| Author | Monruedee Moonkhum |
| Call Number | AIT Thesis no.EV-07-25 |
| Subject(s) | Sewage--Purification--Activated sludge process
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-07-25 |
| Abstract | Ultrasound pretreatment is very attractive option to enhance the digestion efficiency of waste activated sludge (WAS). It is gaining popularity because of its ability to breakdown the recalcitrant particles, compact design and no additional chemical requirement. The efficiency of the aerobic digestion of waste activated sludge containing 3% TS using ultrasonic pretreatment was determined at 2 different SRT of 10 and 20 days. WAS was sonicated for 150s with the ultrasonic density of 1.9 W/mL, at the frequency of 20 kHz and specific energy input of 9.5 kJ/kg TS. The ultrasonic pretreatment achieved the subsequent aerobic digestibility resulting better removal of Dissolved organic carbon (DOC). The DOC removal efficiency of part stream and full stream reactor improved by 26% and 28% respectively, at 10 days SRT compared to control reactor. Similarly, at 20 days SRT the efficiency of DOC removal of part stream and full stream reactor enhanced to 20% and 23% respectively, compared to control reactor. Correspondingly, VS removal of part stream and full stream reactor were found enhanced to 46% and 50% respectively at 10 days SRT in comparison to control reactor. Whereas at 20 days SRT VS removal efficiency were higher than control reactor by 32% and 36% respectively, for part stream and full stream reactor. TS removal efficiency of part stream and full stream reactor were found improved as well at 10 and 20 days SRT. Moreover, ultrasound pretreatment affected to enhance nitrification of part stream and full stream reactor. Due to the higher nitrate concentration was observed in part stream and full stream reactor. However, ultrasound pretreatment could not improved the dewater ability of digested sludge. As removal efficiency observed from part stream reactor were observed as in the same range. Thus, part stream reactor can be the better choice due to economic reasons. |
| Year | 2007 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-07-25 |
| 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 (EV) |
| Chairperson(s) | Visvanathan, C.; |
| Examination Committee(s) | Thammarat Koottatep;Dutta, Animesh;Khanal, Samir Kumar; |
| Scholarship Donor(s) | RTG Fellowship.; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2007 |