Biogas production from an anaerobic co-digestion of sewage sludge and brewery sludge | |
| Author | Jenjira Sae-tang |
| Call Number | AIT Thesis no.EV-04-06 |
| Subject(s) | Biogas Sewage sludge |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-04-06 |
| Abstract | As the Beer-Thai (1991) Co., Ltd does not have its own digester and the amount of beer sludge will be increasing everyday, the land for sludge drying becomes scarce. Not only that the land becomes the problem but also the Beer sludge has the disgusting smell. Bangkok Metropolitan Administration (BMA), oppositely, has possessed a completed series of digesters, so brewery sludge was introduced to mix together. This is called winwin situation because brewery sludge can be treated while BMA sludge can be further used that sludge mixtures in agricultural application, lowering concentrations of heavy metals to meet the requirement as bio-solids and also yield valuable biogas as a by-product. The prime objective of this research was to investigate the sludge quality to be used in agricultural application and the biogas production from the sludge mixtures of BMA sewage sludge to Brewery sludge at different ratios; 100:0, 75:25, 50:50, 25:75 and 0:100. A batch anaerobic reactor under mesophilic condition with a 40 day period of digestion was conducted on the lab scale units. The sludge mixtures at different ratios were feed into the reactors. Optimum mixing ratio would be determined. Analyzes of digested sludge from a reactor showed that pure BMA sludge from NongKhaem has Cu content exceeded the BMA guidelines. This might be because of illegal leaking from small scale industries. For Brewery sludge, the value of Pb and Cd were a little bit high. The source of them might be from the groundwater that was used as raw water or chemicals in processing line. Though the results of sludge mixtures showed the levels of many toxic compounds are not subjected to the standard that would pose a health or environmental risk, but considering the annual loading rate of heavy metal in kg/ha/yr, the values were well below the standard of US and UK. The investigation showed sludge mixtures at 25:75 is recommended for agricultural application and yielded higher biogas production. A good sludge treatment has a good influence on the sludge characteristics such as lower number of pathogen, lower content of heavy metals concentration together with high nutrient, nitrogen ~4.95%. Less volatile solid reduction resulted in disgusting smell from all digested sludge mixtures. Based on the total weight of sludge mixtures of 12 kg wet weight basis, the biogas production from Sewage Sludge to Brewery Sludge at the ratio of 100:0, 75:25, 50:50, 25:75 and 0:100 were 0.08L, 16.22L, 92.50L, 126.67L and 143.58L. The more the brewery sludge content, the higher the biogas production. As quantity of sludge generated by BMA is about 73 m3 /d and from brewery is about 110 m3/d, at optimum mixing ratio 25:75, about 24,098,361 MJ/yr of energy could be gained. This large amount of biogas is equivalent to 1.44 million kWh/yr of electricity, 550,000 L/yr of diesel oil and 950,000 L/yr of gasoline. |
| Year | 2004 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. EV-04-06 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Preeda Parkpian |
| Examination Committee(s) | Annachhatre, Ajit P.; Thammarat Koottatep; Babel, Sandhya Babel |
| Scholarship Donor(s) | Asian Institute of Technology Fellowship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2004 |