques) permettent de déterminer la catégorie (nom ou verbe) à laquelle appartient un signe. Afin d'y parvenir, deux types de corpus de la LSQ ont été analysés. Le premier est constitué de donées élicitées (en forme de citation et dans le contexte d'une phrase) auprès de sept participants sourds. Le deuxième est constitué de productions naturelles d'un signeur sourd tirées d'une entrevue publique menée en LSQ. Les résultats obtenus montrent que le mouvement des noms et des verbes en contexte est sujet à la variation et que la longueur et la répétition du mouvement ne constituent pas des critères qui permettent de les distinguer. De plus, nous avons montré que le mouvement des noms et des verbes en forme de citation est lui aussi sujet à la variation. Nous avons proposé, à l'instar de Bouchard et al. (2005), qu'il est possible d'utiliser les caractéristiques morphosyntaxiques suivantes afin de déterminer si l'élément dessert une fonction nominale ou verbale: l'utilisation de l'espace, la présence du marqueur possessif POSS., de la négation el de l'aspect. De plus, nous avons identifié les caractéristiques distinctives suivantes: l'emploi d'une préposition ou d'un adjectif numéral devant un signe permet d'identifier celui-ci en tant que nom, et la juxtaposition du nom et du verbe d'une paire nom/verbe dont les éléments sont sémantiquement et formellement reliés permet d'identifier la catégorie de chacun. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Langue des signes québécoise, Catégorisation, Nom, Verbe.