Acrylonitrile (AN) is a major volatile waste generated in the production of acrylamide and often associated with aromatic contaminants (toluene and styrene) in plant effluents. We examined Rhodococcus rhodochrous DAP 96622 to determine if it could be adapted to efficient biodegradation of acrylonitrile (AN) in a bioreactor. A model bioreactor with granular activated carbon (GAC) as a substratum for Rhodococcus with AN as sole carbon or in combination with toluene was established. The kinetics of AN biodegradation by immobilized and planktonic cells were evaluated and compared. Inlet load and empty retention time were varied to test the removal efficiency in fed-batch and single-pass mode reactor. In addition, the three dimensional structure and characteristics of the biofilm were followed using confocal scanning laser microscopy (CSLM) and relative software. Immobilized cells in the bioreactor, at starting concentrations of AN up to 1150 mg l-1 in the presence of Tol, had at least 13 fold higher AN degradation rates than that seen of planktonic cells. A near steady state of AN degradation was maintained at 75-85% for AN and 80%-90% for Tol within the parameter of EBRT=8 min and AN and Tol inlet loads between 50-200 mg l-1 h-1 and 200-500 mg l-1h-1, respectively. However, when the inlet load of AN was increased to more than 200mg l-1 h-1 and 500 mg l-1 h-1 for Tol, a reduction in efficiency of AN degradation was observed. Biofilms with discrete microcolonies interspersed with voids and channels were observed. Precise measurement of biofilm characteristics agreed with the assumption that the biomass and thickness of the biofilm increased along the carbon column depth. With a porous attachment material like GAC, substrate diffusion is most likely not a limiting factor for AN degradation. Rhodococcus rhodochrous DAP 96622 in a non-sterile activated charcoal column showed efficient degradation of AN in the presence of Tol. The Rhodococcus bioreactor may provide a potential practical waste gas and water treatment system.

The Sudbury, ON, Canada region has been the site of metal mining and processing operations for more than 100 years. The study site for my thesis, Junction Creek, flows southwest through the City of Greater Sudbury and receives cumulative inputs including from the Garson Mine wastewater treatment plant (WWTP), Nolin Creek WWTP (stormwater) and CVRD Inco Limited WWTP (process water) as well as effluent from municipal WWTPs and untreated urban runoff, aerial deposition and historical contamination from multiple sources. Elevated levels of ammonia, Ni, Cu, Co, Pb and As, as well as reduced benthic invertebrate community diversity and density have been observed in the Junction Creek system below certain mine inputs. In addition, the Sudbury region has cold winters, with average daily air temperatures below 0°C from November to March.<p> The winter stress syndrome hypothesis proposes that the combination of winter conditions and contaminants (acting as physiological stressors) in the aquatic environment could reduce fish condition and deplete energy (lipid) reserves to the point of decreased survival, thus negatively impacting wild fish populations. However the winter stress syndrome hypothesis has rarely been tested in the field. I hypothesized that juvenile fish challenged with a physiological stressor (treated wastewater) in combination with winter conditions would have decreased growth and energy stores as a result of increased metabolism.<p> The approach I used to examine the potential effects of treated metal mine and municipal wastewaters on bioenergetics and growth, as they related to overwinter survival potential and the winter stress syndrome, of juvenile fish was a combination of a field study and a laboratory experiment. The first objective was to test the winter stress syndrome hypothesis under field conditions. Juvenile fathead minnows (Pimephales promelas), creek chub (Semotilus atromaculatus) and white sucker (Catostomus commersoni) were collected in fall and the following spring from sites along Junction Creek, Sudbury, ON downstream of two metal mining wastewater treatment plants as well as a municipal wastewater treatment plant. The second objective was to test the winter stress syndrome hypothesis in the laboratory by determining the effect of diluted (45 percent) treated CVRD Inco Limited wastewater effluent (CCWWTP) on juvenile fathead minnow growth and energy storage under simulated summer and winter conditions of reduced temperature, photoperiod and food ration. The effect on growth and energy storage of exposure to environmentally relevant ammonia concentrations was also assessed. In both the field and laboratory portions of this study, overwinter survival potential was assessed indirectly through measurements of growth (length, weight, muscle RNA/DNA ratio, muscle proteins) and energy stores (whole body triglycerides). There were inconsistent effects between the field study and the laboratory experiment. In contrast to my hypothesis, fathead minnows in the field study were larger with greater triglyceride stores at exposure sites compared to the reference site. White suckers were smaller at exposure sites but did not differ in triglycerides among sites and creek chub had no clear trend. For the laboratory portion of this study, only fathead minnows were used. After a 90 day exposure to reference or diluted CCWWTP water under simulated winter or summer conditions, juvenile fathead minnows raised in winter CCWWTP water (4°C) had lower whole body triglyceride concentration than those raised in winter reference water. There was no difference in triglycerides in fathead minnows raised in diluted CCWWTP or reference water under summer conditions. This lends support to the winter stress syndrome hypothesis, but the traditional measures of growth showed no significant differences in any of the treatments. In a separate experiment, fathead minnows were exposed from 10-100 days post hatch to graded concentrations of ammonia (0.02 to 0.40 mg unionized NH3/L) under summer conditions only. There was no effect of ammonia exposure on growth parameters, but a significant increase in total body triglycerides at the highest exposure concentration (0.40 mg/L) was observed.<p> The results of this study emphasize that laboratory-based hypotheses must be tested in the field to determine their environmental significance. The winter stress syndrome may not apply to northern fish adapted to living and feeding in colder climates and was not strongly supported by my study.

The hybrid Zero Valent Iron (hZVI) process is a novel chemical treatment platform that has shown great potential in our previous bench-scale tests for removing selenium, mercury and other pollutants from Flue Gas Desulfurization (FGD) wastewater. This integrated treatment system employs new iron chemistry to create highly reactive mixture of Fe^0, iron oxides (FeOx) and various forms of Fe (II) for the chemical transformation and mineralization of various heavy metals in water. To further evaluate and develop the hZVI technology, a pilot-scale demonstration had been conducted to continuously treat 1-2 gpm of the FGD wastewater for five months at Plant Wansley, a coal-fired power plant of Georgia Power. This demonstrated that the scaled-up system was capable of reducing the total selenium (of which most was selenate) in the FGD wastewater from over 2500 ppb to below 10 ppb and total mercury from over 100 ppb to below 0.01 ppb. This hZVI system reduced other toxic metals like Arsenic (III and V), Chromium (VI), Cadmium (II), Lead (II) and Copper (II) from ppm level to ppb level in a very short reaction time. The chemical consumption was estimated to be approximately 0.2-0.4 kg of ZVI per 1 m^3 of FGD water treated, which suggested the process economics could be very competitive. The success of the pilot test shows that the system is scalable for commercial application. The operational experience and knowledge gained from this field test could provide guidance to further improvement of technology for full scale applications. The hZVI technology can be commercialized to provide a cost-effective and reliable solution to the FGD wastewater and other metal-contaminated waste streams in various industries. This technology has the potential to help industries meet the most stringent environmental regulations for heavy metals and nutrients in wastewater treatment.

Els Processos Avançats d'Oxidació (PAOs) són tècniques de degradació química basades en la producció in situ del potent reactiu radical hidroxil. L'acoblament entre PAOs i sistemes biològics pel tractament d'aigua contaminada amb compostos biorecalcitrants és una alternativa útil als mètodes de gestió convencionals. El principal benefici d'aquests tractaments acoblats és la minimització del pretractament químic fins a generar intermedis més biodegradables. Subseqüentment, un tractament convencional d'aigües residuals, basat en la activitat de microorganismes, es pot utilitzar per eliminar completament la matèria orgànica del medi.Aquest tesi desenvolupa una estratègia d'acoblament entre sistemes químics i biològics per tractar herbicides específics com exemple de contaminants tòxics i no biodegradables produïts per l'home. / Advanced Oxidation Processes (AOPs) are chemical degradation techniques based on the in situ production of the powerful reactive hydroxyl radical. The coupling between AOPs and biological systems for the treatment of water polluted with biorecalcitrant compounds is a useful alternative to conventional management methods. The main benefit of these coupled treatments is the minimization of the chemical pretreatment to generate more biodegradable by-products. Subsequently, a conventional wastewater treatment, based on the activity of microorganisms, can be used to completely remove organic matter from solution. This thesis deals with the development of a chemical and biological coupling strategy to treat some specific herbicides as examples of toxic and non biodegradable anthropogenic pollutants.

Aggravated by rapid population growth, urbanization, and industrialization and most recently by climate change events, the availability of water especially in the third world is reaching critical proportions.  This is aggravated by the non treatment of wastewater (sewage) and discharged of untreated wastewater into water bodies. The study focused on identifying and reviewing four wastewater treatment methods from a sustainability perspective; waste stabilization pond, constructed wetland, up-flow anaerobic sludge blanket reactor and sedimentation/thickening tank systems suitable for the Limbe Urban Municipality (LUM) of Cameroon in Central West Africa with an estimated population of 120, 000 inhabitants and experiencing 4.7 per cent annual growth rate. The attractiveness of these four methods stems from their apparent energy efficiency, simplicity, robustness, low cost effectiveness in situations where as in the LUM, there are huge tracts of available land, warm temperatures, and their capacity to promote effluent re-use opportunities for various sectors. Issues of sustainability of the water supply and wastewater treatment systems, untreated sewage, and their contribution to escalating environmental and public health impacts in LUM (Cameroon) were critically evaluated and discussed with the aid of Kärrman (2000) framework approach that employs different sets of sustainability criteria (Environmental, Health and Hygiene, and Functional), sub-criteria and indicators. Results obtained reveal that water and wastewater treatment systems in LUM do not operate or conforms to sustainability perspectives. Inhabitants do not still have access to clean drinking water (an approximate 45 per cent) especially in the dry periods of the year, low sanitation coverage (with the tradition of sewage treatment in septic tanks and pit latrines), rising yearly public health impacts associated with water-borne (cholera, dysentery, malaria, typhoid fever and diarrhea) infections and 6 deaths reported in LUM. These leading problems are directly or indirectly linked to consumption of contaminated water or foods in different communities such as Mile II, Isokolo, Bonadikombo (Mile four) etc, and New Town areas and flood prone zones in the Limbe urban municipality.

La escasez de agua se presenta como uno de los mayores retos para asegurar el desarrollo sostenible. Entre otras actuaciones, se deben investigar e implementar sistemas eficientes de tratamiento de aguas biorecalcitrantes, que necesitan ser condicionadas antes de su depuración biológica. Uno de los posibles pre-tratamientos es el proceso Fenton de oxidación avanzada, que presenta dos principales inconvenientes: la utilización de sales de hierro como catalizador homogéneo, que abandonan continuamente la etapa de oxidación, y el elevado consumo de oxidante, en parte desaprovechado. La presente tesis se centra en el estudio de la mejora del proceso Fenton de aguas fenólicas mediante su acoplamiento con tecnologías de membrana como la nanofiltración, la emulsificación con membranas o los reactores de membrana. El acoplamiento de dichas tecnologías con el proceso Fenton permite el confinamiento del catalizador y el aumento de la eficiencia de oxidación, mejorando así el tratamiento en términos ambientales y económicos. / Water scarcity is one of the major challenges for assuring a sustainable development. Among other measures, research into efficient wastewater treatment systems to deal with biorefractory wastewaters, which need to be amended before their biological degradation, is required. The Fenton process is an advanced oxidation process that can be used as potential pre-treatment for this purpose. However, the pre-treatment presents two main limitations: the use of iron salts as homogeneous catalyst, which are continuously thrown away in the reactor effluent, and the high consumption of oxidant, which is partially wasted. The present thesis aims at studying the improvement of the Fenton process applied on phenolic wastewater through its coupling with membrane technologies such as nanofiltration, membrane emulsification or membrane reactors. The coupling allows confining the catalyst and increasing the oxidation efficiency, thus enhancing the treatment efficiency in environmental and economic terms.

Water consumption and wastewater generation depletes water resources and has a destructive impact on the environment. Recent attention has aimed at preserving water resources and preventing pollution through several routes. Restrictions on wastewater discharge into the environment, recycling, reuse and regeneration of wastewater streams are now common practices toward achieving these objectives. Membrane and integrated membrane processes have been shown to be effective at reducing water usage and recovering valuable compounds. This thesis focuses on topics related to the optimal synthesis of wastewater treatment networks by hybrid membrane systems. The use of superstructures has been a useful tool to synthesize chemical engineering process flowsheets. The approach postulates all possible alternatives of a potential treatment network. Within the representation, an optimal solution is assumed to be hidden in the given superstructure. State space is a framework to process synthesis problems which involves heat and mass exchange. In this representation, unit operations, utility units and utility streams can be embedded in such a way that all the process synthesis alternatives can be realized. Such a framework can be applied for water and wastewater synthesis problems. Several research optimization studies presented membrane and hybrid membrane process synthesis problems for wastewater treatment. Nonetheless, the problems in fact can be represented in several ways. Therefore, the mathematical programs are expected to be different for every postulated representation. Comparison between different representations and their mathematical programs are analyzed to highlight the relationship between the superstructure representation and their mathematical programming formulations. Possible improvement of these superstructures is addressed. Also, a generic representation is provided to give a systematic and clear description for assembling hybrid membrane system superstructures via the state space approach. The synthesis of reverse osmosis networks (RON) for water and wastewater treatment network is presented as a superstructure problem. The mathematical programming model describes the RON through a nonconvex mixed integer nonlinear program (MINLP). A mixed integer linear program (MILP) is derived based on the convex relaxation of the nonconvex terms in the MINLP to bound the global optimum. The MILP models are solved iteratively to supply different initial guesses for the nonconvex MINLP model. It is found that such a procedure is effective in finding local optimum solutions in reasonable time. Water desalination and treatment of aqueous wastes from the pulp and paper industry are considered as case studies to illustrate the solution strategy. The RON mathematical program is a nonconvex MINLP which contains several local optima. A deterministic branch and bound (B&B) algorithm to determine the global optimum for the RON synthesis problem has also been developed. A piecewise MILP is derived based on the convex relaxation of the nonconvex terms present in the MINLP formulation to approximate the original nonconvex program and to obtain a valid lower bound on the global optimum. The MILP model is solved at every node in the branch and bound tree to verify the global optimality of the treatment network within a pre-specified gap tolerance. Several constraints are developed to simultaneously screen the treatment network alternatives during the search, tighten the variable bounds and consequently accelerate algorithm convergence. Water desalination is considered as a case study to illustrate this approach for global optimization of the RO network. Wastewater and groundwater streams contaminated with volatile organic compounds (VOCs) require proper treatment to comply with discharge standards or drinking requirement restrictions. Air stripping and pervaporation are two common treatment technologies for water streams contaminated with VOCs. The combination of these technologies for water treatment which are representative of hybrid membrane systems may offer advantages over stand-alone treatments. Superstructure optimization uses the framework of hybridization to determine the optimal treatment network and the optimal operational requirements for the treatment units to achieve desired water qualities. Two case studies are presented to illustrate the proposed approach and sensitivity of the optimal solutions to given perturbations is analyzed.

In Sweden more than 400 000 private households have not yet sufficient wastewater purification. These effluent is considered as an increasing problem and many onsite purification methods have been studied. In this investigation, the method of reactive bed filters have been tested by column and batch experiments. Five different kinds of filter materials with reactive surfaces have been studied concerning their capacity to absorb ammonium and phosphorus from wastewater. The materials that were examined are Filtra N, wollastonite Filtra P, blast furnace slag and Polonite®. The first two materials were examined for their capacity to remove ammonium, and the others for their phosphorus removal capacity. Ten columns were used, two for each material. A synthetic solution with the ammonium and phosphate concentration similar to that of domestic wastewater (NH4-N 30 mg/l; PO4-P 5 mg/l) were pumped to the columns under two flow regimes. Five columns were continuously saturated with solution and the other five columns were saturated under three one hour periods a day The solution was pumped three times a day to the columns at a volume equal to the pore volume of each material. The objective of the batch experiment was to find out how variations in pH-value and concentration of the nutrients influenced the sorption capacity of the materials. The result was then used for modelling in the computer program Visual Minteq to determine the probability of precipitation of known compounds. Results from the column experiment showed that sorption of phosphorus in both saturated columns and intermittently saturated columns were 96 % or more for blast furnace slag, Filtra P and Polonite®. Filtra N showed the best ammonium sorption with 92 %. Sorption of ammonium was much better in periodically saturated columns for the material wollastonite. The wollastonite used in this experiment showed a higher phosphorus sorption capacity than expected. A possible explanation could be that the easy weathering of Ca-silicate compounds favoured the sorption of phosphorus. Results from Visual Minteq modelling showed that the probability of calcite formation in Filtra P and Polonite® are very likely. The two materials had high pH-values and the calcite was most likely formed at values of pH &gt; 10. Hydroxyapatite is the most common precipitation when phosphorus sorption occurs and is suggested to be formed in wollastonite. / Mer än hälften av Sveriges enskilda avlopp bedöms inte uppfylla kraven i miljöbalken på längre gående rening än slamavskiljning. Dessa står för en betydande del av fosfor- och kväveutsläppen till hav, sjöar och vattendrag. Åtskilliga systemlösningar utreds, men i denna rapport har filter med fosfor- och kvävesorberande förmågor testats eller s.k. reaktiva filter. Mineraliska filter som ingått i studien är Filtra N, wollastonit, Filtra P, hyttsand och Polonite®. De två första filtren studerades speciellt på deras förmåga att avskilja ammonium och de tre övriga främst på deras fosforavskiljnings förmåga. Kolonnförsök utfördes med tio kolonner där fem belastades med mättat flöde och de övriga med intermittent mättat flöde. Kolonnuppsättningen var två kolonner per filtermaterial med vardera olika flödesförhållanden. Belastningen på kolonnerna sattes till betydligt högre än traditionell infiltration/markbädd. Ett artificiellt avloppsvatten användes och tillreddes med en koncentration av kväve (NH4-N) på 30 mg/l och fosforkoncentration (PO4-P) på 5 mg/l. De valda koncentrationerna efterliknar ett vanligt hushållsspillvatten. Skakförsök utfördes för att undersöka sorptionsförmågan hos de olika mineraliska filtren där vikten låg på hur koncentrationen av näringsämnena och pH påverkar sorptionen. Resultaten från skakförsöken utvärderades med jämviktsmodellen Visual Minteq. Sannolikheten att kända utfällningar bildas studerades. Resultaten från kolonnförsöken visade att hyttsand, Filtra P och Polonite® gav bäst fosforavskiljning med över 96 % för båda flödesregimerna. Filtra N var den bästa ammoniumavskiljaren med över 92 %. Wollastonit hade en bättre avskiljning med intermittent mättat flöde med 65 % jämfört med 11 % för mättat flöde. En intressant iakttagelse var att wollastonit hade en bättre fosforavskiljning än ammoniumavskiljning med ca 60 % för båda flödena. Det kan bero på att filtret innehåller lättvittrade Ca-silikatföreningar som ökar fosfatavskiljningen. Skakförsöken resulterade i att för Filtra P, hyttsand och Polonite® sorberades all tillsatt fosfat. Filtra N visade samma resultat som i kolonnförsöken med över 92 % sorption. Endast fosfat sorberades vid försök med tillsättning av både fosfat och ammonium till hyttsand och wollastonit. Vid modellering i Visual Minteq finns det en viss sannolikhet att kalcit bildats i Filtra P och Polonite® p g a deras höga pH, kalcit fälls ut vid pH &gt; 10. Hydroxyapatit som är den vanligaste utfällningen av kalciumfosfat vid avskiljning av fosfor bildades mycket troligt i wollastonit.

The continuous process of urbanization results in demands on research and development for ecological and sustainable city development. Because of this, the current systems for wastewater treatment may have to be improved. In order to evaluate new technologies for municipal wastewater treatment, a development project has been initiated for the new district Hammarby Sjöstad in Stockholm. The project is lead by the company Stockholm Water. High environmental standards have been put up for the district, as it must be twice as good as an ordinary new district. To achieve this goal, a new water treatment plant is planned to be build. In the testing facility Sjöstadsverket, several new water treatment processes for municipal wastewater are being evaluated. This thesis is concerned with the evaluation of one of these processes. The process in question is anaerobic and consists of the following steps: pre-treatment, UASB (Upflow Anaerobic Sludge Blanket), aerobic polishing for nitrogen reduction, a drum filter and reverse osmosis. The evaluation is performed by analysis of water sample taken from the whole process. It is difficult to make any conclusions about the process as a whole, since not all of the individual parts have been in use at the same time. The production of gas in the UASB system has been quite low. The cause of this is probably that gas is dissolved in the effluent water. The aerobic polishing is sensitive and it will need adjustments of the pH-value in order to treat the water as planned. The use of chemical precipitation of phosphorus over the drum filter does not reduce the amount of phosphorus below the desired level. Furthermore, the demands on the treated water cannot be reached with the use of reverse osmosis, at least not in its current implementation. / Den allt större inflyttningen till städer och tätorter har gjort att behoven av forskning och utveckling kring ekologiskt hållbar stadsutveckling har ökat. Detta innebär i sin tur att det befintliga systemet för avloppsvattenrening kan behöva förändras. För att utvärdera ny och delvis obeprövad teknik inom behandling av avloppsvatten har ett utvecklingsprojekt startat för Stockholms nya stadsdel Hammarby Sjöstad. Stockholm Vatten har fått i uppgift att leda projektet. För stadsdelen har ett antal ambitiösa miljömål formulerats vilka i korthet innebär att stadsdelen skall vara dubbelt så bra som övrig nybyggnation. För att klara dessa miljömål görs förberedelser för ett eget reningsverk i stadsdelen. I Stockholm Vattens pilotanläggning Sjöstadsverket utvärderas en rad olika behandlingslinjer för rening av avloppsvatten från hushåll och syftet med detta examensarbete är att utvärdera en av dessa försökslinjer. Försökslinjen är anaerob och består av försedimentering, UASB (Upflow Anaerobic Sludge Blanket), ett biologiskt poleringssteg för kvävereduktion, trumfilter samt omvänd osmos (RO). Utvärderingen har gjorts genom analyser av vattenprover längs försökslinjen. Det är svårt att dra några slutsatser om linjen som helhet eftersom inte alla ingående komponenter varit igång samtidigt så som planerat. Gasproduktionen över UASB-systemet har varit relativt låg och det beror troligen på att en del av gasen löser sig i det utgående vattnet. Den biologiska poleringen för kvävereduktion är en känslig process som kommer att behöva pH-justeras för att klara att behandla vattnet från Sjöstaden. Med nuvarande utformning av anläggningen kan man inte med kemisk fällning av fosfor över trumfiltret komma ner under utsläppsgränserna. Kraven på utgående vatten kan inte heller nås med den RO som finns på Sjöstadsverket idag.

The risk of the Iraq’s marshlands disappearing is still high unless serious measures are adopted. Sewage discharge and irrigation-water pressure, compounded by the effects of climate changes and the extent of the planned dam construction in upstream countries, make this event more likely. Most of the marshlands’ inhabitants (Marsh Arabs) are suffering from lack of access to safe, clean water and lack of sanitation and are reluctant to look for better places to live and work. Constructed wetlands are among the best alternatives to solve their problems. The application of constructed wetlands to meet more stringent standards for wastewater reuse in agriculture contributes to mitigating the wastewater impact and irrigation pressure on the marshland ecosystem. It is here proposed that a 3.6 ha free-surface flow wetland  could manage the more stringent standard for reuse (15 mg/l) for BOD5 and TSS. A monitoring programme should nevertheless be associated with this kind of project to minimize health risks that may arise as a result of implementation. Despite the absence of studies that deal with wastewater reuse in irrigation projects at the national level (in Iraq), similar studies worldwide provide evidence of reuse possibilities. Furthermore, a performance requirements framework for wastewater reuse in irrigation projects such as the one suggested by Biswas, draws an approach to meet sustainable development indicators and would likely contribute to support and encourage the Marsh Arabs to settle back in their own areas.