Thesis (Master of Environmental Management)--Cape Peninsula University of Technology, 2018. / Fresh water is a renewable resource, but it is also finite, especially given environmental
impacts from anthropogenic activities. Globally, there are countless signs that untreated
industrial discharge into fresh watercourses is one of the main causes of ecosystem
degradation. Poultry slaughterhouse wastewater (PSW) amongst the main pollutants of fresh
water sources. In recent years, the world’s pre-eminent researchers have developed
innovative wastewater treatment processes to treat the large quantity of wastewater
generated as well as to manage the environmental health concerns arising from PSW
discharged into the environment. Furthermore, increasing wastewater treatment capital costs
and the implementation of increasingly rigorous government legislation to mitigate
environmental pollution whilst minimizing fresh water source contamination, requires that
wastewater such as PSW, be adequately treated prior to discharge.
In order to assist the small-scale poultry producers in South Africa (SA), process simulation
for a small-scale poultry slaughterhouse wastewater treatment plant was proposed using
Sumo Wastewater treatment plant (WWTP) simulation software. Sumo is an innovative and
most versatile wastewater simulation package on the market. The simulator is capable of
modelling treatment plants of unlimited complexity, focusing largely on Biochemical oxygen
demand (BOD), Chemical oxygen demand (COD), nitrogen and phosphorus removal; with
digester, and side streams design options, being available. Considering the possible
advantages in modelling and ongoing studies of implementing wastewater treatment to
increase water management, anaerobic digestion of high strength wastewater such as PSW,
warranted this research study. Model development from the simulation included the
evaluation of numerous design options to assist small scale poultry producers, to have a
variety of designs to choose from in their PSW WWTP designs.
With the aid of Sumo, two models were designed in this study, namely a single-stage and a
two-stage anaerobic digestion without a recycle. The PSW used as feed was obtained from
a local poultry slaughterhouse (Western Cape, South Africa). Both model designs predicted
the reduction of the organic matter (COD, BOD5) total suspended solids (TSS), and volatile
suspended solids (VSS) in the PSW. The digester for the single stage anaerobic digestion
system modelled was set to operate at steady state for 150 days under mesophilic
temperature (35 ˚C) with a solid retention time (SRT) of 25 days. The COD, TSS, VSS and
BOD removal efficiencies reached a maximum of 64%, 77%, 84%, and 94%, respectively, at
an organic load rate (OLR) of 143.6 mg COD/L/day. A minute increase in the ammonia
(NH3) and phosphate (PO3-
4) concentration was observed once the simulation was
completed.
As for the two-stage anaerobic digestion system, both digesters were set to perform at
mesophilic temperatures (35 ˚C) and a SRT of 13 days in the first digester and 25 days in
the subsequent digester. The two-stage anaerobic digestion showed better performance in
comparison to the single-stage anaerobic digestion system. The COD, TSS, VSS and BOD5
removal efficiencies reached a maximum of 69%, 79%, 85%, and 96%, respectively, at an at
an OLR of 143.6 mg COD/L/day. A similar trend regarding phosphate and ammonia removal
was noticed in the two-stage anaerobic digestion, suggesting a tertiary treatment system to
be in place for further treatment.
Although, the two-stage anaerobic digestion demonstrated adequate performance, for the
purpose of this study, the single-stage was the process recommended for PSW treatment,
as it is less costly and will be suitable for small scale poultry producers; albeit biogas
production is much higher when digesters are connected in series.
The PSW treatment modelling for this study was successfully employed with the resultant
effluent being compliant with the City of Cape Town (CCT) wastewater and industrial effluent
by-law discharge limits. Although, both the PO3-
4 and NH3 were suggested to require further
monitoring.
Therefore, the poultry slaughterhouse from which the PSW was obtained will be able to
safely discharge the treated wastewater proposed in this research into local water bodies,
i.e. rivers in the Western Cape, SA; however, the treated PSW will not be suitable for re-use
as process water.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/2886 |
| Date | January 2018 |
| Creators | Ndeba, Nganongo Lionnel Neddy Aymar |
| Contributors | Ntwampe, S.K.O., Prof, Itoba-Tombo, E., Dr, Szabolcs, S., Dr |
| Publisher | Cape Peninsula University of Technology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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