| Author | Naqvi, Ali Ahmad |
| Call Number | AIT Thesis no. EV-98-11 |
| Subject(s) | Fertilizers--Environmental aspects
|
| Note | A thesis submitted in pa1tial fulfillment of the requirements for the degree of Master of
Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | The prime objective of this study was to evaluate the trace metal and heavy metal composition
of chemical fertilizers and soil amendment material most commonly used in Asian region.
The eleven types of thirty chemical fertilizers are selected for analysis of eight metals and
these eleven types of feitilizers accounts for 85 percent of consumption and usage in the
Asian region and seven types of soil amendment materials are analyzed for metal contents.
Acid digestion procedure was used for digestion of chemical fertilizers and results indicate
that concentration of trace metals and heavy metals in Phosphate fettilizer>K fertilizer>
N fertilizer.
Soil amendment materials were analyzed by three different techniques of total digestion,
DTP A extraction and sequential extraction. Analysis of total metal content is done by total
digestion, bioavailability of metals in soil amendment material is assessed by DTP A
extraction and sequential extraction test was used to fractionate pool of metals into six
operationally defined groups; exchangeable, carbonated, easily reducible, moderately
reducible, sulphitic and residual. The residual fraction was the most abundant pool for all
eight metals examined. DTP A extraction results of amendment materials are correlated with
(exchangeable + carbonated) fraction and regression coefficient for all metals ranged between
0.75 to 0.98. Incomplete digestions of fly ash and bottom ash were observed by HN03-HCl04
so results of fly ash and bottom ash are not evaluated.
Extraction with DTPA and sequential extraction ( exchangeable+carbonated) showed that
almost 4% to 40% of trace metals and heavy metals in soil amendments exist in bioavailable
forms for plants. while major proportion of most of the metals in all amendment materials are
associated with residual fraction and could be classified as of geochemical origin.
Estimation of build up of heavy metals by application of chemical fertilizers and soil
amendment material is done for the soils of Thailand and this is compared with the maximum
permissible concentrations in the soils. It was found that chemical fertilizers and liming
materials are environmentally safe with regard to heavy metals input, as no significant amount
of heavy metals buildup in the soils occurs by use of chemical fertilizer and liming materials
as recommended by the DO A Thailand, but if sludges and city composts are applied in the
soils it is needed to monitor potentially toxic metals in the soils. |
| Year | 1998 |
| 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) | Preeda Parkpian |
| Examination Committee(s) | Eckhardt, Ing Heinz ;Apisit Eiumnoh |
| Scholarship Donor(s) | Asian Institute of Technology, Partial Scholarship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1998 |