Thesis (MSc Food Sc)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The wine industry significantly contributes to South Africa's water demand and subsequent pollution of the limited resource. Wastewater is produced throughout the year with an increase in volume and organic load during the vintage season. Anaerobic digestion (AD), specifically the upflow anaerobic sludge bed (UASB) technology has been shown to be feasible in the treatment of cellar wastewater. However, the legal standard for chemical oxygen demand (COD) for disposal in a natural water resource (75 rnq.L") is often not met. The aim of the study was to conduct a laboratory-scale investigation into the feasibility of combining pre- and post-ozonation processes with AD in order to achieve a final COD closer to the legal disposal limit. While acclimatising an UASB bioreactor containing mixed anaerobic granules to a cellar wastewater with a pH set at 8.0, stable-state conditions were not reached. Sucrose additions to the substrate, increased substrate loads, heattreatment of the substrate and an addition of isolated cellar effluent bacteria to facilitate degradation prior to AD, were all unsuccessful in maintaining stable-state in terms of COD removal efficiency. Once the substrate pH was re-set to 7.5, the reactor stabilised. The lowest efficient operational pH was found to be 5.73 resulting in a COD removal of 88% at a substrate COD < 5 000 rnq.L". At a substrate pH of 6.0, the lowest efficient operational hydraulic retention time (HRT) and corresponding organic loading rate (OLR) were 19.7 hand 9.75 kg COD.m-3d-1 , respectively, with the COD removal being maintained around 84%. The reactor effluent still had a final COD of 1280 rnq.L", which was well above the legal South African limit. Dominant bacteria were isolated from raw cellar wastewater and identified as Acinetobacter haemolyticus, Burkholderia cepacia and Cryseomonas luteola. In order to investigate the possibility that ozonation improved biodegradability, the growth of the isolates at 35°C was monitored over 24 h in sterile ozonated and non-ozonated substrates from the vintage and non-vintage seasons. All the isolates increased by at least 1.5 log cycles in the control substrates from both seasons. Ozonation of the wastewater batches for 10 min at a rate of 73 rnq.L" led to slightly increased growth of the inoculants in the substrate batch from the vintage season. For the substrates from the non-vintage season, ozonation had an inhibitory effect on the bacterial growth. A 5 min ozonation treatment at a concentration of 73 rnq.L" was found to be optimal for both a pre- and post-treatment to UASB-treatment of cellar wastewater. Both UASB treatment and ozonation were effective in reducing the COD by 85% and 20%, respectively. The COD reduction was improved to 88% when UASB treatment was combined with post-ozonation. The total reduction in total suspended solids (TSS) for the combined process was 97%, compared to 80% for UASB and 73% for an ozone treatment alone. The reduction for volatile suspended solids (VSS) was 98% compared to 81% for UASB and 73% for the ozone treatment alone. The total reduction when using a pre-ozonation UASB treatment combination was an average of 86% for COD. The TSS and VSS were both reduced by 95%. Biogas production increased from 1.4 L.d-1 to 3.8 L.d-1 when an ozonated wastewater was used as substrate. When the UASB treatment was combined with both a pre- and post-ozonation treatment process, the COD was reduced by 89% while TSS and VSS were both reduced by 99%. This study showed that pre- and post-ozonation treatment processes could successfully be utilised to improve UASB treatment of cellar wastewater. Although the legal limits for discarding into a natural resource were not met, significant progress was made in reducing COD levels. Cellar wastewaters do however, vary according to season and the wastewater composition could affect the efficiency of a pre-ozonation process. / AFRIKAANSE OPSOMMING: Die wynindustrie maak "n beduidende bydrae tot die eise wat aan Suid-Afrika se waterbronne gestel word en gevolglik die besoedeling van die beperkte hulpbron. Afloopwater, wat in volume en organiese lading gedurende die parstyd toeneem, word reg deur die jaar opgelewer. Anaërobiese vertering (AV), spesifiek die "Upflow anaerobic sludge blanket" (UASB) tegnologie, is alreeds suksesvol gebruik om kelderafloop te behandel. Die wetlike vereiste vir chemiese suurstof behoefte (CSB) vir storting in "n natuurlike hulpbron (75 rnq.L"), word egter dikwels nie bereik nie. Die doel van die studie was om in "n laboratorium-skaal ondersoek AV te kombineer met voor- en na-osoneringsprossesse, om sodoende te poog om "n CSB nader aan die wetlike standaard te verkry. Terwyl"n UASB bioreaktor wat gemengde anaerobiese granules bevat het, geakklimatiseer is tot kelderafloop met "n pH gestel tot 8.0, kon stabiele toestande nie bereik word nie. Die byvoeging van sukrose tot die substraat, verhoogde substraatladings, hitte-behandeling van die substraat en die byvoeging van geïsoleerde kelderafloop bakterië om substraatafbraak voor AV aan te help, was onsuksesvol om stabiliteit in terme van CSB-verwydering, te handhaaf. "n Verstelling van die substraat pH na 7.5, het gelei tot reaktorstabiliteit. By die laagste doeltreffende bedryfs-pH van 5.73 en substraat CSB < 5 000 rnq.L", was die CSB-verwydering 88%. By "n substraat pH van 6.0 was die laagste doeltreffende bedryfs-hidroliese retensie tyd en -organiese ladingstempo 19.7 h en 9.75 kg CSB.m-3d-1, onderskeidelik, terwyl die CSB verwydering rondom 84% gehandhaaf is. Die CSB van die reaktoruitvloesel van 1 280 rnq.L", was steeds ver bo die wetlike vereiste. Dominante bakterië is uit kelderafloop geïsoleer en as Acinetobacter haemolyticus, Burkholderia cepacia en Cryseomonas luteola, geïdentifiseer. Die moontlikheid dat osonering bioafbreekbaarheid bevorder, is ondersoek deur die groei van die isolate by 35°C oor 24 h in steriele geësoneerde en ongeësoneerde substrate te monitor. Die substrate is berei vanaf kelderafloop wat in die parsseisoen sowel as die nie-parsseisoen versamel is. AI die isolate het met ten minste 1.5 log siklusse in die kontrole substrate van beide seisoene, vermeerder. Vir die kelderafloop wat in die parsseisoen versamel is, het osonering vir 10 min teen 73 rnq.L" gelei tot effens verbeterde groei van die innokulante. Osonering het 'n onderdrukkende effek op die groei van bakterië in die afloopwater versamel in die nie-parsseisoen, gehad. Osonering vir 5 min teen 'n konsentrasie van 73 rnq.L" is as optimum vir beide voor- en na-osoneringsbehandeling tot UASB-behandeling van die kelderafloop, gevind. UASB-behandeling en osonering het die CSB met 85 en 20% onderskeidelik, verminder. Die vermindering kon tot 88% verhoog word wanneer UASB-behandeling met na-osonering gekombineer is. Die vermindering in totale gesuspendeerde vastestowwe (TGV) vir die gekombineerde proses was 97%, in vergelyking met 80% vir UASB- en 73% vir osoonbehandeling alleen. Die vermindering in vlugtige gesuspendeerde vastestowwe (VGV) was 98% in vergelyking met 81% vir UASB- en 73% vir osoonbehandeling alleen. Die totale CSB verwydering vir 'n voor-osonerings UASB kombinasie was gemiddeld 86%. Die TGV en VGV is beide met 95% verminder. Biogasproduksie het ook vermeerder vanaf 1.4 L.d-1 tot 3.8 L.d-1 toe geosoneerde afloopwater as substraat gebruik is. Die kombinasie van UASB-behandeling met voor-osonering, sowel as na-osonering het gelei tot 'n CSB-verwydering van 89% terwyl TGV en VGV beide met 99% verminder is. Hierdie studie het getoon dat voor- en na-osonering suksesvol gebruik kan word om UASB-behandeling van kelderafloop te verbeter. Hoewel wetlike vereistes vir storting in 'n natuurlike hulpbron nie bereik is nie, is beduidende vordering gemaak in die verlaging van CSB-vlakke. Die verskil in die samestelling van kelderafloop gedurende die onderskeie seisoene, kan egter die doeltreffendheid van die voor-osoneringsproses beïnvloed.

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.