| Author | Chatcharee Lerdsirivichai |
| Call Number | AIT Thesis no.EV-11-01 |
| Subject(s) | Paraquat
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environment Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Paraquat is extensively used as weed clearance for soil preparation, pre-plantation, aquatic weed control etc. This study investigated sorption, membrane filtration and hybrid process for paraquat removal from agricultural run-off water. In sorption experiment, four adsorbents (PAC, chitosan, alumina, soil) were tested. PAC is the best of them to remove paraquat. PAC sorption can be explained with Langmuir isotherm, which indicates formation of paraquat monolayer on PAC surface. The sorption capacity of PAC for paraquat was 116 mg/g. A kinetic study, showed that paraquat adsorption on PAC was very fast in the initial period. The initial sorption rate was 0.0011- 0.0211 g/mg/min. The steady state of paraquat sorption (99%) was obtained after 15 hours. In the filtration experiment, nanofiltration and ultrafiltration membranes were tested. TS80 nanofiltration membrane was the most effective membrane, with a 95% paraquat removal. In view of permeate flux; however, low permeate flux (0.04-0.13 m³/(m².d.b)) was found at high concentration applied (30 mg/L of paraquat) resulting from the effect of concentration polarization and membrane fouling. In hybrid experiment, hybrid ultrafiltration UE10 process showed higher paraquat removal (64%) than sorption and direct filtration. Paraquat removal in hybrid NF processes (95% in hybrid TS80 and 65% in hybrid XN45), was slightly lower than in direct filtration. Higher permeate flux was observed in all the hybrid processes compared with direct filtration due to low fouling, scouring effect, and assisting layer. In addition, the effect of humic acid contamination on sorption and filtration was studied. It was found that the presence of humic acid had only minor effect on sorption efficiency and permeate flux. |
| Year | 2011 |
| 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) | Visvanathan, C.; |
| Examination Committee(s) | Annachhatre, Ajit P.;Preeda Pakpian; |
| Scholarship Donor(s) | Thailand HM (Queen); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2011 |