Thesis (MTech. degree in Water Care ) - Tshwane University of Technology, 2007. / This research project investigated the total nitrogen removal capabilities of a nitrification
and denitrification system treating two medium strength municipal landfill leachates. The
characteristics of the leachates differed as one was obtained from general waste (GLB+)
and the other from mixed industrial and general waste (H:h). This project was
commissioned to develop a leachate treatment philosophy and a leachate management plan
for the Vissershok landfill site near Cape Town. The aim of this leachate treatment trial
project was to establish leachate treatability of different types of leachate, characterise
leachate and effluent quality, determine alkalinity requirements, assess hydraulic retention
periods and sludge production and confirm whether leachate quality can inhibit successful
treatment in a sequencing batch reactor system.
The two units were operated as simple Sequencing Batch Reactors (SBRs) by treating the
leachate in a biological treatment process. Both units were initially seeded with activated
sludge obtained from a sewage treatment works. Provision was made to supplement
carbonaceous nutrient and phosphorus to the system. In the first stage of the study a
controlled nitrification system was maintained to treat ammoniacal-nitrogen and the next
stage denitrification was used to treat nitrate and nitrite-nitrogen levels. A completely
automated daily cycle was used to treat the leachate and altered according to process
requirements.
The results showed that during nitrification ammoniacal-nitrogen concentrations as high as
2032.4 mg/l were consistently reduced to less than 0.1 mg/l. Similarly, for denitrification,
nitrate-and nitrite-nitrogen concentrations were also consistently reduced to less than 0.1
mg/l, with a methanol utilisation ratio of CH3OH:N at 4.80:1. Chemical oxygen demand
(COD) removal efficiencies were in the range 57-65% depending on loading rates applied.
In conclusion it was shown that:
(a) the biodegradable organics (COD) was reduced considerably
(b) complete nitrification and denitrification occurred
(c) no constituents of the leachate caused inhibition of the biological process.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:tut/oai:encore.tut.ac.za:d1001050 |
| Date | January 2007 |
| Creators | Traut, Melanie |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | |
| Rights | © 2007 Tshwane University of Technology |
Page generated in 0.0016 seconds