Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: A severely polluted industrial effluent is generated by the local gelatinmanufacturing
industry. Due to increasingly stringent restrictions on discharge
qualities enforced by the National Water Act of 1998 and National
Environmental Management Act of 1998, as well as increasing trade-effluent
charges implemented via the Local Municipal Bylaws, the industry is
compelled to consider a system to pre-treat the polluted effluent.
A study was undertaken to examine the viability of anaerobic treatment
of the gelatin-manufacturing effluent, since the anaerobic digestion technology
is well recognised for the high success rate in the treatment of high-strength,
complex wastewaters. Various laboratory and pilot-scale studies were done,
using different hybrid Upflow Anaerobic Sludge Blanket (UASB) and contact
designs.
Two mesophilic laboratory-scale hybrid UASB digester designs, fitted
with polyethylene (AD-1) and polyurethane (AD-2), performed well at a
hydraulic retention time (HRT) of 1.0 d. Chemical oxygen demand (COD)
removal efficiencies of up to 90% (avg. 53%) for AD-1 and 83% (avg. 60%) for
AD-2 at organic loading rates (OLR) of 9.56 and 4.62 kg COD.m-3.d-1,
respectively, were obtained. High sulphate (S04) removal efficiencies of up to
96% (avg. 86%) for AD-1 and 98% (avg. 82%) for AD-2 were also achieved,
respectively. A maximum total solid (TS) removal of 65% (avg. 25%) for AD-1
and 62% (avg. 28%) for AD-2 was reported. An average methane content of
80% (AD-1) and 79% (AD-2) with average methane yields per COD removed
of 2.19 and 1.86 m3. kg CODremoved.df-o1r AD-1 and AD-2 were found,
respectively.
When the same digesters (AD-1 and AD-2) were combined in a muItiphase
series configuration, a total COD removal efficiency of up to 97% (avg.
80%) at an OLR of 8.32 kg COD.m-3.d-1,was achieved. Excellent total S04
removals of 96% (avg. 69%) were accomplished. Up to 82% TS (avg. 29%)
was also removed during this study and the biogas consisted of 89% methane
(avg. 79%). For this multi-phase combination up to 92% volatile fatty acids
(VFA) (avg. 48%) were removed, indicating possible selective phase
separation of the respective fatty acid producing/utilising bacterial populations. The use of a laboratory-scale UASB bioreactor with recirculation,
resulted in COD removal efficiencies of up to 96% (avg. 51%) at an HRT of 3.0
d, and 95% (avg. 54%) at a HRT of 1.0 d. Low performances were generally
found, with average S04 and TS removals of 59% (max. 97%) and 26% (max.
67%), respectively at an HRT of 1.0 d. The biogas production was very low
throughout the study (0.05 - 0.63 I,d-1
).
A pilot-scale UASB reactor (300 I) was constructed and performed
satisfactory with a 58% average COD removal and maximum of 96%. S04
and TS removals up to 96% (avg. 44%) and 93% (avg. 63%), respectively,
were obtained. The methane content of the biogas was 85%. The pilot-scale
studies were conducted under actual field conditions, where various shock and
organic loads had to be absorbed by the system.
The pilot-scale contact configuration (300 I) did not perform satisfactory
as a result of continuous blockages experienced in the feed and recirculation
lines. Maximum COD, S04, VFA and TS removal efficiencies of 41% (avg.
27%), 62% (avg. 41%), 64% (avg. 27%) and 39% (avg. 21%), respectively,
were obtained.
The results of all the studies indicated acceptable COD removals with
increasing OLR's. Indications of the presence of active methanogenic and
sulphate-reducing bacterial populations were apparent throughout the studies.
One possibility for the successful start-up and commissioning of the anaerobic
reactors was the use of a well-adjusted biomass, which consisted of highly
selected and adapted microbial consortium for the specific gelatinmanufacturing
effluent.
It was clear from this study that gelatin-manufacturing effluent can be
treated successfully, especially with the use of the UASB design. A welldefined
data base was constructed which could be of great value for further
upscaling to a full-scale digester. / AFRIKAANSE OPSOMMING: 'n Hoogs besoedelde industriele uitvloeisel word gegenereer deur die plaaslike
gelatien-vervaardigings industrie. As gevolg van toenemende streng
beperkings op die kwaliteit van uitvloeisels wat bepaal word deur die Nasionale
Water Wet van 1998 en Nasionale Omgewings Bestuurs Wet van 1998, asook
toenemende munisipale heffings wat geimplementeer word via Plaaslike
Munisipale Wette, word die industrie verplig om die uitvloeisel vooraf te
behandel.
'n Studie is onderneem om die lewensvatbaarheid van anaërobe
behandeling van gelatien-vervaardigings uitvloeisel te ondersoek, aangesien
anaërobe verterings tegnologie alombekend is vir die goeie sukses behaal in
die behandeling van hoë-sterkte, komplekse uitvloeisels. Verskeie
laboratorium- en loods-skaal studies is gedoen, met verskillende hibried
Opvloei Anaërobe Slykkombers (OAS) en kontak ontwerpe.
Goeie werksverrigting was verkry by 'n hidroliese retensie tyd (HRT) van
1.0 d met twee mesofiliese laboratorium-skaal hibried OAS verteerder
ontwerpe wat uitgevoer was met poli-etileen (AD-1) en poli-uretaan (AD-2)
materiaal. Chemiese suurstof behoefte (CSB) verwyderings van so hoog as
90% (gem. 53%) vir AD-1 en 83% (gem. 60%) vir AD-2 by organiese
ladingstempo's (OLT) van 9.56 en 4.62 kg CSB.m-3.d-1,was onderskeidelik
verkry. Hoë sulfaat (S04) verwyderings van tot 96% (gem. 86%) vir AD-1 en
98% (gem. 82%) vir AD-2 was ook onderskeidelik verkry. 'n Maksimum totale
vaste stof (TVS) verwydering van 65% (gem. 25%) vir AD-1 en 62% (gem.
28%) vir AD-2 is gerapporteer. 'n Gemiddelde metaan inhoud van 80% (AD-1)
en 79% (AD-2) met 'n gemiddelde metaan opbrengs per CSB verwyder van
2.19 en 1.86 m3.kg CSBverwyder.dv-i1r AD-1 en AD-2, was onderskeidelik
gevind.
Met die aanwending van dieselfde twee verteerders (AD-1 en AD-2) in
'n series gekoppelde multi-fase konfigurasie, is 'n totale CSB verwydering so
hoog as 97% (gem. 80%) verkry by 'n OLT van 8.32 kg CSB.m-3.d-1.
Uitstekende totale S04 verwydering van 96% (gem. 69%) is behaal. Tot 82%
TVS (gem. 29%) was vewyder gedurende die studie en die biogas het uit 89%
metaan (gem. 79%) bestaan. Vir die multi-fase kombinasie is 'n maksimum van 92% vlugtige vetsure (WS) (gem. 48%) verwyder, wat dui op die
moontlike skeiding van selektiewe fases van die onderskeie vetsuur
produserende/verbruiker bakteriële populasies.
CSB verwydering van tot 96% (gem. 51%) by 'n HRT van 3.0 d en 95%
(gem. 54%) met 'n HRT van 1.0 d was verkry, tydens die gebruik van In
laboratorium-skaal OAS bioreaktor met hersirkulasie. Lae werksverrigting was
oor die algemeen waargeneem, met gemiddelde S04 en TVS verwyderings
van 59% (maks. 97%) en 26% (maks. 67%) by In HRT van 1.0 d. Die biogas
produksie was baie laag gedurende die studie (0.05 - 0.63 I,d-\
In Loods-skaal OAS verteerder was opgerig en bevredigende resultate
was verkry met In gemiddeld van 58% CSB verwydering en maksimum van
96%. S04 en TVS verwyderings so hoog as 96% (gem. 44%) en 93% (gem.
63%) is onderskeidelik verkry. Die metaan inhoud van die biogas was 85%.
Die loods-skaal studie was uitgevoer gedurende ware veld kondisies,
waartydens verskeie skok en organiese ladings deur die sisteem geabsorbeer
is.
Die loods-skaal kontak konfigurasie (300 I) het nie bevredigende
resultate getoon nie, as gevolg van voortdurende blokkasies wat ondervind is
in die toevoer en hersirkulasie pype. Maksimum CSB, S04, WS en TVS
verwyderings van 41% (gem. 27%), 62% (gem. 41%), 64% (gem. 27%) en
39% (gem. 21%) was onderskeidelik verkry.
Die resultate van al die studies het aanvaarbare CSB verwydering
aangedui by toenemende OLT's. Indikasies van aktiewe metanogene en
sulfaat-reduserende bakteriële populasies was ook teenwoordig gedurende die
studies. Die suksesvolle aansit-prosedure en begin van die anaërobe
verteerders kan toegeskryf word aan die gebruik van In goed aangepaste
biomassa, wat uit hoogs selektiewe en aangepaste mikrobiese populasies vir
die spesifieke uitvloeisel bestaan.
Hierdie studie het getoon dat gelatien-vervaardigings uitvloeisel
suksesvol met die OAS ontwerp behandel kan word. In Goed gedefinieerde
data basis kan voorsien word, wat van groot waarde sal wees vir verdere
opgradering na In volskaalse verteerder.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/51582 |
| Date | 12 1900 |
| Creators | Lloyd, Magaretha Hester |
| Contributors | Van der Merwe-Botha, M., Britz, T. J., Stellenbosch University. Faculty of Science. Dept. of Microbiology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 181 p. : ill. |
| Rights | Stellenbosch University |
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