Enhancement of natural attenuation of soil and water contaminated by trichloroethylene (TCE) and in co-contamination with cadmium | |
| Author | Mohsin, Md. |
| Call Number | AIT Thesis no.EV-04-09 |
| Subject(s) | Hazardous wastes--Natural attenuation Soil pollution Trichloroethylene Water|xPollution Cadmium |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, Asian Institue of Technology; Inter-University Program on Environmental Toxicology, Technology and Management, Chulabhom Research Institute and Mahidol University |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-04-09 |
| Abstract | Trichloroethylene (TCE) is a persistent volatile organic contaminant, which due to its unique properties and solvent effects has been widely used as an ingredient in industrial cleaning solution and as a universal degreasing agent. Now it is considered as probably (Group 2A) carcinogenic to man. Since TCE has been used in metal degreasing solvent, therefore co-contamination of heavy metal with TCE might be occured. Existing technologies are adequate to remove bulk of TCE contamination, but in many cases they fail to meet the low concentration limit, which is of important concerned in long term contamination and chronic effect. Considering this and to develop a sound remediation of TCE in co-contamination with heavy metal, cadmium(Cd), the study was carried out at green house level by using the phytoremediation technique with natural plant water mushroom and bioremediation technique using compost dairy manure to attenuate the cocontamination in water and soil, respectively. TCE and Cd were used as spiking test chemicals. The loading rates of TCE were 1 mg/l, 300 mg/l and 500 mg/l in water and 3 mg/kg and 1000 mg/ kg in soil. The loading rates of cadmium were 0.50 mg/I, 1.00 mg/l and 5.00 mg/I in water and 3.00 mg/kg and 100 mg/kg in soil. Hydroponic system was used for testing water mushroom and soil pot using finished compost was used to test for soil. Volatilization of TCE with and without water flow, degradation of TCE in water, uptake and accumulation of TCE and Cd by water mushroom, growth performance, toxicity, bioaccumulation and mass balance were studied. Degradation ofTCE and fate of Cd was also studied in soil. In water, with water flow 99% and without water flow 70% TCE remediate in one week. Water mushroom can also uptake and evapotranspirate TCE in both low and high contamination. The maximum concentration found in water mushroom was 10.87 μg/kg in leaves. In all the treatments the mean concentration was highest in the root than stem and leaves, which indicated the rhizofiltration by the root system of water mushroom. Water mushroom can uptake TCE even in co-contamination with cadmium. However, in high contamination with cadmium the young plants died in one week. On the other hand, young plants with low concentration of Cd (0.50 mg/l) are tolerable. Old plants are tolerable in both low and high (5.00 mg/l) contamination with cadmium. In high contamination, only with TCE, both young and old plants are tolerable and can uptake TCE. Mass balance study has shown that water mushroom can remediate3. l 1 % of TCE contaminant. Water mushroom could also uptake and accumulate cadmium. The highest concentration was observed 5.24 mg/kg in root. The concentration was always higher in root than stem and leaves. The bioconcentration factor (BCF) in water mushroom for cadmium was higher (14.57) than TCE (0.11), which indicated that TCE was not accumulative. The concentration of TCE in soil was found degraded faster in first twenty days. Significant (P<0.05) reduction by composting was observed in day twenty and thirty in low contamination with TCE as compared to low co-contamination with Cd. In high co-contamination significant reduction observed only in day twenty. A very low but gradual reduction in cadmium concentration was also observed in soil study. |
| Keyword | phytoremediation, rhizofiltration, bioremediation, degradation, hydroponics, TCE, Cd, evapotranspiration, bioconcentration. |
| Year | 2004 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-04-09 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Preeda Parkpian |
| Examination Committee(s) | Jutamaad Satayavivad;Satoh, Hiroyasu |
| Scholarship Donor(s) | Government of Japan (Joint Japan/World Bank Graduate Scholarship) |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2004 |