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.
| Identifer | oai:union.ndltd.org:CALPOLY/oai:digitalcommons.calpoly.edu:theses-4531 |
| Date | 01 June 2024 |
| Creators | Lira Campaigniac, Marcus |
| Publisher | DigitalCommons@CalPoly |
| Source Sets | California Polytechnic State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Master's Theses |
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