Idag är många städer belägna längs kusten och när städerna växer innebär det att stora ytor våtmark försvinner. Våtmarker i urban miljö kan genom rätt utformning erbjuda varierade miljöer med ett antal värdefulla ekosystemtjänster. Exempel på sådana ekosystemtjänster är vattenrening, omhändertagande av stormvatten, kvarhållande av näringsämnen i marken och möjlighet till rekreation i grönskande miljöer.1 Att anlägga våtmarker i en urban miljö kan innebära ett värdefullt utbyte mellan människa och natur. Dock kan det finnas utmaningar kring att kombinera en rik biologisk miljö och en urban miljö med människans förväntningar på tilltalande estetik och möjlighet för rekreation. För att urbana våtmarker lågsiktigt ska restaureras och anläggas i stadsmiljö krävs det att de accepteras av stadens befolkning.

The last hundred years humans have drastically changed the amount of available nitrogen in nature. Today human activities release twice as much available nitrogen as all natural processes are doing together. We also have degraded nature´s possibilities to take care of nitrogen through the draining of wetlands and straightening of rivers. In order to regain the potential of nitrogen retention in the water systems there now requires a reshape of the landscape we live in. A planned expansion of the mining activities in Garpenberg, Dalarna, would double the content of nitrogen in the waters below the mine.

One of the environmental problems today in seas, lakes and streams is eutrophication. This is often caused by nutrients such as phosphorus (P) and nitrogen (N) that leak from agricultural areas. A measure to partly prevent the nutrient discharge is to construct or restore wetlands.In order to control the efficiency of nutrient reduction of existing wetlands in the county, the administrative board in Västra Götaland wants to find different criterias for reference wetlands. These reference wetlands should represent other wetlands and be used in future evaluations of reduction of nutrients and design of constructed wetlands. According to the administrative board in Västra Götaland the reference wetlands should have a catchment area of about 50 hectare consisting of at least 70 % arable land, to represent wetlands created to remove nutrients.

This work is a part of the project ?Våtmarker i odlingslandskapet ? uppföljning av miljömålen? (Wetlands in arable land ? following-up of the environmental goals). The main objective with this project is to study nitrogen and phosphorus retention in a constructed wetland by using mass balance calculations. Continuous measurements of nutrients and water flow through the inlet and the outlet of the wetland are made. However, substantial amounts of nitrogen and phosphorus were assumed to reach the wetland with a drain-pipe transporting wastewater from nearby houses (10 persons).

The euthropthication of the Baltic Sea is a threat that is beginning to be taken seriously by the governments concerned. In Sweden, regulations concerning the allowed nitrogen (N) concentration in the effluent water from wastewater treatment plants are being tightened up. The Rimbo wastewater treatment plant has been imposed to reduce the annual mean concentration of total N in the effluent water to levels below 15 mg l-1. A more and more common way to reduce the nitrogen level in wastewater is to let the water pass through a wetland. This study investigates the possibility to build this kind of wetland at the outlet of the Rimbo wastewater treatment plant.A prestudy of the topography, soil characteristics and groundwater flow indicates that the land area in question is well suited for the construction of a wetland.

During the nineties, ecological handling of urban storm water became very popular in Sweden. Together with Chalmers University of Technology and two Swedish communities, DHI Water and Environment has been doing research of storm water ponds and constructed wetlands. This thesis work is a part of that research project. The work has been applied at the Bäckaslöv storm water treatment plant in Växjö, Sweden. The plant consists of one storm water pond and a downstream constructed wetland.

Wetlands are important ecosystems and form habitat for both common and threatened species. In Sweden, as well in many other places on earth, there is a lack of wetlands. There is an expressed will to adjust this lack through restoration of wetlands with reduced function and through construction of new wetlands. Follow-ups and evaluations are important steps to optimize these actions. The wetland Vattenparken was constructed 1999 ? 2000 for treatment of surface water.

A water treatment unit consisting of two aeration basins, two settling tanks, a residence basinand a horizontal subsurface flow wetland were used to treat wastewater from an eggprocessing factory in Brazil. The aim of this paper was to determine the efficiency of thesystem in reducing nitrogen, phosphorus, BOD5 and TSS (among other parameters) andgetting a further understanding on different kinds of constructed treatment wetlands as well astheir nitrogen and phosphorus removal processes. The wastewater from the factory consistedof process water from manufacturing and water used for cleaning, no stormwater or sewagewater entered the system. Tests were taken three times a month from October 2013 ?til April2014.

This study was made as a part of a feasibility study on a polishing wetland at Rimbo wastewater plant (wwp) in Norrtälje municipality. The wwp had to decrease the nitrogen discharge to reach the limit 15 mg tot-N/l. The nitrogen in the outlet was mainly in the form of nitrate, hence the wetland mainly ought to support denitrification. The proposed area for the wetland was situated right next to the wwp and was already in the municipalitys posession. One aim of this study was to examine what spieces of plants needed to achieve highest possible denitrification.

Pharmaceuticals that are found in marine ecosystems are a threatening environmental concern, which is known to harm both animal and plant life. One of the reasons for this problem is that the waste water treatment techniques are not optimized to clear waste water from its pharmaceuticals contain. In this master thesis four Swedish treatment wetlands were studied, and their ability to reduce numerous pharmaceuticals in waste water. The four treatment wetlands that were studied were those in Oxelösund, Trosa, Nynäshamn and Eskilstuna. Two ecotoxicological tests and chemical analysis were used.

The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.

The practice of landscape architectural involves forming the space in our cities and suburbs, as well as the landscape surrounding. The need of exploiting green environment leads up to, among other issues, flood problem during heavy rain and overfed water environments. The problem is partially caused by the shortage of knowledge, how the environment is responding of the innovations made by the city- urban planning and how to get sustainability. Research and knowledge how to take care of our environment, in a natural way, is increasing. The object of the thesis is to propose control and balance in Urban wetlands, and discuss the difference a plant design can do. The thesis deals with discourses in the field of landscape architecture, biological diversity, dam construction, limnology, planting design and management, pollution of the environment and urban design practice.

The aim of the study was to investigate if methane emission in a constructed wetland changed in a diurnal pattern correlating to temperature, humidity or light conditions. The gas measurements were carried out with a static chamber technique. The wetland (in Nykvarn outside of Linköping, Sweden) takes care of wastewater to reduce the nitrogen loads. Measurements were carried out at three different occasions in the summer of 1998 on two sites in the wetland. One site was close to the inflow, inhabited by Lemnaceae, and another site was located further downstream inhabited by the emergent macrophyte Typha latifolia.

It is important to construct or recreate different types of wetlands and study their retention of nutrients, since knowledge of their effectiveness in this matter is poor. In 2003 a wetland was constructed on an old meadow on the western shore of Lake Bornsjön in central Sweden. The main purpose of the wetland was to reduce the amount of phosphorus entering the lake, which is the back-up water supply for Stockholm when the city cannot obtain water from Lake Mälaren. Large areas around Lake Bornsjön consist of agricultural land and the nutrient concentrations in the inflows to the lake are usually relatively high (approx. 1 mg/l total nitrogen and 0.05-0.1 mg/l total phosphorus).

Uppsats för avläggande av filosofie kandidatexamen i Kulturvård, Landskapsvårdens hantverk, 15 hp, 2012.