Dissertation submitted in fulfillment of academic requirements for the Degree of Master of Technology: Chemical Engineering, Durban University of Technology, 2008. / Currently KwaZulu-Natal (KZN) province is populated with textile industry, which produces wastewater, some of which is not biodegradable. Due to the stringent environmental regulations the wastewater cannot be discharged into the rivers or public owned treatment systems. The alternative solution is to co-dispose this wastewater with easily biodegradable waste (labile effluent). The aim of this investigation was to develop a process protocol for the codigestion of high strength and toxic organic effluents under mesophilic conditions (35°C ± 2°C), with emphasis on the effect of biomass acclimation. A total of four effluents were chosen for this study, two labile (distillery and size) and two recalcitrant (scour dye and reactive dye). Two anaerobic batch experiments and two pilot scale trials were performed. The first batch anaerobic experiment investigated the influence of biomass source in anaerobic treatability. The second batch test investigated, whether biomass acclimation enhanced the biodegradability of pollutants. The pilot scale trials were the scale up version of the biomass acclimation test. The results showed sludge from Umbilo Wastewater Treatment Works was a superior biomass source, producing more gas and methane compared to Mpumalanga waste. For the high strength organic waste, the acclimated size and distillery samples produced 50% more biogas and methane compared to non-acclimated samples. This confirms that the biomass acclimation enhances the biodegradability. The biomass acclimation did not enhance the biodegradability of the recalcitrant effluent (scour dye). The pilot scale trials did not yield meaningful data; therefore it could not be proven if acclimation works on a larger scale. / Water Research Commission

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: It was found that bacterial sludge from anaerobic water treatment systems is produced internationally at a rate of 60 grams per person per day and the accumulation of the potentially hazardous by-product has become of increasing concern. The produced bacterial sludge is frequently pumped into dams, dried out and used as agricultural fertilizer. This bacterial sludge is expected to have a relatively high heating value and as such, has the potential to produce energy from the biomass. It is, therefore, advisable to utilize this energy potential as an alternative to conventional sludge disposal. This project aimed to improve the yield of syngas by optimizing the reactor design to partially oxidize bacterial sludge using a sonochemical reactor that is operated at bulk atmospheric conditions. The effect of different conditions was investigated and the optimum settings for syngas production were found by investigating temperature, pressure and the effect of the amplitude of operation that regulates the energy input by the ultrasonic equipment. The optimum conditions were used to investigate the kinetics involved in this process as well as to determine the energy consumption by the process. It was also required to study the feasibility of partially oxidizing bacterial sludge using a sonochemical reactor instead of conventional steam gasification and also as an alternative means of sludge disposal. By eliminating this pollutant source, the future environmental threat posed by an increasing population size will be minimized and energy will be utilized from a thus-far wasted energy source. The syngas that is produced is used as a green alternative to fossil fuels in the Gas-to-Liquids (GTL) process to produce liquids fuels. A thus-far wasted energy source will be consumed and fossil fuels can be saved in the process. It was found that the maximum hydrogen mole percentage produced is 0.141 mole % of the vapour phase with the maximum carbon monoxide mole percentage in the vapour phase at 1.896 mole %. This shows an improvement on work conducted by Beyers (2011) of 59 % for hydrogen, 92% for carbon monoxide and a reduction of 49 % for carbon dioxide. A kinetic study of the process indicated that the rate equations that describe the hydrogen and carbon monoxide production are zero order and, therefore, independent of initial concentration of the sludge. The rate constants were 0.0146 (mol % hydrogen/s) and 0.0183 (mol % hydrogen/s) for hydrogen and carbon monoxide, respectively. It was found that the most severe change to the higher heating value of the feed was a mere 0.27 mJ/kg from an original value of 9.81 mJ/kg. This therefore confirms that the reaction has not proceeded to completion. The statistical model predicted a maximum value for hydrogen production at 0.151 mole % in the product gas, 0.01 mole % from the measured maximum. It was also found that hydrogen is produced during the sonolysis of distilled water and that this confirms that the hydrogen production during partial oxidation of the sludge sample comes mainly from the water present in the sludge. The hydrogen produced when only using water, was found to be 0.127 mole % and when using the active sludge, the value was 0.116 mole % hydrogen in the vapour phase. The thermal decomposition of calcium carbonate in the lime that is used to treat the pH of the unit where the sludge originates from, followed by the formation of carbon monoxide during the Boudouard reaction, led to an increased amount of carbon monoxide present in the product gas. Ultrasonic intensity is defined as the amount of energy that is transferred to the sample per cubic meter of the internal surface area of the reactor vessel. It was found that the intensity that was delivered to the reactant was lower than expected as the reactor was operating at an efficiency of only 36%. The design intensity was 1.44 W/m2 and the actual delivered intensity was 0.52 W/m2. Based on a maximum yield of 0.00012 Nm3/kg, the cost of syngas production under the conditions described by this study, would amount to R 19.98/Nm3. This cost only implicates the operational expenses and does not take further downstream processing and initial capital investment repayments into account. Conventional steam gasification at a yield of 0.67 Nm3/kg has an operational syngas production cost of R 1.48/Nm3. This process was therefore found to not be economically feasible as the cost of utilizing ultrasound as opposed to normal steam gasification is more than ten times more expensive. It was concluded that the process was successfully optimized by the redesigning of the reactor and that carbon dioxide production was limited by excluding oxygen from the feed gas. It was also concluded that the sonolysis of water and the thermal decomposition of calcium carbonate, followed by the conversion of carbon dioxide to carbon monoxide, supplements the syngas production under the current operational conditions. Based on the production of no methane during the course of this study, the sonochemical process can be tied into the GTL process after the steam reforming unit. Due to the relatively high carbon dioxide content, the process will need to join the main feed gas stream that is fed into the carbon dioxide removal unit before it enters the GTL process to correct the desired feed gas ratio. Based on the very low syngas yields, the low hydrogen to carbon monoxide ratio in comparison to the required ratio of 2 as well as the high energy intensity required for this process, it can be concluded that the partial oxidation of biomass sludge in a sonochemical reactor is not feasible as an alternative technology to conventional steam gasification. The operating costs of the sonochemical unit would be nearly ten times that of steam gasification and is therefore concluded to not be a competitive technology to conventional steam gasification. It is recommended that the reactor design is reinvestigated to improve the delivered ultrasound intensity as well as the surface area where the ultrasonic waves are intensified. This would eliminate dead-zones. It was also recommended that the argon gas is continuously bubbled through the reactant mixture during experiments to eliminate the degassing effect caused when the ultrasound is initially emitted. The gas outlet of the process can then be connected to an online gas chromatograph (GC) with a thermal conductivity detector (TCD) and flame ionization detector (FID) methanizer in series as the TCD does not destroy the sample and this setup would improve the analytical process. The production of carbon monoxide from lime as well as the production of hydrogen from water during sonolysis needs to be investigated. The effect of radicals can also be studied by the addition of a radical scavenger to the process. It is recommended that the experimental design is reinvestigated and a design that will deliver similar information utilizing fewer data points should be chosen. Based on this model as well as further kinetic testing, it is recommended that a complete ASPEN model is developed to simulate the energy requirements to tie the ultrasonic process into the commercial plant. Based on this model, a complete feasibility study can then be conducted to determine the capital costs involved, the operating costs, the repayment period as well as taking the current costs of sludge disposal into account. / AFRIKAANSE OPSOMMING: Daar is gevind dat bakteriele slik internasionaal geproduseer word deur anaerobiese waterbehandelingseenhede teen ‘n tempo van 60 gram per person per dag en dat die opberging van hierdie gevaarlike byproduk ‘n groeiende probleem word. Die geproduseerde bakteriele slik word in damme gestoor, uitgedroog of gebruik as kunsmis in die landbou bedryf. Daar word vermoed dat hierdie baketriele slik oor ‘n hoe verwarmings waarde beskik en het daarom die potensiaal om energie te produseer uit die biomassa. Daarom is dit voorgestel om alternatiewe prosesse te ondersoek om van hierdie slik ontslae te raak en moontlik die energie wat beskikbaar is te gebruik. Die projek is daarop gefokus om die produksie van syngas te verbeter deur die reaktorontwerp te optimeer deur gebruik te maak van parsiele oksidasie van slik onder atmosferiese kondisies deur klankgolwe te gebruik. Die effek van verskillende operasionele kondisies is ondersoek en die optimale vlakke van syngas produksie is gevind deur temperatuur, druk en amplitude wat die hoeveelheid energie wat oorgedra word aan die reaktor reguleer, te ondersoek. Die optimale kondisies is ook gebruik om die kinetiese aspekte van die proses te ondersoek en ook om te kyk wat die sisteem se energie benodighede behels. Die haalbaarheid om baketriele slik parsieel te oksideer in ‘n sonochemiese reaktor is vergelyk met dit van konvensionele stoom vergassing van die biomassa en is ook ondersoek as ‘n alternatief om van die slik ontslae te raak. Deur die slik te verwyder as ‘n potensiele bron van besoedeling, kan die toekomstige omgewing’s risiko wat deur die toename in die bevolkkingsgroote tot gevolg is, verwyder word deur ‘n energie bron te gebruik wat tot dusver geignoreer is. Die syngas wat geproduseer word kan dan gebruik word in die “Gas-to-Liquids” (GTL) process om vloeistof brandstowwe te produseer. Dus sal ‘n omgewingsrisiko verminder word, ‘n energiebron word benuttig wat nooit van tevore benuttig is nie en fosiel brandstowwe kan gespaar word. Die maksimum waterstof wat geproduseer is, was 0.141 mol % in die gas fase met ‘n maksimum waarde vir koosltof monoksied van 1.896 mol % in die gas fase. Dit toon ‘n verbetering van 59 % vir waterstof, 92 % vir koolstof monoksied en ‘n vermindering van 49% in die koolstof dioksied wat deur Beyers (2011) geproduseer is. Die kinetiese studie het ondervind dat die “rate equation” van waterstof en koolstofmonoksied beskryf word deur nul-orde kinetika. Hierdie konstantes was 0.0146 (mol % waterstof/s) en 0.0183 (mol % waterstof/s) vir waterstof en koolstofmonoksied. Daar is ook gevind dat die grootste moontlik verandering in die hoe verwarmings waarde van die biomassa is ‘n skamele 0.27 mJ/kg van die oorspronklike waarde van 9.81 mJ/kg. Hierdie waarneming staaf dus die uitkoms dat die reaksie dus nie tot die einde verloop het nie. Die statistiese model het ‘n maksimum van 0.151 mol % voorspel wat 0.01 mol % meer was as die waarde wat gemeet is. Dit is ook gevind dat waterstof geproduseer word deur die sonoliese van water en dat hierdie bykomende waterstof deel uitmaak van die produkgas aangesien die slik grootliks uit water bestaan.Die hoveelheid waterstof in die gas fase wat geproduseer is tydens sonoliese van ‘n suiwer water monster, was 0.127 mol %. Die hoeveelheid waterstof in die gas fase wanneer die slik behandel is ten optimal kondisies, was 0.116 mol % gemiddeld. Die hitte degradering van kalsium karbonaat wat teenwoordig is in die kalk wat gebruik word om die pH van die produksie eenheid te reguleer, gevolg deur die Boudouard reaksie, het tot gevolg dat addisionele koolstof monoksied ook gevorm word. Ultrasoniese intensiteit kan gedefineer word as die hoeveelheid energy wat oorgedra word aan ‘n reaktant gebasseer op die oppervlak area aan die binnekant van die reaktor. Die intensiteit waarteen die voermateriaal blootgestel word aan die klankgolwe was laer as verwag met ‘n 36 % effektiwiteit. Die ontwerp spesifiseer ‘n intensiteit van 1.44 W/m2 en die intensiteit wat fisies gelewer is, was 0.521 W/m2. Die maksimum produksie van syngas was 0.00012 Nm3/kg, wat lei tot ‘n operasionele koste van R 19.98/Nm3 onder die kondisies van hierdie studie. Hierdie koste neem nie die oorsponkilke kapitaal vir die konstruksie, of die koste van verdere behandelik van die gas, in ag nie. Konvensionele stoom vergassing teen ‘n opbrengs van 0.67 Nm3/kg het ‘n operasionele koste van R 1.48/Nm3 tot gevolg. Die proses is dus ekonomies nie ‘n aantreklike opsie nie aangesien die kostes van syngas produksie met ultraklank meer as tien keer meer is as konvensionele stoom vergassing. Daar is tot die gevolgtrekking gekom dat die reaktor optimering suksesvol was en deur geen stuurstof te voer nie, die koolstofdioksied persentasie verminder is. Daar is ook tot die gevolgtrekking gekom dat die sonoliese van water, en die hitte degradering van kalsium karbonaat, gevolg deur die Boudouard reaksie, die syngas produksie supplementeer. Aangesien geen metaan gedurende hierdie studie geproduseer is nie, kan die sonochemiese proses inskakel by die GTL aanleg na die stoom hervormingseenhed. As gevolg van die hoe koolstofdioksied konsentrasie, sal die prosesstroom gemeng moet word met die produk stroom uit die stoom hervormings proses, wat gevoer word na die koolstofdioksied verwyderings eenheid. Hierdie eenheid is daarvoor verantwoordelik om die korrekte verhouding van gasse vir die GTL voer stroom te reguleer. Gebasseer op die baie lae syngas opbrengs, die lae waterstof tot koolstofmonoksied verhouding en die hoe energie behoeftes, is daar tot die gevolgtrekking gekom dat die parsiele oksidasdie van die biomassa in ‘n sonochemiese reaktor nie ‘n haalbare alternatief is vir konvensionele stoom vergassing nie. Die operasionele koste van die sonochemiese eenheid is ongeveer tien keer meer as die van stoom vergassing en daarom is die proses nie kompeterend nie. Daar word voorgestel dat die reaktor ontwerp hersien word om die gelewerde intensiteit te verbeter, sowel as om die kontak area waar die klankgolwe gekonsentreer is, te vergroot. Dit sal dooie sones uitskakel. Daar word ook voorgestel dat argon gas gedurende die eksperiment aanhoudende geborrel word deur die reaktant vloeistof in die reaktor om die ontgassingseffek uit te skakel sodra die klankgolwe aangeskakel word. Die gas uitlaat kan dan inlyn gekoppel word aan ‘n gas chromatograaf met ‘n termiese geleidings detektor (TCD) en ‘n vlam ionisasie detektor (FID) met metaan omskakeling, aangesien die TCD nie die monster vernietig nie. Hierdie opstelling behoort analitiese methodes te verbeter. Die produksie van koolstofmonoksied uit kalk sowel as die produksie van waterstof uit water gedurende sonoliese, moet verder ondersoek word. Die effek van radikale kan ook verder bestudeer word deur die gebruik van ‘n radikaal rower gedurende die proses. Daar word ook voorgestel dat die statistiese ontwerp herondersoek word sodat minder eksperimente gebruik kan word om soortgelyke resultate te bekom met minder data punte. Gebasseer op hierdie nuwe model en ‘n kinetiese studie, word dit aangeraai dat ‘n volledige ASPEN model gebou word om te simuleer hoe hierdie sonochemiese eenheid sal inskakel met die kommersiele eenheid. Dit sal dan moontlik wees om die energie benodighede van die proses te verstaan en gebasseer daarop, kan ‘n volledige haalbaarheid studie gedoen word wat kyk na oorspronklike installasie kostes, onderhouskostes, operasionele kostes sowel as die terugbetaling van die konstruksie kostes. Dan kan ‘n vergelyking getref word met die huidige kostes om van hierdie slik ontslae te raak en om die slik as ‘n brandstof te benut.

Este estudo teve como objetivo avaliar a partida de reator anaeróbio de fluxo ascendente e manta de lodo (UASB), em escala real, no tratamento de esgoto sanitário, sob condições hidráulicas desfavoráveis. O reator UASB faz parte do sistema de tratamento da ETE Água Vermelha, e é seguido de um biofiltro aerado submerso e de uma unidade de desinfecção por ultravioleta. Foi utilizado metade do volume do reator (117 \'M POT.3\'), possibilitando menor tempo de detenção hidráulica (TDH). A pesquisa foi dividida em duas fases, uma sem a adição de inóculo (fase I) e outra com inoculação (fase II). Na fase I, foram aplicados vazão de 480 \'M POT.3\'/dia e carga orgânica volumétrica (COV) de 1,74 kgDQO/\'M POT.3\'.dia com TDH de 6 horas. Para a fase II, estes valores foram de 600 \'M POT.3\'/dia, 2,88 kgDQO/\'M POT.3\'.dia e 5 horas. Os resultados mostraram que as excessivas velocidades ascensionais não permitiram que o reator tivesse desempenho satisfatório. Ocorreu remoção de matéria orgânica e sólidos suspensos apenas na fase II, com exceção dos sólidos suspensos voláteis, que apresentaram remoção nas duas fases. Os lançamentos indevidos de lodo de fossas à que a ETE está submetida, provocaram aumento de sólidos dissolvidos e alcalinidade no efluente. Os leitos de lodo formados nas fases I e II possuíam concentrações semelhantes de sólidos, porém o segundo apresentou maior eficiência de tratamento. Na fase I a remoção de matéria orgânica foi pequena e não ocorreu a formação da manta de lodo. Na fase II ocorreu o provável início da estabilização do processo, aproximadamente 60 dias após a inoculação, a partir de quando a remoção de matéria orgânica dissolvida foi considerada constante e foi observada a formação da manta de lodo. O descarte de 8,5 \'M POT.3\' de lodo pode ser feito a cada 30 dias. / The objective of this study was to evaluate the start-up of a full-scale upflow anaerobic sludge blanket (UASB) reactor, treating domestic sewage, under unfavorable hydraulic conditions. The UASB reactor is part of the wastewater treatment plant of Água Vermelha (São Carlos, SP, Brazil), and it is followed by a submerged aerated biofilter and an ultraviolet radiation disinfection unit. Half of the reactor volume was used (117 \'M POT.3\'), making it possible to work with a low hydraulic retention time (HRT). The research was divided in two phases, one without reactor seeding (phase I), and another when the reactor was seeded (phase II). At phase I, a flow rate of 480 \'M POT.3\'/d and a volumetric loading rate of 1,74 kgDQO/\'M POT.3\'.d were applied, with 6 hours of HRT. At phase II, this values were 600 \'M POT.3\'/d; 2,88 kgDQO/\'M POT.3\'d and 5 hours. The results showed that excessive upflow velocities prevented satisfactory performance of the reactor. Removal efficiencies of COD, BOD and TSS were obtained only in phase II, except for VSS, which showed removal in both stages. Unauthorized inputs of septic tanks sludge caused increase in dissolved solids and alkalinity in the effluent. The sludge beds obtained in phases I and II had similar solids concentration; however, the second presented better treatment efficiency. At phase I, organic matter removal efficiency was low and the blanket sludge was not observed. At phase II, the process likely stabilized 60 days after inoculation (operations\' day 240). From then on, dissolved organic matter digestion was constant and the sludge blanket was observed. The removal of the excess sludge can be done every other 30 days.

Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2017. / For more than a decade, poultry product consumption increased in developed and developing countries, with more than 470 new slaughterhouses being constructed in South Africa (SA). Customer demand for poultry products resulted in a rapidly growing poultry industry, with consequential increases in the quantity of organic solid and liquid waste being produced from the poultry slaughterhouses. Annually, the productivity and profitability within the livestock production sector has increased, an evaluation based on the number of slaughtered and sold animals. Potable water is required for these animals, resulting in the generation of high strength wastewaters. Instantaneous disposal of such wastewaters into the environment is concerning as it results in odour and the spreading of diseases in local rivers and freshwater sources. The generated poultry slaughterhouse wastewater (PSW) contains a high quantity of biodegradable organic, suspended and colloidal matter in the form of proteins, fats, oil and grease (FOG), protein from meat, blood, skin, and feathers, resulting in high Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), which can contribute to environmental deterioration if not treated adequately before discharge. On average, PSW contains a high concentration of BOD, COD, nitrogen, pathogenic and non-pathogenic viruses, bacteria and parasites, including their eggs. These characteristics make PSW highly polluted with a large quantity of bird carcass debris including FOG. Due to the high concentration of organic matter and suspended solids in the wastewater, it is necessary to pre-treat the PSW prior to sequential anaerobic treatment. Most of the contaminants present in the PSW can be reduced by means of numerous treatment steps, i.e. physical, chemical and biological treatment. For this study, biological treatment methods, physical separation methods, and a membrane bioreactor system, were used to treat PSW. The biological treatment methods used were an anaerobic digester (AD) followed by a single stage nitrification/denitrification reactor and then a third stage in which an ultrafiltration (UF) and Microfiltration (MF) membrane bioreactor (MBR) was used. The AD used was an Expanded Granular sludge Bed Reactor (EGSB) as anaerobic digestion is one of the most effective biological wastewater treatment methods used, as it reduces the organic matter to even produce biogas as a renewable energy source. The basis of anaerobic treatment method relies on suitable bacteria cultivated in the absence of dissolved oxygen, facilitating decomposition of organic matter into a renewable source such as biogas. Similarly, biological nitrification/denitrification processes for the removal of total nitrogen (TN) in wastewater has become one of the most commonly used processes within the wastewater treatment sector. Nitrification and denitrification processes can be performed by some microorganisms within the wastewater in Wastewater Treatment Plants (WWTPs) The PSW used was collected at different times from a local poultry slaughterhouse in the Western Cape (South Africa) and stored in a refrigerator at 4°C until it was fed to the first stage of the treatment which was the EGSB. Before being fed to the EGSB, the PSW was filtered with a sieve to remove feathers and agglomerated FOG to avoid clogging of the tubing. The EGSB was inoculated with 0.747 L anaerobic granular sludge, had a working volume of 2.7 L, an inner diameter of 0.065 m and a height of 0.872 m respectively. Ceramic marbles with an average diameter of 0.0157m were placed at the bottom of the bioreactor as packing for the underdrain and to maintain the granular sludge within the heated section of the bioreactor. The EGSB was fed with three types of PSW: 50% (v/v), 70% (v/v), which was diluted with distilled water. Thereafter once the system stabilised the reactor was fed with undiluted PSW (100%). Each dilution was operated at different Hydraulic Retention Times (HRTs) and Organic Loading Rates (OLRs), with average HRTs used being 62.5, 57.5 and 49.65 h. Furthermore, the average OLRs were 1, 2 and 3 g tCOD/L.day respectively. The performance of the EGSB was determined using tCOD, Total Suspended Solids (TSS) and FOG, with overall averaged removal rates for these constituents being 69%, 98% and 92% respectively. The highest tCOD removal of 93 % (optimal efficiency) was obtained at an average HRT of 57.5 h with a corresponding average OLR of 2 g tCOD/L.day.

Este estudo teve como objetivo avaliar a partida de reator anaeróbio de fluxo ascendente e manta de lodo (UASB), em escala real, no tratamento de esgoto sanitário, sob condições hidráulicas desfavoráveis. O reator UASB faz parte do sistema de tratamento da ETE Água Vermelha, e é seguido de um biofiltro aerado submerso e de uma unidade de desinfecção por ultravioleta. Foi utilizado metade do volume do reator (117 \'M POT.3\'), possibilitando menor tempo de detenção hidráulica (TDH). A pesquisa foi dividida em duas fases, uma sem a adição de inóculo (fase I) e outra com inoculação (fase II). Na fase I, foram aplicados vazão de 480 \'M POT.3\'/dia e carga orgânica volumétrica (COV) de 1,74 kgDQO/\'M POT.3\'.dia com TDH de 6 horas. Para a fase II, estes valores foram de 600 \'M POT.3\'/dia, 2,88 kgDQO/\'M POT.3\'.dia e 5 horas. Os resultados mostraram que as excessivas velocidades ascensionais não permitiram que o reator tivesse desempenho satisfatório. Ocorreu remoção de matéria orgânica e sólidos suspensos apenas na fase II, com exceção dos sólidos suspensos voláteis, que apresentaram remoção nas duas fases. Os lançamentos indevidos de lodo de fossas à que a ETE está submetida, provocaram aumento de sólidos dissolvidos e alcalinidade no efluente. Os leitos de lodo formados nas fases I e II possuíam concentrações semelhantes de sólidos, porém o segundo apresentou maior eficiência de tratamento. Na fase I a remoção de matéria orgânica foi pequena e não ocorreu a formação da manta de lodo. Na fase II ocorreu o provável início da estabilização do processo, aproximadamente 60 dias após a inoculação, a partir de quando a remoção de matéria orgânica dissolvida foi considerada constante e foi observada a formação da manta de lodo. O descarte de 8,5 \'M POT.3\' de lodo pode ser feito a cada 30 dias. / The objective of this study was to evaluate the start-up of a full-scale upflow anaerobic sludge blanket (UASB) reactor, treating domestic sewage, under unfavorable hydraulic conditions. The UASB reactor is part of the wastewater treatment plant of Água Vermelha (São Carlos, SP, Brazil), and it is followed by a submerged aerated biofilter and an ultraviolet radiation disinfection unit. Half of the reactor volume was used (117 \'M POT.3\'), making it possible to work with a low hydraulic retention time (HRT). The research was divided in two phases, one without reactor seeding (phase I), and another when the reactor was seeded (phase II). At phase I, a flow rate of 480 \'M POT.3\'/d and a volumetric loading rate of 1,74 kgDQO/\'M POT.3\'.d were applied, with 6 hours of HRT. At phase II, this values were 600 \'M POT.3\'/d; 2,88 kgDQO/\'M POT.3\'d and 5 hours. The results showed that excessive upflow velocities prevented satisfactory performance of the reactor. Removal efficiencies of COD, BOD and TSS were obtained only in phase II, except for VSS, which showed removal in both stages. Unauthorized inputs of septic tanks sludge caused increase in dissolved solids and alkalinity in the effluent. The sludge beds obtained in phases I and II had similar solids concentration; however, the second presented better treatment efficiency. At phase I, organic matter removal efficiency was low and the blanket sludge was not observed. At phase II, the process likely stabilized 60 days after inoculation (operations\' day 240). From then on, dissolved organic matter digestion was constant and the sludge blanket was observed. The removal of the excess sludge can be done every other 30 days.

Anaerobinis dumblo stabilizavimas taikomas siekiant sumažinti organinių medžiagų kiekį esantį dumble. Šiame darbe nagrinėjami perteklinio veikliojo dumblo parametrų kitimai, keičiantis apkrovai stabilizavimo metu. Atlikta duomenų analizė. Eksperimentų pagalba nustatyta peleningumo priklausomybė nuo reaktoriaus tūrinės apkrovos. (Vilniaus miesto nuotekų valymo įrenginiuose susidarančiam pertekliniam veikliajam dumblui jį stabilizuojant). Taip pat darbe apžvelgti pagrindiniai veiksniai, įtakojantys veikliojo dumblo stabilizavimą. Atlikti šie bandymai: nustatyta dumblo koncentracija, dumblo peleningumas, pH, lakiosios riebiosios rūgštys, šarmingumas, biodujų kiekis. Pagal turimus duomenys nustatytos peleningumo, pH, šarmingumo, dujų kiekio priklausomybės nuo tūrinės anaerobinio reaktoriaus apkrovos. Darbe pateikiami bandymų metu atlikti tyrimų rezultatai, kurie buvo analitiškai ir dalinai statistiškai apdoroti. Darbo pabaigoje pateikiamos išvados. Darbą sudaro šios dalys: įvadas, trys skyriai, išvados, literatūros sąrašas, priedai. / Reducing organic material amount in sludge an anaerobic excess sludge is applied. In this work was considerated variation of excess active sludge parameter alternating of organic matter during anaerobical digestion. Analysis of data were done. With the help of experiments was ascertained correlation between volatile solids and loading of reactor. (excess active sludge in Vilnius city wastewater treatment plant was stabilized). Was looked through main subjects that have influence for stabilization of excess sludge. Such experiments were done: concentration of sludge, volatile solids, pH, volatile fatty acids, alkalinity, biogas amount. Using existing data correlation between volatile solids, pH, alkalinity, biogas amount and anaerobic reactor loading were found. In the work are represented facts obtained in experimentations. Facts were analyzed and statistically treated. In the end of work conclusions are presented.

Thesis (MSc Food Sc )--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The potential use of the upflow anaerobic sludge blanket (UASB) bioreactor is limited by the extended start-up periods due to the time-consuming granulation process and the fact that seeding inoculum is not freely available in most developing countries like South Africa. The mass cultivation of granules would provide the waste water treatment industry with suitable seeding inoculum and, therefore, an efficient waste water treatment option would be more easily available. By applying 'stress' conditions on a bioreactor system seeded with raw anaerobic sludge, the population dynamics of the anaerobic community change and the acidogens start to produce extracellular polymers, which in turn enhance the granulation process by providing a matrix for the bacterial cells to adhere to. These "environmental stress" conditions include changes in the C:P:N ratio's. The aim of this study was, therefore, to assess the impact of different carbon and nitrogen sources on the enhancement of granulation in a batch system, and to determine the best preservation technique in terms of retainment of activity. It was found that the carbon source and concentration had a significant influence on batch granule enhancement. Low concentrations (2.g.l ̄ ¹) of glucose gave the best granule enhancement over a 14 day incubation period. Fruit cocktail effluent was found to be a cheap and effective carbon source for batch granule cultivation. It was found that different nitrogen sources did not have the same impact on granule enhancement, however, urea, at all concentrations tested, gave the best granule enhancement. A major problem encountered during the study was the standardisation of the inoculum. Significant granule enhancement comparisons between the different carbon sources were impeded by the lack of a suitable and reliable form of sludge standardisation. Future research needs to address this problem of the standardisation of the sludge inoculum as this would lead to more kinetically comparable results. Mass granule culturing will require granule preservation without risking the loss of activity. In the second study, six different preservation techniques and storage periods were evaluated in terms of the retainment of activity. These involved freeze-drying, vacuum freeze-drying, vacuum-drying, freezing, cold storage and room temperature preservation. Activity testing was used for comparing the efficiency of the different preservation techniques in terms of the tempo of biogas and methane production. Freeze-drying the granules, with storage for up to 90 days was found to give the best retainment of activity, followed by vacuum freeze-drying. The room temperature preserved samples showed a sudden increase in activity by day 120, which could possibly be explained by cell hydrolysis of the granules after day 90. The highest activity was achieved after 10 h of incubation, and it was, therefore, suggested that activity testing for evaluation purposes should use an incubation time of only 10 h. Furthermore, only the basic test medium with added glucose should be used for activity testing as it was observed that the addition of lactate and acetic acid played no decisive role in determining the level of activity of the granules. This study recommends the use of low concentrations of glucose for optimum granule enhancement during the mass cultivation of granules, and the addition of low concentrations of lactate to ensure a stable system with no acidification. It is also advisable to use a standardised sludge inoculum, as this will allow more efficient comparisons. Freeze-drying is recommended as preservationtechnique as this technique showed the best retainment of activity. A storage period of 90 days is, however, too short to be of much use for the industry. This will have to be investigated, together with the phenomenon of increased activity after 90 days as shown by the room temperature preserved granules. / AFRIKAANSE OPSOMMING: Die potensiële gebruik van die "uptflow anaerobic sludge blanket" (UASB) bioreaktor word beperk deur verlengde aansitprosedure as gevolg van die tydsame granulasieproses en die feit dat geskikte inokulums nie vrylik beskikbaar is in die meeste ontwikkelende lande, bv. Suid-Afrika nie. Die massa-kweking van granules sal die afvalwater-industrie voorsien van 'n geskikte inokulum, en sodoende 'n effektiewe opsie vir die behandeling van afvalwater beskikbaar stel. Deur die aanwending van "stres" toestande op 'n reaktor, wat geinokuleer is met rou anaerobe slyk, vind daar 'n verandering in die samestelling van die anaerobe populasie plaas. Die laktaat-benuttende asidogene begin om ekstrasellulêre polisakkariede te produseer wat die granulasieproses versnel deur 'n matriks te voorsien waaraan die bakteriële selle kan heg. Hierdie "omgewings stres" toestande sluit veranderinge in die C:P:N verhoudings in. Die doel van hierdie studie was om die invloed van verskillende koolstof- en stikstofbronne op die vermeerdering van granules te bepaal, asook om die beste preserveringstegniek in terme van die behoud van aktiwiteit te bepaal. Daar is gevind dat die koolstofbron en konsentrasie 'n betekenisvolle invloed op granule-vermeerdering het. Lae konsentrasies glukose (2 g.I ̄ ¹) het tot die grootste vermeerdering in granules oor 'n 14 dae inkubasieperiode gelei. Vrugtekelkie-afvalwater is geidentifiseer as 'n goedkoop en effektiewe koolstofbron wat ook gebruik kan word vir die kweking van granules. Voorts is gevind dat die stikstofbron en konsentrasie nie so 'n groot invloed op granule-vermeerdering het nie. Urea het nietemin die beste granule-vermeerdering vir al die konsentrasies wat getoets is, gegee. Standaardisasie van die inokulum was 'n groot probleem gedurende die studie. Betekenisvolle vergelykings tussen die granule-vermeerderings verkry met die verskeie groeimedia is bemoeilik deur die afwesigheid van 'n geskikte en betroubare standaardisasie-metode. Toekomstige navorsing moet hierdie probleem aanspreek aangesien dit sal lei tot meer kineties vergelykbare resultate. Massa-kweking van granule sal 'n metode van granule-preservering vereis sonder enige verlies van aktiwiteit. In die tweede studie is ses verskillende preserverings-tegnieke en opbergings-periodes in terme van die behoud van aktiwiteit geëvalueer. Die tegnieke sluit in: vriesdroging; vakuum-vriesdroging; vakuumdroging; bevriesing; koelopberging en kamertemperatuur-preservering. Aktiwiteitstoetsing is gebruik vir die vergelyking van die effektiwiteit tussen die verskillende preserverings-tegnieke in terme van die tempo van biogas- en metaanproduksie. Die granules wat met behulp van die vriesdroogtegniek gepreserveer is, het die beste behoud van aktiwiteit getoon, gevolg deur die vakuum-gevriesdroogde granules. Die monsters wat by kamertemperatuur gepreserveer is, het 'n skielike toename in aktiwiteit na 120 dae van opberging getoon en 'n moontlike verklaring vir hierdie verskynsel kan sel-hidrolise van die granules na 90 dae van opberging wees. Die meeste aktiwiteit is behaal na 'n 10 h inkubasietyd, en dus word hierdie inkubasietyd aanbeveel indien aktiwiteitstoetse vir evaluerings-doeleindes gedoen word. Verder word aanbeveel dat slegs die glukose-verrykte basiese toetsmedia vir aktiwiteitstoetsing gebruik word aangesien die byvoeging van laktaat en asynsuur geen noemenswaardige rol speel in die bepaling van die vlak van aktiwiteit van die granules nie. Hierdie studie beveel die gebruik van lae glukosekonsentrasies aan vir optimale vermeerdering van granules tydens die massakweking daarvan, asook die byvoeging van lae konsentrasies laktaat om 'n stabiele sisteem met geen versuring te verseker. Die gebruik van 'n gestandaardiseerde slyk-inokulum word sterk aanbeveel aangesien dit meer vergelykbare resultate lewer. Vriesdroging (as preserveringstegniek) het die beste behoud van aktiwiteit in die granules getoon en word dus as preserveringstegniek aanbeveel. 'n Opbergingsperiode van 90 dae is egter te kort om van veel waarde vir die industrie te wees. Hierdie probleem, asook die verskynsel van 'n verhoging in aktiwiteit na 90 dae van die granules wat by kamertemperatuur gepreserveer is, moet verder ondersoek word.

Thesis (MSc Food Sc)--Stellenbosch University, 2002. / ENGLISH ABSTRACT: The start-up period of Upflow Anaerobic Sludge Bed (UASB) reactors can significantly be reduced by enhancing the time-consuming granulation process through the batch cultivation of anaerobic granular sludge and thus seeding the reactor with this cultivated granular sludge, instead of raw anaerobic sludge. The precise mechanism for granule formation is not well known, but it is believed that extracellular polymers (ECP) play a critical role in the granulation process. Information on the precise role of ECP is also limited and no universal standardised method for ECP extraction is used at present. Therefore, comparison of results from different researchers has to be made with great caution. The objectives of this study were to evaluate an ECP extraction methód so as to optimise the extraction time, and then to correlate ECP composition of UASB granules with granule metabolic activity. The impact of changes in the environmental conditions, such as sludge sources (Paarl and Kraaifontein-sludge), carbon growth substrates (yeast extract lactate, glucose medium and fruit cocktail effluent) and batch cultivation techniques (roller-table and shake-waterbath), on batch cultivation studies was also evaluated in terms of granule activity, ECP composition and granule formation. A physical extraction method was used to quantify the ECP content of UASB granules from six different sources. The optimal extraction time was taken as the time needed before cell lysis took place, and before intracellular material started contributing to the ECP content of the granules. It was concluded that the ECP composition was affected by the wastewater composition fed to the original UASB reactors, It was also found that the activity test results could be used to indirectly predict the activity of the different trophic groups present in the UASB granules. A correlation was found between the activity test results and the total ECP content, and this showed that the granules with the higher ECP yields exhibited greater biogas (SB) and methanogenic (SM) activities. However, based on the activity data and total ECP content, it appeared that a protein:carbohydrate ratio < 1 affected the activity of the granules, The sludge source used as inoculum for batch cultivation of anaerobic granular sludge had a significant effect on granule formation. The use of a pre- granulated raw anaerobic sludge, such as the Paarl-sludge, resulted in a greater increase in granule numbers at the end of the cultivation period. The acetic acid activity profiles showed that the acetoclastic methanogens that are involved in initiation of granulation by nucleus formation, were inactive or absent in the different batch systems, with the exception of the roller-table glucose cultivated Kraaifontein-sludge (RKG) batch system. The addition of glucose as carbon growth substrate for batch cultivation not only enhanced the activity of the acidogenic population, but also led to the establishment to a greater variety of granule trophic groups within all the glucose cultivated batch systems. The addition of fruit cocktail effluent as carbon substrate enhanced ECP production in the Paarl-sludge cultivated batch systems. However, the addition of carbon substrates showed no discernible trend on granule formation itself. The roller-table cultivation technique resulted in the higher increase in granule numbers, and it was speculated that the more vigorous shake-waterbath technique probably shortened the contact time between biomass and substrate. Large variations in the ECP composition of the different batch systems were found, and these were ascribed to the composition heterogeneity of different sludges. For future studies, it is advisable to characterise sludge, both chemically and microbiologically before using as inoculum. The selection of an appropriate sludge inoculum should then lead to optimisation of the granulation process. / AFRIKAANSE OPSOMMING: Die aanvangsperiode van "Upflow Anaerobic Sludge Bed" (UASB) bioreaktors kan noemenswaardig verminder word deur die tydsame granulasie proses te versnel deur die vooraf lot-kweking van anaërobe granulêre slyk waarmee 'n reaktor dus geïnokuleer kan word in plaas van rou anaërobe slyk. Die presiese meganisme van granulevorming is nog nie welbekend nie, maar daar word beweer dat ekstrasellulêre polimere (ECP) wel 'n kritiese rol speel in die granulasie proses. Inligting; oor die presiese rol van ECP is ook nog beperk, en tans word daar nog , geen universele standaard metode vir ECP-ekstraksie gebruik nie. Gevolglik moet resultate vanaf verskeie navorsers met groot omsigtigheid vergelyk word. Die doelwitte van hierdie studie was om 'n ECP ekstraksiemetode te evalueer deur die ekstraksietyd te optimiseer, en dan te korreleer met die ECP samestelling en metaboliese aktiwiteit van die UASB granules. Die inwerking van veranderinge in omgewingskondisies, soos slykbronne (Paarl- en Kraaifontein-slyk), koolstofbronne (gisekstrak-Iaktaat-, glukose-medium en vrugtekelkie-uitvloeisel) en lot-kwekingstegnieke (rol-tafel en skud-waterbad) op lot-kweking studies in terme van granule aktiwiteit, ECP-samestelling en granulevorming is ook ondersoek. 'n Fisiese ekstraksie metode is gebruik om die ECP-inhoud van UASB granules vanaf ses verskillende bronne te bepaal. Die optimale ekstraksietyd is geneem as die tyd benodig voordat sellise sal plaasvind en die intrasellulêre materiaal 'n bydrae sal lewer tot die ECP-inhoud van granules. Dit is afgelei dat die ECP-samestelling beïnvloed word deur die samestelling van die afvalwater wat vir die oorspronklike UASB bioreaktors gevoer is. Voorts is gevind dat die aktiwiteitstoets resultate indirek gebruik kan word vir die voorspelling van aktiwiteit van die verskillende trofiese groepe wat in die UASB granules teenwoordig is. 'n Korrelasie is gevind tussen die aktiwiteitstoets resultate en die totale ECP-inhoud wat aangedui het dat granules met hoër ECP opbrengste, beter biogas (SB) en metanogeniese (SM) aktiwiteit getoon het. Volgens die aktiwiteitsdata en totale ECP-inhoud het dit egter geblyk dat 'n proteïen:koolhidraat verhouding < 1 die aktiwiteit van granules beïnvloed het. Die slykbron wat as inokulum gebruik is vir lot-kweking van' anaërobiese granulêre slyk het 'n noemenswaardige invloed gehad op granulevorming. Die gebruik van 'n rou anaërobe slyk wat reeds 'n mate van granulasie getoon het, soos die Paarl-slyk, het 'n hoër toename in granule getalle aan die einde van die kwekingsperiode teweeg gebring. Die asynsuur aktiwiteitsprofiele het aangedui dat die asetoklastiese metanogene, wat hoofsaaklik betrokke is by inisiëring van granulasie deur kernvorming, onaktief of afwesig was in al die verskillende lotsisteme, met die uitsondering van die roltafel glukose-gekultiveerde Kraaifonteinslyk (RKG) lot-sisteem. Die toevoeging van glukose as koolstofbron vir lot-kweking het nie alleenlik die aktiwiteit van die asidogene populasie verhoog nie, maar het ook bygedra tot die vestiging van 'n groter verskeidenheid van granule trofiese groepe. Die toevoeging van vrugtekelkie-uitvloeisel as koolstofbron het die produksie van ECP verhoog in die Paarl-slyk gekweekte lot-sisteme. Die toevoeging van koolstofsubstrate het egter geen merkbare verandering getoon in granulasie opsigself nie. Die rol-tafel kwekingstegniek het 'n hoër toename in granule getalle tot gevolg gehad, en dit is gespekuleer dat die meer kragtige skud-waterbad tegniek waarskynlik die kontaktyd tussen die substraat en biomassa verkort het. Groot variasies is gevind in die ECP-samestelling van die verskillende lotsisteme, en dit is toegeskryf aan die heterogene samestelling van die verskillende slyke. Vir toekomstige navorsing is dit raadsaam om slyk voor gebruik as inokulum beide chemies en mikrobiologies te karakteriseer. Die keuse van 'n geskikte slyk-inokulum sal bydra tot die optimisering van die granulasie proses.

Thesis (MScFoodSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Large volumes of high strength wastewater are generated annually by distilleries. Treatment of this wastewater is essential to increase its reuse potential. Anaerobic digestion (AD) has been widely applied as high strength wastewater treatment. Additionally, grain distillery wastewater (GDWW) is high in fats, oils and grease (FOG) which can cause problems during AD. Pre-treatment is therefore often required to make the AD process more efficient. The overall objective of this study was to investigate the operational efficiency of upflow anaerobic sludge blanket (UASB) reactors while treating GDWW as substrate. The first aim was to investigate the pre-treatment of the GDWW specifically for the removal of FOG by evaluating the effect of pH adaption, coagulant concentration and ozone (O3) dosages on the FOG reduction efficiency. Secondly, the effect of two different pre-treatments (only coagulant and coagulant and ozone) on the subsequent UASB treatment step was investigated. The pH of raw GDWW (pH 3.4) was adapted to three different pH values (5.0, 6.0, and 7.0) and the coagulant, aluminium chlorohydrate (ACH) (140 mg.L-1), was added. To make the process more economically viable, the lowering the coagulant concentration (to 100 mgACH.L-1) was also investigated. Optimal reductions for chemical oxygen demand (COD) (33.2% ± 4.93), total suspended solids (TSS) (91.9% ± 1.73) and FOG (84.1% ± 1.98) were, however, achieved at a higher coagulant concentration of 140 mgACH.L-1, and at a wastewater pH of 7.0. The effect of additional ozone treatment was also investigated. Maximum reductions for the ozone treatment were obtained at 100 mgO3.L-1 for COD (3.6% ± 4.08), and at 900 mgO3.L-1 for TSS (27.7% ± 5.58) and FOG (23.9% ± 1.83). The ozone treatment was most efficient for FOG reduction (in terms of mg FOG reduced per mg ozone) at 100 mgO3.L-1. An ozone dosage of 300 mgO3.L-1, was decided on based on economic feasibility, findings in literature on toxicity of ozone and the potential degradation of recalcitrant compounds at this dosage. The final pre-treatment thus included pH adaption to 7.0, coagulant dosage of 140 mgACH.L-1, and an ozone dosage of 300 mgO3.L-1. The second part of this study involved the operation of two 2 L laboratory scale UASB reactors for 277 days. The substrate of the first reactor contained GDWW that had only undergone coagulant pre-treatment (Rcontrol), while the substrate of the second UASB reactor consisted of GDWW that had undergone coagulant and ozone pre-treatment (Rozone). Both reactors treated the pre-treated GDWW successfully at ca. 9 kgCOD.m-3d-1. COD reductions of 96% for Rcontrol and 93% for Rozone, were achieved. FOG reductions (%) showed variations throughout the study and maximum reductions of 88% and 92% were achieved for Rcontrol and Rozone, respectively. The Rozone produced more biogas, but the methane content was similar for both reactors. The additional ozone pre-treatment did not show any added benefits to the reactor performance results. UASB granule washout in Rcontrol did, however, suggest possible toxicity of unsaturated fatty acids present in the non-ozonated substrate. The feasibility of FOG removal was shown as both reactors successfully treated pre-treated GDWW. Ozonation, after a coagulant dosage, which resulted in further reduction in the FOG content of the GDWW, is thus not essential to ensure the success of an anaerobic digestion step. Ozonation of the pre-treated GDWW could, however, be beneficial to gas production and the efficiency of a tertiary biological process. / AFRIKAANSE OPSOMMING: Groot volumes hoë-sterkte afloopwater word jaarliks deur distilleerderye opgelewer. Die behandeling van hierdie afloopwater is noodsaaklik om die hergebruiksmoontlikheid daarvan te verhoog. Die toepassing van anaërobiese vertering (AV) is wydverspreid in hoë-sterkte afloopwaterbehandeling. Graandistillerings-afloopwater (GDAW) is boonop hoog in vette, olies en ghries (VOG), wat probleme kan veroorsaak tydens AV. Voorbehandeling word dus dikwels verlang om die AV meer doeltreffend te maak. Die oorhoofse doelstelling van hierdie studie was om die doeltreffendheid van opvloei-anaërobieseslykkombers- (OAS-) reaktore wat GDAW as substraat behandel, te ondersoek. Die eerste mikpunt was om die voorbehandeling van die GDAW, te ondersoek vir die verwydering van VOG. Dit is uitgevoer deur die uitwerking van pH aanpassing, koagulantkonsentrasie en osoon(O3)dosis op VOG vermindering te evalueer. Tweedens is die uitwerking van twee verskillende voorbehandelings (slegs koagulant asook koagulant en osoonbehandeling) op die opvolgende OAS-behandelingsstap ondersoek. Die pH van rou GDAW (pH 3.4) is aangepas tot drie verskillende pH waardes (5.0, 6.0 en 7.0) en die koagulant, aluminium-chlorohidraat (ACH), is bygevoeg (140 mg.L-1). Om die proses meer ekonomies uitvoerbaar te maak is ‘n verlaagde koagulantkonsentrasie (verlaag tot 100 mgACH.L-1) ook ondersoek. Die optimale afnames vir chemiese suurstofvereiste (CSV) (33.2% ± 4.93), totale oplosbare vastestowwe (TOV) (91.9% ± 1.73) en VOG (84.1% ± 1.98) is egter bereik teen ‘n hoër koagulant konsentrasie van 140 mgACH.L-1, en teen ‘n afloopwater-pH van 7.0. Die uitwerking van ‘n bykomende osoonbehandeling is ook ondersoek. Die hoogste afnames tydens die osoonbehandeling is bereik teen 100 mgO3.L-1 vir CSV (3.6% ± 4.08), en teen 900 mgO3.L-1 vir TOV (27.7% ± 5.58) en VOG (23.9% ± 1.83). Die osoonbehandeling was mees doeltreffend vir VOG (in terme van mg VOG verwyder per mg osoon) teen 100 mgO3.L-1. Daar is besluit op ‘n van 300 mgO3.L-1, as gevolg van die ekonomiese uitvoerbaarheid, bevindinge in literatuur vir die toksisiteit van osoon, en die moontlike afbraak van moeilik-afbreekbare komponente teen hierdie dosis. Die finale voorbehandeling het dus bestaan uit ‘n aanpassing van die afloopwater-pH na 7.0, ‘n koagulantdosis van 140 mgACH.L-1, en ‘n osoondosis van 300 mgO3.L-1. Tydens die tweede gedeelte van hierdie studie is twee 2 L laboratoriumskaal OAS reaktore bedryf vir 277 dae. Die substraat van die eerste reaktor het GDAW bevat wat slegs ‘n koagulant-voorbehandeling ondergaan het (Rkontrole), terwyl die substraat van die tweede OAS-reaktor GDAW bevat het wat koagulant- en osoon-voorbehandeling ondergaan het (Rosoon). Beide reaktore het die voorbehandelde-GDAW suksesvol behandel teen ‘n organieseladingstempo van ca. 9 kgCSV.m-3d-1. Afnames in CSV van 96% vir Rkontrole en 93% vir Rosoon, is bereik. Tydens die studie is deurlopende wisseling in VOG verwydering (%) waargeneem, en die hoogste verwyderings wat bereik is, is onderskeidelik 88% en 92% vir Rkontrole en Rosoon. Die Rosoon het meer biogas geproduseer, maar die metaanpersentasie was soortgelyk vir beide reaktore. Die osoon-voorbehandeling het nie enige toegevoegde voordele getoon in die reaktorprestasie resultate nie. Die uitwas van die OAS-granules vir die Rkontrole het egter moontlike toksisiteit van onversadigdevetsure aangedui, wat moontlik teenwoordig kon wees in die nie-geösoneerde substraat. Die uitvoerbaarheid van VOG verwydering is getoon aangesien beide reaktore voorbehandelde GDAW suksesvol behandel het. Osonering, wat verdere afname in die VOG inhoud van GDAW teweeggebring het (na ‘n koagulant dosis), is dus nie noodsaaklik vir die suksesvolle verloop van ‘n anaërobiese-verteringsstap nie. Osonering van die voorbehandelde GDAW kan egter voordelig wees vir gasvorming, en kan ook verder die doeltreffendheid van ‘n tersiêre biologiese behandeling verhoog.

Thesis (MScFoodSc)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Waste generated by the distillery industry is a major ecological concern and disposal thereof without a suitable treatment can have damaging effects on the environment. The characteristics of this type of wastewater are highly variable and dependent on the raw material used and production process followed. Grain distillery wastewater (GDWW) is also rich in fats, oils and grease (FOG). Successful treatments of distillery wastewater and GDWW have been reported using an upflow anaerobic sludge blanket (UASB) reactor technology. The aim of this study was to investigate the ability of lab-scale UASB reactor to treat FOG-reduced GDWW and the subsequent enhancement thereof following an unique feeding strategy approach. Firstly, a coagulation/flocculation-centrifugation step was developed to obtain FOG-reduced GDWW. Secondly, the efficiency of a lab-scale UASB reactor was investigated treating FOG-reduced GDWW at pre-determined operational parameters as well as the verification of biomass acclimatisation. Lastly, the effect of a unique feeding strategy of FOG-reduced GDWW to lab-scale UASB reactor granules was investigated in terms of COD, FOG-reduction and biomass acclimatisation. It was found that a coagulation/flocculation-centrifugation treatment removed sufficient amounts of FOG and TSS from GDWW. Different commercially available coagulation/flocculation products were evaluated whilst used in combination with a centrifugation step for improved sedimentation and separation. The FOG removal remained between 90 and 97% for the ferric chloride (FeCl3) and Ferrifloc 1820 treatments, respectively, whereas the TSS removal ranged between 56 and 93%, respectively. The use of a high molecular weight polymer (Ultrafloc 5000) and an aluminium chlorohydrate (Ultrafloc 3800) proved to be less effective in terms of FOG removal efficiency, ranging from 72 to 86%. It was decided to pre-treat GDWW with FeCl3 in combination with centrifugation to obtain FOG-reduced GDWW for subsequent UASB reactor treatment investigations. The FOG-reduced GDWW was fed into a laboratory-scale UASB reactor (2 L) over a period of 331 days. During the operational period different feeding parameters were attained to establish the ability of the UASB reactor to efficiently treat FOG-reduced GDWW. The COD removal increased from 60 to 85% at an organic loading rate (OLR) of ca. 5.5 kgCOD.m-3.d-1 (pH = 7.5) whilst FOG removal remained between 45 and 70%. COD removal increased to 90% with the attainment of an OLR of ca.10 kgCOD.m-3.d-1 (pH = 7.5) whereas FOG removal remained in the region of 55 and 65%. COD and FOG removal remained above 85% and 50%, respectively, when substrate pH was decreased to 6.50 (OLR ca. 10 kgCOD.m-3.d-1). A granule activity test was performed on seed and FOG-reduced GDWW fed granules to determine biomass acclimatisation. FOG-reduced GDWW fed granules showed higher activity in terms of methane production rate and cumulative methane production suggesting biomass acclimatisation. The FOG-reduced GDWW was fed to a laboratory-scale UASB reactor following a unique feeding approach. The feeding approach consisted of several feeding and starvation cycles. Improved average biogas production was observed during the feeding (0.26 to 11.3 L.d-1) and starvation (1.8 to 4.2 L.d-1) cycles as higher loading rates were obtained during each feeding cycle. After the completion of the strategic feeding the UASB reactor was continuously fed at an organic loading rate of ca. 5 kgCOD.m-3.d-1. The COD reduction efficiency improved from 70 to 80%, however, FOG removal remained in the region of 60%. Granule activity tests done on days 0, 215 and 279 showed improved UASB granule activity to FOG-reduced GDWW with operation time in terms of methane production rate and cumulative methane production. This study has proven that a coagulation/flocculation-centrifugation treatment of GDWW can remove sufficient amounts of FOG and TSS before the commencement of a UASB treatment, however, such a technique would require more refinement. It was also found that a UASB reactor can successfully treat FOG-reduced GDWW, however, it must be advised that close monitoring of the UASB reactor is required in order to maintain efficient COD reduction. A strategic feeding approach proved to be successful, but further improvement of the UASB efficiency to treat FOG-reduced GDWW in terms of stable COD and FOG reduction, stable effluent pH, improved biogas production and biomass activity must still be explored. / AFRIKAANSE OPSOMMING: Afloop water wat gegenereer word deur die distillerings-industrie veroorsaak ‘n ekologiese kommer en wegdoening daarvan sonder geskikte behandeling, kan ernstige gevolge op die omgewing hê. Die eienskappe van hierdie tipe afvalwater kan varieer en is afhanklik van die rou materiale gebruik en die produksie proses wat gevolg is. Graan distillery afloop water (GDAW) deel dieselfde eienskappe met die van distillery afloop water, alhoewel dit ook hoog is in vette, olies en ghries (VOG). Suksesvolle behandeling van distillery afloop water en GDAW met n opvloei-anaërobiese slykkombers (OAS) reaktor is deur verskeie navorsers gerapporteer. Die doel van hierdie studie was om die uitvoerbaarheid van laboratorium skaal OAS reaktor, wat VOG-verminderde GDAW behandel te ondersoek, asook die daaropvolgende verbetering deur n unieke voer strategie te volg. Eerstens, was ‘n koagulasie/flokkulasie-sentrifigasie tegniek ontwikkel om VOG-verminderde GDAW te kry. Tweendens, die effektiwiteit van ‘n lab-skaal OAS reaktor ondersoek, wat gevoer was met VOG-verminderde GDAW, by voorafbepaalde parameters. Laastens, die effek van ‘n unieke voer strategie van VOG-verminderde GDAW op lab-skaal OAS reaktor granules. Dit was vasgestel dat ‘n koagulasie/flokkulasie-sentrifigasie voor behandeling voldoende hoeveelhede VOG en TSS verwyder van GDAW. Verskillende kommersieel beskikbare koagulasie/flokkulasie produkte was in kombinasie met ‘n sentrifugasie stap geëvalueer om sedimentasie en skeiding te verbeter. Dit was nie ‘n plan om die stap te perfek nie, maar dat dit eerder sou dien as ‘n voorbehandeling stap vir opeenvolgende ondersoeke. Die VOG verwydering het tussen 90 en 97% gevariëer vir ferri chloride (FeCl3) en Ferrifloc 1820 (Chlorchem) en TSS verwydering het tussen 56 en 93% gewissel. Die gebruik van ‘n hoë molekulêre gewig polimeer (Ultrafloc 5000) en ‘n aluminium chlorohidraat (Ultrafloc 3800) was minder effektief met n VOG verwydering wat tussen 72 en 86% gewissel het. Die VOG-verminderde GDAW was in ‘n laboratorium-skaal OAS reaktor oor ‘n tydperk van 331 dae behandel. Verskillende voer doelwitte was geëvaluaeer om te bepaal of ‘n OAS reaktor GDAW suksesvol kan behandel. CSB afbraak het van 60 to 85% gestyg teen ‘n organiese lading van 5.5 kgCOD.m-3.d-1 (pH 7.50), met VOG verwydering wat tussen 45 en 70% gewissel het. Die CSB afbraak het na die bereiking van 10 kgCOD.m-3.d-1 (pH 7.50) gestyg na 90% met VOG afbraak tussen 55 en 60% gewissel het. Die CSB en VOG verwydering het bo 85% en 50% onderskeidelik gebly, met die verlaging van substraat pH na 6.50 (CSB ca. 10 kgCOD.m-3.d-1). ‘n Aktiwiteits toets is uitgevoer met saad granules en VOG-verminderde GDAW gevoerde granules. Granules (VOG-verminderde GDAW gevoer) het ‘n hoer aktiwiteit getoon teenoor saad granules in terme van metaan produksie tempo en kumulatiewe metaan produksie. Die VOG-verminderde GDAW was gevoer in ‘n OAS reaktor deur gebruik te maak van ‘n strategiese voertegniek. Die strategie het uit verskeie voer en hongersnood fases bestaan. Verbeterde biogas produksie was tydens voer (0.26 tot 11.3 L.d-1) en hongersnood (1.8 tot 4.2 L.d-1) -fases opgelet soos ‘n hoër lading bereik was. Na die voltooing van die strategiese voer fase was die OAS reaktor op ‘n deurlopende basis teen ‘n lading van 5 kgCOD.m-3.d-1 gevoer. Die CSB verwydering het van 70 na 80% verhoog terwyl VOG afbraak in die omgewing van 60% gewissel het. Biomassa aktiwiteits toetse was uitgevoer is op dag 0, 215 en 279 het verhoogde aktiwiteit vertoon, met ‘n strategiese fase en deurlopende fase teenoor die aanvanklike (ongeaklamatiseerde) granules. Hierdie studie het bewys dat ‘n flokkulasie/koagulasie-sentrifugasie behandeling van GDAW kan dien as ‘n voorbehandelings stap vir opeenvolgende OAS reaktor studies. Dit was gevind dat ‘n OAS reaktor die VOG-verminderde GDAW kan behandel, maar dit word aanbeveel dat die OAS reaktor so sorgvuldig as moontlik gemonitor word om effektiewe CSB verwydering te handhaaf. Ten slotte, ‘n strategiese voer strategie was suksesvol, maar verdere verbetering van die OAS reaktor ten opsigte van die behandeling van VOG-verminderde GDAW moet verder ondersoek word.