Philosophiae Doctor - PhD / As a consequence of various cellar activities the wine industry produces copious volumes of potentially hazardous wastewater each year. South Africa is one of the top ten wine-producing countries, making the successful treatment of cellar effluent an important environmental obligation in this country. Constructed wetlands (CWs) are resilient to the seasonal input fluxes associated with agri-industrial waste and are ideal systems for the in-situ treatment of cellar effluent in small to medium-sized wineries not connected to municipal reticulation systems. In a project sponsored by the Water Research Commission of South Africa, a number of studies were undertaken to assess the remediation of winery wastewater and common components of winery wastewater in sand-filled pilot-scale constructed wetlands operated in batch mode. This thesis contains the results of three studies. The first study evaluated the temporal aspects of CW equilibration as a basis for future studies of system response to amendment. Microbial biomass and hydraulic conductivity values were monitored and microbial community fingerprints were obtained using denaturing gradient gel electrophoresis. The study showed that microbial community fingerprinting provides a valuable tool to assess the time-scales of microbial equilibration, which was found to be in the order of 100 days. In the second study, the biodegradation and mineralization of ethanol by acclimated and non-acclimated microbial populations in CWs were compared. By increasing the influent ethanol concentration at incremental intervals (incremental priming), the biodegradative capacity was significantly enhanced. At an influent COD concentration of 15 800 mg/L, no volatile fatty acids were detected in the effluent of an incrementally primed system and the maximum effluent COD measured was 180 mg/L. In contrast, an identical, unprimed system, amended with a lower concentration of COD (7587 mg/L), exhibited a maximum effluent COD concentration of 1 400 mg/L, with the metabolites butyrate and propionate accounting for up to 83% of the effluent COD. It was conclusively demonstrated that the use of incremental priming, together with the batch mode of operation enhanced long-term function of the CWs. In the third study, the removal of the phenolic component of winery wastewater was evaluated in CWs, as well as in sand columns and microcosms. It was found that at low influent phenolic concentrations in CWs, complete organic removal was accomplished, but at high concentrations, there was incomplete substrate removal and an accumulation of potentially toxic metabolites, including catechol. The sand provided a suitable substrate for the treatment of phenolic-laden waste, and both biotic (48%) and abiotic (52%) removal mechanisms effected the removal of model phenolics. Prior acclimation of microbial communities increased the biodegradation rate of phenolic acids significantly.

Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The production of wine globally has increased over the past years, increasing the volume of water used and wastewater generated for every litre of wine produced. In the past, the small volumes of winery wastewater that were produced by wineries had little effect on the immediate environment. However, with the increasing wine production all around the world, winery wastewater is a rising concern for the contamination of soil and subsurface flow. In order to fully understand the impacts of winery wastewater, it is important to establish the volumes and chemical characteristics of the wastewater, before considering possible treatments. The first aim of this study was to determine the influence of certain winemaking practices on the water usage. Two wineries in the Stellenbosch Winelands District were monitored during two harvests and one post-harvest season. It was evident through this study that water plays a vital role during the production of wine and that water is needed at virtually all the winemaking steps. However, the volume of clean water needed differs immensely during the course of the production process. It was noticed that throughout the harvest period at both wineries the clean water demand was highest and decreased during the course of the post-harvest period and steadily increased again towards the end of the year. The harvest period contributes between 30 and 40% of the yearly water usage at the respective wineries. It was also noticed that certain winemaking practices including filtering with a bulk filter, washing of barrels and bottling contributes heavily to the water usage throughout the year. Activities that increase water usage during harvest include the washing of the press and processing a combination of red and white grapes on the same day. Furthermore, it was identified that one of the wineries used a smaller volume of water on a daily basis and per tonnage during harvest than the other, indicating that the cleaner production strategy established 10 years earlier has a positive impact on their water usage. The second aim of this study was to monitor the raw and treated winery wastewater from the two wineries during a period of 15 months, including two harvests and one post-harvest season. This was done to investigate the characteristics of the raw and treated wastewater. Firstly, to determine the impact of the different winemaking practices on the chemical composition of the wastewater and secondly, to determine the efficiency of the existing constructed wetlands on the wastewater and the characteristics of the treated wastewater. From this study it was possible to make two main observations concerning the chemical oxygen demand (COD) concentrations of the two wineries. Primarily, it was observed there were variations in the raw wastewater characteristics of the two wineries and above all, that both wineries showed a decrease in the COD of the raw wastewater produced. Not only did the decrease in the raw wastewater COD over this period show promising results when a cleaner production plan is established and managed it also seems to show a decrease in the volumes of water used by the respective wineries and increase in quality. / AFRIKAANSE OPSOMMING: Gedurende die afgelope paar jaar het wynproduksie wêreldwyd toegeneem en as gevolg hiervan toenemende hoeveelhede water gebruik en afvalwater gegenereer. In die verlede het die klein volumes kelderafvalwater wat deur wynkelders geproduseer is min effek op die onmiddelike omgewing gehad, maar gegewe die toenemende produksie van wyn regoor die wêreld is daar groeiende kommer oor die besoedeling van gronde en ondergrondse vloei deur kelderafvalwater. Dit is belangrik om die volumes en chemiese eienskappe van die afvalwater te bepaal om die impak van die water ten volle te verstaan, voordat moontlike behandelings oorweeg word Die eerste doel van hierdie studie was om te bepaal hoe sekere wynmaakpraktyke watergebruik beïnvloed. Twee wynkelders in die Stellenbosch Wynland Distrik is gedurende twee parsseisoene en een na-pars seisoen gemonitor. Hierdeur het dit duidelik geword dat water ‘n noodsaaklike rol speel in wynproduksie en benodig word vir feitlik alle stappe in die wynmaakproses. Die volume skoon water wat benodig word verskil wel noemenswaardig tydens die produksieproses. Die gebruik van skoon water van beide kelders was hoog tydens die parsseisoen, het afgeneem gedurende die loop van die na-pars periode en het geleidelik weer toegeneem teen die einde van die jaar. Die parsseisoen dra tussen 30 en 40% by tot die jaarlikse waterverbruik van die onderskeie kelders. Dit is ook opgemerk dat sekere wynmaakpraktyke, insluitend filtrasie met ‘n grootmaat filter, die was van vate en bottelering, grootliks bydrae tot die waterverbruik deur die loop van die jaar. Aktiwiteite wat waterverbruik tydens parstyd verhoog sluit in die gebruik van die pers en die verwerking van ‘n kombinasie van rooi en wit druiwe op dieselfde dag. Daar is ook vasgestel dat een van die wynkelders tydens parstyd ‘n kleiner volume water gebruik op ‘n daaglikse basis asook per tonnemaat wat daarop dui dat die “skoner” produksie strategie wat dié kelder 10 jaar gelede gevestig het wel ‘n positiewe impak op waterverbruik het. Die tweede doel van hierdie studie was om die onbehandelde en behandelde afvalwater van hierdie twee wynkelders te monitor oor 'n tydperk van 15 maande, wat twee paste en een na-pars seisoen insluit. Dit is gedoen om die impak van verskillende wynmaakpraktyke op die chemiese samestelling van die afvalwater te ondersoek asook om die doeltreffendheid van bestaande kunsmatige vleilande in terme van afvalwaterbehandeling te bepaal en die eienskappe van die behandelde afvalwater te ondersoek. Gevolglik is twee belangrike waarnemings oor die chemiese suurstof behoefte (CSB) konsentrasie van die twee wynkelders gemaak. Variasies in die onbehandelde afvalwater eienskappe is waargeneem by beide wynkelders en daar was ‘n afname in CSB van die onbehandelde afvalwater by beide wynkelders. Die afname in CSB van die onbehandelde afvalwater oor hierdie tydperk is belowend en dit blyk dat wanneer ‘n “skoner” produksie plan opgestel en bestuur word dit wel ‘n afname in waterverbruik en verhoog in kwaliteit by die kelders tot gevolg het.

This study began the process of evaluating hollow-fiber ultrafiltration for treatment of winery wastewater pond effluent in preparation for drip irrigation. In areas subject to drought, wastewater recycling is becoming an increasingly popular practice. In California’s central coast region, winery wastewater recycling for irrigation can be hindered by clogging of the drip irrigation systems with suspended solids. To address this issue, this study investigated the feasibility of using hollow fiber ultrafiltration membranes as a polishing step for winery wastewater treated in an aerated lagoon-facultative pond series. A bench-scale, hollow-fiber ultrafiltration membrane system was assembled, and experimental testing was performed to determine the operational parameters of the membrane including flux, transmembrane pressure (TMP), and recovery over a range of flowrates and concentrate valve configurations using off-season (from outside of the Harvest season) pond-treated winery wastewater. Based on these characterization trials an initial effluent-to-permeate (Pond 2, an algae-rich pond following an aerated lagoon, effluent used as influent for the membrane system) flux of 258 L/m2·hr and a concentrate valve configuration of 60°-closed (TMP ranging between 5 – 32 PSI) were selected for performing ultrafiltration tests on winery wastewater collected from the effluent pond at a central coast winery. Through testing a range of times, optimal wastewater filtration and backwash times of 1.5 minutes and 30 seconds, respectively, were determined for the membrane system. DI water was used for backwashing, as a baseline. For a clean-in-place (CIP) system, the effective chemical types and concentrations were determined to be 0.4-M NaOH and 0.9-M acetic acid. Both chemicals were recirculated through the membrane for 1 hour, starting with the 0.4-M NaOH followed by the 0.9-M acetic acid. This CIP procedure was not able to remove fouling sufficiently for practical operation. For this reason, two forms of wastewater pretreatment were tested: using a 177 µm screen prior to the ultrafilter and filling the screen with sand. For the conditions tested, both forms of pretreatment proved to be ineffective. Only when the wastewater was given sufficient time to naturally flocculate was the screen system effective on its own. This residual fouling also prevented adequate testing to calculate the following membrane fouling characteristics: reversible fouling ratio, irreversible fouling ratio, flux recovery ratio, and total fouling ratio. In the annual cycle of winery operations, different winery processes have different effects on the quality of the wastewater. Therefore, wastewater quality analyses were conducted throughout the duration of the study (October 2023 – May 2024) to understand the concentration ranges and trends of several wastewater quality indicators. Specifically, total suspended solids (TSS), volatile suspended solids (VSS), pH, Alkalinity, and turbidity were measured throughout the study. The levels of TSS, VSS, and turbidity were expectedly highest during the harvest season. The VSS constituted the majority of the measured TSS, averaging about 85% of the TSS. The pH was consistent throughout the study, while alkalinity increased in the off-season period of the study. The measured levels of TSS and pH were within the ranges reported in literature for winery wastewater. No prior reports were found for VSS, alkalinity, and turbidity levels for winery wastewater, so this study may provide new information in this regard.