Ozonation combined with membrane bio-reactor for landfill leachate treatment | |
| Author | Alia Chaturapruek |
| Call Number | AIT Thesis no. EV-03-2 |
| Subject(s) | Ozonization Bioreactors Sanitary landfills -- Leaching |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-03-2 |
| Abstract | Landfill leachate consisting of refractory compounds has characteristics similar to that of high-strength wastewater. The present treatment sequence includes Ammonia stripping process and Membrane Bioreactor (MBR) process scheme further required the development of post-treatment. Ozonation is one of the advanced oxidation processes which could be effective as a post biological treatment. A major advantage of the ozonation process is ability of ozone to oxidize and convert the non-biodegradable compounds into lower molecular weight compounds, which would enhance biodegradability. For this reason, a sequence of MBR and ozonation was developed in order to achieve maximum pollutant removal efficiency. The experiments were conducted in the laboratory scale experiments. The MBR system consists of yeast and bacterial systems. The effluents from both reactors were used for ozonation. The effect of ozone in terms of COD, TOC, Color, and BOD removal were determined. After the optimization of all parameters, the optimum conditions were used for combined MBR and ozonation system. The effect of ozone in the sludge of both the yeast and bacteria based MBR for sludge treatment and disposal was also studied. The results obtained from the experiments indicated that: A) The ozone transfer efficiency was low, which indicated the poor ability of ozone in the gas phase to transfer into the liquid phase. B) The optimum ozone concentration was found to be 75 mg/L for both effluents in terms of maximum COD, TOC, and Color removal. C) The optimum ozone contact time for yeast effluent was 90 minutes, where the COD, TOC, and Color removal efficiency were 49 %, 34.5 %, and greater than 95 %, respectively. The optimum ozone contact time for bacterial effluent was 45 minutes, where the biodegradability improvement indicated as BOD/COD ratio increased from 0.0342 to 0.0847. The COD, TOC, and Color removal efficiency for bacterial effluent at optimum condition were 39 %, 30 %, and greater than 95 %, respectively. D) The addition of Hydrogen Peroxide did not improve the removal efficiency of ozone. Thus, ozonation alone was used in the combined system. E) The overall COD removal efficiency of the combined system consisting of MBR and ozonation process was found slightly improved compared to original system. The efficiency increased from 79 % to 83.4 % for yeast and from 78.4 % to 82.5 % for bacterial system. F) Ozone was effective in sludge disintegration with a sludge reduction of 59 % and 28 % for yeast and bacterial sludge, respectively. Ozone also helped in improving the settleability and dewatering ability of sludge. From the overall results, it could be concluded that ozonation is an effective method as a post-biological treatment for landfill leachate especially in terms of color removal. |
| Year | 2003 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-03-2 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Visvanathan, C. |
| Examination Committee(s) | Chongrak Polprase ;Lee, Seung-Hwan |
| Scholarship Donor(s) | Her Majesty the Queen| |