Avloppsreningsanläggningar är idag utformade för att rena bort föroreningar i form av organiskt material, suspenderade fasta ämnen och växtnäringsämnen (exempelvis fosfater och nitrater). Myndighet i Sverige har satt upp restriktioner och lagar gällande hur mycket av de olika föroreningarna som det är okej att utgående vatten innehåller. En typ av föroreningar som dock inte blivit undersökt och som inte har lika tydliga restriktioner och utsläppslagar är utsläpp av läkemedelsrester och aktiva läkemedelssubstanser. Den största andelen av läkemedelsrester som återfinns i avloppsvatten är på grund av mänsklig konsumtion. Människan har under evolutionen alltid strävat efter att hitta nya metoder för att leva längre, må bra och undvika smärta. Under de senaste årtiondena har konsumtionen av läkemedel ökat, detta på grund av behandling av åldersrelaterade och kroniska sjukdomar, i kombination med en ändrad och mer generös receptutskrivning från sjukhusen.  Läkemedlen som vi konsumerar kommer inte att brytas ner helt av våra kroppar, och restprodukterna kommer utsöndras vida urinen. Urinen kommer sedan, vi avloppen, komma till ett av de lokala avloppsreningsverken, som idag inte har förmåga att rena bort de aktiva läkemedelssubstanserna från vattnet. Det kommer sedan att påverka omgivande vattendrag, djurliv och på lång sikt även ekosystemen.  Tidigare studier har genomförts med syfte att hitta miljövänliga och hållbara metoder för att rena vattnet från mikroföroreningar och läkemedelsrester. En av teknikerna som undersökts är oxidation och adsorption processer. Ett sätt att genomföra oxidation är genom ozonering, som genom sin höga oxidationspotential och miljövänliga slutprodukter i form av bland annat syre gör den till ett miljövänligt alternativ. Vad gäller adsorption processer så är aktivt kol en av de vanligaste teknikerna som används idag och det har visat på goda resultat. Ett vanligt förekommande problem med aktiva kolfilter är att det måste bytas ut när det blivit mättade vilket både kostar pengar, arbetskostnader och en avstannad vattenprocess.  Denna avhandling behandlar utvärdering och process optimering av vattenrening vid behandling av ozon med avseende att rena vatten från aktiva läkemedelssubstanser. För att göra detta har två pilotanläggningar för vattenrening, placerade på två olika platser i Sverige (plats 1 och plats 2) undersökts och optimerats. Båda systemen är utrustade med ett sandfiltersteg, ozonerigssteg anst ett avslutade poleringssteg i form av aktivkolbädd. De två olika systemen är kopplade så inkommande vatten är utgående vatten från likat avloppsreningsverk. Undersökta variabler är injicerad ozonhalt (uteffekt baserat på ozongeneratorns kapacitet) och i ett av fallen, vattenflödet genom systemet. Syftet med arbetet var att hitta optimala driftförhållande med avseende på reducerad mängd läkemedelssubstanser i vatten och energiförbrukning.  Resultaten visade att den parameter som influerade resultatet mest var mängden ozon som injicerades till systemet. Systemet som var installerat på plats 2 var det mest effektiva baserat på både energiförbrukning per m3 vatten och med avseende på reningsgraden på vattnet. Systemet rena vattnet från läkemedelssubstanser upp till mellan 95–100%, vid ett vattenflöde på 16 m3/h och en uteffekt av ozongeneratorn på 75%.  Systemet på plats 1 hade en halverad ozonkapacitet jämfört med systemet på plats 2 och visade inte på fullt lika effektiv rening. Vattnet som bäst renat till 80%, vid ett vattenflöde på 2,5 m3/h och en uteffekt av ozongeneratorn på 100% (motsvarar 50% på plats 2). / Wastewater treatment plants today are designed to reduce pollutants in the form of organic material, suspended solids, plant nutrients (phosphates and nitrates) and microbes from the water. Governments have set up restrictions and laws around in what amount release of different pollutants is acceptable or not. But one type of pollutant that have not been investigated to the same degree is the micropollutants such as pharmaceuticals or active pharmaceutical ingredients (APIs). The biggest amount of APIs release to water is due to human consumption of medicine. Humans have during the evolution strived to find new ways to live longer, stay healthier and avoid pain. Over the last decade there has been an increased consumption of medicine, due to the need to treated ageing related and chronic diseases, together with a change in the clinical practice leading to a more generous prescription approach.  The APIs that we consume will not be totally decomposed in our body, which means that we sooner or later will exude it in form of example urine. The urine will end up in the local WWTP, which today, does not have the ability to reduce APIs in large amount. Due to this, release of APIs to surrounding watercourse will come to affect the animals and eco-system.  Many studies have been done with a goal to find an environmentally friendly way to reduce micropollutants from the wastewater. One of the techniques that has been investigated is oxidation (e.g., ozonation) and adsorption (e.g., activated carbon) processes. Ozonation is an ideal technique due to the high oxidation potential of ozone, environmentally friendly end-products (e.g. oxygen) and low sludge production. Several reports elucidated that application of ozonation for wastewater can have a reducing effect of APIs, and a more studied technique for removal of micropollutants and APIs is activated carbon (AC). But AC has some common struggle, one example is that it works as a filter and that it due to adsorption can be saturated.  The project contained evaluation and process optimization of water purification by oxidation with ozone with aim to purifying water from APIs. To do this, two pilot plants for water purification, located in two different locations in Sweden (location 1 and location 2) will be evaluated and optimized. Both systems are equipped with a sand filter, ozonation step and a polishing step of activated carbon. The two different systems are connected so that incoming water to the system, is outgoing water from a local wastewater treatment plant. The variables evaluated are injected ozone concentration (output power based on the capacity of the ozone generator) and in one of the cases, the water flow through the system. The purpose of the work was to find optimal operating conditions regarding reduced amount of drug substances in water and energy consumption.  The system installed at location 2 is the most effective system from a perspective of both micropollutants reduced and energy used per m3. The API reduction is between 95-100% for the outgoing water and the ozonation step stands for 95-100% of that reduction, which increases the lifetime of the GAC filter. For optimal process settings a water flow of 16 m3/h and an out effect of 75% from the ozone generator was determined.  At location 1 the APIs reduction achieved was 80% after ozonation and 100% after the GAC filtration, and the process settings were 100% out effect (correspond to 50% at location 2) on the ozone generator and a water flow of 2.5 m3/h.

Polychlorinated biphenyls (PCBs) are toxic and persistent chemicals that have been largely dispersed into the environment. The biological and abiotic transformations of PCBs often generate hydroxylated derivatives, which have been detected in a variety of environmental samples, including animal tissues and feces, water, and sediments. Because of their toxicity and widespread dispersion in the environment, hydroxylated PCBs (OH-PCBs) are today increasingly considered as a new class of environmental contaminants. Although PCBs are known to be susceptible to microbial degradation under both aerobic and anaerobic conditions, bacterial degradation of OH-PCBs has received little attention. The overall objective of this study is therefore to evaluate the transformation of mono-hydroxylated PCBs by the well characterized aerobic PCB-degrading bacterium, Burkholderia xenovorans LB400. In order to achieve our overall objective, a series of model mono-hydroxylated PCBs have been selected and they are used to determine the toxicity of hydroxylated congeners toward the bacterium B. xenovorans LB400. The biodegradation kinetics and metabolic pathways of the selected OH-PCBs by B. xenovorans LB400 are then characterized using GC/MS. To understand further the molecular basis of the metabolism of OH-PCBs by B. xenovorans LB400, gene expression analyses are conducted using reverse-transcription real-time (quantitative) polymerase chain reaction (RT-qPCR) and microarray technology. More formally, the specific aims of the proposed research are stated as follows: (1) To evaluate the toxicity of selected mono-hydroxylated derivatives of lesser-chlorinated PCBs toward the bacterium B. xenovorans LB400. (2) To assess the degradation of the selected OH-PCBs by B. xenovorans LB400. (3) To gain further understanding of the molecular bases of the metabolism of the selected OH-PCBs by B. xenovorans LB400. Three hydroxylated derivatives of 4-chlorobiphenyl and 2,5-dichlorobiphenyl, including 2'-hydroxy-, 3'-hydroxy-, and 4'-hydroxy- congeners, were significantly transformed by Burkholderia xenovorans LB400 when the bacterium was growing on biphenyl (biphenyl pathway-inducing conditions). On the contrary, only 2'-OH-4-chlorobiphenyl and 2'-OH-2,5-dichlorobiphenyl were transformed by the bacterium growing on succinate (conditions non-inductive of the biphenyl pathway). Gene expression analyses showed that only exposure to 2'-OH-4-chlorobiphenyl and 2'-OH-2,5-dichlorobiphneyl resulted in induction of key genes of the biphenyl pathway, when cells grown on succinate. These observations suggest that 2'OH-PCBs were capable of inducing the genes of biphenyl pathway. These results provide the first evidence that bacteria are able to cometabolize PCB derivatives hydroxylated on the non-chlorinated ring. Genome-wide transcriptional analyses using microarrays showed that 134 genes were differentially expressed in cells exposed to biphenyl, 2,5-dichlorobiphenyl, and 2'-OH-2,5-dichlorobiphneyl as compared to non-exposed cells. A significant proportion of differentially expressed genes were simultaneously expressed or down regulated by exposure to the three target compounds i.e., biphenyl, 2,5-DCB, and 2'-OH-2,5-DCB, which suggests that these structurally similar compounds induce similar transcriptional response of B.xenovorans LB400. Results of this study may have important implications for the natural attenuation of PCBs and fate of OH-PCBs in the environment. The recalcitrance to biodegradation and the high toxicity of some OH-PCBs may provide a partial explanation for the persistence of PCBs in the environment. / Civil Engineering

The objectives of this study were to determine: (1) whether or not heterotrophic microorganisms exert an effect on the trihalomethane (THM) or total organic halogen (TOX) formation potentials of algal extracellular products (ECP), and (2) whether or not diurnal cycling of THM and TOX precursors occurs in vitro. These objectives were addressed through culture studies of heterotrophic microorganisms and pure algae from both the green and blue-green divisions. Culture conditions were varied to study different aspects of algal and bacterial interactions. Results from continuous light assays indicated that heterotrophs, grown in the same culture vessel with algae, affected an increase in the potential of chlorinated culture filtrate to form THMs. No significant changes in TOX-formation potential were observed. Heterotrophs grown in volumes of algal ECP (cell-free filtrates of algal cultures) used the algal-produced organic carbon as their sole carbon source. These microorganisms further reduced both the dissolved organic carbon (DOC) concentration and the concentration of the DOC fraction that reacted to form TOXs. The fraction which produced THMs was not reduced. Heterotrophic microorganism metabolic activity increased the rate at which THMs fanned from chlorinated algal ECP but did not alter the seven-day THM-formation potentials. Their activity also increased the initial rate of TOX formation, but decreased the seven-day formation potential of these compounds. Attempts to demonstrate diurnal cycling of the concentration of THM precursors and other halogenated organic precursors, a phenomenon previously demonstrated in a eutrophic reservoir, were unsuccessful. / M.S.

[EN] The contamination of water resources with many industrial, agricultural and other chemicals is one of the key environmental problems that humanity is facing nowadays. Despite the fact that they are usually present at very low concentration, they possess a significant risk to aquatic and human life. To address this issue many national and international institutions set different regulations to monitor and control the water quality. Currently, the monitoring of compounds included in official watch lists is conducted by chromatographic and mass spectroscopic methods. These techniques are approved as "gold standards" for analytical quantitation of organic residues in water. Although they are sensitive and reproducible, cannot be used on-site. The need of sampling and centralized laboratory measurements makes not only the overall cost high but lowering the efficiency of the analysis. Therefore, there is an urgent need to develop suitable field methods to facilitate the in situ measurements at a low cost. Biosensors are therefore an alternative technology that can provide sensitive results in a fast and affordable way. This thesis has focused on the development of a biosensor based on immunoassays and compact disk technology, for the multiplex detection of priority water contaminants. As the methods based on the immunorecognition events are challenging in terms of the selectivity and sensitivity, the major part of the thesis was the selection of the immunoreagents, assay form and procedure. For the detection part, gold nanostructures were selected as sensitive tags for signal enhancement. Therefore, different nanoparticles were studied in order to select the optimal size in terms of the signal enhancement, sensitivity and antibody amount used. Also, the assays performances with signal enhancement and without any amplification were evaluated. The best immunoassay was selected for developing the multiplexed assay. Furthermore, an approach to improve the readout sensitivity of microimmunoassays based on used of gold nanoparticles as both capture and detection species was demonstrated. The method is based on the performance of the immunorecognition event in a homogeneous mode and detection part in the heterogeneous format. Finally, representative water samples were analysed to confirm the applicability of the multi-residue assay. The analytical properties have been established for each methodology and the obtained results have been validated by comparison with reference techniques. The investigations carried out in this work, have resulted in new insights in immunoassay technique that could be useful for screening applications. / [ES] La contaminación de aguas superficiales causada por plaguicidas y productos industriales es actualmente, uno de los grandes problemas medioambientales. Aunque estas sustancias están presentes a niveles muy bajos, tienen efectos perjudiciales en el medio en general y especialmente en humanos. Por este motivo, diferentes instituciones han regulado los niveles de contaminantes en áreas de controlar de la calidad de las aguas, creando listas prioritarias de sustancias peligrosas y tóxicas para el medio ambiente. Actualmente, la monitorización de los contaminantes incluidos en las listas oficiales se realiza mediante técnicas cromatográficas y espectrometría. Estos métodos analíticos están aprobados como técnicas de referencia para la determinación de residuos orgánicos presentes en aguas naturales. A pesar de ser técnicas fiables, reproducibles y sensibles, los métodos cromatográficos no están exentos de inconvenientes. Este tipo de metodologías requiere una instrumentación costosa y una laboriosa preparación de muestra, que hacen que el análisis sea en general complejo. Por ello, el desarrollo de métodos analíticos alternativos que faciliten hacer medidas in-situ a bajo coste y con gran capacidad de trabajo es de gran utilidad. En este sentido, las técnicas inmunoquímicas tienen un gran potencial analítico ya que son en general sensibles y selectivas, se pueden utilizar en el lugar de la toma de muestra y tienen capacidad multianalito. Esta tesis se ha centrado en el desarrollo de un sistema biosensor, basado en la tecnología de disco compacto, para la detección multianalito de diversos contaminantes prioritarios en aguas naturales. Las limitaciones más críticas para el desarrollo de un biosensor multianalito mediante métodos inmunoquímicos son los relacionados con su sensibilidad y selectividad. Por lo tanto, una parte importante de la tesis se ha centrado en la selección de inmunoreactivos, formato y optimización de diferentes parámetros claves del ensayo. Una estrategia utilizada para aumentar la sensibilidad de los ensayos ha consistido en marcar la inmunoreacción con nanopartículas de oro. Para ello, se ha estudiado diferentes tipos (esféricas y cilíndricas) de distinto tamaño y se han comparado sus prestaciones analíticas (relación señal ruido, sensibilidad etc.) También, se han desarrollado inmunoensayos cuantitativos sin necesidad de amplificación de la señal. Por otro lado, se ha desarrollado una aproximación que hemos denominado "inmunocaptura" basada en el uso de nanopartículas de oro como especie de captura de analitos en disolución y que actúa como marcador de la inmunointeracción que tiene lugar en la fase sólida. Finalmente, se han analizado muestras de agua naturales dopadas con distintos niveles de los analitos objeto de estudio para evaluar la utilidad de las metodologías desarrolladas como herramienta de screening masivo en el área medioambiental. Los resultados obtenidos han sido comparados con los obtenidos mediante las técnicas de referencia. Las investigaciones realizadas han permitido desarrollar nuevos formatos de ensayo y conocimientos inmunoquímicos aplicados a la tecnología de disco compacto, aportando nuevas herramientas de screening que permiten la determinación simultánea de contaminantes en aguas naturales por debajo de las concentraciones establecidas en la normativa europea de calidad de agua. / [CA] La contaminació d'aigües superficials causada principalment per plaguicides i altres productes industrials és un dels grans problemes mediambientals actuals. Malgrat que aquestes substàncies estan presents en nivells molt baixos, tenen efectes perjudicials en humans i animals. Per aquest motiu, diferents institucions estatals han regulat els nivells de contaminants en àrees de control de la qualitat de l'aigua, creant llistes prioritàries de substàncies perilloses i tòxiques per al medi ambient. Actualment, la monitorització dels contaminants inclosos en les llistes oficials es realitza mitjançant tècniques cromatogràfiques i d'espectroscòpia de masses. Aquests mètodes analítics estan aprovats com a tècniques de referència per a la determinació de residus orgànics presents en aigües naturals. Malgrat ser tècniques fiables, reproduïbles i sensibles, els mètodes cromatogràfics no estan exempts d'inconvenients. Aquest tipus de metodologies requereix una instrumentació costosa i una laboriosa preparació de mostres que fan que l'anàlisi sigui, en general, complex. Per això, el desenvolupament de mètodes analítics alternatius que facilitin la possibilitat de fer mesures in-situ a baix cost i amb gran capacitat analítica és de gran utilitat. En aquest sentit, les tècniques inmunoquímiques tenen un gran potencial analític ja que són, en general, sensibles i selectives, es poden utilitzar en el lloc de presa de la mostra i tenen capacitat multianalit. Aquesta tesi s'ha centrat en el desenvolupament d'un sistema biosensor, basat en la tecnologia de disc compacte, per a la detecció multianalit de diversos contaminants prioritaris en aigües naturals. Les limitacions més crítiques per al desenvolupament d'un biosensor multianalit mitjançant mètodes inmunoquímics són sensibilitat i selectivitat. Per tant, una part important de la tesi es va centrar en la selecció de inmunoreactius, format i optimització de diferents paràmetres clau de l'assaig. La detecció es va dur a terme mitjançant l'ús de nanopartícules d'or com a marcadors de la inmunointeracció i amplificació de la senyal analítica. S'han estudiat diferents estructures d'or (esferes i cilindres) de diferents tamanys, i s'han comparat les seves prestacions analítiques (relació senyal-soroll, sensibilitat, etc.). També s'han desenvolupat immunoassaigs quantitatius sense necessitat d'amplificació del senyal. Per altra banda, s'ha desenvolupat una aproximació que hem denominat "inmunocaptura", basada en l'ús de nanopartícules d'or com a espècie de captura d'analits en dissolució i que actua com a marcador de la inmunointeracció que té lloc en la fase sòlida. Finalment, s'han analitzat mostres d'aigües naturals dopades amb diferents nivells dels analits objecte d'estudi per avaluar la utilitat de les metodologies desenvolupades com a eina de "screening" massiu en l'àrea mediambiental. Els resultats obtinguts han sigut avaluats per comparació amb els obtinguts mitjançant tècniques de referència. Les investigacions realitzades han permès desenvolupar nous formats d'assaig i coneixements inmunoquímics aplicats a la tecnologia de disc compacte, aportant noves eines de "screening" que permetin la determinació de contaminants en aigües naturals per sota dels límits de concentració establerts per les normes internacionals de la qualitat de l'aigua. / Dobosz, PD. (2017). Screening methodologies for the determination of water contaminant residues by compact disk technology [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/79548

Water pollution is a growing concern for mankind due to its harmful effects on humans, animals and plants. Usually, several pollutants are present in wastewater. For example, dyes and antibiotics are found in wastewater because of their widespread use in factories and hospitals. However, one single technique, e.g. either adsorption or photocatalysis, cannot easily remove more than one kind of pollutant, especially by using one single material in water. For this reason, here multifunctional iron(II,III) oxide/poly(N-isopropylacrylamide-co-methacrylic acid)/silver-titanium dioxide (Fe₃O₄/P(NIPAM-co-MAA)/Ag–TiO₂) nanocomposites were used to remove a mixture of pollutants from water. Specifically, three types of experiments were performed to evaluate the adsorption capacity and photodegradation activity of the nanocomposites towards the dye basic fuchsin (BF) and the antibiotic ciprofloxacin (CIP), which were added sequentially to the nanocomposites dispersion or were concurrently present as a mixture. The results demonstrated that the nanocomposites could adsorb BF, and subsequently photodegrade CIP under visible-light irradiation, if BF was the first added pollutant. As well, the nanocomposites could first degrade CIP under visible-light irradiation, and then adsorb BF if they were initially put in contact with CIP. Finally, the ability of adsorbing BF and photodegrading CIP was confirmed in the co-presence of the two pollutants.

This thesis presents the development of a numerical model for one-dimensional pollutant transport in a porous medium. A computer program POLUTE1D has been developed. The numerical model is based on the flow and mass transport equations and the finite element method has been used for its formulation. The problem involves unsaturated flow and convective dispersive transport of a contaminant species. A literature survey on the evaluation of the dispersion coefficient is included. A waste disposal dump site is analysed as a one-dimensional problem by using this model. The effect of the liner thickness, the liner permeability, the ponding head and the initial condition of the porous domain on the spread of the contaminant is studied. Conclusions are presented based on a parametric study. / M. Eng.

The relationships between contaminant removal from impervious pavements and raindrop impact energy, cumulative kinetic energy of rainfall events, and rainwater fit were evaluated. A commercial urban area was chosen to perform simulated rainfall experiments. The runoff from these experiments was collected and analyzed for total suspended solids, volatile suspended solids, total Kjeldahl nitrogen, soluble Kjeldahl nitrogen, oxidized nitrogen, ammonia, ortho-phosphate, total phosphorus, soluble phosphorus, total lead and total zinc. Raindrop impact energy, rainfall intensity, rainfall duration, and rainwater pH were factors which were varied to examine their effect on contaminant wash-off phenomena. The present exponential decay theory of contaminant removal was verified and modified to incorporate the cumulative kinetic energy of rainfall events. An empirical model for contaminant removal was also developed. Data showed that both raindrop impact energy and cumulative storm energy had significant effects on contaminant removal. Contaminant wash-off was found to be independent of rainwater pH except for solids removal at low rain intensities. Additional results indicated that there is a "threshold impact energy" necessary before significant removal of contaminants associated with insoluble material can occur. The kinetic energy attributed to surface runoff overflow was found to be very important in the mechanisms responsible for contaminant removal at high rainfall intensities. / M.S.

The molecular size, charge, and solubility, distributions of natural DOC in raw and treated surface waters were investigated to determine the types of organic compounds removed by coagulation and settling. The distribution of organic precursors that react with chlorine to form organic halide compounds was also determined, along with the reaction rates. DOC removal by coagulation was size dependent. Compounds over 5,000 d were readily removed while compounds under 1,000 d were largely unaffected. Acidic and basic molecules were precipitated much more effectively than neutral ones. Both hydrophilic and hydrophobic molecules were selectively removed compared to compounds of intermediate solubility. Two groups of organic halide precursors were identified. Fulvic acids had high specific organic halide yields, and fast reaction rates with chlorine, but could be effectively removed by coagulation. Nonpolar neutral compounds were lower in molecular weight, slower to react with chlorine, and produced less organic halide, but could not be precipitated by coagulation. / Ph. D. / incomplete_metadata

Das Sächsische Landesamt für Umwelt, Landwirtschaft und Geologie analysiert seit 1992 jährlich die Schadstoffbelastung der Fische in den sächsischen Fließgewässern. Im Herbst 2010 wurden jeweils 20 Fische aus der Zwickauer und Freiberger Mulde sowie 100 Fische aus der Elbe entnommen. Trotz des höheren Lebensalters der untersuchten Fische im Vergleich zu den Vorjahren waren die Schadstoffkonzentrationen nicht oder nur wenig erhöht. Zu Überschreitungen der zulässigen Höchstwerte kommt es nur in Ausnahmefällen - das betrifft besonders große und damit ältere Exemplare der Fischarten Rapfen, Zander, Barbe und Döbel. Bei älteren Rapfen gemessene Quecksilberkonzentrationen überschritten beispielsweise die zulässige Höchstmenge teilweise um das Doppelte. Ebenfalls untersuchte Lebern von 19 größeren Fischen wiesen in der Mehrzahl zu hohe Werte an Dichlordiphenyltrichlorethan und Hexachlorbenzol auf. Die Messergebnisse bei anderen chlorierten Kohlenwasserstoffen und Cadmium lagen dagegen wie schon in den zurückliegenden Jahren auf niedrigem Niveau.

Der übermäßige Einsatz insbesondere mineralischer Dünger in der Landwirtschaft trägt signifikant zu deren negativen globalen Umweltauswirkungen bei. Aus diesem Grund werden innovative Technologien benötigt, um Nährstoffe aus alternativen Quellen, bspw. aus häuslichem Abwasser, zurückzugewinnen. Insbesondere das stickstoffreiche Zentrat, welches klärwerksintern rezirkuliert wird, bietet ein hohes Rückgewinnungspotential. Durch gesteigerte Effizienz in der Nährstoff- und Wassernutzung kann zudem die Etablierung hydroponischer Kultivierungsysteme für die Nahrungsmittelproduktion zur nachhaltigen Transformation der Landwirtschaft beitragen. Jedoch stellt die Verwendung von Abwasser als Nährstoffquelle insbesondere in hydroponischen Systemen durch abwasserinhärente Kontaminanten ein Risiko für die Nahrungsmittelproduktion dar. Der Fokus dieses Dissertationprojekts lag daher auf der Untersuchung potenziell pflanzenverfügbarer polarer organischer Spurenstoffe, Metalle und Metalloide in einem Prozess zur Nährstoffrückgewinnung aus Zentrat. Die im Rahmen dieser Dissertation durchgeführten Studien, untersuchten (I)~pflanzenverfügbare Spurenstoffe im Zentrat einer örtlichen kommunalen Kläranlage, (II)~die Spurenstoffentfernung in einem zweistufigen System, bestehend aus einem Membranbioreaktor (MBR) und einer Elektrodialyse (ED), das für die Nährstoffrückgewinnung aus dem Zentrat konzipiert war, und (III)~einen möglichen Ansatz zur Optimierung der Entfernung von Spurenstoffen in der ED. Die Untersuchung des Zentrats zeigte, dass die Konzentrationen einiger organischer Spurenstoffe im Zentrat höher waren als im Ablauf und sogar im Zulauf der Kläranlage. Für die Industriechemikalie Benzotriazol sowie das Arzneimittel Valsartan wurden dabei die höchsten durchschnittlichen Konzentrationen von 80 µg/L bzw. 60 µg/L ermittelt. Unter den Schwermetallen zeigten Zn und Ni die höchsten Konzentrationen mit etwa 50 µg/L bzw. 20 µg/L. Insgesamt unterlag die Konzentration der organischen Spurenstoffen einer bemerkenswert geringen zeitlichen Fluktuation. So zeigte die Konzentration einer Gruppe von Spurenstoffen mit geringerer Polarität eine relative Standardabweichung von nur 7~\% bei täglicher Probenahme über einen dreiwöchigen Zeitraum. Die Studie zeigte jedoch auch, dass Veränderungen in den Betriebsparametern des Entwässerungsprozesses auch kurzfristige Fluktuationen der Spurenstoffkonzentration im Zentrat zur Folge haben. Während der Nährstoffrückgewinnung aus Zentrat, zeigte der zweistufige Prozess, bestehend aus MBR und ED, Eliminationsraten von mehr als 90 % für 21 der dabei untersuchten 22 organischen Spurenstoffe und sechs der neun untersuchten Metalle. Durch die Kombination beider Prozessschritte war das System auch unempfindlich gegenüber Schwankungen in der Entfernungsleistung des MBR. So konnte eine vorübergehende Reduktion der MBR Entfernungsleistung für Carbamazepin um 87 % durch die ED ausgeglichen werden, sodass die resultierende Entfernungsleistung im Gesamtsysten nur um 6 % abnahm. Diese Redundanz in der Entfernung durch beide Prozessschritte wurde hauptsächlich für neutrale Stoffe beobachtet und wirkte auf ionische Verbindungen in geringerem Maße. Deshalb wurde untersucht, ob die Entfernung ionischer Verbindungen in der ED durch eine Anpassung des pH in deren Zulauf gesteigert werden kann. Da die Entfernung neutraler Moleküle in der ED höher ist, sollten durch die pH Anpassung die ionisierbaren Verbindungen in den neutralen Protonierungszustand überführt werden, um deren Entfernung zu erhöhen. Entgegen der Erwartung konnte die Retention keiner der ionisierbaren Moleküle durch diesen Ansatz verbessert werden. Über einen zweiten Ansatz sollte durch die Erhöhung der Stromstärkedichte, über den Grenzstromfluss hinaus, eine pH-Änderung in der ED erzielt werden. Eine Erhöhung des Rückhalts ionisierbarer Moleküle durch den in der Literatur vorhergesagten \textit{barrier effect} konnte auch hier nicht erreicht werden. Die resultierenden Spurenstoffkonzentrationen im ED-Konzentrat lagen dennoch für mehr als die Hälfte der untersuchten Spurenstoffe nicht über 1 µg/L. Nur einzelne Substanzen wie Valsartansäure, ein biologisches Transformationsprodukt oder auch Benzotriazol erreichten Maximalkonzentrationen von 10 bis 20 µg/L. Unter den Schwermetallen wurden die höchsten Konzentrationen für Zn gefunden, das im ED-Konzentrat bei etwa 400 µg/L vorlag. Für die abschließende Risikoabschätzung war zu berücksichtigen, dass vor der Nutzung des ED-Konzentrat in der Hydroponik eine Verdünnung zur Anpassung der Nährstoffkonzentration an den Pflanzenbedarf erfolgte. Durch die Verdünnung reduzierte sich die Konzentration der Kontaminanten deutlich, sodass die Konzentration kleiner, neutraler organischer Spurenstoffe, welche nachgewiesenermaßen die höchste Tendenz für die Pflanzenaufnahme haben, im Bereich <~1~ng/L lag. Die Konzentration der Schwermetalle lag bereits vor der Verdünnung unterhalb empfohlener Grenzwerte für die Nutzung von Abwasser in der Landwirtschaft. Das gesundheitliche Risiko, das mit der Pflanzenaufnahme der Spurenstoffe verbunden sein könnte, wird daher als gering eingeschätzt. / Excessive use of mineral fertilizer in agriculture contributes significantly to its global environmental impact. Therefore, innovative concepts are needed to recover nutrients from alternative sources, such as municipal wastewater. For instance, centrate from digested sludge dewatering offers potential for nutrient recovery due its high ammonia nitrogen concentration. Furthermore, the use of soilless cultivation concepts, such as hydroponics, can foster the sustainable transformation of agriculture by more efficient use of nutrients and water. During nutrient recovery from wastewater, contamination of the recovered nutrient solution is a concern as plant uptake of wastewater-borne contaminants may pose a threat to human health. This dissertation project focused on the study of potentially plant-available polar organic micropollutants, metals and metalloids in nutrient recovery from centrate. Three studies were conducted in the course of this dissertation project, investigating (I) the occurrence of micropollutants in the centrate on a local municipal wastewater treatment plant, (II) their removal in a two-stage system consisting of a membrane bioreactor (MBR) and an electrodialysis (ED) designed for nutrient recovery from centrate and (III) a possible approach to optimize the removal of micropollutants in the ED. Results showed that the concentrations in the centrate exceeded the concentrations detected in the influent and effluent for a number of organic micropollutants. Median concentrations in centrate up to 80 µg/L and 60 µg/L were found for the chemical benzotriazole and pharmaceutical valsartan, respectively. The concentrations of anaerobically degradable organic micropollutants did not exceed 1 µg/L. Among heavy metals, the highest median concentrations were found for Zn and Ni at around 50 µg/L and 20 µg/L. Overall, concentrations of organic micropollutants showed low variability in centrate, with a subset of less polar micropollutants showing relative standard deviation as low as 7 % over the course of three weeks daily sampling. Nevertheless, indicative evidence suggested that operational changes of the dewatering process had a direct impact on organic micropollutant concentrations in centrate. During the nutrient recovery from centrate, the combination of MBR and ED reduced the loads of 21 out of the monitored 22 organic micropollutants and for six of nine metals by >90 %. The two-stage system was robust against fluctuations in the MBR removal efficiency for neutral organic micropollutants. A temporary 87 % decrease in MBR removal efficiency for the neutral molecule carbamazepine was compensated for in the ED and resulted in as little as 6 % decrease of total removal in the two-stage system. In contrast, reduced removal of ionic compounds was only compensated for to a small extent, as ions are inherently concentrated in the ED. To improve retention of ionizable compounds in the ED, the pH of the feed to the ED was modified as a means to transfer ions to a neutral protonation state. As the retention of neutral compounds was shown to be high, the pH modification was expected to improve the retention of ionizable compounds. Contrary to expectations, the retention of none of the ionizable compounds could be improved. Their transport was found to be independent of feed pH. Additionally, an attempt to utilize the electric current density to achieve the desired pH shift and induce the barrier effect predicted in literature, remained unsuccessful. Still, in the final ED concentrate, concentrations of organic micropollutants were below 1 µg/L for more than half of the monitored compounds and reached a maximum of 10 to 20 µg/L only for individual compounds such as the biological metabolite valsartan acid and benzotriazole. Among heavy metals, highest concentrations were found for Zn, which was present at around 400 µg/L in the ED concentrate. For the final risk assessment it should be considered that the ED concentrate is diluted prior to the use in hydroponics to meet plant-specific nutrient concentrations. After dilution, compounds most relevant for plant uptake, namely small, neutral organic micropollutants will be present at dissolved concentrations around 1 ng/L in the hydroponic nutrient solution. The concentrations of all investigated heavy metals remained below recommended thresholds for safe reuse of wastewater even prior to dilution. Therefore, the risk for human health associated with contaminant uptake from the derived nutrient solution into food plants is considered low.