Dans un contexte interdisciplinaire, l'étude a consisté à évaluer le niveau de robustesse de procédés pilotes de biofiltration appliqués au traitement d'un effluent caractéristique des émissions de compostage de boues d'épuration, soumis à des fluctuations de charge transitoires, répétées, et d'intensité croissante. L'impact de ces perturbations a été examiné à deux niveaux, par la mesure de la résultante fonctionnelle de dégradation d'une part, et par la caractérisation de la structure génétique de la communauté bactérienne totale d'autre part. La mise en relation de ces deux composantes a fait l'objet d'une attention particulière. / The study aimed to evaluate the robustness capacity of pilot-scale biofilters applied to the treatment of sludge-composting emissions. The biofilters were submitted to repeated periodic fluctuations (shock loads) of increasing intensity. Their response was evaluated at two levels: functional resistance and resilience in terms of removal efficiency, and molecular characterization of the bacterial community structure. The objective was to establish the potential links between these two components.

Photocatalysis is a series of advanced light-induced redox reaction processes resulting in the degradation and mineralization of organic pollutants in the presence of oxygen and water. Due to their capability to destroy contaminants under mild conditions, photocatalytic processes have attracted considerable attention in the field of waste-water treatment. However, photocatalytic reactions using the traditional TiO2 photocatalyst suffer from low energy efficiencies under solar irradiation. This low efficiency in the utilization of solar energy lies in its incapability in absorbing visible lights and also the high recombination rate of photo-excited species in photocatalysts. In addition, difficulties in the separation of fluids from micro- or nano-scale catalysts in large scale systems substantially impact cost efficiency in practice. In this thesis, strategies are explored which address these issues in order to improve the feasibility of solar photocatalysis. Two branches of photocatalytic transition metal-oxide semiconductor materials are investigated, namely bismuth-based and silver-based multi-phase heterogeneous photocatalysts. This research is focused on the design of visible-light-active metal-oxide photocatalysts to increase the absorption of visible light and to decrease the rates of electron-hole recombination, resulting in a high photocatalytic efficiency in regards to the degradation of organic pollutants. BiVO4 powder, synthesized from freshly made potassium metavanadate was prepared via hydrothermal treatment, characterized and experimentally investigated for the degradation of rhodamine B under visible light irradiation. The crystal structures and the specific surface areas of the composites, based on BiVO4 single phase crystal structures, are discussed. A multi-phase silver species (Ag2O/Ag3VO4/Ag4V2O7) photocatalyst was synthesized by adjusting the molar ratio of silver to vanadium (Ag to V) via hydrothermal method. The stabilities of as-prepared silver species composites regarding crystal structural changes due to photocatalytic reactions are investigated. Multi-phase silver species composites assisted with graphene oxide (GO-Ag2O/Ag3VO4/AgVO3) were synthesized at room temperature, and exhibited high visible-light photocatalytic activities regarding the degradation of model organic pollutants. The effect of graphene oxide addition on the photoactivity and on the photocorrosion of silver species composites under VLI is explored. The synergistic roles of each individual phase incorporated into the multi-phase composites are discussed regarding the photocatalytic performance.

This Master’s thesis deals with sanitation installation in historic building. The theoretical part of the topic analysis deals with the issue waste water discharge from the building and ground floor. Furthermore, the theoretical solutions are processed sanitation installation and variants of it. Preferable variant is finalized the details of the implementation of the project.

>Magister Scientiae - MSc / South Africa is facing a problem of many municipal waste water treatment works (WWTW) not working efficiently. The environmental impacts of poorly treated effluents on receiving water bodies have required special attention from researchers. In this study, the relationships between water quality variables in the Baths River in the Western Cape province of South Africa were evaluated upstream, at the source and downstream of the Caledon wastewater treatment works between March 2013 to March 2016. The assumption has been tested that water quality is deteriorating downstream of the Caledon Waste Water Treatment Works (WWTW) discharge point in the Baths River and are affected by this change in water quality. / 2023

No / A predictive modelling technique was employed to estimate wastewater temperatures in sewer pipes. The simplicity of abductive predictive models attracts large numbers of users due to their minimal computation time and limited number of measurable input parameters. Data measured from five sewer pipes over a period of 12 months provide 33,900 training entries and 39,000 evaluation entries to support the models' development. Two simple predictive models for urban upstream combined sewers and large downstream collector sewers were developed. They delivered good correlation between measured and predicted wastewater temperatures proven by their R(2) values of up to 0.98 and root mean square error (RMSE) of the temperature change along the sewer pipe ranging from 0.15 degrees C to 0.33 degrees C. Analysis of a number of potential input parameters indicated that upstream wastewater temperature and downstream in-sewer air temperature were the only input parameters that are needed in the developed models to deliver this level of accuracy.

No description available.

The phenomenon of rapid algal blooms in response to nutrient overloads has been adapted to treat synthetic domestic wastewater. Various algal consortia collected from several eutrophied water bodies were subject to high density algal culture (upto 106-107 cells/mL) and screened for rapid algal growth, pollutant removal, nutrient recovery under mixotrophy and auto-flocculation. When tried in laboratory scale algal ponds, these algal consortia showed growth rates between 0.15 and 1.07 d-1. Results indicate that Chlorella occurred frequently among most consortia although not always the largest in number. While individual algal species varied in growth rates among these consortia, the log phase for most of these algae lasted 4-5 d after which the algal species began to flocculate between day 5-8 at different rates. The flocculation stage lasted between Day 6-8 wherein about 65% cells flocculated during monsoon and over 90% in winter. Although over 90% removal of N and 80% removal of P occurred in this period, the net N and P harvested as flocculated algae ranged from ~30-50% and ~40-70%, respectively. A consortia approach, wherein algal cells auto-flocculate after reaching a high cell density and nutrient removal provides an easy, low energy and sustainable approach to simultaneous wastewater treatment as well as energy and nutrient recovery from domestic wastewaters.

In this study, the composite of aluminum metal-organic framework MIL-68(Al) and reduced graphene oxide (MA/RG) was synthesized via a one-step solvothermal method, and their performances for pnitrophenol (PNP) adsorption from aqueous solution were systematically investigated. The introduction of reduced graphene oxide (RG) into MIL-68(Al) (MA) significantly changes the morphologies of the MA and increases the surface area. The MA/RG-15% prepared at RG-to-MA mass ratio of 15% shows a PNP uptake rate 64% and 123% higher than MIL-68(Al) and reduced graphene oxide (RG), respectively. The hydrogen bond and pi-pi dispersion were considered to be the major driving force for the spontaneous and endothermic adsorption process for PNP removal. The adsorption kinetics, which was controlled by film-diffusion and intra-particle diffusion, was greatly influenced by solution pH, ionic strength, temperature and initial PNP concentration. The adsorption kinetics and isotherms can be well delineated using pseudo-second-order and Langmuir equations, respectively. The presence of phenol or isomeric nitrophenols in the solution had minimal influence on PNP adsorption by reusable MA/RG composite.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Acid mine drainage (AMD) is wastewater generated by mine and industrial activity with typically high heavy metal and sulphur content potentially resulting in toxic wastewater upon exposure to dissolved oxygen, water and micro-organisms. Due to the hazardous consequences of untreated AMD, treatment methods such as semi-passive biotic treatments, including constructive wetlands and microbial bioreactors were developed. Microbial bioreactors rely on suitable carbon sources such as ethanol, grasses and manure and the creation of anaerobic conditions for the reduction of sulphate, chemical oxidizable organic matter (COD) and to neutralise pH. Domestic wastewater sludge has also been identified as an economical and readily available carbon source that allows the treatment of both AMD and domestic wastewater. A synthetic medium simulating the COD and the biological degradable organic matter (BOD) of domestic wastewater sludge was formulated to exclude variations in the evaluation of domestic wastewater sludge as carbon source in the treatment of AMD. Firstly the BOD and COD of anaerobic domestic wastewater sludge was determined and used as parameters in the formulation of the synthetic medium. A ratio of 1:1 AMD: synthetic domestic wastewater sludge (SDWWS) was the optimum ratio in terms of sulphate and COD removal. Secondly, medical drip bags were used as anaerobic bioreactors to determine the microbial diversity in AMD treated with SDWWS using different variables. Data analyses from next generation sequencing showed that Chlorobium spp. dominated the 90 d pioneer trials at relative percentages of 68 % and 76 %. Transmission electron microscopy (TEM) images and the bright green colour of the liquid contents confirmed the data analyses. Sulphates and COD were removed at > 98 % and > 85 %, respectively. A shorter incubation time was investigated in the 30 d pioneer trial. Chlorobium spp. was dominant, followed by Magnetospirillum spp. and Ornithobacterium spp. The liquid content changed to a dark brown colour. COD and sulphate concentrations were reduced by 60.8 % and 96 %, respectively, within 26 d, after which a plateau was reached. The effect of an established biofilm in the bioreactors showed that Chlorobium spp. also dominated approximately 62 %, in comparison to the 36 % in the 30 d pioneer trial. A sulphate and COD reduction of 96 % and 58 %, respectively, was obtained within 26 d and the liquid content was the same colour as in the 30 d pioneer trial. It is possible that brown Green sulphur bacteria were present. Therefore, although Chlorobium spp. was present at a higher percentage as in the 30 d pioneer trial, the removal of COD and sulphate was similar. During the 30 d trials a white precipitant formed at the top of the bioreactors, consisting primarily of sulphate and carbon that was also indicative of the presence of Chlorobium spp. Incubation at reduced temperature reduced sulphates by only 10 % and COD by 12 % after 17 d, followed by a plateau. Ornithobacterium spp. dominated in the first trial and Magnetospirillum spp. in the second trial. / AFRIKAANSE OPSOMMING: Suur mynwater (SMW) is afvalwater wat deur die myn- en industriële bedryf gegenereer word en bevat kenmerklik hoë konsentrasies swaar metale en swawel wat potensieel in toksiese afvalwater omskep kan word indien blootgestel aan opgelosde suurstof, water en mikro-organismes. Die skadelike gevolge wat blootstelling aan onbehandelde SMW mag hê, het gelei tot semi-passiewe behandelinge wat vleilande en mikrobiese bioreaktors insluit. Mikrobiese bioreaktore maak staat op n geskikte koolstofbron soos etanol, grasse en bemesting en die skep van ‘n anaerobiese omgewing vir die verwydering van sulfate en chemies oksideerbare organiese material (CSB), asook die neutralisering van pH. Huishoudelike afvalwaterslyk is ook uitgewys as ‘n ekonomies geskikte en algemeen beskikbare koolstofbron wat die behandeling van beide SMW en huishoudelike afvalwater toelaat. ‘n Sintetiese medium wat die CSB en biologies afbreekbare organiese materiaal (BSB) van huishoudelike afvalwater slyk naboots is geformuleer om die variasies in die evaluasie van huishoudelike afvalwater slyk as koolstofbron vir die behandeling van SMW, uit te sluit. Eerstens is die BSB en die CSB van huishoudelike afvalwater slyk bepaal en gebruik as n maatstaf vir die formulering van die sintetiese medium. ‘n Verhouding van 1:1 sintetiese huishoudelike afvalwater slyk (SDWWS) en SMW is optimaal ratio i.t.v. die verwydering van sulfate en CSB. Tweedens is mediese dripsakkies as anaerobiese bioreaktore gebruik om die mikrobiese diversiteit in SMW, wat met SDWWS behandel is, te bepaal deur verskeie veranderlikes te gebruik. Tweede generasie DNA-volgorde bepalingstegnieke is gebruik en data analises het gewys dat Chlorobium spp. die 90 d pionier toetslopie domineer met relatiewe persentasies van 68 % en 76 %. Transmissie elektron mikroskopie fotos en die helder groen kleur van die dripsakkies se vloeistof inhoud het die data analises bevestig. Die sulfate en CSB inhoud is onderskeidelik met > 98 % en > 85 % verminder. ‘n Korter behandelingstydperk is ondersoek met n 30 d pionier toetslopie. Chlorobium spp. was dominant, gevolg deur Magnetospirillum spp. en Ornithobacterium spp. Die vloeistof inhoud het na ‘n donker bruin kleur verander. Die CSB en sulfaat konsentrasies is met 60.8 % en 96 % onderskeidelik verminder na 26 dae waarna ‘n plato bereik is. Die effek van ‘n reeds bestaande biofilm in die bioreaktore het gewys dat Chlorobium spp. ook gedomineer het teen ‘n relatiewe persentasie van 62 % in vergelyking met die 36 % in die 30 d pionier toetslopie. ‘n Vermindering in sulfate en CSB van 96 % en 58 % is onderskeidelik is bereik binne 26 d en die vloeistofinhoud was dieselfde kleur as die bioreaktore in die 30 d pionier toetslopie. Dit is moontlik dat die bruin Groen swawel bakterieë teenwoordig was. Daarom, ondanks ‘n groter teenwoordigheid van die Chlorobium spp. teen ‘n relatiewe persentasie in vergelying met die 30 d pionier toetslopie, was die verwydering van CSB en sulfate soortgelyk. Tydens die 30 d toetslopies het ‘n wit neerslag aan die bokant van die bioreaktore gevorm wat hoofsaaklik uit sulfaat en koolstof bestaan het wat ook ‘n aanduiding van die teenwoordigheid van Chlorobium spp. is. ‘n Toetslopie wat by laer temperature uitgevoer is kon die sulfate en CSB met slegs 10 % en 12 % onderskeidelik verminder nadat ‘n plato na 17 d bereik is. Ornithobacterium spp. het die eerste toetslopie gedomineer waar Magnetospirillum spp. die tweede toetslopie gedomineer het.

<p>Hammarby Sjöstad is a new district in southern Stockholm. A main objective with the Sjöstad project was to halve the environmental impact compared to other construction work. The environmental goals involve a halved water consumption rate, a local treatment of storm water and trials aiming to extract nutrients from the waste water. Sjöstadsverket is an experimental treatment plant used for testing new treatment processes for domestic waste water from Hammarby Sjöstad. The results are to be compared with the conventional process used at Henrikdals treatment plant today. Two aerobic and two anaerobic main treatment processes are to be tested before decision of full scale is taken in 2005.</p><p>Anaerobic treatment without heating, as a way to reduce the content of organic material in the waste water, consumes less energy than conventional methods. Anaerobic reactors are usually operated at 37°C. It is possible to attain a high COD-reduction at lower temperatures, assumed a longer contact time between biomass and waste water. In an Upflow Anaerobic Sludge Blanket (UASB) - reactor the microorganisms form granules with excellent sedimentation properties. The granules are floating with the waste water flowing upwards through the reactor. This makes it possible to reduce the COD-content despite a short hydraulic retention time in the reactor.</p><p>The two UASB-reactors examined in this thesis is a part of the pilot plant. The thesis shows how the startup of the reactors has functioned and evaluates the possibility to reduce the contence of different COD-fractions with this technique.The domestic waste water temperature has during the experiment period dropped from 23°C to 18°C. The total COD-content of the untreated waste water is 567 mg/l. Before the anaerobic step the water is pre-treated by adding of flocculation chemicals and sedimentation. The total amount of suspended material is reduced by 50 % in the pre-treatment and the load on the UASB-reactors is 100 mg/l. With a hydrologic retention time of 2,4 h the pre-treatment and the two-step anaerobic reactor has reduced 64 % of the total COD-content. Over the anaerobic treatment step the COD-reduction was 49 %. The reduction of dissolved COD (<0, 45 μm) was 59 %. When operated in series the main part of the soluble CODreduction has taken place in the first reactor. After more than six months operation there is still a granulated sludge in the reactors and tests show a high metanogenic activity. Gas production from the reactors has been observed but not measured quantitatively.</p><p>The results from this thesis show that anaerobic treatment with a UASB-process functions without heating for the household waste water from Hammarby Sjöstad. The anaerobic process should be combined with pre-treatment and supplementary treatment to reduce the remaining COD and the nitrogen and phosphorus content.</p> / <p>Hammarby Sjöstad i södra Stockholm är en stadsdel under framväxt. Tanken bakom Sjöstadsprojektet var att halvera miljöpåverkan jämfört med annan nybyggnation. Bland annat anges i miljömålen halverad vattenförbrukning, lokal hantering av dagvatten och försök med utvinning av växtnäringsämnen ur avloppsvattnet. Sjöstadsverket är en del av detta projekt; en försöksanläggning för reningen av avloppsvattnet från hushållen i Hammarby Sjöstad. Två aeroba och två anaeroba linjer ska utvärderas innan beslut om full skala tas år 2005.</p><p>Anaerob rening utan uppvärmning är ett resurssnålt sätt att minska innehållet av organiskt material i avloppsvattnet. Anaeroba reaktorer drivs vanligen vid ca 37°C. Det är möjligt att nå en hög reduktion av organiskt material även vid lägre temperaturer, förutsatt en längre kontakttid mellan biomassa och avloppsvatten. I en Upflow Anaerobic Sludge Blanket (UASB)-reaktor utnyttjas mikroorganismernas förmåga att bilda granuler, vilka svävar med avloppsvattnet som flödar uppåt genom reaktorn. Det gör det möjligt att reducera vattnets innehåll av organiskt material trots en kort hydraulisk uppehållstid i reaktorn. I detta examensarbete studeras de två UASB-reaktorer som ingår som en del i pilotanläggningen vid Sjöstadsverket. Examensarbetet visar hur uppstarten av reaktorerna fungerat och utvärderar möjligheten att reducera avloppsvattnets olika fraktioner av COD med denna teknik.</p><p>Temperaturen på vattnet från hushållen har under försöksperioden sjunkit från 23°C till 18°C. Det obehandlade avloppsvattnet har en total COD-halt kring 567 mg/l. Innan det anaeroba reningssteget förbehandlas vattnet genom sedimentering och inblandning av flockningskemikalier. Den totala mängden suspenderat material halveras i förbehandlingen och belastningen på UASB-reaktorerna är kring 100 mg /l. Efter förbehandling är vattnets COD-koncentration ca 400 mg/l. Med en hydraulisk uppehållstid på 2,4 timmar har en COD-reduktion på 64 % uppnåtts i hela systemet, dvs. försedimentering och två-stegs UASB-reaktor. Över det anaeroba reningssteget var reduktionen av COD 49 %. Reduktionen av löst COD (<0, 45 μm) i UASB-reaktorerna var 59 %. Vid seriell drift har merparten av lösligt COD reducerats i den första reaktorn. Efter nio månaders drift finns fortfarande ett granulärt slam i båda reaktorerna. Tester visar på en hög metanogen aktivitet. Gasproduktion har observerats i reaktorerna men inte kunnat mätas kvantitativt.</p><p>Resultaten från detta examensarbete indikerar att anaerob rening med en UASB-process fungerar utan uppvärmning för avloppsvattnet från hushållen i Hammarby Sjöstad. Den anaeroba behandlingen bör kompletteras med förbehandling samt en kompletterande behandling för att minska kvarvarande COD och reducera kväve och fosfor.</p>