Determination of sorption of seventy five pharmaceuticals in sewage sludge

Sorption of 75 active pharmaceutical ingredients (APIs) to three different types of sludge (primary sludge, secondary sludge with short and long sludge age respectively) were investigated. To obtain the sorption isotherms batch studies with the APIs mixture were performed in four nominal concentrations to water containing 1 g of sludge. The range of APIs concentrations was between ng L-1 to mu g L-1 which are found in the wastewater effluents. Isotherms were obtained for approximately 45 of the APIs, providing distribution coefficients for linear (K-d), Freundlich (K-f) and Langmuir (K-L) isotherms. K-d, K-f and K-L ranging between 7.1 x 10(4) and 3.8 x 10(7), 1.1 x 10(-2) and 6.1 x 10(4) and 9.2 x 10(-3) and 1.1 L kg(-1), respectively. The obtained coefficients were applied to estimate the fraction of APIs in the water phase (see Abstract Graphic). For 37 of the 75 APIs, the predicted presence in the liquid phase was estimated to >80%. 24 APIs were estimated to be present in the liquid phase between 20 and 80%, and 14 APIs were found to have <20% presence in the liquid phase, i.e. high affinity towards sludge. Furthermore, the effect of pH at values 6, 7 and 8 was evaluated using one way ANOVA-test. A significant difference in K(d)s due to pH changes were found for 6 of the APIs (variation 10-20%). (C) 2011 Elsevier Ltd. All rights reserved

Läckage och transformation av flamskyddsmedel och mjukgörare under simulerade deponiförhållanden

Many products used in our everyday life contain chemicals added to give them specific properties. Flame retardants (FRs) are added to prevent or retard fires in textiles, plastics etc., while plasticizers are supplied to make plastics more flexible. Through their widespread applications chemicals from both groups are emitted and spread in the environment during usage and disposal. For a long time these products were mainly disposed of in landfills, and in many areas they still are. Thus, since some of these chemicals also pose potential environmental risks and health hazards, there is a need to elucidate their fates during exposure to the landfill environmentThe objectives of this thesis were to investigate the leaching and transformation of FRs and plasticizers from products in which they are used under simulated landfill conditions. To assess the importance of changes in these processes as landfills progress through recognised ageing phases (accompanied by large transitions in both physico-chemical and biological conditions) it was desirable to simulate the changes that typically occur in landfills within a short time period, of 1-2 years.. This was achieved using the newly developed intermediate-scale (3 litre) Modular Environmental Test System (METS).The METS were employed in two studies. The first was an investigation of the leaching and degradation of plasticizers from PVC carpet material incubated at different temperatures (20, 37, 55 and 70°C) prevailing in landfills. Plasticizers subjected to this investigation were the phthalates di-2-ethylhexyl phthalate (DEHP) and benzyl-butyl phthalate (BBP), both of which were found to leach from the carpet. The leaching of DEHP and BBP generally increased with increases in the incubation temperature. However, the most rapid leaching of BBP occurred at 37°C, probably due to high microbial activity at this temperature. Both DEHP and BBP were shown to be degraded within the landfill environment and the degradation potential was highest during the methanogenic landfill phase. In the second METS study the leaching of FRs used in both reactive and additive applications (i.e. chemically bonded to and merely blended with the material, respectively) was characterised. The epoxy oligomer tetrabromobishpenol A (TBBPA) and the phosphorus-based Pyrovatex FRs were selected as representatives for the reactive FRs, while the nitrogen-based melamine and phosphorus-based Proban FRs were selected to represent additive classes. During the incubations, which lasted more than two years, the leaching from melamine was shown to be affected by the landfill phase development. The leaching from the Pyrovatex-treated material and the TBBPA epoxy oligomer seemed to result almost entirely from the washout of unreacted manufacturing residuals. This was also probably true for the FR in the Proban-treated material, although it is durable (despite being additively applied) and thus seemed to leach more slowly (manifested as an increase in phosphate levels in the leachate towards the end of the monitoring period).Finally, due to the paucity of knowledge regarding the fate of ether derivatives of TBBPA (which are also used as FRs) an anaerobic degradation assay was performed. The method employed for this assay was a modified, small-scale ISO standard method. In order to evaluate the degradation assay a uniform analytical protocol was developed. The degradation survey showed that losses of TBBPA, TBBPA-dimethyl ether and bisphenol A dimethyl ether occurred, but no losses of the most hydrophobic compound, TBBPA-dibromopropyl ether, were observed.Många av de varor och produkter vi kommer i kontakt med dagligen innehåller kemikalier, som tillsats för att materialen i produkterna skall få specifika egenskaper. Till dessa sk funktionella kemiska föreningar hör till exempel flamskyddsmedel och mjukgörare. Den förra förhindrar att produkter fattar eld eller minskar omfattningen av brand. Mjukgörare ingår fr a i plaster för att dessa skall bli smidiga och formbara. Eftersom stora mängder av dessa substanser används eller har använts i produkter i samhället har de spridits till många miljöer. Produkterna hamnar ofta på soptipp, då de inte används mer eller är utnötta. Eftersom flera av dessa substanser innebär risk för hälsa och miljö, är det påkallat att utreda hur de beter sig i soptippsmiljön.Syftet med detta avhandlingsarbete är att undersöka eventuell frisättning och omvandling av dessa två typer av funktionella kemikalier i deponimiljö. Sedan tidigare vet man att sådan frisättning kan var starkt kopplad till åldern och därmed utvecklingen av den kemiska och fysiska miljön förändrats fr a genom tillväxten av mikroorganismer i soptippen. För att komma åt att studera frisättningen under de för deponier karakteristiska utvecklingsfaserna utvecklades en metod (Modualr Environmetal Test System; METS) för att simulera faserna över relativt kort tid (ca 1-2 år). I avhandlingen presenteras två studier, där METS utnyttjats: 1) Frisättning av mjukgörare från en PVC-matta i relation till temperaturer, som uppträder i soptippar (20-70oC) samt 2) Läckage av olika flamskyddsmedel i reaktiv respektive additiv användning studerades för olika applikationer. Vid reaktive applikation är flamskyddsmedlet kovalent bundet till polymeren i produktmaterialet, medan det additivt använda flamskyddsmedlet är inblandat i materialet.Två ftalater (di-2-etylhexyl ftalat, DEHP och bensyl-butyl ftalat (BBP), visade sig läcka från mattan, vilket ökade med högre temperature. De frisattes dock som mest vid 37oC, vilket sannolikt beror på den höga mikrobiella aktiviteten vid denna temperatur. Båda ftalterna bröts ned i soptippsmiljön och hastigheten var störst i den metanogena fasen.En epoxyoligomer (tetrabromobishpenol A TBBPA) och Pyrovatex, som bygger på en fosforförening, användes som modeller för reaktiva flamskyddsmedel. Melamin, som klassas som ett kvävebaserat flamskyddsmedel, fick tillsammans med Proban (fosforbaserat) represen-tera de som används additivt. Medan en frisättning av melamin kunde relateras till utvecklingen av deponimiljön simulerad i METS, så verkar den observerade frisättningen av kemikalierna från de reaktivt behandlade Pyrovatexmaterialet och från epoxipolymeren TBBPA förr ha en fysikalisk-kemisk grund oberoende av utvecklingsfaserna i tippmodel-lerna. Flamskyddsmedlen tvättades helt enkelt ut ur de behandlade produkterna. Probanbehandlingen, som motstår förhållandevis många tvättar trots att det används additivt, visade sig läcka långsamt utan en direkt koppling till fasutvecklingen i METS.Kunskaperna om vad som händer med TBBPA:s eterderivat i deponier är i stort sett obefintliga. Flera av dessa derivat används också som flamskyddsmedel. Därför genomfördes en anaerob nedbrytningsstudie av dessa substanser. För att kunna göra denna studie behövdes en omfattande anpassning och utveckling av metodik, vilket resulterade i ett nytt protokoll för analys av dessa ämnen i olika matriser. Studien visade minskning av koncentrationerna av TBBPA, TBBPA-dimetyleter och bisfenol A dimetyl eter, vilket kan tas som ett tecken på att en transformation och/eller nedbrytning skett. Då dessa föreningar kan omvandlas till mer toxiska substanser bör de undersökas vidare

Läckage och transformation av flamskyddsmedel och mjukgörare under simulerade deponiförhållanden

Many products used in our everyday life contain chemicals added to give them specific properties. Flame retardants (FRs) are added to prevent or retard fires in textiles, plastics etc., while plasticizers are supplied to make plastics more flexible. Through their widespread applications chemicals from both groups are emitted and spread in the environment during usage and disposal. For a long time these products were mainly disposed of in landfills, and in many areas they still are. Thus, since some of these chemicals also pose potential environmental risks and health hazards, there is a need to elucidate their fates during exposure to the landfill environmentThe objectives of this thesis were to investigate the leaching and transformation of FRs and plasticizers from products in which they are used under simulated landfill conditions. To assess the importance of changes in these processes as landfills progress through recognised ageing phases (accompanied by large transitions in both physico-chemical and biological conditions) it was desirable to simulate the changes that typically occur in landfills within a short time period, of 1-2 years.. This was achieved using the newly developed intermediate-scale (3 litre) Modular Environmental Test System (METS).The METS were employed in two studies. The first was an investigation of the leaching and degradation of plasticizers from PVC carpet material incubated at different temperatures (20, 37, 55 and 70°C) prevailing in landfills. Plasticizers subjected to this investigation were the phthalates di-2-ethylhexyl phthalate (DEHP) and benzyl-butyl phthalate (BBP), both of which were found to leach from the carpet. The leaching of DEHP and BBP generally increased with increases in the incubation temperature. However, the most rapid leaching of BBP occurred at 37°C, probably due to high microbial activity at this temperature. Both DEHP and BBP were shown to be degraded within the landfill environment and the degradation potential was highest during the methanogenic landfill phase. In the second METS study the leaching of FRs used in both reactive and additive applications (i.e. chemically bonded to and merely blended with the material, respectively) was characterised. The epoxy oligomer tetrabromobishpenol A (TBBPA) and the phosphorus-based Pyrovatex FRs were selected as representatives for the reactive FRs, while the nitrogen-based melamine and phosphorus-based Proban FRs were selected to represent additive classes. During the incubations, which lasted more than two years, the leaching from melamine was shown to be affected by the landfill phase development. The leaching from the Pyrovatex-treated material and the TBBPA epoxy oligomer seemed to result almost entirely from the washout of unreacted manufacturing residuals. This was also probably true for the FR in the Proban-treated material, although it is durable (despite being additively applied) and thus seemed to leach more slowly (manifested as an increase in phosphate levels in the leachate towards the end of the monitoring period).Finally, due to the paucity of knowledge regarding the fate of ether derivatives of TBBPA (which are also used as FRs) an anaerobic degradation assay was performed. The method employed for this assay was a modified, small-scale ISO standard method. In order to evaluate the degradation assay a uniform analytical protocol was developed. The degradation survey showed that losses of TBBPA, TBBPA-dimethyl ether and bisphenol A dimethyl ether occurred, but no losses of the most hydrophobic compound, TBBPA-dibromopropyl ether, were observed.Många av de varor och produkter vi kommer i kontakt med dagligen innehåller kemikalier, som tillsats för att materialen i produkterna skall få specifika egenskaper. Till dessa sk funktionella kemiska föreningar hör till exempel flamskyddsmedel och mjukgörare. Den förra förhindrar att produkter fattar eld eller minskar omfattningen av brand. Mjukgörare ingår fr a i plaster för att dessa skall bli smidiga och formbara. Eftersom stora mängder av dessa substanser används eller har använts i produkter i samhället har de spridits till många miljöer. Produkterna hamnar ofta på soptipp, då de inte används mer eller är utnötta. Eftersom flera av dessa substanser innebär risk för hälsa och miljö, är det påkallat att utreda hur de beter sig i soptippsmiljön.Syftet med detta avhandlingsarbete är att undersöka eventuell frisättning och omvandling av dessa två typer av funktionella kemikalier i deponimiljö. Sedan tidigare vet man att sådan frisättning kan var starkt kopplad till åldern och därmed utvecklingen av den kemiska och fysiska miljön förändrats fr a genom tillväxten av mikroorganismer i soptippen. För att komma åt att studera frisättningen under de för deponier karakteristiska utvecklingsfaserna utvecklades en metod (Modualr Environmetal Test System; METS) för att simulera faserna över relativt kort tid (ca 1-2 år). I avhandlingen presenteras två studier, där METS utnyttjats: 1) Frisättning av mjukgörare från en PVC-matta i relation till temperaturer, som uppträder i soptippar (20-70oC) samt 2) Läckage av olika flamskyddsmedel i reaktiv respektive additiv användning studerades för olika applikationer. Vid reaktive applikation är flamskyddsmedlet kovalent bundet till polymeren i produktmaterialet, medan det additivt använda flamskyddsmedlet är inblandat i materialet.Två ftalater (di-2-etylhexyl ftalat, DEHP och bensyl-butyl ftalat (BBP), visade sig läcka från mattan, vilket ökade med högre temperature. De frisattes dock som mest vid 37oC, vilket sannolikt beror på den höga mikrobiella aktiviteten vid denna temperatur. Båda ftalterna bröts ned i soptippsmiljön och hastigheten var störst i den metanogena fasen.En epoxyoligomer (tetrabromobishpenol A TBBPA) och Pyrovatex, som bygger på en fosforförening, användes som modeller för reaktiva flamskyddsmedel. Melamin, som klassas som ett kvävebaserat flamskyddsmedel, fick tillsammans med Proban (fosforbaserat) represen-tera de som används additivt. Medan en frisättning av melamin kunde relateras till utvecklingen av deponimiljön simulerad i METS, så verkar den observerade frisättningen av kemikalierna från de reaktivt behandlade Pyrovatexmaterialet och från epoxipolymeren TBBPA förr ha en fysikalisk-kemisk grund oberoende av utvecklingsfaserna i tippmodel-lerna. Flamskyddsmedlen tvättades helt enkelt ut ur de behandlade produkterna. Probanbehandlingen, som motstår förhållandevis många tvättar trots att det används additivt, visade sig läcka långsamt utan en direkt koppling till fasutvecklingen i METS.Kunskaperna om vad som händer med TBBPA:s eterderivat i deponier är i stort sett obefintliga. Flera av dessa derivat används också som flamskyddsmedel. Därför genomfördes en anaerob nedbrytningsstudie av dessa substanser. För att kunna göra denna studie behövdes en omfattande anpassning och utveckling av metodik, vilket resulterade i ett nytt protokoll för analys av dessa ämnen i olika matriser. Studien visade minskning av koncentrationerna av TBBPA, TBBPA-dimetyleter och bisfenol A dimetyl eter, vilket kan tas som ett tecken på att en transformation och/eller nedbrytning skett. Då dessa föreningar kan omvandlas till mer toxiska substanser bör de undersökas vidare

Sorption of 71 Pharmaceuticals to Powder Activated Carbon for Improved Wastewater Treatment

In this study, sorption distribution coefficients were determined for 71 pharmaceuticals, aiming to describe their sorption behavior to powder activated carbon (PAC). The data are expected to be applied when designing and upgrading wastewater treatment plants (WWTP) for improved removal of pharmaceuticals by applying sorption to PAC as an additional removal technique. Sorption isotherms were determined for the pharmaceuticals over a concentration interval covering a wide range from 0.08 to 10 &micro;g/L using PAC at a concentration of 10 mg/L. The best fitted sorption isotherms were used to calculate the distribution coefficients (Kd) and these were applied to estimate that the PAC doses needed to achieve a target concentration of 10 ng/L in the effluent. A target concentration was used since neither discharge limit values nor environmental quality standards in general have been defined for these compounds. Using a %-removal approach does not guarantee achievement of concentrations low enough to protect the water ecosystems. Some of the pharmaceuticals will be reduced by the addition of small amounts of PAC. Examples are atenolol, carbamazepine, citalopram, codeine, fluoxetine and ibuprofen. For others, e.g., oxazepam, an alternative treatment has to be considered since the requested dose is too high to be realistic for a target concentration of 10 ng/L

Sorption of 71 Pharmaceuticals to Powder Activated Carbon for Improved Wastewater Treatment

In this study, sorption distribution coefficients were determined for 71 pharmaceuticals, aiming to describe their sorption behavior to powder activated carbon (PAC). The data are expected to be applied when designing and upgrading wastewater treatment plants (WWTP) for improved removal of pharmaceuticals by applying sorption to PAC as an additional removal technique. Sorption isotherms were determined for the pharmaceuticals over a concentration interval covering a wide range from 0.08 to 10 µg/L using PAC at a concentration of 10 mg/L. The best fitted sorption isotherms were used to calculate the distribution coefficients (Kd) and these were applied to estimate that the PAC doses needed to achieve a target concentration of 10 ng/L in the effluent. A target concentration was used since neither discharge limit values nor environmental quality standards in general have been defined for these compounds. Using a %-removal approach does not guarantee achievement of concentrations low enough to protect the water ecosystems. Some of the pharmaceuticals will be reduced by the addition of small amounts of PAC. Examples are atenolol, carbamazepine, citalopram, codeine, fluoxetine and ibuprofen. For others, e.g., oxazepam, an alternative treatment has to be considered since the requested dose is too high to be realistic for a target concentration of 10 ng/L