| Author | Sermsook Pakkattang |
| Call Number | AIT Thesis no. EV-97-38 |
| Subject(s) | Sewage sludge as fertilizer
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-97-38 |
| Abstract | The application of Bangkok nightsoil and sewage sludge to agricultural land was
investigated considering the nutrition value and pathogen problems. Analysis of two sewage
and one nightsoil sludge, a pot study and a field study using sunflowers and grass have been
conducted.
The investigations showed the suitability of this sludges for reuse in agriculture. A
good sludge treatment e.g. anaerobic digestion has a good influence on the sludge
characteristics, such as lower numbers in fecal coliforms and no presence of parasites together
with high nitrogen content ( ~ 4% N).
The application of two sludges to a field study with sunflowers showed linearly
relations between nitrogen application and grain yield. The application of 120 kg N/ha with
sewage sludge from Huay Kwang showed the highest yield. This results are comparable to the
80 Kg N/ha application with chemical fertilizer. Nitrogen applied by sludge is not immediately
available because of the required mineralization in the soil whereas available phosphorus and
exchangeable potassium in the soil were raised, which proved to have certain benefitial effects
on crop yield. In terms of pathogens the sludge amended soils have to be left more than three
months after sludge application to reduce the fecal coliforms until less than 2 MPN per 2 gram
wet weight (the lowest detectable number).
The field study with grass showed a linearly relation between nitrogen application and
fresh biomass yield. The liquid sludge application seemed to be most suitable. Considering
aesthetic aspects the grass fields have to be left 110 days to receive a fecal coliforms free soil. |
| Year | 1997 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-97-38 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Eckhardt, Ing. Heinz |
| Examination Committee(s) | Ishibashi, Yoshinobu;Tinsley, Richard L.;
Preeda Parkpian |
| Scholarship Donor(s) | Royal Thai Government |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1997 |