Sökresultat:
83 Uppsatser om Lakes - Sida 5 av 6
Val av komplementmaterial för våtkompostering av klosettvatten
Emissions of insufficiently treated wastewater, mainly blackwater (i.e. wastewater from toilets), contributes to the eutrophication of Lakes and seas. At the same time, blackwater is a fraction with a low content of heavy metals and, after sanitization, it can recirculate plant nutrients to arable land using the liquid composting treatment method. Liquid composting means that organic material is degraded under aerobic conditions. For sanitization, the blackwater needs to be treated together with energy-rich complementary material.
Kvävestatus och risk för nitrifikation i två avverkade skogsområden i Halland
Nitrogen deposition leads to environmental damage in areas where the nitrogen deposition is high. Southwest Sweden receives an annual nitrogen deposition of up to 20 kg N/ha. Nitrogen that is not assimilated by the vegetation is accumulated in the soil, which may lead to nitrogen saturation and an elevated risk of nitrogen leaching. Nitrogen leaching from forest areas in southern Sweden has proven to be higher than from agricultural areas, which have been thought to be the main contributors to elevated nitrogen levels in rivers and Lakes. The amount of nitrogen that leaches depends on the fraction of the total nitrogen in the soil that consists of nitrate, since nitrate is easily transported through the soil.
Surhetstillståndet i bäckar uppströmskalkdoserare i Dalarnas län
The acid deposition of sulphur- and nitrogenoxides from combustion of coal and oil cause acidification that lowers pH and gives increased contents of metals and altered aquatic biodiversity in the stream. The liming of Lakes and streams, which was introduced to resist the acidification, demand large economic resourses despite of the decreased deposition of the acidifyng substances. Some of the streams are influenced by the acid deposition, while others are naturally acidic. It is therefore importaint to separate the anthropogenically acidified waters from the naturally acidic, in order to optimize the use of governmental fundings for liming. This thesis aims to estimate the acidity status and impact of acidification on 24 catchments upstream liming dispensers, which is part of the liming activities at the County of Dalarna.The acidity status of the streams was classified according to the Swedish Environmental Protection Agency old classification system (Naturvårdsverket 1999) as very acid to acid, with small ability to withstand a pH-change (alkalinity) due to acid deposition.
Kvalitetssäkring av hushållsnära avloppsfraktioner : vad kräver livsmedelsbranschen?
On-site sewage systems are common on the countryside of Sweden with approximately one million on-site systems installed. Due to insufficient function, these contribute significantly to the total discharge of phosphorus to rivers and Lakes, causing eutrophication.
In order to reduce eutrophication and to fulfil one of the environmental quality objectives, the decision was taken by the Swedish Government in 2005 that 60 % of phosphorous in sewage sludge is to be recycled to arable land before 2015. To make recycling a reality, new solutions have to be found. Federation of Swedish Farmers (LRF) takes an active interest in this issue and has initiated this study.
One problem is that the food industry is sceptical towards recirculation due to the risks that products from sewage systems may contain pathogens, heavy metals and unwanted chemical compounds, e.g.
Årstidsdynamik för kvicksilver i ett sövattensediment :
The limit for mercury in fish, set by health authorities, is exceeded in about half of the Lakes in Sweden. Methyl mercury (MeHg) is the most toxic form of mercury and accumulates in fish. Therefore transformation of inorganic mercury (Hg) to methylmercury (MeHg) is an important process that we need to understand in order to possibly counteract the negative effects of mercury in the environment.
The seasonal dynamics of mercury biogeochemistry is likely of great importance for the accumulation of MeHg in the aquatic food web. In thesis the chemical speciation and transformations of Hg and MeHg in bottom waters and sediments is followed in Ängessjön, a small lake located on the east coast in the middle of Sweden. The lake is not directly affected by any industrial pollution and concentrations of Hg in the sediment reflect the atmospheric deposition in this area, as well as processes taking place along the hydrological pathways from soil to lake.
Samples from sediment, bottom- and streamwater were collected in average every second month during the period Feb.
Tillväxtmönster och åldersstrukturer hos opåverkade bestånd av strömlevande Arktisk harr i Sibirien :
It is hard to find streaming waters where humans haven?t affected the fish populations or the
running water it self. In many streams the fish populations are over harvested and this results
in a lack of older and larger fish. This is also the situation for many populations of Grayling
(Thymallus spp.). To be able to develop management plans and to perform actions that
improve the situation for the grayling, it is therefore crucial to know what natural, by humans
unaffected populations look like.
Hydrauliken i Ångersjöns fosforfällor : bestämning av flödesvägar och åtgärdsförslag för optimal fosforbindning vid avloppsrening med reaktiva filter
Discharge of untreated wastewater leads to unnaturally high levels of nitrogen and
phosphorus in rivers, Lakes and the sea, which results in unbalanced ecosystems with
eutrophication and lack of oxygen. Part of the phosphorus in surface waters is coming from
on-site wastewater treatment from scattered households with unsatisfactory purification.
Blast furnace slag is a by-product from iron production, and has in laboratory trials showed good phosphorus binding capacity. To test blast furnace slag as a reactive filter media for phosphorus separation in a full scale experiment, a wastewater treatment plant has been built behind the picnic area at Ångersjön alongside the road E4 in central-eastern Sweden. The plant contains two parallel lines, one with blast furnaces slag and the other with Filtralite-P as phosphorus sorbent. Both filters have showed decreasing phosphorus purification effect with time in spite of a low wastewater load.
Gestaltning av vägar i Skåne - kopplat till sju regionalt viktiga stråk :
This work derives from the question ?What is a beautiful road??. The question is being discussed in interviews with two employees at the Swedish National Road Administration and two former members of the ?Council of environment and beauty? at the Swedish National Road Administration. The interviews are summarized in my own discussion about the concept of ?Beautiful roads?.
Threats and opportunities for the survival of the Yangtze finless porpoise
The Yangtze finless porpoise (Neophocaena phocaenoides asiaorientalis), is a small freshwater cetacean which has recently fallen dramatically in number. It is an endemic species for the Yangtze River and unless drastic action is taken, it risks the same fate as the now functionally extinct Yangtze river dolphin (Lipotes vexillifer). Threats to the porpoise are diverse but they have in common that they are caused by man. Development of the river has been made to supply a growing human population with food, hydropower, and to reduce the risk of flooding. These changes have resulted in a degraded habitat for the porpoise.
Potentiell fosforfrigörelse från sedimentet i Bornsjön, sydvästra Stockholm : The potential leakage of phosphorus from sediment in Lake Bornsjön, south western Stockholm
Lake Bornsjön is situated 30 km southwest of Stockholm in a rift valley lake and consist three basins outstretched in northwest-southeast direction. The surface area is 6,7 km2 with a maximum depth of 18,3 meters, a mean depth of 9,8 meters and a retention time of the water of 6,5 years. The drainage area is 42 km2 and consists mainly of arable land (ca 1000 ha) and productive forestry land (2500 ha), but in the drainage area there are also restored and fairly newly constructed wetlands.Today the Stockholm area receives its drinking water from Lake Mälaren, but if there would be any pollution of this source, Lake Bornsjön would act as the water source. The area surrounding the lake was bought already in 1899 by Stockholm Stad for protection of the lake and was taken over 1993 by Stockholm Vatten AB. It has been a water protection area from 1988 and it was also accepted as a nature reserve in 1995.
Referensvåtmarker för uppföljning av växtnäringsretention i anlagda våtmarker
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.
Concentration and offtake of trace elements and macronutrients in Italian ryegrass (Lolium multiflorum Lam.) and spring barley (Hordeum vulgare L.) grown on soils amended with water treatment residual sludge
Aluminium sulphate (Al2(SO4)3) is usually added during the drinking water treatment processin order to precipitate organic and inorganic material, resulting in aluminium-based drinkingwater treatment residual sludge (WTR). Since 2003 Swedish law no longer permits WTR tobe deposited in Lakes, and there is an interest to explore the possibility to utilize WTR as soilamendment. The aim of this study was to examine the effects of WTR application on cropgrowth and concentrations of macronutrients and trace elements (including micronutrients andpotential toxic elements). A greenhouse pot experiment was conducted with three soils; a clayloam rich in phosphorous (P), a loamy sand rich in P, and a silty loam with a low soil Pconcentration, and two crop species Italian ryegrass (Lolium multiflorum Lam. cv.
Den positiva hälsovågen : En kvantitativ studie om hälsofrämjande arbete
The construction of buildings and paved surfaces changes the natural water balance.Precipitation generates surface runoff and storm water instead of infiltrating into the soil.Storm water has come to be considered as a major source of pollution in Lakes and streams inthe vicinity of urban areas. Reduction of pollutants in storm water is a key action in order toprotect sensitive recipients and maintain high water quality. Storm water is traditionallytransported by storm sewers to the nearest recipient. In recent years the approach to stormwater management has changed; storm water should primarily be disposed of on site, throughlocal disposal of storm water, LOD. LOD is created by a combination of the function ofseveral smaller local facilities and the general sewer system.
Är Lerbodaälven verkligen en problemälv? : undersökning av fosforhalter
Lerbodaälven is a river in the municipality of Kil which, due to high phosphorus content is not meeting the requirements for good ecological status according to the Water Framework Directive. The purpose of this report is to investigate the causes for the high content of phosphorus that has been measured in Lerbodaälven between 1995-2010. Four questions will be answered in this report.
1. Does the sewage treatment work affect the phosphorus level in Lerbodaälven?
The result from the time series analysis shows that the sewage treatment works have a small impact on the phosphorus level in Lerbodaälven.
Tillförsel av använda fosforfilter påverkar inte tillväxten eller fosforupptaget hos korn
The eutrophication of inshore seas, Lakes and watercourses is mainly due to leaching of nitrogen and phosphorus (P) from agriculture. Many efforts are made to reduce the lea-kage of phosphorus in Sweden and the Baltic Sea countries. Phosphorus is also a finite resource and the mining of good quality raw material gets more and more difficult. Se-dimentation dams in combination with filters is one relatively new method to separate P from run-off and drainage water from agricultural land. This study was a part of an IVL Swedish Environmental Research Institute?s project which tests the capacity and func-tion for separation of phosphorus in four phosphorus filters.