| Author | Nguyen Phuoc Dan |
| Call Number | AIT Thesis no.EV-93-23 |
| Subject(s) | Sewage--Purification--Phenol removal
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | This study was conducted to evaluate the capability of a wetland system for treatment of
phenol. One pilot-scale and 3 lab-scale units of an free water surface system (FWS), a type of
constructed wetland, were set-up. Cattails (Typha sp.), an emergent plant, were planted on the lab-scale
and pilot-scale wetland units.
Commercial-grade phenol was mixed with the AIT campus wastewater to achieve influent
phenol concentrations of 25 - 700 mg/L, corresponding to organic loading rate (OLR) of 40 - 400
kg SCOD/(ha-day).
The experiment results revealed that the FWS system with cattails could effectively
remove phenol, SCOD, SS, VSS at the OLRs of 40 - 270 kg SCOD/(ha-day); the optimum
hydraulic retention times (HRT) were 5 - 7 days. At these operating conditions, the overall SCOD
and phenol removal were 97.2 - 99.9% and 99.9 - 100%, respectively (in which SCOD and
phenol removal by volatilization were 12.2 - 18.9% and 25.5 - 22.2%, respectively).
The phenol concentrations of 400 mg/L and above inhibited the photosynthetic and
transpiration capacity of the cattails. However, the bacteria were still able to decompose the
organic matter under these conditions. Phenol was found to be present in the cattail-cells about
1.4 mg/kg of wet weight of the harvested cattails, equivalent to 1.9 kg phenol/ha.
Harvesting by cutting aerial portion of the cattail plants could remove a large amount of
nutrients of 970 kg N/ha/year and 330 kg P/ha/year.
At the outdoor conditions, the average removal rate constant by volatilization for phenolic
wastewater, Kv was 0.0573 day-1
• The removal rate constant by biodegradation, adsorption and
plant uptake, Kb, increased as the initial phenol concentration increased, then reached to peak at
the phenol concentrations of 250-350 mg/L and decreased as phenol toxicity dominated (above
350 mg phenol/L). The Kb reached to maximum at the HRTs of 5-7 days. |
| Year | 1993 |
| 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) | Chongrak Polprasert; |
| Examination Committee(s) | Samorn Muttamara;Tanaka, Shuzo; |
| Scholarship Donor(s) | Bread for The World, Germany; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1993 |