In this report, the application of Principle Component Analysis (PCA) and Partial Least Square (PLS)  regression analyzing methods used to understand the relationship of interdependent loads in municipal wastewater treatment plant. Two different wastewater treatment plants were chosen for analysis of  the relationship between interdependent loads. Firstly, the collected data of incoming wastewater and outgoing water from both Västerås and Eskilstuna wastewater treatment plants were analyzed to find some relationship or correlation between contents and compare the data of both the plants. Secondly, the correlated contents were used to generate the regression model for predicting the value in the future, in this report we have focussed only on ammonium nitrogen value for regression model. The PCA study shows the variation between incoming and outgoing wastewater’s characteristics  given by  Västerås and Eskilstuna plant. / BOD, ammonium nitrogen, nitrogen, phosphorus

Most of wastewater treatment plants (WWTP) are operated under low loading both in water quality and water capacity (flow rate) in Taiwan. Because various treatment methods used in WWTP would cause different power consumptions. In general, the flow rate of wastewater treated is proportional to the power consumption. The purpose of this study is simulating water quality and water capacity with a case of municipal wastewater treatment plant, using standard activated sludge method. In this work we will investigate the feasibility of save power using operation and parameters adjustment in wastewater system. A further step is to conduct the save energy in current WWTP under normal wastewater treatment capacity and national effluent standard. Results showed the major save energy was at inflow pump and aeration system of biological treatment stage. Both power consumptions of two were about 60 ~70 % of total power consumption in the plant. Thus we should focus the operating conditions to plan the save energy project, and calculate the total power system and energy consumption of all unit facilities before we are going to improve the energy save in WWTP. Important note is firstly to select units and facilities having high energy consumption for evaluating the possibility of energy save. Secondly is develop and using a good management system to attain the goal of save energy.

This master thesis gives an account for various aeration schemes that are utilized in conventional activated sludge treatment process in a wastewater treatment plant. By altering between different aeration schemes, the project aimed at reducing energy consumption along with maintaining the treatment performance at the plant. A series of experiments on the treatment performance over several different aeration schemes thus has been conducted on site at Solviken in Mora, Sweden. The project is basically a case study where no parameters were manually controlled except for the aeration schemes at the plant. Energy consumption reduction is logically relative to the ratio between aeration and non-aeration intervals. Several criteria were tested in regards to the treatment performance, including pH value, organic matters, phosphorus substances and microorganisms. The study has come up with a superior aeration scheme for the plant, as well as indicated processes that can be improved at the plant.

Nitrogen removal from wastewater has been exstensively addressed by scientific literature in recent years; one of the most widely implemented technologies consists of the combination of partial nitritation and anaerobic ammonium oxidation (ANAMMOX). Compared to traditional nitrification and denitrification techniques such solution eliminates the requirement for an external carbon source and allows for a reduced production of excess sludge; furthermore, it brings down the costs associated to aeration by 60-90% and the emissions of CO2 by 90%. Similar techniques can turn out to be particularly interesting when stringent environmental regulations have to be met. At present, most of the dedicated research dwells on wastewater at high temperatures, high nitrogen loads and low organic content, as it is typical of sidestream effluents; this project, instead, is focused on mainstream wastewater, characterized by lower temperatures and nitrogen content, but higher COD values. At the center of the thesis is the application of a one-stage reactor treating synthetic mainstream municipal wastewater. The chosen approach consisted in maintaining low DO values, allowing for both for the establishment of a proper reaction environment and for the out-selection of nitrite oxidizers; granular biomass was employed for the experiment, aiming at effective biomass retention. The HRT value was gradually decreased, with a minimum at 6 hours. Resulting nitrogen removal rates proved to be satisfactory, with a maximum TN removal efficiency of 54%. Retention of biomass was also positively enhanced throughout the experiment, and yielded a final SRT value of 15.6 days. The whole process was then inserted into a more complete framework, accounting for possible energetic optimizations of similar treatment plants. Employing COD fractionation as a primary step paves the way for anaerobic digestion side processes, which can produce methane and ultimately provide energy for the main nitrogen removal step. Therefore, envisioning energy-sufficient water treatment processes seems a more and more feasible and realistic possibility.

Many pharmaceuticals are found in municipal wastewater effluents due to their persistence in the human body as well as in conventional wastewater treatment processes. This discharge to the environment can lead to adverse effects in aquatic species, such as feminization of male fish. During the past decade, these findings have spawned investigations and research into suitable treatment technologies that could severely limit the discharge. Adsorption onto activated carbon has been identified as one of the two main technologies for implementation of (future) full-scale treatment. Recent research has put a closer focus on adsorption with powdered activated carbon (PAC) than on granular activated carbon (GAC). Studies where both methods are compared in parallel operation are thus still scarce and such evaluation in pilot-scale was therefore a primary objective of this thesis. Furthermore, recirculation of PAC can be used to optimize the treatment regarding the carbon consumption. Such a setup was evaluated as a separate treatment stage to comply with Swedish wastewater convention. Additionally, variation of a set of process parameters was evaluated. During successive operation at three different wastewater treatment plants an overall pharmaceutical removal of 95% could consistently be achieved with both methods. Furthermore, treatment with GAC was sensitive to a degraded effluent quality, which severely reduced the hydraulic capacity. Both treatment methods showed efficient removal of previously highlighted substances, such as carbamazepine and diclofenac, however in general a lower adsorption capacity was observed for GAC. By varying the input of process parameters, such as the continuously added dose or the contact time, during PAC treatment, a responsive change of the pharmaceutical removal could be achieved. The work in this thesis contributes some valuable field experience towards wider application of these treatment technologies in full-scale. / <p>QC 20161124</p> / MistraPharma

High costs for aeration, greenhouse-gas emissions and excess sludge disposal have entailed a paradigm shift in the wastewater treatment. Microalgal-bacterial-based wastewater treatments have gained increasing attention because of their potential in energy demand reduction and biomass resource recovery. In particular, photosynthetic oxygenation is combined with bacterial activity to treat wastewater avoiding external artificial aeration. To optimize the technology in order to become more competitive than activated sludge, an in-depth investigation about the treatment performance and the microbiology interactions under real operational condition is needed. This work focused on the study of wastewater-borne microalgal-bacterial consortia treating real municipal wastewater. The main objectives were to: (i) Understand the removal mechanisms and the influence of operational conditions to optimize the process; (ii) Analyze the microbial community. At first, a photo-sequencing batch reactor (PSBR), called Pilot, was started up and continuously monitored for two years to analyze the evolution of the treatment performance and of the biomass composition. At the same time, other two lab-scale PSBRs were installed to evaluate if microalgal inoculation is essential to start up a consortium. Samples of these consortia were collected over a period of one year and analyzed through microscopic observations, flow cytometry and metagenomics, to investigate the microbial structure and diversity.A second part of the research focused on the optimization of the Pilot to explore its limit in view of the scale-up of the system. In addition, respirometry was adapted to test microalgal-bacterial consortia to estimate the removal kinetic parameters for future modelling. To conclude, the research project addressed many aspects and lay the foundation to apply a methodological research approach to scale-up this promising technology.

Wastewater treatment is essential to protecting the environment and human welfare. Although chlorination is widely used, the environmental and health concerns associated with chlorine are growing. Treatment facilities are implementing alternative technologies, though the cost and efficiency associated with these practices leave much room in the wastewater field for innovation. Hydropath Technologies Limited introduced a piece of equipment that uses the properties of a transformer to pass an alternating electric current through the pipe and into the contents of the channel. Hydroflow claims that the charged microorganisms react with the oppositely charged water molecule to force osmosis and kill the cell. Disinfection capabilities of three Hydroflow models with varying voltages are tested using municipal wastewater from the secondary clarifier using Escherichia coli concentration as the unit for quantification. After testing the results surrounding theses experiments cannot support the hypothesis that the Hydroflow technology could replace chlorination for municipal wastewater disinfection.

This membrane aerated biofilm reactor (MABR) pilot project was performed at Ekeby wastewater treatment plant (WWTP) in Eskilstuna, Sweden. This plant is facing a future challenge of effluent TN &lt; 10mg/L according to the new standard and the growing population, where higher treatment capacity is needed. The MABR as a newly invented technology, is chosen as a promising countermeasure towards the challenge, because of the simultaneous nitrification and denitrification of this technology. By the time of reporting, this project is still on-going, and more information will be reported later in separate report. The feed water comes from the secondary clarifier of full-scale plant. Dissolved oxygen (DO), processing air and flow rate was manually controlled to test different operational settings. However, there were a lot challenges during the testing period which makes it hard to evaluate the performance of this pilot. The ammonium removal efficiency is satisfying when the pilot was running smoothly. However, the TN removal efficiency did not comply with the expectation, achieved in average of 39,01%, due to the limitation of readily bio-degradable COD (rbCOD), which is a limitation of the biological process in general and is not specific to MABR. This technology is considered as promising by the end of the current testing period, since it can oxidize the ammonium effectively with smaller volume. / Detta pilotprojekt med membranluftad biofilmreaktor (MABR) utfördes på Ekeby avloppsreningsverk i Eskilstuna, Sverige. Denna anläggning står inför en framtida utmaning med utflöde-TN &lt;10 mg / L enligt den nya standarden och den växande befolkningen, där högre behandlingskapacitet behövs. MABR som nyutvecklad teknik, väljs som en lovande motåtgärd för utmaningen på grund av den samtidiga nitrifikationen och denitrifikationen med denna teknik. Vid rapporteringstillfället är projektet fortfarande pågående och mer information kommer att rapporteras senare i separat rapport. Matarvattnet kommer från den sekundärfällningen i fullskaleanläggningen. Löst syre (DO), bearbetningsluft och flödeshastighet kontrollerades manuellt för att testa olika driftsinställningar. Det fanns emellertid många utmaningar under testperioden vilket gör det svårt att utvärdera prestanda för denna pilot. Ammoniumavlägsningsgraden var tillfredsställande när piloten körde smidigt. TN-avlägsningseffektiviteten som i genomsnitt uppnådde 39,01% TN-avlägsning motsvarade emellertid inte förväntan, på grund av begränsningen av lätt biologisk nedbrytbar COD (rbCOD), vilken är en begränsning av den biologiska processen i allmänhet och inte specifik för MABR. Denna teknik anses vara lovande vid slutet av den aktuella testperioden, eftersom den kan oxidera ammoniumen effektivt med en mindre volym.

Rapid urbanization has led to the generation of enormous wastewater after independence. The domestic wastewater generated in municipalities is rich in nutrients such as carbon, nitrogen and phosphorus along with other ions. The generated wastewater due to lack of adequate appropriate infrastructure including low treatment efficiencies are either untreated or partially treated and are let into water bodies. Present sewage treatment plants (STP’s) in the city are either under capacity or malfunctioning and hence are unable to meet the growing demand of burgeoning urban population. Water bodies have the ability to uptake nutrients (remediation by algae, bacteria, macrophytes) provided the wastewater inflow does not exceed the threshold. However, the sustained flow of wastewater beyond the water body’s treatment ability has led to the serious problem of nutrient enrichment in surface water bodies which is evident from algal bloom and profuse growth of invasive exotic macrophytes. This necessitates cost effective environmentally sound treatment options. The current research focuses on the characterisation of domestic wastewater fed ponds/lakes, understanding of nutrient regimes in wastewaters, pond dynamics, nutrient transformation and resource recovery. This has aided in devising an algae based treatment system for Bangalore city. The interplay between various biotic and abiotic factors governs water quality in a water body. Regular monitoring helps in characterisation of the water body and also helps in identifying the sources of external input (if any) to the system. Wastewater generated in urban localities in India, due to lack of adequate appropriate infrastructure including low treatment efficiencies are untreated or partially treated and are let into water bodies. Understanding the nature of the wastewater flow regimes and the turnover of biota with prevalent nutrient conditions is required to design treatment systems. Treatment involves breakdown of complex organism forms into simpler forms and transformations of organic nutrients into inorganic forms that are finally absorbed and assimilated by microbes as algae and bacteria. In wastewater fed urban pond systems, an array of microphytes as well as macrophytes grow and help in nutrient cycling in the system and still manage to remove nutrients to satisfactory levels. However, sustained inflow of wastewater with high nutrients results in the deterioration of the system as nutrient input exceed the supportive and assimilative capability resulting in proliferation of macrophytes, algal blooms, froth formations rendering the system anoxic that results in the loss of functional abilities of the urban pond systems. This biota in the system plays a major role in nutrient removal and recycles. Understanding the nutrient cycling aspects of urban wastewater fed systems is essential to find out the key players in treatment and for devising a sustainable treatment option with resource recovery. The review of wastewater generation, treatment systems highlight shortfall of the treatment systems and need for sustainable treatment for removal and recovery of nutrients such as C, N and P. Characterisation of Varthur water body (spatial extent 220 ha) located in the south of Bangalore city has been done through monthly monitoring for 18 months with the analyses of physico-chemical and biological. The analysis showed BOD removal of 70% (filterable) when the lake functioned as an anaerobic–aerobic lagoon for 6 months at an estimated residence time of 5 days. During this period, the biota of the lake, especially primary producers such as algae, treat the water through remediation of nutrients to nearly standard water quality levels. However, the growth and spread of invasive exotic macrophytes such as water hyacinth rendered the lake anaerobic which reduces its ability (due to absence of low algae) to treat the water. This highlights the role of algae especially Chlorophycean members as Chlorococcum sp., Chlorella sp. and Monoraphidium sp. in treating urban domestic wastewater and the scope for introducing algal ponds/lagoons to treat wastewater treatment and it may be used in a larger number of small towns to enable local reuse of water. The entire pond systems comprises of various components that are deeply affected by the biotic and abiotic factors in the system. Hence, studies on major biotic components were conducted especially on algae and macrophytes and the impact of abiotic factors as wind, light, and precipitation with seasonality’s. The diurnal and spatio-temporal variations in the dissolved oxygen as well other treatment parameters were used for zonation through multivariate analysis. Physico-chemical parameters confirm the nutrient enrichment (high Amm.-N) in the water body due to the sustained inflow of wastewater. High levels of nutrients together with BOD have resulted in the lower DO levels affecting the biological life. Study on biota revealed macrophytes altering the photosynthetic regime in the algae in water bodies thus, creating anoxia and nutrient re-suspension. The multivariate analysis showed three distinct zones (clusters) on the basis of physico-chemical variables and nutrient concentrations in the lake. The sedimentary C and N analysis showed a steady increase in the C: N ratio as a function of residence time. Importance of the various sub-systems in the water body in terms of nutrient uptake and accumulation showed algal systems to be efficient. C budgeting accounted to ~ 7 t/d i.e. ~2574 t/y, indicated that the lake is an accumulator of C. An estimated relatively high gas emission across the water/air interface (17 t/d) to carbon burial into sediments (2.3 t/d) further indicates very high emissions compared to sedimentation showing the dominance of internal C cycles. The overall mass balance, gas exchange and carbon burial balance showed Varthur water body as a major emitter of C due to high primary production, substantive allochthonous carbon inputs and intensive anthropogenic activities in the water body. Gaseous carbon emission accounted for 28 % of the total Influx C. The spatial profile of N in sediment ranged from 2280-3539 mg/kg of sediment dry mass. Very low value of N:P ratio in sediments suggested possible N limitation. The determination of ammonification and nitrification showed lower nitrification rates than the ammonification rates. The potentially mineralisable nitrogen content in Varthur pond sediments varied greatly from 21.65% to 75.54% and was strongly correlated (r2=0.85) to sedimentary TN. N budgeting showed NH4-N as the predominant Nr form for microbial uptake and is the major mechanism for nitrogen removal, followed by the sedimentation process. Bacterial biomass, algal biomass and macrophyte biomass accounted for 14, 4 and 1% N removal, respectively. Ammonium concentration and nitrification accounted for 27% and 2%, respectively. While bacterial uptake remained fairly constant throughout the year, micro-algae was the major player during monsoon and winter and macrophytes dominated Nr capture during summer among autotrophs. From the estimates, it has been observed that nearly 55% Nr was recovered, recycled as cell mass and transferred to a crop system when such N-captured water is used for irrigating fodder crops. About 45% of N input into the system was lost and methods to reduce this loss need to be evolved in the future. The spatial profile of P in sediment ranged from 2111.35-3982.03 mg/kg of sediment dry mass. Inorganic-P (IP) ranging from 1270.27-3505.73 mg/kg was found to be the major fraction (61.16-91.56%) of sedimentary P. High p values in both water columns and sediments showed potential P excess conditions. P concentrations in micro and macro-algae collected during the due course of the study (on dry biomass basis) were 0.347% and 0.939% P respectively. The P fractionation revealed metal oxide bound P (NaOH-P) and constituted major fraction of IP indicating, high concentrations of Fe and Al in sediments. High concentrations of sedimentary N and P indicated possible higher trophic status (bio-productivity/unit volume) signifying its towering nutrient status evidenced from the rank order of P fractions: NaOH-P > HCl-P > NH4Cl-P, which is specific for highly enriched water bodies. P budgeting showed that bulk of the P is trapped in sediment layer with a potential of ~50 % recovery from the sediments indicating, ~70% P retention within the system. The biotic components such as bacteria, algae and macrophytes accumulates a substantial amount of P, immobilising ~139, ~482 and ~131 tonness/yr of P. The sequential P extraction shows that ~70 % of sediment bound P is readily reducible during anoxic conditions which can potentially become bio-available to trigger algal growth. Assessment of treatment efficiency of facultative algal ponds, showed moderate treatment levels with 60 % total COD removal, 50% of filterable COD removal; 82% of total BOD removal and 70% of filterable BOD removal. The N removal efficiency was lower. However, a rapid decrease in the suspended solids after a faster euglenoids growth indicated particulate C removal by algal ingestion. Euglenoides dominated the facultative pond and Chlorophycean members were more abundant in the maturation ponds owing to variable surface BOD loadings. Significant correlations between algal biomass and nutrients indicate the importance of the type and nature of algal communities that can be used as an efficient tool for predicting the dynamics of various phases in wastewater treatment systems. Detailed morphological analysis of dominant algal species i.e. euglenoides was also performed. Euglenophycean members (>14 species) sampled from various locations in the facultative pond based system showed various striae patterns and distinct nano channels on the cell surface that might have possible role in cell secretions. Comparative assessment of treatment systems reveal that algal pond systems performed well under higher organic load with a COD removal efficiency of 70%, TN removal efficiency of 73% and TP removal efficiency of 22%. However, the facultative pond based systems were effective in suspended solid (SS) removal up to 93% and BOD removal up to 82%. The conventional wastewater treatment systems were efficient in terms of SS removal up to 88%, COD removal up to 74% and BOD removal up to 63%, but were highly ineffective in nutrient removal. The evaluation of treatment processes in mechanically aerated systems, facultative ponds and large shallow lake based systems in terms of capital and annual O&M costs, COD removal cost and land requirements reveals that the mechanical systems require 5 times more capital and O&M costs than ponds. The treatment systems were also ranked in terms of the total annual cost (e.g., capital, manpower, chemical, repair, electricity, land). It showed that algal pond systems followed by facultative pond based system are economically better choice than mechanical technologies. Finally, it was found that the large pond based systems could be economically the best option for the developing countries considering all factors, including economic viability and treatment efficiency. The treatment efficiency analysis showed that algal pond systems were the most effective options for treating urban wastewater. Culturing native wastewater species in growth media and wastewaters, assessment of efficient cell disruption and solvent systems, lipid profiles of wastewater algal species were studied. Wastewater grown algal species as Euglena sp., Spirogyra sp., Phormidium sp., Lepocinclis ovum, and Chlorococcum sp. are comparatively rich in lipids. These algae grow mixotrophically and can store substantial amount of wastewater carbon as TAG’s in varied environments. Among the different cell disruption methods used for the study, sonication was the most effective. The combination of maceration and methanol: chloroform: water (2:1:0.8, v/v) (Bligh and Dyer’s, solvent) gave highest lipid extraction yield among other combinations. Further more these wastewater algae as Lepocinclis ovum and Chlorococcum sp. were found to grow better in wastewaters. Increased lipid content was recorded during the cell cultures with accumulation of quality FAME with high saturates predominated by C16-C18 fatty acids. These wastewater algal lipids are suitable for bio-energy generation with potential biomass productivity (6.52 t/ha/yr) of wastewater-grown species as Euglena. The studies on Euglena sp. showed mixotrophic mode that offers an efficient removal of TOC, N and P from domestic wastewater without any pre-treatment. Lipid profiles of the extracted algal oil were similar to the vegetative feedstock oils, indicating a good quality fuel for energy generation. Mixed algal consortia’s bioremediation potential (removal of nutrients) with the scope for biofuel production highlights self flocculating abilities of algal consortia aided in the effective treatment of wastewater with substantial algal harvest. Studies on cultivating wastewater algal consortia in novel cascading algal parcel flow reactor (CAPFR) operating in continuous mode showed 70-80 % nutrient and ~90 % C removal with in a residence time of ~4 days with highest cell densities (0.91 g/l) and productivities (0.26 g/l/d) in the last stages. The lipid contents varied from 26-28 % with highest lipid productivities ~58 mg/l/d in the 2nd phase of the bioreactor. Most of the lipids were associated with the pigments as chlorophyll and carotenoids. Furthermore, the algal rector removed bacteria up to 4 log orders. Essential cations and phosphates were responsible for self clumping of algal biomass in the final stages with a high internal P content within the cell. The algal biomass also showed substantial exothermic peaks and high heat values (~18 MJ/kg). Studies on continuous cultivation of Dictyosphaerium sp. showed that this species could adapt to wastewater conditions and also showed good nutrient removal at lower HRT (2.5 days). The high biomass productivities with high lipid content (~36%) at low HRT in the continuous mode offer potential options for economic and feasible nutrient removal with biofuel production. Investigations on city wastewaters showed low nutrient ratio indicating C limitations and possible scope for algal wastewater treatment. Integration of algal ponds in the present treatment network requires an additional land ranging from ~0.37 to 2.75 ha to treat an MLD of wastewater depending on the nutrient content and influent waters fed to algal systems. The treatment plants require an additional ~1.6 ha of land to treat 1 MLD of wastewater considering an average N and P values of 18 and 5 mg/l. The continuous algal bio-processes implemented at decentralised levels would help in the economical ways for nutrient removal and recycling of the nutrient free waters after treatment. This meets multiple objectives of low cost treatment of wastewater, nutrient recovery and fuel production. Algal nutrient capture and consequent biofuel production would ensure sustainability through i) water purification ii) nutrients capture and iii) biofuel to meet the growing energy demand, and would be an optimal treatment option for urban wastewater. The thesis consists of 10 chapters and basically deals with the development of a sustainable and economically viable bioprocess for wastewater treatment and biomass production. Chapter 1 provides a brief introduction to wastewater; domestic wastewater composition, generation and treatment in developing nations and in the country and review of the various techniques for treatment of domestic wastewaters, advantages of algal processes in nutrient removal (C, N and P) and production of valued by-product such as lipid generation, for its use as biofuel. Chapter 2 is based on primary field investigations in a wastewater fed urban water body/pond systems involving monthly sampling and analysis of various physico-chemical and biological parameters. Assessment of treatment capabilities of the continuous systems through detailed characterisation of treatment parameters is explained in the second chapter. Chapter 3 discusses the role of the major biotic (algae and macrophytes) and abiotic factors in nutrient transformations, the diurnal variations in parameters especially dissolved oxygen, multivariate spatio-temporal analysis of functional abilities for zoning, the activities in the sludge/sediment and transitions in the CN ratio as a function of residence time. Chapter 4 involves studies in C, N and P quantification and budgeting in such pond systems and partitioning of the nutrients and their distribution in various biotic and abiotic subsystems. This chapter also highlights the major nutrient losses from the system and un-utilised nutrient stocks, paving way for beneficial use of nutrients from such man made lagoon wastewater systems. Chapter 5 discusses the mechanisms and efficacies of algal pond based treatment systems through a detailed study and highlight its advantages over the mechanical ASP based systems. This has been done through a comparative assessment of treatment efficiency, economics and environmental externalities. This study also provides necessary insights and potential of wastewater algal species such as Euglena for its abilities in nutrient removal and biomass generation. This provides insights to algal treatment options for optimal resource recovery and utilisation from wastewaters. Chapter 6 focuses on testing the growth, biomass and lipid production of various wastewater algae isolated from treatment ponds. The chapter identifies suitable cell disruption and extraction routes for efficient lipid extraction and assesses the potential of these wastewater grown algae for regional and national biofuel production. Chapter 7 discusses the effectiveness of wastewater grown Euglena sp. and algal consortia in nutrient removal and as a source of lipids for biofuel generation. Chapter 8 involves the design and operation of a continuous algal (uni-algal/algal consortia) bioreactor devised taking insights from earlier field based studies and their potential as efficient urban wastewater treatment systems. Chapter 9 discusses the present nutrient levels in the city wastewaters and also an analysis of the temporal and spatial variation of nutrients in city sewers and elaborates the scope for integration of the algal modules i.e. continuous algal bioreactors (designed in the previous chapter) into existing STP’s. Chapter 10 elaborates significant contributions and outcome of the research.

Det senaste årtiondet har man uppmärksammat läkemedelsrester i den akvatiska miljön. Kommunala avloppsreningsverk är en av de viktigaste källorna till detta. Denna rapport behandlar frågan om att bygga ut avloppsreningsverk med teknik för att reducera läkemedel från kommunalt avloppsvatten. En telefonenkät har genomförts med personal på kommunala avloppsreningsverk. Med hjälp av den försöker rapporten sammanfatta läget för läkemedelsrening i svenska kommuner, hur långt man har kommit, vilka drivkrafter som kan stimulera arbetet och utmaningar som kan komma med det. Rapporten försöker också identifiera skillnader mellan kommuner som kan avgöra om man jobbar för att införa läkemedelsrening. Undersökningen visar att majoriteten av svenska kommuner ännu inte har börjat jobba med frågan; de som har börjat är främst stora kommuner. De flesta har dock hört talas om minst en reningsteknik för läkemedelsrening. I små kommuner är ekonomi och brist på kunskap en framtida utmaning. För de flesta kommuner skulle lagstiftning och lokala politiska beslut vara de viktigaste drivkrafterna för att börja jobba med frågan. Ungefär hälften av kommunerna uppgav att de trodde man skulle börja jobba med frågan inom 15 år. / Pharmaceutical residues in the aquatic environment has been a growing concern in the last decade, and municipal wastewater treatment plants (WWTPs) are an important source of pharmaceuticals to the aquatic environment. This paper treats the question of upgrading public WWTPs with technology for reducing pharmaceutical residues in wastewater. By means of a telephone survey directed at personnel at municipal WWTPs, this report tries to conclude the position of Swedish municipalities; what work has already been done in this area, what possible motives might propel upgrading WWTPs, and challenges that might follow with it. The report also investigates whether there are any differences between municipalities that might determine whether a municipality has engaged in this area. The investigation shows that the majority of Swedish municipalities has not yet started working towards upgrading WWTPs. Those that have are mainly large municipalities. However most have heard of treatment techniques. For small municipalities economy and a lack of knowledge pose a future challenge. For most of the municipalities, legislation and local political decisions would be the most important drives towards upgrading WWTPs. About half of the municipalities in the survey thought that they might start working towards upgrading WWTPs within 15 years.