| Author | Jutamas Juntaramitree |
| Call Number | AIT Thesis no. EV-99-38 |
| Subject(s) | Sewage--Purification--Heavy metals removal
|
| 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 |
| Abstract | Sewage sludge utilization on agricultural application as soil amendment has raised concerns
regarding the toxic accumulation of its heavy metals. Fly ash and bottom ash from Mae Moh
power plant were used as adsorbing materials for heavy metal removal. The objective of this
study was to examine fly ash and bottom ash characteristics and their capacities to bind some
heavy metals deriving from sewage sludge applied to agricultural land in order to minimize
contamination of undesirable pollutants in soil. The effect of metals on seed germination of
some test seeds was also evaluated.
To determine the optimum conditions of ashes mixed sludge both fly ash and bottom ash were
applied to anaerobically digested and dewatered sewage sludge from Huay Kwang wastewater
treatment plant in the ratio 1:1, 1:5 and 1:10 by weight, respectively. The experiment showed
that 1 :5 fly ash-sludge mixture and 1: 10 bottom ash-sludge mixture were the ratios that
minimized toxic elements and provided sufficient nutrients.
The pot experiments were conducted in Thonburi and Rangsit soils. The results indicated that
the selected ash-sludge mixtures could minimize heavy metals in amended soils and provided
adequate plant nutrients. Particularly, in Rangsit soil that presented acidic condition aluminum
toxicity was the severe problem. The ash-sludge mixture increased soil pH value and
decreased heavy metals.
As a result of seed germination test, the seed germination percentages increased when soils
were applied with sludge and ash-sludge mixtures. The increased seed germination
percentages were high as incubation time increased. However, in week 12 of the incubation
period the germination percentages decreased. Since the pH values decreased to the severe
limits and caused toxicity to plants. |
| Year | 1999 |
| 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) | Preeda Parkpian; |
| Examination Committee(s) | Apisit Eiumnoh ;Nguyen Thi Kim Oanh; |
| Scholarship Donor(s) | The Electrical Generation Authority of Thailand (EGAT) ; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1999 |