Abstract The understanding of flow processes is a key to evaluating treatment efficiency in constructed wetlands. This work focuses on the effects of flow paths on phosphorus (P) and nitrogen (N)retention in four treatment wetlands constructed on pristine peatlands in Finland. Particular attention was paid to water residence time, effective flow area and effective flow depth. Both an artificial tracer test and a new method based on the analysis of stable oxygen and hydrogen isotope distributions were employed. Tracer tests were used to calibrate steady-state flow models created using a groundwater modelling MODFLOW code. Furthermore, concentrations of P, Al and Fe in the peat and concentration of N in the surface water were measured. Surface water tracer distributions showed overland flow to be the dominant flow process and it was divided into a preferential flow area and dead zones. Also, active channel formation was observed during the years of the study (2002–2005). The results indicate that the hydraulic performance might deteriorate drastically within a short period of time. The active flow areas in the peatlands comprised only about 40–48% in summer, meaning that large areas with potential for nutrient removal were left unused. Flow simulations showed that a more optimal length of the distribution ditch will create a larger effective flow area and possibly could prevent channel formation. The peat P concentration was 1.8±3.9 mg g-1, and P was accumulated in the preferential flow area. The peat P concentration correlated positively with Al in the Ruka peatland treating wastewater. The results indicate that precipitation chemicals increase the P retention capacity of peatland substantially and maintain P retention at a stable level despite variable P loads. Furthermore, the results indicate that the accumulation of P to peat via adsorption and chemical precipitation is the major P removal process even after 10 years of loading. In Ruka, calculated N concentrations in surface water obtained with a first-order area model, together with regression analysis of the rate constant, were in good agreement with observed N concentrations. If a removal of 70% is to be achieved, the NH4-N loading to the peatland should be below 0.10 mg m2 d-1.

The depth of constructed wetlands (CWs) significantly affects the construction investment that influences the efficiency of the CW and is an important design consideration for optimal performance. The aim of the study was to examine the influence of depth on nitrogen retention in 12 pilot scale free surface water CWs in Plönninge (56◦43 45 N, 12◦43 33 E): 6 shallow wetlands with a maximum depth of 0.5 m and 6 deeper wetlands with a maximum depth of 0.8 m. The outlet N concentration in shallow and deep wetlands were found to be significantly different (p<0.05, p= 0.017). Outlet N concentration over the months June to December in deep and shallow wetlands, was found to be significantly different (F (6,60 = 20.594, p< 0.05). and the N concentration in deep and shallow wetlands was significantly different (F (1,10) = 8.087, p<0.05). The N concentration in September was found to be significantly different from those in all other months. The first order rate constant k was calculated for shallow and deep wetlands; higher k value indicates higher nitrogen retention. The deeper wetlands had higher k values than shallow wetlands and was statistically different (p<0.05, p= 0.002) from the k values for shallow wetlands. This implies that the N retention was higher in deeper wetlands than in shallow and was the highest in September. This was most likely due to the effect of temperature and vegetation in the wetlands.

Language is a central concern of science fiction. From first contact to interstellar warfare, stories about aliens inevitably raise questions of communication. But how do we conceive of alien languages within the constraints of human language? And what do depictions of alien languages reveal about our own language use? Several studies have established the significance and magnitude of the theme of language in (predominantly twentieth century western) science fiction. Building on these studies, I combine macro-analysis with close reading to argue that these alien languages fall on a spectrum of alterity. Within this spectrum, I organise these languages into three distinct gradations of alterity: they help to define their speakers as alien people, creatures or inscrutable beings. The languages of alien 'people’ are structurally similar to our own, and explore the socio-political relationship between language and culture. Those of ‘creatures’ are radically, physically unlike human languages and explore the boundary between humans, animals and aliens. Finally, the languages of ‘beings’ are incomprehensible and prone to spiritualisation. They bring to light the aspects of experience we deem beyond language. This typology provides a framework through which to explore the major themes and questions regarding language, humanity and alterity in science fiction. By presenting these categories in increasing degrees of alterity, I aim to demonstrate that language, like the figure of the alien, is a fundamentally anthropocentric concept. Each category identifies different facets of our language use that simultaneously alienate and define us.

Horizontal subsurface flow (HSSF) constructed wetlands were evaluated for the treatment of flow-through trout farm effluent, phosphorus sorption affinity of gravel-bed media, and influence on Rhodamine WT (RWT) transport. HSSF wetlands coupled with mechanical pretreatment demonstrated significant (p <0.05) removal of total ammonia-nitrogen (TAN), total phosphorus (TP), total organic carbon (TOC), total suspended solids (TSS), five-day biochemical oxygen demand (BOD5), and turbidity. Treatment occurred predominantly within the wetland cells, with minimal removal of studied water quality parameters by means of sedimentation or microscreen filtration (80 ?m mesh). HSSF wetlands removed 69% of influent TSS, 24% of influent TP, and reduced turbidity by 66%. The removal of organic matter within the wetlands, as measured by BOD5, COD, and TOC was 62%, 50%, and 55%, respectively. After receiving effluent from a flow-through trout farm for about one year, the gravel media exhibited moderate removals of soluble phosphorus in batch and column sorption experiments. Partition coefficients (Kd) from batch sorption tests ranged from 45-90 mL/g. Low (60 mL/min) and high (165 mL/min) flow column experiments removed about 50 and 40% of influent PO4-P, respectively. The conservative nature of RWT in subsurface media has been called into question by many authors. Tracer response curves from tests conducted in pilot-scale HSSF wetlands exhibited elongated tails and dual peaks, in addition to mean tracer retention times far exceeding the theoretical value. Laboratory column testing of RWT and the more conservative NaCl tracer supported field data, indicating that RWT was more reactive within the wetland media. / Master of Science

The main objectives of this study were to investigate (i) anovel wetland treatment technology and (ii) selected bed filtermedia for the removal of contaminants from landfill leachate. Areview of the literature concerning experiences of the use ofconstructed wetlands (CW) for the removal of nitrogen fromlandfill leachate, showed that at least three groups oftreatment systems are in practice: sub-surface flow wetlands,hybrid systems (a combination of vertical and horizontal flowwetlands) and, compact constructed wetland (CCW). Most of thesetypeswere generally effective in reducing nitrogen (N,e.g.NH4-N, dominant N species in leachate) down toeffluent concentrations of about 10 mg L-1. Unfortunately, very little evidence ofresponsible mechanisms for the removal of N was presented,although some data indicated denitrification. The treatmentperformance of a compact constructed wetland (CCW) applied atthe Tveta Landfill, Södertälje, Sweden, wasevaluated. Chemically purified leachate and untreated leachatewere applied in periods of 7 day submergence and 7 day drainageto different sections of the CCW. The removal efficiency variedbetween 40 and 82%, and a mass removal rate of up to 5.1 g m2d-1was achieved. The chemical pre-treatment had adecisive role for the highest removal efficiencies obtained andit was unclear whether that treatment enhanced the efficiencybecause of lower toxicity and/or content of fewer competingcations. The possible combination of bed filter media and CCWas an ecotechnological treatment method for landfill leachatewas investigated by bench-scale laboratory column experiments.Reactive filter media (sorbents) was selected from their knownor suggested capacities for removal of heavy metals, nitrogenand phosphorus. Quartz sand or natural sand from an esker wasused as reference medium. Peat was used as an additionalcomponent in mixtures with the reactive media Polonite®(product from the bedrock opoka) and blastfurnace slag (BFS). A small column study also involved zeolite.Phosphorus was efficiently removed by Polonite®and NH4-N to some extent. Concerning metal removal, thebest performance was found as well for Polonite®, especially for Mn, Fe, Zn and Cu. The BFSshowed good removal efficiency for Cu, Ni and Mo. The removalof different elements was suggested to be a combination ofseveral factors,e.g.precipitation, ion exchange and adsorption. Priorto full-scale application of reactive filters at a landfillsite, matrix selection, filter design and operationalprocedures must be developed. Keywords:Blast furnace slag; Compact constructedwetland; Metals; Nitrogen; Polonite; Sorbents

Bitumen extraction in the Athabasca oil sands causes significant disturbance of landscapes originally rich in wetland and forest ecosystems, which now require reclamation as mandated by the Alberta Government. However, most research to date has focused on upland-forest ecosystems with little attention on wetland-peatland ecosystems, which are considered more challenging to construct due to salinization potential from ubiquitous salts used in the oil sands extraction and treatment processes; with particular focus on elevated Na+ due to its detrimental ecological effects. Syncrude Canada Ltd. (SCL) has constructed an upland-wetland system, the Sandhill Fen Watershed (SFW), to advance the understanding of wetland reclamation in the oil-sands region. The SFW is a highly engineered and managed system. Water is supplied from an artificial fresh water source and drainage is enhanced through a constructed surface outlet and an under-drain system intended to provide a downward hydraulic gradient to inhibit the upward movement of salts from the underlying waste material. The objective of this research is to understand the hydrochemical response of the SFW to variations in hydrological management with respect to sources, flow pathways and major chemical transformations of water as it moves throughout SFW. Through surface and pore water sampling, the electrical conductivity and major ions were measured throughout the growing season of 2013 and 2014. Results indicate that the combination of freshwater inflow, flushing of the system with the outflow pump and open underdrains in 2013 kept the overall salinity within the SFW relatively low, with most lowland sites under 1000 µS/cm. Major ion results indicate that most water throughout the SFW classified as Ca-HCO3 or Ca-SO4 in 2013, with higher concentrations in the uplands however Na+ concentrations did not exceed 250 mg/L at any sampling sites. With minimal management in 2014 and consequent limited freshwater input and flushing of the system, the overall salinity of the SFW increased considerably and EC at most sites in lowlands exceeded 1000 µS/cm. Na+, Ca+2, SO4-2 and HCO3- concentrations increased across the SFW, with higher concentrations in the uplands than the lowlands. Although most sites classified as Ca-SO4, the most notable change in 2014 was the presence of several Na+ “hotspots” along the southern hummocks in the SFW, where water samples classified as Na-SO4 and Na+ concentrations reached as high as 886 mg/L. Results provides evidence of modelled upward movement of Na+ from underlying waste materials and subsequent seepage from hummocks with limited pump management in the SFW. / Thesis / Master of Science (MSc)

Phosphorus (P) in stormwater runoff has detrimental effects on water quality and ecosystem health when it reaches surface waters and promotes algal blooms. Constructed wetlands (CWs) have been utilized to combat this problem by containing stormwater and removing excess nutrients. Including filter materials in the design of CWs has shown promise for increasing their capacity for nutrient removal. This mesocosm scale study was conducted outdoors over a 12-month period to evaluate the effectiveness of three filter materials in their ability to adsorb phosphorus, retain water, and support plant life. The filter materials examined were electric arc furnace (EAF) slag, engineered biochar, and sand. All treatments demonstrated positive plant response and the ability to retain water. The EAF slag and biochar removed significant amounts of P from effluent and appear to be suitable materials for integrating into CW design. Sand was found to be ineffective as a P filter.

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