Evaluation of photobioreactor coupled in cess-to-fit model for treating blackwater. | |
| Author | Chawalit Chaiwong |
| Call Number | AIT Thesis no.EV-16-03 |
| Subject(s) | Biochemical engineering. Photobiochemistry. Hydrogen--Biotechnology. |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-16-03 |
| Abstract | Cesspool system, onsite sanitation systems, is popularly used in Thailand. However, treatment performances of the cesspool system could not be functioned properly. Additionally, in order to deal with the problem, Cess To Fit model (CTF) is a new technology proposed to be retrofit to the cesspool system for enhancing the treatment performance. Although prototype of CTF was found with relatively high treatment efficiency, effluent from CTF still however contains high organic and nutrient pollutant as well as qualities of the effluent could not meet the national standard. Moreover, in order to improve treatment of Cess To Fit, CTF is proposed to be equipped with additional compartment. The additional compartment is proposed to be functioned as photobioreactor for removing organic and nutrient in effluent from the Cess To Fit system. Hence, this research aims to evaluate treatment performances of PBR under various operational conditions. Algal growth test were conducted in the first phase by mixing AIT pond water (PW) as algal inoculums with effluent from septic tank (WW) as nutrient for algae with ratio 7:3, 5:5, 3:7 PW/WW. Moreover, algal biofilm culture test were carried out by using optimal condition obtained from previous experiment. In additional, in operational phase, Flat plate photobioreactor (PBR) with 22 L of effective volume and 86 m²/m³ of specific area were operated under several conditions. The PBRs with Octa-media (OC-media) and Plastic strip-media (PS-media), lighted by LED lamp (100 μmole/m²/s) continuously and sunlight (860 μmole/m²/s) diurnally, were operated under 24, 48 and 72 hours. Effluent from commercial septic tank was fed intermittently to the PBRs. Results of 2.6 to 6.3 mg/L, average 3.8 mg/L, of DO concentration were found in PBR+LED and PBR+SUN having DO of 1.5 to 13.5, average 5.9 mg/L, were observed. COD were in range of 40 to 64 %. Organic removal rate were found in range of about 43 to 106 gCOD/m³/d. The minimum result was found in PBR+SUN with OC-media under HRT 24 hours while highest efficiency was found in PBR+LED with PS-media. TN and TP removal efficiencies were found between 15 to 46 % and 18 to 35%, respectively. Furthermore, NRR in PBRs were found in rage of about 5 to 16 g TN/m3/d and and PRR were found in rage of 1.30 to 4.88 gTP/m³/d. This study found that under different media and light conditions, organic removal efficiencies of PBRs were not different. Meanwhile, TN and TP removal efficiencies of PBR lighted by LED were higher than that of PBRs lighted SUN but there were not significant differences of TN and TP removal between two types of media. Similarly, biofilm productivities of PBRs+ LED were higher than that of PBRs+ SUN which this result is corresponded to TN and TP removal in PBRs. In additionally, nitrification processes were found in PBR+LED while nitrification process in PBR+SUN could not be observed during this experiment period. Furthermore, Chlorella sp and Synechocystis sp were dominant algal species in all PBRs. Moreover, this study also found that OLR, NRR, PRR, and HRT could have effect on removal rates and efficiencies of organic (COD) and nutrient (TN and TP) in PBRs. Stover-Kincannon model can be fit for COD, TN and TP removal in PBRs. |
| Year | 2016 |
| 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) | Thammarat Koottatep; |
| Examination Committee(s) | Nguyen, Thi Kim Oanh;Nawatch Surinkul;Ksemsan Suwarnarat; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Sc.) - Asian Institute of Technology, 2016 |