Evaluation of anaerobic photobioreactor utilizing purple phototrophic bacteria for the treatment of poultry processing wastewater | |
| Author | Phaisit Buaban |
| Call Number | AIT Thesis no.EV-26-16 |
| Subject(s) | Poultry industry--Environmental aspects Photosynthetic bacteria Sewage--Purification |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Abstract | Poultry processing wastewater contains high concentrations of organic matter and nutrients, requiring efficient treatment to meet discharge standards and enable nutrient recovery. This study evaluates the performance of an anaerobic photobioreactor (AnPBR) using purple phototrophic bacteria (PPB) for treating poultry processing wastewater under different operational conditions, including hydraulic retention time (HRT), solids retention time (SRT), and membrane coupling. The system was operated in two configurations: (i) AnPBR with settling tank recirculation, and (ii) AnPBR coupled with external microfiltration ceramic membrane module. The reactor was operated for 116 days with HRT ranging from 8 to 2 days, SRT from 32 to 12 days, and membrane flux of 5 and 7 LMH. Performance indicators included COD, TKN, TP, biomass concentration and biokinetic parameters. Wastewater was collected from a poultry processing factory in Min Buri, Bangkok, Thailand.The AnPBR coupled with a settling tank achieved treatment performance under HRT 8 days and SRT 32 days, with a steady-state COD removal efficiency of 89.40 ± 2.21%. TKN and TP removal efficiencies were 67.22 ± 6.05% and 26.35 ± 1.91%, respectively, with COD removal reaching up to 90% during Day 23–28. Decreasing HRT and SRT resulted in reduced COD, TKN, and TP removal efficiencies.The membrane-coupled AnPBR significantly improved performance due to enhanced biomass retention. COD removal reached approximately 90% during Day 101–104 at HRT 4 days and SRT 12 days, with an average value of 87.75 ± 1.66%, while TKN and TP removal efficiencies were 52.40 ± 5.21% and 22.05 ± 2.27%, respectively. Biomass concentration increased significantly from 453.19 ± 27.93 mgTSS/L (settling tank) to 503.95 ± 32.49 mgTSS/L (membrane module) (p < 0.0001).Membrane permeates effluent during Period IV-I showed the highest performance, achieving 88.96 ± 0.74% COD, 57.63 ± 5.53% TKN, and 23.55 ± 2.21% TP removal. Membrane permeate COD remained below 120 mg/L during operation, meeting Thailand industrial discharge standards.HRT was identified as the most critical parameter affecting removal efficiency, while SRT mainly influenced biomass concentration. Membrane flux (5–7 LMH) did not significantly affect removal efficiency (p > 0.05) but increased operational TMP. The average crude protein content of PPB biomass was 58.98 ± 2.87% gCP/g dry mass. Biokinetic parameters based on the Monod kinetics model were determined using 7 days steady-state data for each operating period, Kd = 0.076 day⁻¹, Y = 0.39 mgVSS/mgCOD, Ks = 102.96 mgCOD/L, k = 0.584 mgCOD/mgVSS·day, and μmax = 0.228 day⁻¹. Overall, the integration of a microfiltration membrane module with AnPBR enhances biomass retention, improves treatment efficiency, and ensures stable system performance. This study demonstrates the strong potential of membrane-coupled AnPBR systems for the treatment of poultry processing wastewater and their applicability for future scale-up. However, Further studies are recommended to improve phosphorus removal and to evaluate long-term membrane operation stability, as well as microbial community dynamics under different operational conditions. |
| Year | 2026 |
| Type | Thesis |
| School | Faculty of Civil and Environmental Engineering (2026) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering and Management (EEM) |
| Chairperson(s) | Ghimire, Anish |
| Examination Committee(s) | Cruz, Simon Guerrero;Xue, Wenchao |
| Scholarship Donor(s) | Royal Thai Government Fellowship |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2026 |
 | |