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In this thesis project, different existing granular activated carbon regeneration methods/technologies are assessed based on existing literature. The project aims to identify and analyse the method with the highest on-site regeneration potential by using the Himmerfjärdsverket wastewater treatment plant as a reference and performing a cost estimation analysis.  Information is gathered about different methods from the literature study and then sorted into the following parts: working principle, technology readiness and cost, advantages and disadvantages, and references (case studies). The methods are then assessed and compared by a scoring and weightage system, where the factors which are regeneration efficiency, ease of implementation, sustainability, cost, and reliability are weighted and then scored for each method. Furthermore, the highest scoring method is then compared to the proposed regeneration method at Himmerfjärdsverket.  The results from my comparison and assessment show that chemical regeneration is the highest scored method, followed by microwave and wet-oxidation regeneration methods. On applying chemical regeneration at Himmerfjärdsverket, it is found out that it may indeed be cheaper and more sustainable than the proposed off-site regeneration method. However, thermal and biological regeneration are better alternatives at Himmerfjärdsverket than microwave and wet- oxidation.  From the above results, chemical regeneration has the highest potential for on-site regeneration of granular activated carbon in Sweden. / Läkemedel i vatten är ett stort hot mot miljö och hälsa. Kommunalt avloppsvatten består av avloppsvatten från hushåll, privata och offentliga institutioner och dagvattenavrinning. En viktig läkemedelskälla i avloppsvatten är ett läkemedel som kommer in via urin och / eller avföring. Olika tekniker finns för avlägsnande av farmaceutiska rester och andra mikroföroreningar från avloppsvatten. En sådan teknik är adsorptionen av dessa rester med hjälp av Granulärt Aktivtkor (GAC). Aktivtkor (AC) är ett kolhaltigt material med liten pordiameter, stora porvolymer och hög specifik yta rea vid bearbetning. Det anses vara det bästa adsorptionsmedlet för att adsorbera organiska, oorganiska och giftiga metalljoner som finns i avloppsvattnet. Det finns två typer av aktivtkol som används för att avlägsna farmaceutiska rester: Granulärt aktivtkol och pulveriserat aktivt kol.  Denna forskning syftar till att identifiera, jämföra och bedöma befintlig regenereringsteknik för att hitta den teknik som har störst potential och använda den på ett referensavloppsreningsverk. Det finns olika metoder för regenerering av använt aktivt kol (SAC). Dessa är termisk regenerering, kemisk regenerering, biologisk regenerering, elektrokemisk regenerering, mikrovågsregenerering och våt-oxidationsregenerering. Metoderna listas och förklaras med hjälp av deras arbetsprincip, beredskap, kostnad, fördelar, nackdelar och referenser till studier där de har använts.  Flera kriterier / faktorer beaktas för bedömning och jämförelse av olika regenereringsmetoder. Faktorerna poängsätts sedan med hjälp av ett viktat poängsystem. Var och en av de ovannämnda faktorerna görs mellan 0–5 och tilldelas en vikt mellan 1–3. En högre poäng betyder bättre prestanda i den givna faktorn. Medan en högre vikt betyder betydelsen av faktorn.  Från bedömningen visar sig kemisk regenerering vara den mest lämpliga metoden för regenerering av GAC på plats. Den minst lämpliga metoden är biologisk regenerering med en total poäng på 39. De två bästa regenereringsmetoderna på plats är kemisk och mikrovågsregenerering. I procent har kemisk regenerering och mikrovågsregenerering en rating på 93,3% och 90%. För att validera resultatet av bedömningen används Himmerfjärdsverket som referensavloppsverk.  Himmerfjärdsverket bygger om och expanderar till en högteknologisk anläggning. Den nya anläggningen kommer att bestå av modern reningsteknik och hög reningskapacitet. Den planerade nya anläggningen förväntas vara klar 2025, medan byggandet påbörjades i januari 2020.  I en studie genomförd av Syvab i samarbete med Ramboll, IVL och SU anges att det skulle behövas kolförbrukning på 15–20 g / m3 vatten. Den totala kostnaden per behandlat avloppsvatten skulle sannolikt öka med 20–30% till 2027 om läkemedelsreningen genomförs på Himmerfjärdsverket med hjälp av GAC och av regenereringsmetoden utanför anläggningen. Himmerfjärdsverket kommer att konsumera 3,92 ton kol dagligen eller 27,56 ton varje vecka. Detta kommer att kosta 28,7 miljoner SEK / år för 20 000 EBV (i värsta fall) och 11,5 miljoner SEK / år för 50 000 EBV.  Medan kostnaden för kemisk regenerering av GAC med högsta regenereringseffektivitet uppskattas till 27,4 miljoner SEK / år för användning av flytande NaOH-lösning och 17,7 miljoner SEK / år för användning av fast NaOH för 20 000 EBV. För mängden 573 t / år kol kommer NaOH-förbrukningen att vara 2083,5 t / år, vilket kommer att kosta 7,1 och 10,9 miljoner SEK / år för 50 000 EBV.  Eftersom kostnad är en av de viktigaste faktorerna som motverkar tillämpningen av metoder som är lika tillförlitliga som termisk regenerering. Om termisk regenerering implementeras på Himmerfjärdsverket kan installationen användas för att regenerera GAC från andra reningsverk från Stockholm. 2 GAC-bio filter i serieskapare bättre förutsättningar för biologisk regenerering av GAC samt ger låga föroreningskoncentrationer och höga syrekoncentrationer. För att lägga till det producerar Himmerfjärdsverket biogas som kan användas för att uppnå höga temperaturer som krävs enligt denna metod eller generera den erforderliga elen eller båda. I alla tre fall kommer kostnaden att minskas ytterligare.  Avslutningsvis har kemisk regenerering den högsta regenereringspotentialen på plats bland alla andra studerade metoder. Medan termisk regenerering är nära den andra på grund av kolförlusten. En pilotstudie krävs för att validera de regenereringseffektivitet som nämns i litteraturen och bearbetningsförhållandena och typerna av adsorbera vid Himmerfjärdsverket behöver utvärderas liksom behandlingsförhållandena.

Aevitas is an industrial wastewater treatment plant that receives about 300 m3/day of mixture of wastewater from different industries. The chemical oxygen demand of higher 600 ppm and the variety of the chemical constitution of industrial wastewater are two significant problems on Aevitas. Therefore, there is a strong need for developing advanced analytical techniques that can identify the specific compounds that are the source of COD. During 10 months, about 75 industrial samples were characterized using a battery of tests including GC/MS, COD, TOC, and pH to identify the chemicals that are main source of COD in the industrial wastewaters. Results showed that the COD of 87% of 75 provided samples from Aevitas plant was higher than 600. At the first step of process design, activated carbon was used to eliminate the identified organic chemicals from the wastewaters. The maximum and minimum of COD removal (depends on the chemical composition) of the wastewaters were obtained as 94 and 24%, respectively. Moreover, the amount of COD and TOC that can be adsorbed on the surface of 1 gram of the activated carbon were 25 and 7 mg, respectively. Although activated carbon is capable to reduce the COD, its capacity of adsorption is limited. To overcome this problem an alternative process, membrane filtration was applied for COD removal. Two types of crossflow NF (NF270, NF90, NFX, NFW, NFS, TS80, XN45, and SXN2_L) and RO (BW60 and TW30) membranes in two modules of the spiral wound and flat sheet were used. The filtration results of 11 different industrial wastewaters showed that NF90, TS80, NFX, and NFS were effective in COD removal. However, in terms of output flux NFX and NFS flat sheet were better than others were. Similar to the activated carbon process, the COD removal in filtration process was between 30 and 90%. The obtained results can be used to scale up the membrane filtration process at Aevitas. / Thesis / Master of Chemical Engineering (MChE) / Aevitas is an industrial wastewater treatment plant, which is situated at the City of Brantford. Every day, this plant receives about 15 trucks of the mixture of wastewaters from many different industries. The input wastewater into the plant should be treated and meet the environmental standard so that it can be discharged into a municipal wastewater plant. Currently, the maximum allowable chemical oxygen demand (COD) for discharging the treated wastewater from Aevitas to the municipal wastewater treatment plant is 600 ppm. Despite the fact, the current system in Aevitas is not efficient to meet this criterion. Thus, we strive to design efficient processes to overcome the problem. To this end, 75 samples were collected from Aevitas to observe the kind of chemicals that are the source of COD and then, two processes including activated carbon adsorption and membrane filtration were used for further reduction of COD. Although activated carbon can reduce the COD, the limited adsorption capacity was a major concern for its long-term application, especially if the COD of influent wastewater is higher than 2000 ppm. Membrane filtration was used as an alternative for activated carbon and the results showed that membrane could reduce the COD below 600 in 48% of the cases.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第23517号 / 工博第4929号 / 新制||工||1769(附属図書館) / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 佐野 紀彰, 教授 宮原 稔, 教授 河瀬 元明 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Yes / The character of dissolved organic matter (DOM) present in drinking water treatment systems greatly impacts its treatability by coagulation–flocculation. Powdered activated carbon dosing has been suggested to enhance DOM removal when combined with coagulation–flocculation. However, optimising powdered activated carbon (PAC) dosing requires further research. In this study, fluorescence spectroscopy combined with parallel factor analysis (PARAFAC) and liquid chromatography with organic carbon detection (LC–OCD) has been used to characterise DOM removal in three ways: (a) coagulation–flocculation–sedimentation without PAC dosing, (b) PAC dosing prior to- and (c) PAC dosing during coagulation–flocculation–sedimentation treatment. It was shown that only coagulation–flocculation–sedimentation preferentially removed biopolymer and humic substance chromatographic fractions and fluorescent DOM, whereas dosing PAC preferentially removed building blocks and low molecular weight neutral chromatographic fractions. The DOM treatability that was achieved when PAC was dosed both prior to- and during coagulation–flocculation–sedimentation was comparable, but higher than what was achieved without any PAC dosing. Introduction of PAC to the coagulation–flocculation–sedimentation process significantly improved DOM removal, with fluorescent components removed by 97%. This study also highlights that a combination of fluorescence spectroscopy and LC–OCD is essential to track the removal of both, fluorescent and non-fluorescent DOM fractions and understand their impacts on DOM treatability when using different treatment processes. Overall, lower residual DOM concentrations were obtained in the treated water when PAC adsorption and the coagulation–flocculation–sedimentation processes were combined when compared to treating the water with only one of the processes, despite differences in source water character of DOM.

Yes / In this work, adsorption desulfurization is considered for making cleaner fuel. New efficient adsorbents have been designed by using two active metal oxides mainly potassium permanganate (KMnO4) and potassium phosphate (KPO4·3H2O) on Activated Carbon (AC). Ultrasonic assisted impregnation method (IWI) is used in designing the adsorbents offering high pore volume, pore size, surface chemistry, and high surface area. Use of ultrasonic method increases the dispersion of the active material (groups) on AC leading to increased number of collisions between O-atom on AC-support resulting in high sulfur removal from fuel. KMnO4 on AC shows higher adsorption capacity towards sulfur than KPO4·3H2O at the same operating conditions. New results with respect to sulfur removal has obtained compared with those obtained by previous studies. Finally, the adsorption kinetic parameters of such process are developed. Thomas and Yoon-Nelson models and the experimental data are used for this purpose using linear and non-linear regression analysis. Yoon-Nelson kinetic model fits well with the experiments data better than Thomas kinetic model in the entire adsorption column system.

The Fe(II) regeneration process is an important aspect of Alternate Anode Reaction Technology (AART) using Fe(II)/Fe(III)-SO2 reactions for copper hydrometallurgy; however little has been done to study it specifically. The process regenerates Fe(II) via Fe(III) reduction by SO2(aq), catalyzed by activated carbon particles. To better understand and improve the process, two studies have been conducted with respect to variable factors and their affects on the regeneration. A study of fundamental kinetics confirms that the regeneration reaction is mass transfer-controlled, requiring adsorption of reactants onto the catalyst surface for reaction. The reaction rate is limited by the diffusivity of Fe(III). Initial Fe(III) concentration and carbon particle size are determined to be the most influential factors on the rate under the condition studied. Furthermore, it is observed that flow rate may inhibit the reaction by reducing ion diffusivity. A rate expression for the regeneration is derived and experimentally validated, and the Fe(III) diffusivity is determined to be 1.1x10-7 cm2/s. An optimization problem is also developed and solved for the process, constrained by the requirement that negligible SO2 could be present in the process effluent. Before optimization, a relationship is developed between regeneration rate and variable factors. Again, carbon size and initial Fe(III) are the most influential factors on the regeneration rate, related to it linearly; temperature is significant with a squared relationship to the rate; initial SO2 is insignificant. Optimal conditions are found with minimum carbon particle size, maximum initial Fe(III) concentration, and moderate temperature. / Master of Science

The main objective of this study was to determine the applicability of advanced water treatment processes namely granular activated carbon (GAC) adsorption, ultraviolet (UV) light disinfectant and ozone in the management of deteriorating water quality in the Mid-Vaal River system for drinking purposes. Both the scarcity and the deteriorating quality of water in South Africa can be addressed by investigating advanced water treatment processes such as GAC adsorption, UV light disinfectant and ozone. Previously disregarded water resources have the potential to be purified and advanced treatments can improve water quality where conventional water treatments have failed. In addition, advanced treatment processes can be applied to treat used water. The two sampling sites selected for the study, Rand Water Barrage (RWB) and Midvaal Water Company (MWC), are both located in the Middle Vaal Water Management Area with RWB upstream of MWC. RWB uses GAC adsorption and UV light disinfection and MWC uses ozone as pre- and intermediate treatment process steps for water purification. The quality of the source water at both sampling sites was determined by analysing the physical and chemical characteristics as well as the algal and invertebrate compositions of the source water. The physical and chemical water quality variables measured included pH, conductivity, turbidity, dissolved organic carbon (DOC), total organic carbon (TOC), total photosynthetic pigments (TPP), microcystin and geosmin. The source water of both sites was characterised as hypertrophic on account of high chlorophyll concentrations. The water quality of the two sites was distinctly different and a downstream change was observed. The source water of RWB was characterised by high microcystin, geosmin, DOC, TOC and conductivity measurements and dominated by Bacillariophyceae (diatoms) and Cyanophyceae (blue-green bacteria). Problematic species that were present in the source water of RWB included Aulacoseira sp., other unidentified centric diatoms, Pandorina sp., Anabaena sp., Microcystis sp., Oscillatoria sp., Cryptomonas sp., Ceratium sp. and Trachelomonas sp. The source water of MWC was characterised by high pH, turbidity and TPP measurements and was dominated by Chlorophyceae (green algae) and Bacillariophyceae (diatom) species. Problematic algal species that were present in the source water of MWC included Cyclotella sp., Coelastrum sp., Pediastrum sp. and Scenedesmus sp. The source water of MWC was deemed to be of a better quality due to the lower Cyanophyceae concentrations and lower microcystin levels. The invertebrate composition of both sites was similar with Rotatoria as the dominant invertebrate group. The efficacy of GAC adsorption/UV light disinfection/ozonation on restoring the physical and chemical characteristics of the source water at both sampling sites as well as the algal and invertebrate compositions was determined by ascertaining the nature of the change in or the percentage removal of a water quality variable. The potable water of both sites complied with the standards of water intended for domestic use except for the conductivity at RWB that was slightly elevated. The phytoplankton was removed effectively from the source water of both sites but the removal of invertebrates was unsatisfactory. GAC adsorption and filtration proved to be more effective in the removal of TPP, turbidity, DOC, microcystin and geosmin than ozone. Ozone effected an increase in DOC. UV light disinfection had no or little effect on restoring the water quality variables investigated in this study. / M (Environmental Sciences), North-West University, Potchefstroom Campus, 2015

The main objective of this study was to determine the applicability of advanced water treatment processes namely granular activated carbon (GAC) adsorption, ultraviolet (UV) light disinfectant and ozone in the management of deteriorating water quality in the Mid-Vaal River system for drinking purposes. Both the scarcity and the deteriorating quality of water in South Africa can be addressed by investigating advanced water treatment processes such as GAC adsorption, UV light disinfectant and ozone. Previously disregarded water resources have the potential to be purified and advanced treatments can improve water quality where conventional water treatments have failed. In addition, advanced treatment processes can be applied to treat used water. The two sampling sites selected for the study, Rand Water Barrage (RWB) and Midvaal Water Company (MWC), are both located in the Middle Vaal Water Management Area with RWB upstream of MWC. RWB uses GAC adsorption and UV light disinfection and MWC uses ozone as pre- and intermediate treatment process steps for water purification. The quality of the source water at both sampling sites was determined by analysing the physical and chemical characteristics as well as the algal and invertebrate compositions of the source water. The physical and chemical water quality variables measured included pH, conductivity, turbidity, dissolved organic carbon (DOC), total organic carbon (TOC), total photosynthetic pigments (TPP), microcystin and geosmin. The source water of both sites was characterised as hypertrophic on account of high chlorophyll concentrations. The water quality of the two sites was distinctly different and a downstream change was observed. The source water of RWB was characterised by high microcystin, geosmin, DOC, TOC and conductivity measurements and dominated by Bacillariophyceae (diatoms) and Cyanophyceae (blue-green bacteria). Problematic species that were present in the source water of RWB included Aulacoseira sp., other unidentified centric diatoms, Pandorina sp., Anabaena sp., Microcystis sp., Oscillatoria sp., Cryptomonas sp., Ceratium sp. and Trachelomonas sp. The source water of MWC was characterised by high pH, turbidity and TPP measurements and was dominated by Chlorophyceae (green algae) and Bacillariophyceae (diatom) species. Problematic algal species that were present in the source water of MWC included Cyclotella sp., Coelastrum sp., Pediastrum sp. and Scenedesmus sp. The source water of MWC was deemed to be of a better quality due to the lower Cyanophyceae concentrations and lower microcystin levels. The invertebrate composition of both sites was similar with Rotatoria as the dominant invertebrate group. The efficacy of GAC adsorption/UV light disinfection/ozonation on restoring the physical and chemical characteristics of the source water at both sampling sites as well as the algal and invertebrate compositions was determined by ascertaining the nature of the change in or the percentage removal of a water quality variable. The potable water of both sites complied with the standards of water intended for domestic use except for the conductivity at RWB that was slightly elevated. The phytoplankton was removed effectively from the source water of both sites but the removal of invertebrates was unsatisfactory. GAC adsorption and filtration proved to be more effective in the removal of TPP, turbidity, DOC, microcystin and geosmin than ozone. Ozone effected an increase in DOC. UV light disinfection had no or little effect on restoring the water quality variables investigated in this study. / M (Environmental Sciences), North-West University, Potchefstroom Campus, 2015