The aim of the thesis is to Mutěnice wastewater treatment plant, which lies in the wine region of Moravia sub-slovácko propose technological measures to the Autumnal wine campaign harboring extreme overload wastewater treatment plant Mutěnice. It will establish a number of options which will be compared with each other.

The target of the first part of this diploma thesis is focused on the problems relating to the sludge production from the wastewater treatment plant and subsequent sludge treatment. In this thesis complete process of the wastewater treatment is described. Predominantingly is described the process in digestion tanks, therefore stabilization process, whereas the paper is focused on sludge pre-treatment (disintegration) of waste activated sludge before stabilization. The second part of this thesis is focused on the design of the disintegration unit for the wastewater treatment sludge in assist with experimental data. According to measured and fixed parameters the unfired pressure vessel has been designed. On the vessel has been further realized the strength calculation, the heat balance and the economic balance.

The diploma thesis is focused on the optimalitzation of an operation on SWTP and improvement of figures of drainge from sewage water treatment plants. Possible options of the optimalization are also included. The second part of the thesis deals with the optimalization of operation of the concrete sewage water treatment plant using the WEST programme.

Water scarcity has become a global problem due to diminishing water resource and pollution of the remaining resources. The problems arising fromwater scarcity are exacerbated rapid urbanisation and industrialisation. Water quality management systems are introduced. Numerous water management methods exist some of which, if applied e ectively, can remedy these problems. In South Africa, water management systems are urgently needed to start addressing issues around the longterm sustainability of our limited water resource. Water quality modelling is one of the tools employed to assist in validating decisions made during the planning phase of a water quality management system. It also provides a means of exploring viable options to be considered when these decisions are to be made. A range of management options exist and implementing all of them may prove costly, therefore optimisation techniques are utilised to narrow down options to the most e ective and least costly among the available choices. Commonly, water quality models are used to predict concentrations in the river from which constraint equations are generated. The constraint equations are used in optimisation models to generate feasible solutions by either maximising or minimising the objective function. In this case the objective function is wastewater treatment cost. Constraints equations are based on the set in-stream water quality standard at selected theoretical measuring stations (checkpoints) in the stream and a feasible solution is one that suggests a treatment method that will ensure water quality standards are met at the lowest regional treatment cost. This study focused on the Upper Olifants river catchment near Witbank in Mpumalanga province. This catchment is subjected to extensive wastewater e uents from various mining operations and wastewater treatment plants. The aim here was to develop a water quality model for predicting dissolved oxygen (DO) concentration in the river, and to use a modelling approach to generate constraint equations for the system. A Streeter-Phelps stream simulation model was employed to predict DO concentration in the river. A mixed-integer programming technique was then used to evaluate the impact of nine wastewater treatment facilities discharging e uent into the river. Treatment levels were varied to test model reliability. The coupled stream simulation and optimisation model produced feasible solutions under 2 minutes, with each solution suggesting a range of treatment levels which ensured that the critical DO concentration was above 5 mg/L and the most stringent DO concentration the system could manage without violations anywhere else in the stream was obtained to be 7mg/L. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Chemical Engineering / unrestricted

L'objectif de ce travail de thèse était de tester le textile lumineux en termes de performances photocatalytiques en milieu aqueux. La durabilité des textiles face à une exposition prolongée à une irradiation UVA a été testée. Les tests ont mis en évidence un problème de vieillissement des tissus enduits de TiO2, induisant l'apparition d'une inhomogénéité de l'émission de lumière sur la surface du textile. Un modèle mathématique a été développé afin d'exprimer et de prévoir ce vieillissement en fonction du temps d'exposition aux UVA. Le dépôt d'une couche protectrice de silice a permis de résoudre ce problème de vieillissement. Parallèlement, les textiles lumineux enduits de TiO2 ont été caractérisés. La localisation de SiO2 et TiO2 par MEBE et analyse EDX a été démontrée comme étant homogène sur la surface des fibres optiques, mise à part pour le dépôt de TiO2 P25 localise en amas. La quantité de photocatalyseur déposé sur les textiles ainsi que l'absorbance des dépôts ont été évaluées. L'étude de l'adhérence des dépôts a démontré la stabilité du TiO2. Enfin, les performances photocatalytiques des différents textiles enduits de photocatalyseur ont été testées sur la dégradation de deux polluants modèles, l'acide formique et le phenol, en réacteur ferme. L'étude de la vitesse de dégradation en fonction de la masse de TiO2 a permis de déterminer la masse optimum (environ 2mg cm-2). Des rendements photoniques de l'ordre de 30 à 55% dans le cas de l'acide formique et de 6 à 8% pour le phenol ont été obtenus. Un réacteur pilote plan, ouvert, a permis de confirmer les résultats obtenus et ouvre la voie à une configuration multicouche, en vue d'une application industrielle / The objective of this thesis was to test luminous textiles in terms of photocatalytic performances in aqueous medium. The durability of textile under long-time UVA irradiation was tested. Results showed the aging of luminous textile coated by TiO2, involving an inhomogeneity of light emission on the overall surface of the textile. A mathematical model was developed to express and predict the aging depending on the time of exposure to UVA. Also, a protective layer of silica allows avoiding the optical fiber aging. In parallel, luminous textiles coated by TiO2 were characterized. The location of SiO2 and TiO2 by ESEM and EDX analysis was shown to be uniform over the surface of optical fibers textiles, except for TiO2 P25 coating, located in clusters. The amount of photocatalyst deposited on the textiles, and the absorbance of the coatings were determined. Moreover, the study of coating adhesion demonstrated excellent adhesion and stability of the photocatalyst layer. Finally, the photocatalytic performances of the different TiO2 coatings were tested for degradation of two model pollutants, formic acid and phenol, in batch reactor. The study of the evolution of the degradation rate with the mass of photocatalyst was used to determine the optimum mass of TiO2 (about 2mg cm-2). Photonic yields ranging from 30 to 55% in the case of formic acid and 6 to 8% in the case of phenol were obtained. A continuous plan pilot reactor confirmed the results and opens the way for a multi-layer configuration, for industrial application

Aus der Einleitung: "Xenobiotika werden durch den Menschen in die Stoffkreisläufe der Natur eingebracht, sie sind dort ursprünglich nicht anzutreffen. Dazu zählen auch Medikamente, die der menschliche Körper in kurzer Zeit wieder ausscheidet ohne diese abzubauen. Die bestehenden Abwasserreinigungsanlagen sind derzeit nicht in der Lage diese Frachten vollständig zu eliminieren, sodass sie unweigerlich in die Umwelt gelangen und dort undefiniert Einfluss nehmen. Xenobiotika können bereits in den großen Wasserreservoirs der Erde detektiert werden, die Prognose für die nächsten Jahre zeigt eine 30% Steigerung der Emissionen auf. In Deutschland gelangen z.B. jährlich 63 Tonnen des Schmerzmittels Diclofenac in die Flüsse (Bundesumweltamt 2014). Der Mensch hinterlässt regelrechte anthropogene Fußabdrücke, bestehend aus Schmerzmitteln, Antibiotika und Hormonen. Die problematischen Emissionen einiger Xenobiotika treten anhand von Folgeerscheinungen weltweit immer gravierender zutage (Bundesumweltamt 2014). So müssen das globale Artensterben (Geier in Indien), die Verweiblichung von Tierpopulationen in aquatischen Systemen und Krebserkrankungen mit partiell hohen Xenobiotika-Belastungen in der Umwelt in Zusammenhang gebracht werden. Die Entfernung von Xenobiotika insbesondere aus den Wasserkreisläufen stellt eine große ökonomische als auch ökologische Herausforderung zum Schutz der Lebensräume dar. ..."

The treatment of water for human consumption results in the production of residual waste flows that vary depending on source waters and water treatment technologies. Water treatment plant residual waste is defined as a pollutant that requires treatment either on site or through other means. Due to strict and evolving regulatory requirements, treatment of water treatment plant residual waste several common methods of disposing of water plant residuals exist including discharge to surface waters, discharge to sanitary sewers, and sanitary landfill disposal of dewatered wastes. Although originally discharged to the neighboring City Reservoir, the Carbondale Water Treatment Plant (CWTP) conducted an initial study to determine if plant residual waste could be treated at one of the City’s two wastewater treatment plants. No negative impacts were identified as part of this study and infrastructure was put in place to divert CWTP residual waste from the City Reservoir to the Carbondale Southeast Wastewater Treatment Plant (SEWWTP). This study focused on accessing and quantifying any impacts of Carbondale Water Treatment Plant (CWTP) residual solids sewer discharge on biological treatment processes, effluent water quality, and sludge production at the SEWWTP. The Carbondale SEWWTP treats raw water influent through a number of physical and biological processes including screening, clarification, nitrification/denitrification, and aeration. Of the tests run as part of this study daily samples were collected of SEWWTP influent, mixed liquor, return sludge, and effluent and measured for changes in pH, biochemical oxygen demand (BOD), solids, sludge volume index (SVI), dissolved oxygen (DO), and nitrogen. No significant changes were documented other than percent BOD removal did improve after the introduction of the residuals. Anions were also tested weekly. Samples were collected from the SEWWTP’s oxidation ditch to monitor biological life using biological activity reaction tests (BART) for nitrifying, denitrifying, and heterotrophically active bacteria. BART testing showed no decline in biological activity and increased populations of denitrifying bacteria. Additionally, both metals and acute toxicity of SEWWTP effluent were tested by outside testing facilities to confirm that CWTP residual solids sewer discharge did not interfere with discharge limits established as part of the plant’s permits. No significant changes were observed during testing but plant staff did indicate that more extensive cleaning of the basins was implemented post-introduction. Overall, the case study confirmed that the treatment of CWTP residual solids sewer discharge did not negatively impact treatment processes at the SEWWTP and is sustainable.

L'utilisation des microalgues dans le traitement des eaux usées est de plus en plus étudiée pour intégrer/remplacer les systèmes de traitement actuels permettant d'éliminer les nutriments et autres polluants. Cependant, l’utilisation des microalgues dans le traitement des eaux usées en est principalement au stade de la recherche, par exemple faible élimination des nutriments et croissance de la biomasse des microalgues. Le but de cette thèse était de permettre une élimination efficace des éléments nutritifs et de la matière organique des eaux usées par les microalgues tout en favorisant la production de biomasse de microalgues. C. vulgaris et S. acuminatus ont été cultivés dans des photobioréacteurs discontinus avec des digestats issus de la digestion anaérobie (AD) de boues biologiques de boue de vidange provenant d’une station d’épuration municipale (ADMW) et d’une usine de traitement des eaux usées d’une usine de pâtes et papiers (ADPP). Les rendements d’élimination de l’ammonium étaient supérieurs à 97% lorsque les deux microalgues étaient cultivées séparément dans de l’ADPP. Toutefois, 24 et 44% de l’ammonium ont été retirés de l’ADMW par C. vulgaris et S. acuminatus, respectivement. Les deux microalgues ont efficacement éliminé le phosphate (> 96%), tandis que la couleur (74–80%) et la DCO soluble (27–39%) ont été partiellement éliminées de ADMW et d'ADPP. La plus forte concentration de biomasse de S. acuminatus (7,8 à 10,8 g L-1 VSS) dans l'ADPP figure parmi les rendements les plus élevés signalés pour les microalgues dans les eaux usées réelles. Des rendements de biomasse supérieurs de S. acuminatus ont été obtenus dans de l'ADPP thermophile (10,2 ± 2,2 et 10,8 ± 1,2 g L-1) par rapport à de l'ADPP mésophile prétraité (7,8 ± 0,3 g L-1). En outre, les concentrations les plus élevées en biomasse et en méthane de microalgues ont été obtenues dans le même système intégré de culture de AD et de microalgues. Les concentrations de fer (0,1, 1,0 et 1,9 mg L-1) et de sulfure de soufre (3,7, 20 et 35,8 mg L-1) affectaient davantage l'efficacité de l'élimination de l'azote et la concentration de la biomasse de microalgues davantage dans les ammonium probablement dû à différents mécanismes d'assimilation de microalgues. Dans cette étude, le milieu contenant du nitrate comme source d'azote avec 1,0 mg de L-1 de fer et 35,8 mg de L-1 de sulfate et de soufre a permis d'obtenir la plus forte concentration de biomasse de microalgues. L'effet de la concentration en fer sur l'efficacité d'élimination des nitrates et la croissance des microalgues était plus significatif que la concentration en sulfate, alors que l'effet d'interaction entre le sulfate et le fer n'était pas observé. L'efficacité moyenne d'élimination de l'ammonium (14 à 30%) et la concentration en biomasse de microalgues (0,55 à 1,17 g de POC L-1) dans un photobioréacteur à membrane à flux continu ont été améliorées par addition de zéolite (0,5 g L-1). La zéolite fournissait probablement un habitat pour la croissance attachée de microalgues et une grande disponibilité d'ammonium pour la croissance à la surface de la zéolite en raison de l'adsorption d'ammonium par la zéolite. Une augmentation supplémentaire de la concentration en zéolite (de 0,5 à 1 et 5 g L-1) n’a pas amélioré l’efficacité de l’élimination de l’ammonium ni la concentration de la biomasse, probablement en raison de la turbidité accrue de la solution provoquée par la fragmentation de la zéolite ajoutée en particules plus fines, ce qui a réduit la disponibilité de lumière. Ces travaux ont montré la possibilité d'utiliser des microalgues dans le traitement des eaux usées pour éliminer efficacement les nutriments et les matières organiques, tout en favorisant la croissance des microalgues. La sélection d'espèces de microalgues adaptées aux eaux usées spécifiques pour éliminer les nutriments et les matières organiques est essentielle pour promouvoir les applications de traitement des eaux usées à base d'algues / Use of microalgae in wastewater treatment has been increasingly studied to integrate with or replace the present treatment systems for removal of nutrients and other pollu-tants. The potential advantages of this integration (wastewater treatment and microalgal cultivation) could be simultaneous recovery of nitrogen and phosphorus and the use of produced microalgal biomass as feedstock for e.g. biofuel, fertilizer and/or energy. However, the use of microalgae in wastewater treatment is mainly in research stage due to e.g. low nutrient removal and microalgal biomass growth. The aim of this thesis was to enable efficient nutrient and organic matter removal from wastewaters by mi-croalgae while promoting microalgal biomass production. Chlorella vulgaris and Scenedesmus acuminatus were successfully grown in batch photobioreactors with liquid digestates from anaerobic digestion (AD) of biosludge from a municipal wastewater treatment plant (ADMW) and a pulp and paper mill wastewater treatment plant (ADPP). The final ammonium removal efficiencies were above 97% when cultivating both microalgae separately in ADPP, however, only 24% and 44% of ammonium were removed from ADMW by C. vulgaris and S. acuminatus, respectively. Both microalgae efficiently removed phosphate (>96%), while color (74–80%) and sol-uble COD (27–39%) were partially removed from ADMW and ADPP. The obtained highest S. acuminatus biomass concentration (7.8–10.8 g L-1 VSS) in ADPP is among the highest yields reported for microalgae in real wastewaters. Higher S. acuminatus biomass yields were obtained in thermophilic ADPP (without and with pretreatment prior to AD: 10.2±2.2 and 10.8±1.2 g L-1, respectively) than in pretreated mesophilic ADPP (7.8±0.3 g L-1). In addition, the highest microalgal biomass concentration and methane yields were obtained in the same integrated AD and microalgal culti-vation system (thermophilic AD with pretreatment).The iron (0.1, 1.0, and 1.9 mg L-1) and sulfate-sulfur (3.7, 20, and 35.8 mg L-1) concen-trations were found to affect nitrogen removal efficiency and microalgal biomass con-centration more in the media with nitrate than with ammonium, probably due to different microalgal assimilation mechanisms for nitrate and ammonium. In this study, synthetic medium with nitrate as nitrogen source with 1.0 mg L-1 iron and 35.8 mg L-1 sulfate-sulfur enabled the highest microalgal biomass concentration. The effect of iron concentration on nitrate removal efficiency and microalgal growth was more significant than that of sulfate concentration, while the interaction effect between sulfate and iron was not observed. The average ammonium removal efficiency (14 to 30%) and microalgal biomass con-centration (0.55 to 1.17 g particulate organic carbon per L) in continuous-flow mem-brane photobioreactor were promoted by adding a low concentration of zeolite (0.5 g L-1). The zeolite likely provided a habitat for attached growth of microalgae and high availability of ammonium for growth on the surface of the zeolite due to ammonium adsorption to zeolite. Further increase in zeolite concentration (from 0.5 to 1 and 5 g L-1) did not improve ammonium removal efficiency or biomass concentration. This was likely due to the increased solution turbidity caused by breaking apart of added zeolite particles into finer particles, which reduced light availability.In summary, this work showed the possibility of utilizing microalgae in wastewater treatment to efficiently remove nutrients and organic matter, and simultaneously pro-mote microalgal growth. Selecting suitable microalgal species for the specific wastewater to remove nutrients and organic matter is essential to promote algae-based wastewater treatment applications

This thesis is focused to the comparison of two wastewater treatment systems - constructed wetlands and mechanical-biological wastewater treatment plant. The main goal of the theses is to compare two types of wastewater treatment systems and to evaluate hypothesis that constructed wetlands are cheaper and more efficient than mechanical-biological wastewater treatment plant. To be able to compare two various wastewater treatment systems 18 (9 constructed wetlands and 9 mechanical-biological plants, three size groups of both types of plants) wastewater treatment plant were chosen and compared. The treatment effectiveness, investment and operating costs, advantages and disadvantages of both the systems were compared. The information about all individual systems was obtained from the local municipalities, operators and partially from the Ministry of Environment of CR. Obtained data involved treatment technology, amount of annual treated water, building data and capital and operating costs. In some waste water treatment plant (WWTP) the water samples were taken and the analyses of chosen parameters (not measured in WWTP) were done. Once in 2010 year the samples of water, sediments and sludges were taken and the analyses of heavy metals was done. For assessment of operational problems in constructed...

In Sweden, the dominating source for emissions of degradable organic substances to water is the pulp and paper industry. The organic substances increase oxygen consumption in the recipient which subsequently threatens aquatic species. Improved process engineering, process closures and use of external treatments have in recent years drastically lowered the Biological Oxygen Demand (BOD). However, the Chemical Oxygen Demand (COD) has not been reduced to the same extent, as some organic substances are more persistent and must be treated with more advanced techniques. Chemical precipitation, which can bind large parts of the remaining COD into solid matter, making it possible to be removed from the effluent by various separation technologies, contributes to an efficient COD removal. However, the direct operating cost for the treatment is high as large amount of chemicals are used in the process, and large quantities of sludge generated. In the near future EU pulp and paper industry will have to meet new regulatory demands on COD discharges, and pulp mills in Asia, South-America and Oceania will meet stringent discharge demands. It is therefore of interest to review alternative treatments in regards to technical, environmental and economical feasibility in the treatment of pulp and paper mill wastewaters. Much interest has been shown for Advanced Oxidation Processes (AOP), which is why these techniques have been evaluated in this thesis. The first part of the report consists of a literature review where processes with the following oxidants have been reviewed: 1. Ozone (O3); 2. Ozone + Hydrogen peroxide (O3/H2O2); 3. Fenton’s reagent (Fe2+/ H2O2); 4. Ozone + Ultraviolet light (O3/UV); 5. Hydrogen peroxide + Ultraviolet light (H2O2/UV); 6. Photo-Fenton’s reagent (Fe2+/ H2O2/UV); 7. Titanium dioxide + Ultraviolet light (TiO2/UV). Ozone treatment (1) and ozone in combination with hydrogen peroxide (2) were chosen for further experimental studies. The experiments were conducted at Wedecos (Xylem Water Solutions) laboratory in Germany and tested on wastewater from three different Swedish mills: A, B and C. The experimental results indicate that treatment with ozone is an efficient method for elimination of COD from pulp and paper mill wastewaters. A relatively high COD reduction (41 % for Mill A, 31% for Mill B and 53% for Mill C) was achieved for all wastewaters with an applied ozone dosage of 0.2g O3/L, without an appreciable impact on other parameters such as pH, N-tot, NO2-, NO3-, NH4+, P-tot and PO43-. There are indications that the nature of the wastewater has an impact on the COD removal efficiency and that TMP wastewater is easier to oxidize in comparison to wastewater from sulphate mills. The combination with hydrogen peroxide did not show any further COD reduction compared to ozone treatment alone, thus confirming the results Ko et al. showed in their study in 2009. Oxidation with ozone is seen as more environmental alternative in comparison to chemical treatment (precipitation/flocculation) because contaminants in the wastewater are destructed rather than concentrated or transferred into a different phase, which leads to the decrease of COD, colour and toxicity without the need to handle large amounts of sludge. However, a subsequent biological treatment may be necessary for removal of BOD as a BOD increase is registered for all wastewater treated in this study. The costs are on the other hand higher in comparison to chemical treatment even though there are indications of cases when treatment with ozone can be profitable (e.g. if the cost for sludge handling increases in the future, price for chemicals increases and electricity price decreases). There are some uncertainties regarding the system and there is no clear evidence that toxic by-products are not formed. More research must be done and more full-scale installations must be reported before the pulp and paper industry is willing to invest in oxidation technology. / I Sverige, är massa- och pappersindustrin den dominerande utsläppskällan av nedbrytbart organiskt material till vatten. När det organiska materialet når recipienten ökar syreförbrukningen eftersom stora mängder syre erfordras för nedbrytningen av materialet. Detta leder i sin tur till att de vattenlevande organismerna hotas och utsätts för syrebrist. Förbättrad processteknik, ökad processlutning och utbyggnad av extern avloppsvattenrening har under de senaste åren drastiskt sänkt den biokemiska syreförbrukningen (BOD). Däremot har den kemiska syreförbrukningen (COD) inte reducerats i samma utsträckning då delar av det organiska materialet är mer persistent och måste behandlas med mer avancerad teknik. Kemisk fällning kan idag binda stora delar av det kvarvarande COD till fast material som sedan kan avlägsnas via olika separationsmetoder. En stor nackdel med den här typen av rening är att stora mängder kemikalier används som i sin tur genererar stora mängder slam som måste tas om hand, vilket introducerar höga driftkostnader. Inom en snar framtid kommer massa- och pappersbruk inom EU att möta nya regulatoriska krav för COD utsläpp, och bruk i Asien, Sydamerika och Oceanien kommer även de att möta väldigt hårda utsläppskrav. Det är därför av intresse att granska alternativa reningsmetoder och utvärdera dess tekniska, miljömässiga och ekonomiska genomförbarhet vid behandling av avloppsvatten från massa- och pappersbruk. Mycket intresse har visats för Avancerade Oxidationsprocesser (AOP), varför dessa tekniker valts att utvärderas i detta examensarbete. Första delen av rapporten innefattar en litteraturstudie där processer med följande oxidanter studerats: 1. Ozon (O3); 2. Ozon + Väteperoxid (O3/H2O2); 3. Fenton’s reagens (Fe2+/ H2O2); 4. Ozon + Ultraviolett ljus (O3/UV); 5. Väteperoxid + Ultraviolett ljus (H2O2/UV); 6. Foto-Fenton’s reagens (Fe2+/ H2O2/UV); 7. Titaniumdioxid + Ultraviolett ljus (TiO2/UV). Utav dessa valdes ozon behandling (1) och ozon i kombination med väteperoxid (2) för vidare experimentella studier. Behandlingarna har utförts vid Wedecos (Xylem Water Solutions) laboratorium i Tyskland och undersökts på avloppsvatten från tre olika svenska bruk; A , B och C. Experimentella resultat tyder på att ozonering är effektiv behandlingsmetod för reducering av COD i avloppsvatten från massa- och pappersbruk. En relativt hög COD reducering (41% för bruk A, 31% för bruk B, och 53% för bruk C)  uppvisades för samtliga avloppsvatten med en tillämpad ozondosering på 0.2 g O3/L, utan någon märkbar inverkan på andra parametrar så som pH, N-tot, NO2-, NO3-, NH4+, P-tot och PO43-. Det förekommer indikationer om att typ av avloppsvatten har en inverkan på COD reduktionen och att TMP avloppsvatten är lättare att oxidera i jämförelse mot avloppsvatten från sulfatmassabruk. Kombinationen av ozon och väteperoxid uppvisade ingen ytterligare COD reduktion i jämförelse mot ozon som enda oxidant, och bekräftade därmed de resultat Ko et al. uppvisade i sin studie 2009. Ozonering ses som ett miljövänligare alternativ till kemisk rening (fällning/flockning) eftersom föroreningarna i vattnet destrueras istället för att koncentreras, vilket innebär att COD, färg och toxicitet kan minskas utan att stora mängder slam genereras. Dock kan en efterföljande biologisk behandling vara nödvändig för avskiljning av BOD då en BOD ökning uppvisats för samtliga avloppsvatten i denna studie i takt med att COD brutits ned till lättnedbrytbart biologisk material. Kostnaderna är däremot höga i jämförelse mot kemisk fällning även om det förekommer indikationer på fall när behandlingen kan vara lönsam (t ex om slamhanteringskostnaderna blir högre i framtiden, inköpspriset för kemikalier ökar och elpriset sjunker). Det råder vissa tveksamheter gällande systemet och det finns inga konkreta bevis på att toxiska biprodukter inte bildas. Mer forskning måste utföras och fler fullskaliga installationer måste rapporteras och innan massa- och pappersindustrin är villig att investera i oxidationstekniken.