| Author | Manivasakan, Muthukumaraswamy |
| Call Number | AIT Thesis no. EV-88-17 |
| Subject(s) | Soils--Cadmium content
|
| 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 | A mass transport model, AFLEM(Advective flow, Film transfer and Local Equilibrium Model) has been developed to describe the contaminant
movement through the sub surface soil. An idealized, saturated, homogeneous, isotropic and aggregated soil and non-degradable contaminant are
considered in this model. Advection, film diffusion and adsorption are
considered as model mechanisms in this model. A finite difference solution
is presented in detail. A computer program CADTRA ' is given to solve
the mathematical model AFLEM ' and the model is validated for transport
of Cadmium under saturated conditions. Simulation results of the model
show that AFLEM 'to be a versatile tool to predict contamination transport in the subsurface soil in normal cases. Using the values of model
parameters, such as film transfer coefficient from column experiments and
Freundlich isotherm constants from batch experiments, the concentration
profile could be able to be simulated successfully .
The transport mechanisms and the factors affecting the transport
mechanisms of Cadmium were studied using laboratory scale experiments in
detail. The two major transport mechanisms Adsorption and Precipitation
were considered in detail. The transport mechanisms at different pH values
were distinguished. From the batch experiments, it was found that when
the pH is less than 7.0 adsorption was the only predominant mechanism and
at pH values greater than 7.0 precipitation was the dominant mechanism
which affect the transport of Cadmium. The pH, initial Cadmium concentration and foreign metal concentration were changed in the detail investigation and it was found that adsorption of Cadmium increases with
increasing pH upto pH 7.0 and beyond that it decreases. Further, an increase in Calcium concentration and decrease in initial Cadmium concentration were found to decrease the adsorption of Cadmium. In an attempt
to quantify the amount of precipitation of Cadmium, Jar test experiments
were conducted. Also, the change of pH, mixing rate and settling time
on precipitation was investigated in detail and found that an increase
in each of them favors precipitation of Cadmium. |
| Year | 1988 |
| 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) | Vigneswaran, Saravanamuthu
|
| Examination Committee(s) | Chongrak Polprasert ;Samorn Muttamara ;Kriengsak Udomsinrot |
| Scholarship Donor(s) | Norwegian Agency for International Development |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 1988 |