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Transport of wastewater containing heavy metals in soil under saturated conditions | |
Author | Tiwaree, Ram Sharma |
Call Number | AIT Thesis no.EV-89-26 |
Subject(s) | Soils--Heavy metal content |
Note | A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
Publisher | Asian Institute of Technology |
Abstract | Mechanisms involved in the transport of wastewater containing heavy metals in soil were studied by a one dimension a l advection limited solute transport model with t h e assumption of saturated flow conditions. Local equilibrium was assumed for adsorption with the introduction of Freundlich isotherm in t h e model . Batch and column adsorption experiments for the adsorption of heavy metals (cadmium, zinc ) in sandy loam soil were performed st pH 6. These experiments revealed that Freundlich isotherm gave better correlation for t h e a d sorption of these trace metals. Th e sandy loam soil s h owed its high affinity for the adsorption of these metals with little preference to cadmium contaminant, and the sorption isotherms were s lightly curvilinear. Significant effect of influent concentrations and pore water velocities on the adsorption of these metals were observed. Furthermore , due to the competition for adsorption sites in the sandy loam soil , decrease in its adsorption capacity for these metals was found significant. Applicability of o n e dimensional advection limited reactive solute transport model was investigated by using the Freundlich isotherm parameters derived from both batch and column adsorption experiments. The o n e dimensional solute transport model predicted t h e observed breakthrough data satisfactorily only when the isotherm parameters (K and n ) derived from column adsorption experiments were used. A factor ' ¢ ' was in traduced to the retardation factor in this model to quantify the decrease in the adsorption of cadmium in the sandy loam soil due to the presence of zinc in bisolute system. It was found that the presence of zinc (2 mg/L) decreased the adsorption of cadmium (100 to 1000 µg/L) by 72 % to 65 % . Thus, the relative cadmium Darcy velocity was higher for lower concentration of cadmium. Similarly, decrease in the adsorption of zinc due to the competition between cadmium and zinc for adsorption sites in the same soil was also quantified. Batch a nd column adsorption experiments of zinc refinery wastewater in the sandy loam soil revealed t h at decrease in the adsorption of both cadmium and zinc present in this wastewater is more than in bisolute system. This wastewater contains more metals other than cadmium and zin c. A further research to observe the transport behavior of this wastewater is required. |
Year | 1989 |
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) | Samorn Muttamara ;Tran, Francis T. ;Yamamoto, Kazuo |
Scholarship Donor(s) | DAAD, The Government of Federal Re public of Germany |
Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1989 |