Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater
Thesis (MEng)--Stellenbosch University, 2017.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | en_ZA |
| Published: |
Stellenbosch : Stellenbosch University
2017
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867614043595866112 |
|---|---|
| access_status_str | Open Access |
| author | Smit, Jason |
| author2 | Burger, A. J. |
| author_browse | Burger, A. J. Smit, Jason |
| author_facet | Burger, A. J. Smit, Jason |
| author_sort | Smit, Jason |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MEng)--Stellenbosch University, 2017. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/100988 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:45:45.384Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/100988 The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater Smit, Jason Burger, A. J. Sigge, G. O. Stellenbosch University. Faculty of Engineering. Dept. of Process Engineering. Anaerobic sequencing batch reactor Anaerobic digestion pH control Wastewater -- Purification -- Anaerobic treatment Wastewater -- Purification -- Anaerobic treatment Wine and wine making -- Environmental aspects UCTD Thesis (MEng)--Stellenbosch University, 2017. ENGLISH SUMMARY:Legal requirements and high production costs have resulted in wineries having to seek alternative methods of reducing operating costs with regards to the reduction of fresh water intake as well as treating the wastewater they produce. Winery wastewater typically contains varying concentrations of monosaccharides, volatile fatty acids and ethanol. To legally dispose of winery wastewater, its chemical oxygen demand (COD) needs to be reduced to below 400 mg/ℓ when disposing between 50 and 500 m3 daily. An anaerobic sequencing batch reactor (ASBR) has been recommended as a possible method to treat winery wastewater due to several benefits over typical aerobic systems. Anaerobic digestion systems produce useful biogas and, compared to aerobic digestion systems, generate low volumes of sludge. These advantages, together with the simplicity and relatively low installation costs of sequencing batch reactor (SBR) systems, make ASBR technology an attractive option for treatment of winery wastewater. Winery wastewaters have varying pH (3.5 – 8.0) due to the various sources from the plant. As such, the main objective of this study was to determine whether an ASBR can be operated with in-situ pH control and without adjusting the feed alkalinity. Exploratory simulations were performed with the Anaerobic Digestion Model no. 1 (ADM1) to understand where the potential problems could occur with the experimental ASBR. Sludge retention in the ASBR was simulated through the incorporation of a clarification model in the ADM1. The simulation results indicated that winery wastewater with high monosaccharide concentrations would cause a sudden drop in pH early in the ASBR process due to rapid production of volatile fatty acids. It therefore followed that in-situ pH control would be required. The ADM1 was found to be unstable when poor initial guesses of the soluble and sludge component concentrations were used in the simulations. With the ADM1 simulation, the pH was identified as the variable which would easily indicate instability in the model. Following the ADM1 simulations, a 14-litre laboratory scale ASBR was used to treat different synthetic winery wastewaters while operating with in-situ pH control. Two artificial feed solutions were prepared, the first with a high ammonium sulphate concentration and the second without ammonium sulphate. Both solutions contained high concentrations of glucose and fructose. The ASBR could handle the ammonium sulphate between organic loading rates (OLRs) 1.1 and 2.1 g-CODfeed.ℓ-1ASBR.day-1. Under these conditions, the ASBR achieved a COD reduction of at least 60 %. In the absence of ammonium sulphate, the ASBR achieved a COD reduction of at least 80 %. Biogas containing methane, carbon dioxide and nitrogen was produced. Theoretically excluding the nitrogen from the biogas resulted in a methane fraction in excess of 80 mol%, with the balance being carbon dioxide. 𝐾𝑂𝐻 was dosed as a nutrient. Correcting the feed pH to 7.4, allows for an approximate saving of 8 – 12% on the total amount of 𝐾𝑂𝐻 required for feed substrate dosing and in-situ pH control. In-situ pH control was deemed to be the most important during the first five hours of a batch. After this, the methanogens generally consumed acetic acid fast enough to counter the effect that volatile fatty acid formation has on the pH of the system. AFRIKAANS OPSOMMING: Weens wetsvereistes en hoë produksiekoste moet wynkelders met alternatiewe metodes vorendag kom om bedryfskoste te verlaag wat die vermindering van varswaterinname en die behandeling van afvalwater betref. Die afvalwater van wynkelders bevat gewoonlik wisselende konsentrasies monosakkariede, vlugtige vetsure en etanol. Om op ’n wettige manier van kelderafvalwater ontslae te raak, moet die chemiese suurstofbehoefte (CSB) tot onder 400 mg/ℓ verminder word om daagliks met tussen 50 en 500 m3 weg te doen. ’n Anaërobiese opeenvolgende lotreaktor (AOLR) word aanbeveel as ’n moontlike metode om kelderafvalwater te behandel omdat dit verskeie voordele bo tipiese aërobiese stelsels inhou. Anaërobiese verteerstelsels produseer byvoorbeeld nuttige biogas en, vergeleke met aërobiese verteerstelsels, lae volumes slyk. Hierdie voordele, tesame met die eenvoud en betreklik lae installasiekoste van opeenvolgende lotreaktor- (OLR-)stelsels, maak AOLR-tegnologie dus ’n aanloklike moontlikheid vir die behandeling van afvalwater. Kelderafvalwater het ’n wisselende pH (3.5 – 8.0) as gevolg van die verskillende bronne in die aanleg. Daarom was die hoofdoel van hierdie studie om te bepaal of ’n AOLR bedryf kan word met in situ-pH beheer en sonder om die alkaliniteit van die toevoer aan te pas. Ondersoekende simulasies is uitgevoer met die anaërobiese verteermodel nr 1 (“ADM1”) om te verstaan waar moontlike probleme met die eksperimentele AOLR kan voorkom. Slykbehoud in die AOLR is gesimuleer deur die insluiting van ’n verhelderingsmodel by die ADM1. Die simulasieresultate het getoon dat kelderafvalwater met hoë monosakkariedkonsentrasies ’n skielike pH-daling vroeg in die AOLR-proses sal veroorsaak as gevolg van die snelle produksie van vlugtige vetsure. In situ-pH beheer sou dus nodig wees. Daar is bevind dat die ADM1 onstabiel is wanneer swak aanvanklike raaiskote van die oplosbare en slykkomponentkonsentrasies in die simulasies gebruik word. Die pH is uitgewys as die veranderlike in die ADM1-simulasie wat maklik op onstabiliteit in die model sal dui. Na aanleiding van die ADM1-simulasies is ’n laboratoriumskaal-AOLR van 14 liter gebruik om verskillende sintetiese kelderafvalwaters te behandel terwyl in situ-pH-beheer toegepas word. Twee kunsmatige toevoeroplossings is voorberei: die eerste met ’n hoë ammoniumsulfaatkonsentrasie, en die tweede sonder ammoniumsulfaat. Albei oplossings het hoë konsentrasies glukose en fruktose bevat. Die AOLR kon die ammoniumsulfaat tussen organiese ladingstempo’s (OLT’s) van 1.1 en 2.1 g-CSBtoevoer.ℓ-1AOLR.dag-1 hanteer. In hierdie omstandighede het die AOLR ’n CSB-vermindering van ten minste 60% behaal. Sonder ammoniumsulfaat is ’n CSB-vermindering van ten minste 80% verkry. Biogas wat uit metaan, koolstofdioksied en stikstof bestaan, is geproduseer. Toe die stikstof teoreties van die biogas uitgesluit is, is ’n metaaninhoud van meer as 80 mol% verkry en het die res uit koolstofdioksied bestaan. KOH is as ’n voedingstof toegedien. Die regstelling van die toevoer-pH tot 7.4 maak ’n besparing van ongeveer 8 – 12% moontlik op die totale hoeveelheid KOH wat vir toevoersubstraattoediening en in situ-pH-beheer vereis word. In situ-pH-beheer was die belangrikste gedurende die eerste vyf uur van ’n lot. Daarna het die metanogene die asynsuur oor die algemeen vinnig genoeg verteer om die uitwerking van vlugtigevetsuurvorming op die pH van die stelsel teen te werk. Masters 2017-02-13T16:54:03Z 2017-03-29T11:54:43Z 2017-02-13T16:54:03Z 2017-03-29T11:54:43Z 2017-03 Thesis http://hdl.handle.net/10019.1/100988 en_ZA Stellenbosch University xv, 172 pages ; illustrated application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Anaerobic sequencing batch reactor Anaerobic digestion pH control Wastewater -- Purification -- Anaerobic treatment Wastewater -- Purification -- Anaerobic treatment Wine and wine making -- Environmental aspects UCTD Smit, Jason The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater |
| title | The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater |
| title_full | The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater |
| title_fullStr | The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater |
| title_full_unstemmed | The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater |
| title_short | The effect of feed pH and in-situ pH adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater |
| title_sort | effect of feed ph and in situ ph adjustment on the behaviour of an anaerobic sequencing batch reactor treating synthetic winery wastewater |
| topic | Anaerobic sequencing batch reactor Anaerobic digestion pH control Wastewater -- Purification -- Anaerobic treatment Wastewater -- Purification -- Anaerobic treatment Wine and wine making -- Environmental aspects UCTD |
| url | http://hdl.handle.net/10019.1/100988 |
| work_keys_str_mv | AT smitjason theeffectoffeedphandinsituphadjustmentonthebehaviourofananaerobicsequencingbatchreactortreatingsyntheticwinerywastewater AT smitjason effectoffeedphandinsituphadjustmentonthebehaviourofananaerobicsequencingbatchreactortreatingsyntheticwinerywastewater |