Thesis (MSc)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: Large volumes of wastewater are generated annually during the grape harvest season from various processing and cleaning operations at wineries, distilleries and other wine-related industries. South African regulatory bodies dictate that wastewater should have a pH of 5.5 to 7.5 and a chemical oxygen demand (COD) lower than 75 mg/L. However, winery wastewater has a typical pH of 4 to 5 and a COD varying between 2 000 and 12 000 mg/L. Urban wineries channel the wastewater to local sewage treatment facilities and are often heavily fined for exceeding governmental requirements. Rural wineries usually have little or no treatment operations for their wastewater and it is often irrigated onto crops, which may result in environmental pollution and contamination of underground water resources. Various criteria are important in choosing a wastewater treatment system, such as an ecofriendly process that is flexible to withstand various concentration loads and characteristics, requiring low capital and operating costs, minimal personal attention and do not require too much land. In this study, a large variation in COD, pH and chemical composition of the winery wastewater was observed that could be related to varying factors such as the harvest load, operational procedures and grape variety. Wastewater from destemming and pressing operations contained higher concentrations of glucose, fructose and malic acid, which originated from the grape berries. The fermentable sugars (glucose and fructose) contributed to almost half of the COD with a smaller contribution from ethanol and acetic acid. The low pH can be ascribed to relative high concentrations of organic acids in the wastewater. The efficacy of biological treatment systems depends strongly on the ability of microorganisms to form biofilm communities that are able to degrade the organic compounds in the wastewater. Preliminary identification of microorganisms that naturally occur in winery wastewater indicated the presence of various bacterial and yeast species that could be effective in the biological treatment of the wastewater. When evaluated as pure cultures under aerobic conditions, some of the yeast isolates effectively reduced the COD of a synthetic wastewater, whereas the bacterial isolates were ineffective. The most effective yeast isolates were identified as Pichia rhodanensis, Kloeckera apiculata, Candida krusei and Saccharomyces cerevisiae. Our search for cost-effective biological treatment systems led to the evaluation of a Rotating Biological Contactor (RBC) for the treatment of winery wastewater. The RBC was evaluated on a laboratory scale with 10% (v/v) diluted grape juice and inoculated with a mixed microbial community isolated from winery wastewater. The results showed a reduction in the COD that improved with an extended retention time. Evaluation of the RBC on-site at a local winery during the harvest season resulted on average in a 41% decrease in COD and an increase of 0,75 pH units. RFLP analysis of the biofilm communities within the RBC confirmed a population shift in both the bacterial and fungal species during the evaluation period. The most dominant yeast isolates were identified with 18S rDNA sequencing as Saccharomyces cerevisiae, Candida intermedia, Hanseniaspora uvarum and Pichia membranifaciens. All these species are naturally associated with grapes and/or water and with the exception of Hanseniaspora uvarum, they are able to form either simple or elaborate pseudohyphae. / AFRIKAANSE OPSOMMING: Groot hoeveelhede afloopwater word jaarliks gedurende die druiwe-oestyd deur verskeie prosessering- en skoonmaakoperasies deur wynkelders, distilleer- en ander wynverwante industrieë gegenereer. Suid-Afrikaanse beheerliggame vereis dat afloopwater ‘n pH van 5.5 tot 7.5 en ‘n chemiese suurstofbehoefte (COD) van minder as 75 mg/l moet hê. Kelderafloopwater het egter gewoonlik ‘n pH van 4 tot 5 en ‘n COD van 2 000 tot 12 000 mg/L. Stedelike wynkelders voer die afloopwater na ń plaaslike rioolsuiweringsaanleg wat dikwels tot swaar boetes vir oortreding van die wetlike vereistes lei. Plattelandse wynkelders het gewoonlik min of geen behandelingsprosesse vir hul afloopwater nie en gebruik die water dikwels vir gewasbesproeiing, wat tot omgewingsbesoedeling en kontaminasie van ondergrondse waterbronne kan lei. Verskeie kriteria is belangrik in die keuse van ‘n waterbehandelingstelsel, byvoorbeeld ‘n omgewingsvriendelike proses wat verskillende konsentrasieladings en samestellings kan hanteer, ‘n lae kapitaal- en bedryfskoste en minimale persoonlike aandag vereis en min ruimte benodig. Hierdie studie het getoon dat kelderafloopwater ‘n groot variasie in COD, pH en chemiese samestelling het wat met wisselende faktore soos die oeslading, operasionele prosesse en selfs die druifkultivar verband kan hou. Afloopwater van ontstingeling- en parsoperasies het hoër konsentrasies glukose, fruktose en appelsuur wat van die druiwekorrels afkomstig is. Die fermenteerbare suikers (glukose en fruktose) dra tot amper 50% van die COD by, met ‘n kleiner bydrae deur etanol en asynsuur. Die lae pH kan grootliks aan organiese sure in die afloopwater toegeskryf word. Die effektiwiteit van biologiese behandelingstelsels steun sterk op die vermoë van mikroorganismes om biofilmgemeenskappe te vorm wat die organiese verbindings in die afloopwater kan afbreek. Voorlopige identifikasie van mikro-organismes wat natuurlik in wynafloopwater voorkom, het die teenwoordigheid van verskeie bakteriese en gisspesies aangedui. Evaluering van hierdie isolate onder aërobiese toestande het getoon dat sommige van die gis-isolate die COD van ‘n sintetiese afloopwater effektief kon verlaag, terwyl die bakteriese isolate oneffektief was. Die mees effektiewe gis-isolate is as Pichia rhodanensis, Kloeckera apiculata, Candida krusei en Saccharomyces cerevisiae geïdentifiseer. Ons soektog na ‘n koste-effektiewe biologiese behandelingsisteem het tot die evaluering van ‘n ‘Rotating Biological Contactor’ (RBC) vir die behandeling van afloopwater gelei. Die RBC is op laboratoriumskaal met 10% (v/v) verdunde druiwesap geëvalueer en met ‘n gemengde mikrobiese gemeenskap wat uit afloopwater geïsoleer is, innokuleer. Die resultate het ‘n verlaging in die COD getoon wat met ‘n langer retensietyd verbeter het. Evaluering van die RBC by ‘n plaaslike wynkelder gedurende die oesseisoen het gemiddeld ‘n verlaging van 41% in die COD en ‘n verhoging van 0,75 pH eenhede getoon. RPLP analise van die biofilmgemeenskappe in die RBC het ‘n bevolkingsverskuiwing in beide die bakteriese en swamspesies aangetoon. Die mees dominante gisspesies is met 18S rDNA volgordebepaling as Saccharomyces cerevisiae, Candida intermedia, Hanseniaspora uvarum en Pichia membranifaciens geïdentifiseer. Al hierdie spesies word gewoonlik met druiwe en/of water geassosieer en is, met die uitsondering van Hanseniaspora uvarum, in staat om òf eenvoudige òf komplekse pseudohife te vorm.

M.Tech. (Civil Engineering) / This study presents work on the design and construction of three dual-chamber microbial fuel cells (MFCs) using a sandwich separator electrode assembly (SSEA) and membrane cathode assembly (MCA) for the dual purposes of energy generation from domestic wastewater and wastewater treatment. MFC1 was designed using an improvised SSEA technique (i.e. a separator electrode membrane electrode configuration, SEMEC) by gluing a sandwich of anode, membrane and a mesh current collector cathode to an anode chamber made from a polyethylene wide-mouth bottle. The reactor was filled with 1500 mL of domestic wastewater and operated on a long fed-batch mode with a residence time of 3 weeks. The reactor was inoculated with a mixed culture of bacteria present in the wastewater stream. The aim was to study the impact of wastewater COD concentration on power generation and wastewater treatment efficiency. For MFC2 and MFC 3, cathodes were constructed using the MCA technique consisting of a membrane and a mesh current collector cathode, with the anode electrode at the opposite side of stacked Perspex sections used for the anode chamber. The impact of electrode material on current production was examined in this study. For MFC2 a mesh current collector treated with polytetrafluoroethylene (PTFE) and activated carbon (AC) functioned as the cathode, while the MFC3 cathode was an uncatalyzed mesh current collector. The two reactors were both filled with 350 mL of domestic wastewater...

Water is a fundamental need for existence of mankind. Only 0.01 % of total global water is readily available for human consumption as fresh water. The rapid increase in human population and consequent rise in urbanization and industrialization is producing a stress on this meager water resource. Water at the same time is a renewable resource, ie with suitable treatment it can be made re-useable. Aeration is one of the important processes employed in activated sludge process of the biological treatment units of wastewater. In this process the level of dissolved oxygen in the effluent is raised to the required amounts to decompose organic matters present in the effluent and thereby to reduce the BOD (biochemical oxygen demand) of the effluent by a physical means called “aeration process”. The aeration process consumes as much as 60-80% of total power requirements of wastewater treatment plants. Therefore, the efficiency in design of aeration process is required so that treatment and its power consumption can be economized. With the objective of optimizing the aeration process the present work in this thesis endeavors to develop an aeration which is efficient as well as economical. The various geometric parameters that affect the aeration process in mechanical surface aerators have been optimized. In the present work circular surface aeration tanks have been used. There are two types of circular tanks: Baffled and unbaffled. Separate optimal geometric parameters have been obtained for baffled and unbaffled circular tanks. With optimal geometric similitude scale up studies were done. Reynolds number and Froude number criteria has been found unsuitable for scaling oxygen transfer rates. Theoretical power per unit volume parameter is the most suitable scaling parameter for oxygen transfer rates in both baffled and unbaffled circular tanks. Baffled circular tanks are found to give better performance in terms of oxygen transfer rates as compared to unbaffled tanks. In contrast unbaffled tanks give better performance in terms of power consumption as compared to baffled circular tanks. General correlations have been developed for oxygen transfer rates for both baffled and unbaffled circular surface aerations tanks which incorporate all the geometric and dynamic parameters. These correlations help in the design of new treatment facilities as well as evaluating and up gradation of existing facilities. Power consumption studies have also been conducted on circular surface aeration tanks. Geometric parameters affect the power consumption significantly. Using the optimal geometric similarity conditions obtained for oxygen transfer rates the scale up studies for power consumption has also been done. Reynolds and Froude criteria are found to be giving scale effects for non dimensional power consumption parameter, power number. Theoretical power per unit volume parameter is found to be the scaling parameters for power number and a suitable correlation equation has been developed for baffled circular surface aeration tanks. General correlations have been developed for power number in baffled and unbaffled circular tanks. A novel type of self aspirating tube sparger system has been developed. It is like a bubble aerator with a rotor. The various geometric parameters that affect oxygen transfer rates have been optimized in baffled circular surface aeration tank. The optimal geometrically similar tanks have been used for scale up studies. Theoretical power per unit volume parameter is found to be the scaling parameter for oxygen transfer rates in circular surface aeration tanks with self aspirating sparger systems. Circular baffled tanks with a special sparger system gives very much higher oxygen transfer rates (as much as 5.7 times) as compared to circular tanks. The oxygen transfer rates data from literature also show lower values as compared to the system developed in this thesis. Geometrically similar unbaffled tanks have also been used with self aspirating sparger system. For same power consumption oxygen transfer rate in circular surface aeration tanks with self aspirating sparger system is higher as compared to circular tanks without self aspirating system. Mixing mechanisms in surface aeration tanks depend upon two different extreme length scales of time, namely macromixing and micromixing. Small scale mixing close to the molecular level is referred to as micromixing; whereas macromixing refers to the mixing on a large scale. The effect of geometrical parameters on macromixing time has been studied. The scaling parameters for macromixing and micromixing have been developed and simulation equations governing these time scales are also presented.

M. Tech. Chemical Engineering. / Discusses the general objective of this research is to study the application of a combined advanced oxidation and adsorption process, with a view to developing a novel technique for the treatment of tea industry effluents prior to discharge into receiving water bodies. The specific objectives of the research are: a) To tailor natural zeolite physico-chemical properties in attempt to enhance its adsorptive performance ; b) To evaluate the decolourization efficiency of functionalized zeolite in tea industry effluent treatment. c) To evaluate the effect of the following operational parameters: pH, initial concentration,temperature and the sorbent mass, on the removal of colour in tea industry effluent. d) To apply adsorption and advanced oxidation independently and to combine the two into one process.

Thesis (M.Tech.: Chemical Engineering)-Dept. of Chemical Engineering, Durban University of Technology, 2005 1 v. (various pagings) / In bubble-less aeration oxygen diffuses through the membrane in a molecular form and dissolves in the liquid. Oxygen is fed through the lumen side of silicone rubber tube. On the outer surface of the membrane there is a boundary layer that is created by oxygen. This then gets transported to the bulk liquid by convective transport created by water circulation through the pump. The driving force of the convective transport is due to concentration difference between the dissolved oxygen in water and oxygen saturation concentration in water at a particular temperature and pressure. The design of a membrane aerated bioreactor needs an understanding of the factors that govern oxygen mass transfer. It is necessary to know the effects of operating conditions and design configurations. Although various methods of bubble-less aeration have been reported, there still exists a lack of knowledge on the immersed membrane systems. This study is aiming at contributing to the development of an immersed membrane bioreactor using silicone rubber tubular membrane as means of providing oxygen. The secondary objective was to investigate the influence that the operating conditions and module configuration have on the system behaviour. From the experimental study, the characteristic dissolved oxygen -time curve show that there is a saturation limit equivalent to the equilibrium dissolved oxygen concentration, after which there is no increase in dissolved oxygen with time. At ambient conditions the equilibrium dissolved oxygen is approximately 8 mg/L. This is when water is in contact with air at one atmospheric pressure. At the same conditions the equilibrium dissolved oxygen concentration when water is in contact with pure oxygen is approximately 40 mg/L. This is why all the experiments were conducted from 2mg/L dissolved oxygen concentration in water, to enable enough time to reach equilibrium so as to determine mass transfer coefficient. The most important parameters that were investigated to characterise the reactor were, oxygen supply pressure, crossflow velocity, temperature and module orientation. Observations from the experimental study indicated that when the system is controlled by pressure, crossflow does not have a significant effect on mass transfer. When the system is controlled by the convective transport from the membrane surface to the bulk liquid, pressure does not have a significant effect on mass transfer. All four effects that were investigated in the study are discussed.

The inherent thermal resistance of ceramic membranes allows for treatment of industrial waters at elevated temperatures. Traditionally, the high temperature of wastewater has been an issue compromising the integrity of polymeric membrane systems or requiring the temperature to be lowered for further treatments. In ceramic membrane systems, a decrease in viscosity with increasing temperature, however, can be utilized, which increases the permeate flux. In this study, the fouling of ceramic ultrafiltration by feed solutions containing colloidal silica was evaluated at temperatures between 25 – 90 °C seen in various industries. Ceramic membranes were able to perform well at elevated temperatures up to 90 ºC with sustained mechanical and chemical integrity. Results showed net benefit of filtration at elevated temperatures on permeate flux in spite of increasing total fouling resistance with temperature. When the temperature increased from 25 to 90 °C, there was a 90% increase in steady-state permeate flux. The dominant resistance was physically removable fouling, and the increase in fouling with feed temperature was supported by force balance analyses. This study provides a foundation from which further studies can be developed including pilot-scale testing, use of real wastewater, and the effects of operating conditions.

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2007. / The distillery industry generates large volumes of heavily polluted wastewater and thus effective wastewater treatment is essential. It has been reported that a chemical oxygen demand (COD) reduction of more than 90% can be achieved when wine distillery wastewater (WDWW) is treated in an upflow anaerobic sludge blanket (UASB) reactor. The first objective of this study was to investigate UASB treatment of WDWW and to try to enhance the efficiency by using ozonation treatments. Secondly, the impact of grain distillery wastewater (GDWW) on UASB granules was determined. The third objective was to determine whether ozonation and enzymatic treatment combinations might improve the biodegradability of GDWW and thus make GDWW more amenable to UASB treatment. It was found that UASB treatment combined with ozonation improved the WDWW treatment efficiency. When diluted WDWW (chemical oxygen demand COD = 4 000 mg.L-1) was ozonated (dose = 47 mg.L-1) in a 50 L venturi circulating contactor system, the COD reduction was 7%. When WDWW was treated in a laboratory-scale UASB reactor (substrate pH = 7.0, COD = 4 000 mg.L-1 and organic loading rate (OLR) = 4.0 kg COD.m-3.d-1), the COD reduction was 92%. When the UASB treatment was combined with either pre- or postozonation, the COD reduction was 94 and 96%, respectively. When UASB treatment was combined with pre- and post-ozonation, a COD reduction of 98% was achieved. The activity of the UASB granules was also found to improve over time, despite the addition of the ozonation treatment. It has been reported that operational problems occur when GDWW is treated in an UASB reactor as a result of the encapsulation of the granules. This was confirmed when granules from a full-scale UASB treating WDWW became encapsulated in a layer after being exposed to GDWW (COD = 4 000 mg.L-1) for 24 d. The results showed that the lipid content of the granules increased from 1.25 to 60.35 mg lipid.g-1 granule over the 24 d exposure period. Therefore, granules exposed to GDWW were encapsulated in a lipid-rich layer and as a result the contact between the GDWW and microbial consortium in the granules was reduced. The operational problems found during the industrial UASB treatment of GDWW were ascribed to the encapsulation of the granules. Combinations of ozonation (dose = 1 476 mg.L-1) generated in a 2 L bubble column and enzymatic treatments (1% FogFreeTM (FF) dosage and 2 d incubation at 35°C) were found to improve the biodegradability of GDWW. This improvement was in terms of lipid reduction in GDWW, granule activity and visual appearance of the encapsulating layer of the granules. The highest lipid reduction (90%), highest granule activity, lowest lipid content of the granules (3.74 ± 0.10 mg.g-1 granule) and best visual appearance were achieved in ozonated GDWW treated with 1% FF, followed by just ozonation. The higher lipid reduction and subsequent higher granule activity were ascribed to the reduction in lipids which resulted in the fact that fewer lipids were available to encapsulate the granules. As a result of the lipid reduction, the granule activity improved and the GDWW was made more amenable to UASB treatment. This study proved that UASB treatment combined with ozonation led to an enhancement of the treatment efficiency of WDWW. It was also found that the cause of the operational problems during UASB treatment of GDWW was as a result of the granules being encapsulated in a lipid-rich layer. It was established that treating GDWW prior to UASB treatment improved the biodegradability of GDWW. The data from the study showed that high lipid reduction in the GDWW directly led to better granule activity, lower granule lipid content and a thinner encapsulating layer. Based on the data from this study, it is recommended that GDWW be ozonated prior to other treatments because it can be done inline and the costs would be lower than that of enzymatic treatments.

Thesis (MSc Food Sc )--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The South African apple juice processing industry is growing rapidly and during the harvesting season the wastewater volumes and organic loads increase significantly with a considerable environmental impact. These larger apple juice processing wastewater (AJPWW) volumes and chemical oxygen demand (COD) loads subsequently lead to faster increases in the organic loading rate (OLR) of an upflow anaerobic sludge bed (UASB) wastewater treatment system and it is necessary to know if the treatment system can handle such drastic increases over short periods. The objective of the study were to evaluate the efficiency of the UASB process in the treatment of an AJPWW; to determine what effect a substrate viscosity increase, based on a pectin calcium gel has on the performance of an UASB system, and to determine what impact ozonation has on the pectin content, gelformation ability and biodegradability of the AJPWW. The ability of the UASB to maintain stability during the apple-processing season was investigated by increasing the OLR from 2.9 to over 14.0 kg COD.m-3.d-1 in 131 days. During this time the COD removal remained constant at 85%, while the pH and alkalinity remained at levels indicative of good reactor stability. It was thus concluded that the UASB reactor could operate successfully during the apple-harvesting season when wastewater volumes and organic loads increase significantly. In the study it was found that the viscosity of the AJPWW, containing 750 mq.L-1 pectin, increased from 8.5 to 47.0 cps after a 312 rnq.L-1 Ca2 + addition. This increased viscosity substrate was then fed to an UASB reactor at an OLR of 15.0 kg COD.m-3.d-1. During a 12 day increased viscosity (47 cps) feeding stage the COD removal decreased from 94 to 11%, while the reactor pH decreased from 7.5 to 4.9. During this period, pectin accumulated in the UASB and led to biomass washout and rapid UASB failure. The possible elimination of pectin by ozonation was thus investigated, and a 77% decrease in pectin content and 76% decrease in gel formation ability occurred after ozonation. The effect of pre- and post-ozonation on the efficiency of the UASB system was subsequently investigated. It was found that a 10 min pre-ozonation decreased the AJPWW COD by 19% and the total suspended content by 36%, while the soluble portion of the total COD was increased from 81.7 to 92.4%. This increase in soluble COD content should lead to increased wastewater biodegradability. The ozonated AJPWW was then used to replaced the raw non-ozonated AJPWW as reactor feed. Results showed that the COD removal increased from 78 to 90% within 24 h of starting with the ozonated feed. It was also found that the reactor stability improved after AJPWW pre-ozonation as an OLR increase from 10.0 to 16.6 kg COD.m-3.d-1 in 23 days did not detrimentally influence the stability of the reactor. This reactor effluent (COD = 465 rnq.L-1) was then post-ozonated which resulted in 64.8% COD and 79.0% colour reductions. The final effluent had a COD of 180 rnq.L-1 (98% reduction). The ability of the ozonation/digestion system as described in this study to degrade AJPWW at a higher OLR is of value to the apple industry, as it may lead to larger organic pollutant removals and thus a more effiecient treatment system. Increased reactor performance will directly improve the quality of the final wastewater produced, which in turn will have a significant impact on the treatment ability of the South African apple processing industry currently limited by the production of large wastewater volumes. / AFRIKAANSE OPSOMMING: Gedurende die oesseisoen word groot volumes afvalwater met 'n hoe organiese lading in die vinnig groeiende Suid-Afrikaanse appelsapprosesseringsbedryf geproduseer. Dit het 'n groot impak op die omgewing. Die groter volumes appelsapprosesseringsafvalwater (ASPAW) met 'n hoë organiese lading het 'n vinniger verhoging in organiese ladingstempo's (OLT) van 'n UASB-waterbehandelingstelsel tot gevolg. Daarom is dit belangrik om te weet of die stelsel die drastiese verhoging oor kort tydperke kan hanteer. Die doel van hierdie studie was die evaluering van die effektiwiteit van die UASB-proses in die behandeling van ASPAW; om te bepaal watter effek 'n substraatviskositeitsverhoging, gebaseer op 'n pektien-kalsium-jel, op die doeltreffendheid van 'n UASB-stelsel het; en om te bepaal watter impak osonering op die pektieninhoud, jelvormingsvermoe en bioafbreekbaarheid van ASPAW het. Die vermoe van die UASB om stabiliteit te handhaaf gedurende die appelsapprosesseringseisoen is ondersoek deur die OLT van 2,9 tot bo 14,0 kg CSB.m-3.d-1 te verhoog oor 131 dae. Gedurende hierdie tyd het die chemiese suurstofbehoefte- (CSB-) verwydering konstant gebly by 85%, terwyl die pH en alkaliniteit ook op vlakke aanduidend van goeie reaktorstabiliteit gebly het. Daar is sodoende bewys dat die UASB-reaktor suksesvol kan presteer tydens die appelsapprosesseringseisoen, wanneer daar 'n beduidende verhoging in OLT plaasvind. In die studie is daar gevind dat die viskositeit van die ASPAW, wat 750 mq.L-1 pektien bevat, van 8,5 tot 47,0 cps toeneem na die byvoeging van 312 rnq.L-1 Ca2+. Hierdie verhoogde vikositeitsubstraat is tot die UASB-reaktor toegevoeg teen 'n OLT van 15,0 kg CSB.m-1.d-1. Gedurende 'n 12-dae toevoer van verhoogde viskositeit (47 cps), het die CSB-verwydering van die reaktor afgeneem van 94% na 11%, terwyl die pH gedaal het van 7,5 na 4,9. Gedurende hierdie tydperk het pektien in die UASB geakkumuleer, wat gelei het tot die uitspoel van biomassa en vinnige UASB-reaktormislukking. Die moontlike eliminasie van pektien, deur osonering, is daarom ondersoek. 'n Verlaging van 77% in pektieninhoud en 76% in jelvormingsvermoe het na osonering plaasgevind. Die effek van pre- en post-osonering op die effektiwiteit van 'n UASB-stelsel is gevolglik ondersoek. Daar is gevind dat 'n 10 minute pre-osonering die CSB van die ASPAW met 19% verlaag en die totale inhoud van gesuspendeerde vaste stowwe met 36% verlaag, terwyl die oplosbare gedeelte van die totale CSB van 81,7% tot 92,4% gestyg het. Die verhoging in oplosbare CSB-inhoud behoort tot verhoogde bioafbreekbaarheid van ASPAW te lei. Die geosoneerde ASPAW is gebruik om die rou, ongeosoneerde ASPAW as reaktorsubstraat te vervang. Die resultate het getoon dat die CSB-verwydering verhoog het van 78% na 90% na 'n 24-uur toevoer van geosoneerde substraat. Daar is ook gevind dat die reaktorstabiliteit toegeneem het na ASPAW osoneering, aangesien 'n OLT-verhoging van 10,0 na 16,6 kg.CSB.m-3.d-1 in 23 dae nie die stabiliteit van die reaktor nadelig beinvloed het nie. Hierdie reaktoruitvloeisel (CSB = 465 rnq.L-1) is hierna gepost-osoneer, wat 'n 64,8% CSB- en 79,0% kleurverlaging tot gevolg gehad. Die finale uitvloeisel het 'n CBS-inhoud van 180 rnq.L-1 gehad (98,1% verwydering). Die vermoe van die osonering-/verteringstelsel om ASPAW te degradeer teen 'n hoër OLT, soos beskryf in hierdie studie, is van waarde tot die appelsapprosesseringsbedryf, aangesien dit tot groter organiese afvalstofverwydering kan lei en dus 'n meer effektiewe behandelingstelsel tot gevolg kan hê. Verhoogde reaktordoeltreffendheid sal 'n direkte verbetering tot gevolg hê in die gehalte van die finale afvalwater wat geproduseer word, wat op sy beurt 'n beduidende impak sal hê op die behandelingsvermoe van die appelsapprosesseringsbedryf, wat tans beperk word deur die produksie van groot volumes afvalwater.

As indústrias têxteis possuem grande potencial poluidor pois geram grandes quantidades de efluentes contendo compostos recalcitrantes, incluindo corantes. Diversos processos tem sido empregados na descontaminação de efluentes industriais e estudos indicam a adsorção empregando resíduos agroindustriais como matrizes adsorventes como processos promissores na remoção de cor. Neste contexto, o presente trabalho teve como objetivo avaliar a casca de amendoim como adsorvente alternativo no processo de remoção de corante têxtil (Reactive Blue 203) em meio sintético e de efluente industrial. Para isso, foram realizadas análises de caracterização do material adsorvente, revelando elevadas quantidade de fibras (69,25%), dentre elas os polissacarídeos (glucana e xilana) e de lignina (39,4%). A biomassa apresentou um pHpcz de 6,9, a microscopia eletrônica de varredura demonstrou que sua superfície é altamente porosa e a análise da superfície especifica por BET, indicou uma área superficial de 0,4431 m2.g-1 e diâmetro médio de poro de 20,120 Å na biomassa moída com tamanho de partícula de 0,250 mm. Um Delineamento Composto Central Rotacional 23 foi empregado para avaliar e definir as melhores condições de processo, sendo estudadas a influência dos parâmetros pH, temperatura da solução e granulometria do adsorvente sobre a capacidade de remoção de cor de efluente sintético (Reactive Blue 203). As variáveis pH e temperatura apresentaram influência significativa no processo de remoção de cor e como melhores condições de processo foram definidos pH de 3,0, temperatura de 30o C e granulometria de 0,250 mm. O tempo de equilíbrio foi alcançado após 400 minutos de contato. O modelo cinético de pseudo-segunda ordem foi o que melhor descreveu o processo de adsorção. As isotermas de adsorção foram avaliadas a partir dos modelos matemáticos de Langmuir e Freundlich, sendo que o modelo de Langmuir foi o que melhor descreveu o processo. Os parâmetros termodinâmicos indicam que a energia livre de Gibbs apresenta valores positivos indicando que o processo não é espontâneo. Valores negativos da entalpia sugerem uma natureza exotérmica da adsorção e valores negativos da entropia indicaram um aumento no grau de organização do sistema. A energia de ativação do processo de adsorção do corante sobre matriz a estudada, indicam uma adsorção química ativada. A casca de amendoim demonstrou ter potencial de remoção de cor em efluente industrial (66,83%), o que pode ser melhorado empregando condições de processos mais específicas. Por outro lado, a reutilização do material não foi ótima nas condições de dessorção empregas devendo ser melhor avaliado devido à natureza química da adsorção. / The textile industries have great potential for pollutants because they generate large quantities of effluents containing recalcitrant compounds, including dyes. Different processes have been employed in the decontamination of industrial effluents and studies indicate the adsorption using agroindustrial residues as adsorbent matrices as promising processes in the removal of color. In this context, the present work had the objective of evaluating peanut shell biomass as an alternative adsorbent in the process of dye removal (Reactive Blue 203) in synthetic and industrial effluent. For this, characterization analyzes of the adsorbent material were performed, revealing a high amount of fibers (69,25%), among them polysaccharides (glucan and xylan) and lignin (39,4%). The biomass showed a pHzcp of 6,9, the scanning electron microscopy demonstrated that its surface is highly porous and the BET specific surface analysis indicated a surface area of 0,4431 mg.g-1 and mean pore diameter of 20,120 Å in ground biomass with a particle size of 0,250 mm. A 23 central composite rotational design was use to evaluate and define the best process conditions, studing the influence of the parameters pH, solution temperature and adsorbent granulometry on the color removal capacity of synthetic effluent (Reactive Blue 203). The pH and temperature variables showed a significant influence on the color removal process and, as the best process conditions, pH of 3,0, temperature of 30oC and particle size of 0,250 mm were define. The equilibration time was reach after 400 minutes of contact. The kinetic model of pseudo-second order was the one which best described the adsorption process. The adsorption isotherms were evaluate from the mathematical models of Langmuir and Freundlich, and the Langmuir model best described the process. The thermodynamic parameters shown that Gibbs free energy presents positive values, indicating that the process is not spontaneous. Negative enthalpy values suggest an exothermic nature of the adsorption and negative entropy values indicate an increase in the degree of organization of the system. The activation energy of the dye adsorption process on the studied matrix indicates an activated chemical adsorption. The peanut hulls showed potential for color removal in industrial effluent (66,83%), which can be improved by employing more specific process conditions. On the other hand, the reutilization of the material was not optimal under the desorption conditions because the chemical nature of adsorption.

Os processos industriais de produção têxtil têm como característica o uso de grandes volumes de água durante as etapas de lavagem e tingimento de tecido, resultando em efluentes com enorme diversidade e complexidade química. A presença de corantes dissolvidos no efluente é bastante visível e problemática, considerando sua recalcitrância e cinética de degradação lenta. Neste trabalho, o fungo ascomiceto L. theobromae MMPI foi avaliado quanto à capacidade de remoção de cor do efluente sintético contendo corante azul reativo e de efluente industrial. Os ensaios com efluente sintético foram realizados em incubadora orbital shaker e em biorreator com cuba de 5 L. O meio foi suplementado com MgSO4.7H2O 2 g L-1, K2HPO4 2 g L-1, autoclavado (121o C/15 min), e acrescido de sacarose, nitrato de amônio e velocidade de agitação de acordo com delineamento composto central rotacional (DCCR), temperatura 28o C, inóculo padronizado e tempo para retirada das amostras de 72 h. A eficiência de remoção de cor variou de 31,58% até 91,60% e a produção de biomassa de 0,40 g L-1 a 8,70 g L-1. Foi observada ainda, a produção de um exopolissacarídeo (EPS) na ordem de 0,66 g L-1 a 9,70 g L-1. Na análise das estimativas dos efeitos (p<0,05) apenas o efeito linear da concentração de sacarose (p<0,000) e o efeito quadrático da concentração de nitrato de amônio (p<0,018) se mostraram significativos. O modelo obtido foi avaliado através da ANOVA, apresentando coeficiente de regressão elevado considerando um sistema biológico (R2 0,8483). Este modelo foi validado através de experimento a posteriori, indicando excelente correlação entre o valor preditivo (74,8%) e o valor observado (73,8%). Os ensaios em biorreator ratificaram o comportamento observado em incubadora shaker, obtendo-se 86% de descoloração do efluente sintético ao final de 72 horas de tratamento e 91,3% de descoloração ao final de 168 horas de tratamento para o efluente industrial. Após 168 h de incubação observou-se atividade enzimática de lacase (0,0563 U / ml). Os ensaios de toxicidade aguda com Artemia salina indicaram que a CL50 foi de aproximadamente 14,72% (v / v) para o efluente bruto, enquanto que o efluente submetido ao tratamento de oito dias o valor aproximado foi de 4,98% (v / v). Diversos autores relacionam os processos de descoloração a atividade enzimática, no entanto os resultados obtidos sugerem que a remoção de cor está relacionada a adsorção do corante na biomassa produzida. Estudos posteriores devem ser realizados para o melhor entendimento e confirmação de que a remoção de cor não está associada a biossíntese de enzimas degradadoras de estruturas fenólicas como as lacases. / The industrial processes of textile production are characterized by the use of large volumes of water during the steps of washing and dyeing fabric, resulting in effluent with enormous diversity and chemical complexity. The presence of dye dissolved in the effluent is quite noticeable and problematic, considering its recalcitrance and slow degradation kinetics. In this work, the fungus ascomiceto L. theobromae MMPI were evaluated for the ability to color removal from synthetic effluent containing blue dye reactive and industrial effluent. The tests with synthetic effluent were performed in incubator orbital shaker and in bioreactor with tub of 5L. The media was supplemented with MgSO4.7H2O 2 g L-1, K2HPO4 2 g L-1, autoclaved (121 C/15 min), plus sucrose, ammonium nitrate and stirring speed according to central composite design (CCDR), temperature 28 C, inoculum standardized and time to withdrawal of samples 72h. The color removal efficiency ranged from 31.58% to 91.60% and the biomass yield 0.40 g L-1 to 8.70 g L-1. It was still observed the production of an exopolysaccharide (EPS) in the range of 0.66 g L-1 to 9.70 g L-1. In the analysis of estimated effects (p <0.05) only the linear effect of sucrose concentration (p <0.000) and quadratic effect of the concentration of ammonium nitrate (p <0.018) were significant. The model was evaluated by ANOVA, with high regression coefficient considering a biological system (R2 0.8483). This model was validated by experiment retrospectively, indicating excellent correlation between the predictive value (74.8%) and the observed value (73.8%). The tests in bioreactor ratified the behavior observed in an incubator shaker to give 86% decolorization of synthetic effluent at the end of 72 hours of treatment of discoloration and 91.3% at the end of 168 hours of treatment for industrial effluent. After 168 h of incubation was observed laccase enzyme activity (0.0563 U / ml). The acute toxicity tests with brine shrimp showed that the LC50 was approximately 14.72% (v / v) for the raw wastewater, while the effluent subjected to the treatment eight days was approximately 4.98% (v / v). Several authors relate the processes of bleaching enzyme activity, however the results suggest that the color removal is related to the adsorption of the dye in the biomass produced. Further studies should be performed for better understanding and confirmation that the color removal is not associated with the biosynthesis of phenolic structures degrading enzymes such as laccases.