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| 5. |
- Levlin, Erik, 1951-
(författare)
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Conductivity measurements for controlling municipal waste-water treatment
- 2010
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Ingår i: Research and application of new technologies in wastewater treatment and municipal solid waste disposal in Ukraine, Sweden and Poland. - 9789174154122 ; , s. 51-62
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Conductivity measurements can be used to monitor the processes in wastewatertreatment that causes changes in conductivity. The processes that in many treatment plants causechanges in conductivity are mainly biological nitrogen removal. Conductivity measurements fromtwo WWTP in Stockholm show no reduction of conductivity in the presedimentation and 21 and28% reduction in the activated sludge process. The conductivity in the inflowing wastewater toLotsbroverket WWTP in Mariehamn, Åland, during 2006 varies from 58 mS/m to 137 mS/m withabout 23% reduction of conductivity in the activated sludge process. At Duvbacken WWTP inGävle, which have biological phosphorus removal and no nitrogen removal, the conductivityvaried between 60 and 100 mS/m with no difference between influent and effluent. Biological Premovalwill give a reduction with 344 to 278 μSm2/g P. However, since the contribution ofphosphate ions can be calculated to about 1 % of measured conductivity phosphorus removal willnot give any decrease in conductivity. Since ammonium nitrogen and alkalinity, which is reducedat biological nitrogen removal, contributes to conductivity with about 33 % and 14 % respectively,it is the three WWTP with biological nitrogen removal that has a decrease in conductivity in thetreatment process. At chemical phosphorus precipitation phosphate will substituted with sulfateand no reduction in conductivity will be achieved. Reduction of conductivity due to biologicalnitrogen removal will consume alkalinity or hydroxide ions. If the amount of available alkalinity ishigh enough (one mole alkalinity per mole ammonia) biological N-removal through nitrificationfollowed by denitrification will give a decrease of conductivity with 842 μSm2/g N. Separationprocesses such as removal of suspended solids through sedimentation or filtration will give nochanges ion conductivity. Separation of nutrients through reverse osmosis will give large changesin conductivity and conductivity can thus be used for controlling the process.
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| 6. |
- Levlin, Erik, 1951-, et al.
(författare)
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Effects of phosphorus recovery requirements on Swedish sludge management
- 2002
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Ingår i: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 46:4-5, s. 435-440
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Tidskriftsartikel (refereegranskat)abstract
- Expected requirements of phosphorus recovery, restrictions on sludge disposal on landfill, and difficulties in obtaining consensus on sludge use on agricultural land has led to several development works in Sweden to change sludge management methods. Especially sludge fractionation has gained interest including following steps to recover products and separate transfer of toxic substances into a small stream. Commercial systems are offered based on technology by Cambi/KREPRO and BioCon and other companies and many other methods are under development. Iron salts are widely used in Sweden as precipitation agents for phosphorus removal and this technology has some disadvantages for phosphorus recovery compared with the use of biological phosphorus removal. The amount of chemicals needed for a KREPRO or a BioCon system was calculated for a treatment plant which has an addition of iron salt resulting in 1,900 mole Fe per tonne DS. The result was compared with the chemical consumption of recovery systems installed at plants with lower use of iron for precipitation. The chemical consumption in equivalents per tonne DS was found to be 5,000 + 6,000 * (molar ratio iron to phosphorus).
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| 8. |
- Levlin, Erik, 1951-, et al.
(författare)
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Fosforåtervinning från avloppsrening med sidoströmshydrolys
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Fosfor kan utvinnas från sidoströmshydrolys i reningsverk med biologisk fosforavskiljning. Lösligt fosfat frigörs vid hydrolys av returslam som är anaerob behandling där kolkälla framställs av slammet. Olika varianter för återvinnning från sidoström är t.ex. PhoStrip-processen, där fosfor utvinns från returslammet av fosforrikt slam från aktivslamprocesser med biologisk fosforreduktion. Ett annat alternativ är att återvinna fosfor från en sidoström som tas ut från den anaeroba delen av aktivslamprocessen, där fosfor har frigjorts till lösningen. Fosforåtervinning från fosforrik partiell sidoström beräknas ge en fosforåtervinning på 60-65%. Försök har utförts med slam från sidoströmshydrolys vid en process med biologisk fosforavskiljning. Efter separation av vattenfasen fälldes fosforn dels med magnesium och dels med kalcium vilket gav en utfällning av fosfor på 79 – 100 %. Vid fällning med magnesium bildades struvit (MgNH4PO4), och med kalcium kalciumfosfat (Ca10(OH)2(PO4)6). Analys av slam före (100 mg P/l) och efter slamhydrolysen visar att 20 % fosfor 20 mg P/l frigörs till vattenfasen. 124 ton fosfor i inkommande avlopp och 20 % frigöring av fosfor vid slamhydrolysen borde ge en fosforåtervinningspotential på 25 ton. Dock, med ett flöde av 54 m3/h genom slamhydrolysen blir fosforåtervinningspotential 9,5 ton per år.
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| 9. |
- Levlin, Erik, 1951-
(författare)
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Förbehandling av bioslam för ökad biogasproduktion och Uppgradering av biogas
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Förbehandling av bioslam för ökad biogasproduktionEftersom bioslam från aktivslamsteget i reningsprocessen ger en lägre metanproduktion än primärslam bör förbehandlingen ske på bioslam. Effekten av olika förbehandlingsmetoder är dock svårbedömd och ofta erhålls inget positivt energiutbyte då energin av ökad produktion av biogas kan vara mindre än tillförd energi vid behandlingen. Vissa förbehandlingsmetoder som ozonering kan vid överdosering oxidera substrat och ge minskad biogasproduktion Litteraturstudien kompletterades med mätning av biometanpotential efter förbehandling av bioslam (Khayi, 2014). Som förbehandlingsmetoder valdes frysning (djupfryst och lättfryst) och uppvärmning. Vid 35 dagars rötning producerade djupfryst slam 221 Nml CH4/g VS, lättfryst 115 Nml CH4/g VS, det uppvärmt 181 Nml CH4/g VS och det obehandlade (referens) 148 Nml CH4/g VS (Nml, normalmilliliter är gasvolym omräknad till en atmosfärs tryck). Djupfrysning och uppvärmning ökade biogasproduktionen medan lättfrysning gav minskad biogasproduktion. Uppgradering av biogasVid uppgradering separeras koldioxid från biogasen varvid metangas erhålles. Uppgradering kan ske genom att koldioxiden absorberas av ett fast (PSA-teknik med zeoliter eller aktivt kol) eller flytande medium (vattenskrubber, polyetylenglykol eller monoetanolamin) eller med membranteknik. Investeringskostnaden för uppgradering är starkt beroende av storleken på anläggningen snarare än av vilken teknik som används, men vid små är investeringskostnaden för membranteknik något lägre. Genom intern metananrikning i rötkammaren kan metanhalten i den producerade biogasen ökas. Detta åstadkommes genom att koldioxid avdrivs från slam som sedan återförs till rötkammaren.
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| 10. |
- Levlin, Erik, 1951-
(författare)
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Intermittent högflödesrening för bräddvatten
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Bräddavlopp från kombinerade avloppssystem är ett stort miljöproblem. Inom VA-kluster Mälardalen har projektet Minimering av utsläpp av föroreningar från bräddning med intermittent högflödesrening initierats för att studera processer för bräddvattenrening. Bräddflödesrening med sedimentering och lagringsvolym bedöms vara en kostnadseffektiv lösning. Om bakterier från bräddning bedöms ge upphov till risk för smittspridning, kan desinfektion av bräddvatten övervägas.
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| 12. |
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| 13. |
- Levlin, Erik, 1951-
(författare)
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Maximazing sludge and biogas production for counteracting global warming
- 2010
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Ingår i: Research and application of new technologies in wastewater treatment and municipal solid waste disposal in Ukraine, Sweden and Poland. - 9789174155235 ; , s. 95-104
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Konferensbidrag (refereegranskat)abstract
- Can wastewater treatment contribute to counteract global warming? Increased biogasproduction for substituting fossil fuel is one possibility. However, using maximum amount of thecarbon source for biogas production there will be no carbon source for biological nutrient removal.This will need development of new methods for nutrient removal without carbon source, for whichstruvite precipitation and can anammox be used. Ozone treatment of digested sludge afterdegassing of CO2 with recycling back to the digestion is a promising method to increase biogasproduction from sludge digestion.At anaerobic digestion half of the energy is utilized as biogas and half remains as organic materialin the digested sludge. To eliminate emission of greenhouse gases from digested sludge, allorganic content in the sludge should be oxidized. At Super Critical Water Oxidation SCWO allorganic content is oxidized and the energy can be utilized.The possibility to use sewage sludge to counteract global warming by recycling carbon to deep seesediments should be studied.
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| 14. |
- Levlin, Erik, 1951-
(författare)
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Maximering av slam och biogasproduktion för att motverka global uppvärmning
- 2010
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Ingår i: Vatten. - 0042-2886. ; 66:1, s. 67-73
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Can wastewater treatment contribute to counteract global warming? Increased biogas production for substitutingfossil fuel is one possibility. However, an active sludge process with biological nitrogen and phosphorus removalconsume organic material, gives a sludge with less digestibility and need energy for aeration. The amountof produced sludge corresponds to half of the organic material in the sewage water. If the degree of digestion is40 % it means that 20 % of the organic content have been transformed to biogas. Anaerobic digestion of thesewage water can give 60 to 80 % conversion of organic material in the sewage water to biogas and thereby 3 to4 times larger biogas production. However, if maximum amount of the carbon source is used for biogas productionthere will be no carbon source for biological nutrient removal. Therefore new methods for nutrient removalwithout carbon source has to be developed, for which struvite precipitation and can anammox be used. Thepilot plant Hammarby Sjöstadsverk is a unique resource owned by KTH and IVL Swedish EnvironmentalInstitute,which can be used for these studies. Also the possibility to use sewage sludge to counteract globalwarming by recycling carbon to deep see sediments should be studied.
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| 17. |
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| 18. |
- Levlin, Erik, 1951-, et al.
(författare)
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Phosphorus recovery from sewage sludge : Ideas for further studies to improve leaching
- 2007
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Ingår i: Integration and optimisation of urban sanitation systems. - 9789171788252 ; , s. 61-70
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Development of methods to recover phosphorus will make handling of sewage sludge moresustainable. In earlier studies sludge incineration ash and SCWO-residues have been leached withacid and base. Acid leaching gives a high degree of recovery but releases besides phosphate alsothe main part of other metals (including heavy metals). This gives a large separation problem andgives a complicated process technology. Leaching with base (NaOH) gives a lower degree ofrecovery (up to about 50 %) however with less dissolution of metals. When leaching with base, thecalcium content in the sludge probably binds phosphorus as calcium phosphate.To improve leaching different possibilities can be studied such as use of a two-step leachingprocess. In a first step acid leaching dissolves calcium and magnesium. Treating the leachate withsulphuric acid, calcium sulphate (gypsum) is precipitated and phosphoric acid is obtained.Remaining ash or SCWO-residual product can afterwards be treated by alkaline leaching. Anotheralternative is to study leaching at anaerobic conditions. Since ferrous iron(II) phosphate is moresoluble than ferric iron(III) phosphate the phosphate is more easily dissolved and the heavy metalcontamination will be lower.
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| 19. |
- Levlin, Erik, 1951-
(författare)
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Phosphorus recovery from sewage sludge : Two-step leaching process with acid and base
- 2007
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Ingår i: Integration and optimisation of urban sanitation systems. - 9789171788269 ; , s. 71-80
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In earlier studies sludge incineration ash and SCWO-residues have been leached with acid andbase. Acid leaching gives a high degree of recovery but releases besides phosphate also the mainpart of other metals (including heavy metals). Leaching with base (NaOH) gives a less dissolutionof metals however with lower degree of recovery (up to about 50 %). When leaching with base,the calcium content in the sludge probably binds phosphorus as calcium phosphate.In this study a two-step leaching process has been tested. Ash and SCWO-residues are in the firststep leached with acid, with the main purpose to dissolve calcium. After leaching experiments withhydrochloric acid and acetic acid at different pH-levels from 3 to 6 leaching with acetic acid at pHlevel4 was chosen as the first leaching step. With a weak acid the dissolution reaction can occur atthe desired pH-level without limitation caused by insufficient amount of acid. In the secondleaching step the solid products was leached with 1 M sodium hydroxide. Two-step leaching gavefor SCWO-residue 23% higher leaching of phosphate and for sludge incineration ash 11 % higherleaching. However, aluminium was also dissolved in the second leaching step, and has to beseparated from the phosphate in a third process step.
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| 23. |
- Levlin, Erik, 1951-
(författare)
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Phosphorus recovery with acid and base from inorganic sewage sludge residues
- 2007
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Ingår i: Water Practice and Technology. - 1751-231X. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Phosphate recovery from sludge incineration ash and sludge residues from Super Critical Water Oxidation, SCWO through leaching with acid HCl and base NaOH was studied. Leaching with base gives a selective dissolution of phosphorus but a low degree of recovery compared to leaching with acid. The high per cent of leached phosphorus compared to leached metals at leaching with acid, and the lower cost for acid makes leaching with acid less expensive. The cost for HCl is estimated to 0.32 Euro/kg P and upward. Since calcium may bind phosphorus at leaching with base, a two-step process was tested. A first leaching step with acid at pH-level 4 to dissolve calcium was followed by a second leaching step with base. Two-step leaching gave more leaching of phosphate, however, not as high as for leaching with acid. The cost for chemicals for two-step leaching was estimated to 1.2 Euro/kg P and upward.
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| 26. |
- Plaza, Elzbieta, et al.
(författare)
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Pilotförsök med MABR på Ekeby avloppsreningsverk : Teknisk rapport av ESEM, KTH & Sweco
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This pilot project with membrane aerated biofilm reactor (MABR) was performed at Ekeby sewage treatment plant in Eskilstuna, Sweden. Ekeby faces a future challenge with growing population, where higher processing capacity is needed and new requirements for total nitrogen <10 mg/L in the discharge, according to the new standard. MABR, a newly developed technology with simultaneous nitrification and denitrification, was chosen as a promising technique to cope with the challenge. The trials were conducted for a 230 days period from July 12, 2017 to February 28, 2018.The pilot was designed as an activated sludge process with pre-denitrification with first an anaerobic tank where Zeelung membrane modules were placed, followed by an aerobic tank and finally a sedimentation unit where the return sludge was returned to the inlet. The feed water for the pilot comes from the treatkment plant's pre-sedimentation. Several analyzes were made on the inflow to the MABR reactor, in the volume with the Zeelung module, in the aerated volume and in outflow from the sedimentation tank. Ammonium content in incoming flow was 27 mg/L at the start of the trial to decrease to an average of 16 mg/L after day 60. Temperature in the inflow decreased during the experiment from 20 °C to 10 °C at day 124, to then stabilize on 12 °C. The reduction of organic material, such as BOD7, decreased from 90% at the start to 60% at the end of the trial, which is attributable to a lack of sludge separation in the final sedimentation.Nitrogen separation increased from 32 % at the start of the trial to an average of 53 % at the end of the trial. Nitrification in the Zeelung module increased from 27 % of oxidized nitrogen at the start of the experiment to 45 % at the end of the experiment. Along with the nitrification in the air volume, the nitrification of ammonium was almost total until day 175, January 3, when it fell sharply to the minimum 40 % on January 23, day 195, due to a combination of load and sludge from the sedimentation stage resulting in a shortened and insufficient sludge age. When the availability of organic carbon for denitrification was considered insufficient to cope with operation at low water temperature, and in combination with low levels of dissolved COD in incoming sewage, acetate was added from day 121. Prior to the addition of carbon source, the denitrification rate was on average 40% after the addition of carbon source, go up to 60% at the end of the test. The processes in the Zeelung module showed better operational stability than in the subsequent aerobic reactor.
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| 27. |
- Tomczak-Wandzel, Renata, et al.
(författare)
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Biogas production from fish wastes in co-digestion with sewage sludge
- 2013
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Ingår i: IWA 2013 Holistic Sludge Management Conference, May 6-8, 2013 Västerås, Sweden. - : Svenska miljöinstitutet (IVL).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Anaerobic digestion of biomass is a commonly used process utilizing troublesome waste for producing biogas. Biogas plants use various types of organic residues including sewage sludge, food industry residues and municipal solid waste. Anaerobic digestion of fish wastes is also possible but is currently not so much used. The amount of fish wastes (by-products and by-catch) depends on fish species, size, season and catch methods. The by-products are generated during fish pretreatment (gutting, heading and filleting).Depending on the efficiency of the production process, even 40-50 percent of total fish catch goes for wastes. Fish wastes have great potential as a source of high valued organic carbon for methane production but also have limitation (high content of ammonia nitrogen). Anaerobic treatment of fish wastes is possible with co-digestion. The main issue for co-digestion process lies in balancing several parameters in the co-substrate mixture: macro- and micronutrients, C:N ratio, pH, toxic compounds, biodegradable organic matter and dry matter. The aim of this work is to find optimal co-digestion substrates to enhance biogas production from fish wastes by determining the most proper ratios of different co-substrates. This work examines the potential for methane production from anaerobic co-digestion fish wastes, grass and sewage sludge (a mixture of primary and secondary).The experiments were carried out in mesophilic temperature with using Automatic Methane Potential Test System (AMTPS II). This equipment automatically measures methane production from batch test. For batch test inoculum is needed and different source for inoculum were used (different SRT). Initial results showed that sludge together with fish intestings produced 0.5 Nm3 CH4/kg VS compared to 0.3 Nm3 CH4/kg VS for grass and fish meat. Sludge and fish as well as grass and fish intestings produced 0.4 Nm3 CH4/kg VS.
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| 29. |
- Trela, Jozef, et al.
(författare)
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Nitritation/anammox-processen för rejektvattenbehandling
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Deammonifikation, baserad på partiell nitritation i kombination med anammox, är som kväveavskiljningsmetod miljövänligare än konventionell nitrifikation/denitrifikation. Detta på grund av minskat energibehov, mindre behov av kemikalier samt lägre utsläpp av CO2 och N2O. Behandlingen av rejektvatten från avvattningsprocessen av rötslam med denna teknik minskar kvävebelastningen på reningsverket som därmed ökar möjligheten att klara framtida strängare reningskrav.Syftet med försöken var att studera strategier för styrning och övervakning av deammonifikationen i biofilmsprocessen i en MBBR (eng. för Moving Bed Biofilm Reactor) och utvärdera inverkan av olika luftningstrategier på processens prestanda och effektivitet. Försök utfördes, både på laboratorienivå och vid en pilotanläggning på Hammarby Sjöstadsverk.En viktig parameter som påverkar hastigheten för kväveavskiljning och aktiviteten hos olika mikroorganismer är koncentrationen av löst syre som bör vara tillräckligt hög för att ammoniumoxiderande bakterier (AOB) skall producera tillräckligt med nitrit för anammoxreaktionen, men inte för hög då det hämmar anammoxprocessen och ger ökad aktivitet hos nitritoxiderande bakterier (NOB).Försöken utfördes med kontinuerlig och intermittent luftning med olika syrehalter och tider för luftade och icke-luftade faser. Aktiviteten hos mikroorganismer i biofilmen mättes genom tester av syreupptagningshastighet (OUR), specifik anammoxaktivitetstest (SAA) och nitratupptagningshastighet (NUR). Onlinemätning av pH, ledningsförmåga och redoxpotential användes för att övervaka processen.Den högsta hastigheten och graden av kväveavskiljning erhölls då syrekoncentrationen var 3,5 mg O2/l och kvoten mellan icke-luftad och luftad fas (R) uppgick till 1/3. Aktivitetstester visade att anammoxbakterier och AOB spelade de dominerande rollerna i biofilmen. De genomsnittliga och maximala värdena för specifika anammoxaktiviteten var 3,0 g N/m2 × d respektive 4,3 g N/m2 × d. Syreupptaget vid AOB-aktivitetstesterna hade ett medelvärde på 4,0 g O2/ m2 × d och ett högsta värde på 5,1 g O2/m2 × d.Intermittent luftning minskade energiförbrukningen och förbättrade processeffektiviteten. Införande av anaeroba faser och hög kvävetillförsel ökar anammoxbakteriernas aktivitet och nitritoxidationen begränsas. Nitritproduktionen är begränsande faktor i enstegs deammonifikationsprocess.Mätning av lustgas i pilotanlägningen, visade att lustgasproduktionen som var beroende av kvävebelastning, koncentrationen av löst syre samt förhållandet mellan luftad och icke-luftad fas (R), varierade mellan 0,4 och 2,0 % av den totala kvävebelastningen.Studien visade att redoxpotential (ORP) kan användas som styrningsparameter för driften av enstegs deammonifikationsprocess. Vid försök med användning av ORP för styrning av luftflödet erhölls den högsta kväveavskiljningshastigheten och effektiviteten när börvärde för ORP var 0 mV.
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| 31. |
- Yatham, Venkata Krishna Reddy, et al.
(författare)
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Enhancing nitrogen removal efficiency of domestic wastewater through increased total efficiency in sewage treatment (ITEST) pilot plant in cold climatic regions of Baltic Sea
- 2017
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Ingår i: International Journal of Sustainable Built Environment. - : Elsevier BV. - 2212-6090. ; 6:2, s. 351-358
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Tidskriftsartikel (refereegranskat)abstract
- The temperatures of sewage water were too low in cold climatic regions of Baltic Sea, which resulted in inefficiency of denitrification in sewage treatment process (STP). This is not prescribed to meet the effluent nitrogen levels (<10 mg/l) as per Urban Wastewater Treatment Directive 98/15/EC. In order to improve the denitrification efficiency and the subsequent removal of nitrogen from the municipal wastewater as per the above European Commission guidelines, modified process was formulated with pre-anaerobic and post-aerobic activated sewage treatment processes. The modified process includes the rise in ambient temperature up to 20 ± 2 °C by using heat exchangers in Increased Technology and Efficiency in Sewage Treatment (ITEST) pilot plant at the Swedish Environmental Research Institute (IVL) laboratory. The experiments were conducted with the modified process of sewage water in one line (treatment line (TL)) and the existing process in another line (reference line (RL)) of the pilot plant. The physical (such as Temperature, Suspended solids and Sludge volume) and chemical (ammonium-nitrate (NH4+-N), nitrate-nitrogen (NO3−-N) and total-nitrogen (TN)) parameters were analyzed. The results concluded that the NH4+-N, NO3−-N and TN concentrations of treated waste water were satisfactory with a concentration of <10 mg/l as per the European Directives 98/15/EEC at treatment line as compared to influent and reference lines. The average nitrogenous-compounds’ removal efficiencies were 84% and 76% of NH4+, 80% and 65% of NO3−, 78% and 62% of TN for TL and RL, respectively.
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