| Author | Kaewta Pungcha-um |
| Call Number | AIT Thesis no.EV-05-13 |
| Note | A thesis submitted in partial fulfillment of the requirements for
the degree of Master of Engineering
Inter-University Program on Environmental Toxicology, Technology and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Trichloroethylene (TCE)and Vinylchloride(VC) are a persistent volatile organic contaminant, which due to their unique properties used as an ingredient in industrial cleaning solution and as a universal degreasing agent and raw material for plastic manufactures. Now TCE is considered as probably (Group 2A) carcinogenic to man and VC increase risk of cancer. 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.Groundwater quality(pH, EC, turbidity and TDS) and concentration of TCE and VC contaminated in drinking water and water supplies around plastic manufactures in Samut Prakarn and Pathum Thani province were observed. Considering this and to develop a sound remediation of TCE, the study was carried out at green house level by using the mesocosm technique with and without cattail plants. This method of study was adopted from the proposed method (Gabriel R., John H. Pradue et al., 2003). TCE was used as a spiked test chemical. The loading rate of TCE was 5 mg/l in tap water upflow to mesocosm units. Each mesocosm unit was filled with bed mixed material(soil 20%, peat 40% and sand 40%). Parameters(pH, EC, Turbidity, TDS and DOC) related to efficiency of TCE remediation were observed, Absorption, anaerobic microorganism degradation, volatilization and phytoremediation of TCE with and without cattail plants were observed from different distances of 24.5,51 ,60 and 65 cm from the bottom of the unit. TCE metabolite (VC) found in mesocosm unit was also monitored. Uptake and accumulation of TCE by cattail plants including growth performance, bioaccumulation and mass balance were studied.Groundwater for drinking water and water supplies from the studied areas were contaminated by TCE and VC concentration over EPA standard and groundwater standard of Thailand. All water parameters monitored indicated that TCE was well degraded. Effective remediation of TCE in mesocosm unit for three months was over 98% removal. A decrease in efficiency after seven week was occurred. TCE was easily metabolized in a short distance perhaps less than 24 cm. An anaerobic mesocosm unit enriched by natural microorganisms from peat had influenced in TCE degradation very effectively. The presence of the plants help increasing remediation efficiency over all the time intervals observed.Cattail can also uptake and evapotranspirate TCE in contaminated growing media. Low concentration of TCE was found in the leaves, indicating of more evapotranspiration and perhaps trace amount of TCE will be eliminated by this process in the gaseous form or dilution effect or both. In contrast to TCE, accumulation of VC was increasing in proportion to plant growth as well as more VC formation occurred in the rhizosphere. Thus absorption of the plants into the roots of cattail was significantly increased over in the leaves. Bioconcentration factor value of cattail in leaves and root(l.76, 0.08) can be confirmed that TCE are not accumulated in cattail plants. Mass balance study has shown that cattail can remediate 0.2% of TCE contaminant.Remediation of TCE was occurred by absorption(l 7.7%), anaerobic microorganism degradation(31.6%) and indirect measured volatilization(23.5%). Lessons learned from mesocosm units suggested that mescosm units have high efficiency remediation for low concentration of TCE and might be cost-effective. The limitation of mesocosm units are selected plant for phytoremediation and type of bed mixed material used in unit that should be selected in proportion to pollutant concentrations. |
| Year | 2005 |
| 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) | Visvanathan, C.;Thammarat Koottatep;Patana Anurakpongsatorn |
| Scholarship Donor(s) | Royal Thai Government;Chulabhorn Research
Institute;Mahidol University ;Asian Institute
of Technology; |
| Degree | Thesis (M.Eng.) -- Asian Institute of Technology, 2005 |