Hydrauliken i Ångersjöns fosforfällor
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 scat...
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| Formato: | Otro |
| Lenguaje: | sueco sueco |
| Publicado: |
2008
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| Acceso en línea: | https://stud.epsilon.slu.se/12219/ |
| _version_ | 1855572022844719104 |
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| author | Jansson, Ellinor |
| author_browse | Jansson, Ellinor |
| author_facet | Jansson, Ellinor |
| author_sort | Jansson, Ellinor |
| collection | Epsilon Archive for Student Projects |
| description | 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. Inhomogenous hydraulic in the phosphorus filters was suspected to result in poorer absorption of phosphorus than expected. This hypothesis was investigated in the present study.
There is no gradient in phosphorus contents between filter material located at the entrance as compared to the outlet in none of the filters. Phosphorus contents decline with height in both filters, indicating that most probably the larger part of the wastewater runs in the lower section of the filter as a result of that both the inlet and the outlet were at the bottom. The phosphorus level of the filter with blast furnace slag decreases more as a function of the distance from the bottom than the filter with Filtralite-P. This may indicate that the waterflow is more uniformly distributed in the filter with Filtralite-P.
The absence of any gradient in phosphorus level between the entrance and the outlet and
continuously increasing phosphorus concentrations in the outlet water indicates that the filter was saturated. Analyses of total phosphorus content in material from the filter with Filtralite-P, done at an external laboratory show higher amounts of phosphorus than my own analyses with another method show. The total phosphorus content indicates that the filter is saturated according to the specifications of the Filtralite-P supplier. Regarding the blast furnace slag, a higher capacity to adsorb phosphorus has been documented in other investigations than the amount adsorbed in the filter at Ångersjön.
To optimize the hydraulics in the filters and thereby the phosphorus adsorbing capacity, the inlet or outlet should be placed in the upper horizon of the filter and the water level should be kept as high as possible. |
| format | Otro |
| id | RepoSLU12219 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish swe |
| publishDate | 2008 |
| publishDateSort | 2008 |
| record_format | eprints |
| spelling | RepoSLU122192017-11-02T09:48:00Z https://stud.epsilon.slu.se/12219/ Hydrauliken i Ångersjöns fosforfällor Jansson, Ellinor Dept. of Soil and Environment Soil chemistry and physics 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. Inhomogenous hydraulic in the phosphorus filters was suspected to result in poorer absorption of phosphorus than expected. This hypothesis was investigated in the present study. There is no gradient in phosphorus contents between filter material located at the entrance as compared to the outlet in none of the filters. Phosphorus contents decline with height in both filters, indicating that most probably the larger part of the wastewater runs in the lower section of the filter as a result of that both the inlet and the outlet were at the bottom. The phosphorus level of the filter with blast furnace slag decreases more as a function of the distance from the bottom than the filter with Filtralite-P. This may indicate that the waterflow is more uniformly distributed in the filter with Filtralite-P. The absence of any gradient in phosphorus level between the entrance and the outlet and continuously increasing phosphorus concentrations in the outlet water indicates that the filter was saturated. Analyses of total phosphorus content in material from the filter with Filtralite-P, done at an external laboratory show higher amounts of phosphorus than my own analyses with another method show. The total phosphorus content indicates that the filter is saturated according to the specifications of the Filtralite-P supplier. Regarding the blast furnace slag, a higher capacity to adsorb phosphorus has been documented in other investigations than the amount adsorbed in the filter at Ångersjön. To optimize the hydraulics in the filters and thereby the phosphorus adsorbing capacity, the inlet or outlet should be placed in the upper horizon of the filter and the water level should be kept as high as possible. Utsläpp av orenat avloppsvatten leder till onaturligt höga halter av kväve och fosfor i rinnande vatten, sjöar och hav med bl.a. rubbade ekosystem och syrebrist som följd. En stor del av fosforn kommer från enskilda avlopp med bristfällig rening. Nya kostnadseffektiva material och metoder för fosforavskiljning behövs på marknaden för att avhjälpa detta. Hyttsand är en biprodukt från järnframställning som i laboratorieförsök har visat sig kunna binda fosfor. För att testa Hyttsand som reaktivt filtermaterial för fosforavskiljning i ett fullskaligt försök har en reningsanläggning med två parallella reningslinjer med Hyttsand respektive Filtralite-P som filtermaterial för avloppsvatten anlagts. Filtralite-P är ett beprövat filtermaterial för fosforavskiljning. Anläggningen ligger vid Ångersjön strax söder om Hudiksvall och startades 2004. Mätvärden från pågående övervakning visar att båda filtren har avtagit i fosforavskiljning sedan start. Brister i hydrauliken i fosforfiltren misstänktes ha en avgörande roll för oväntat låg adsorption av fosfor, varför detta undersöktes i detta examensarbete. Erhållna resultat visar att i båda filtren avtar fosforhalten bundet till materialet med höjden. Det tyder på att vattnet passerar genom de lägre delarna av filtret när inlopp och utlopp är placerade i botten. Skillnaden i fosforhalt i höjdled är procentuellt större i Hyttsandsfiltret än i Filtralite-P-filtret vilket möjligen visar att flödet är jämnare fördelat i Filtralite-P-filtret. Avsaknad av gradient i fosforhalt emellan inlopp och utlopp samt ökande halter i utgående vatten tyder på fosformättnad i filtren. För Filtralite-P-filtret visar analysvärden från ett externt laboratorium att materialet hade tagit upp mer fosfor än vad mina egna analyser med en annan metod visade. De externa analysvärdena visar att filtret var mättat enligt tillverkarens specifikationer. Tidigare studier av Hyttsand anger att materialet kan binda in mer fosfor än vad som skett i anläggningen vid Ångersjön. För att förbättra hydrauliken och därmed fosforadsorptionen till materialet bör inlopp eller utlopp placeras i övre delen av filtret samt vattennivån bör hållas så hög som möjligt. 2008-11-06 Other NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/12219/1/jansson_e_171102.pdf Jansson, Ellinor, 2008. Hydrauliken i Ångersjöns fosforfällor : bestämning av flödesvägar och åtgärdsförslag för optimal fosforbindning vid avloppsrening med reaktiva filter. UNSPECIFIED, Uppsala. Uppsala: (NL, NJ) > Dept. of Soil and Environment <https://stud.epsilon.slu.se/view/divisions/OID-435.html> urn:nbn:se:slu:epsilon-s-8546 swe |
| spellingShingle | Dept. of Soil and Environment Soil chemistry and physics Jansson, Ellinor Hydrauliken i Ångersjöns fosforfällor |
| title | Hydrauliken i Ångersjöns fosforfällor |
| title_full | Hydrauliken i Ångersjöns fosforfällor |
| title_fullStr | Hydrauliken i Ångersjöns fosforfällor |
| title_full_unstemmed | Hydrauliken i Ångersjöns fosforfällor |
| title_short | Hydrauliken i Ångersjöns fosforfällor |
| title_sort | hydrauliken i ångersjöns fosforfällor |
| topic | Dept. of Soil and Environment Soil chemistry and physics |
| url | https://stud.epsilon.slu.se/12219/ https://stud.epsilon.slu.se/12219/ |