Determination of the hydraulic characteristics of Cess-to-Fit system treating blackwater | |
| Author | Suradanai Augsorntung |
| Call Number | AIT Thesis no.EV-15-23 |
| Subject(s) | Cesspools--Thailand Sewage disposal--Thailand |
| 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 |
| Series Statement | Thesis ; no. EV-15-23 |
| Abstract | Cesspool systems are dominant onsite sanitation in developing countries especially in Thailand. This system had been being widely applied due to low construction cost, easy operation and maintenance. There were various designs of cesspool whether one-cesspool, two-cesspools in series, or three-cesspools in series. However, the cesspool systems have generated the serious problems to environment. Many organic particle and pathogens are directly exposed to the environment by the open bottom of cesspool system. Therefore, cess-to-fit system is the new technology to solve the above problems. This research has the aim to develop cess-to-fit system by investigating the hydraulic conditions and evaluating of organic removal efficiency to design the new configuration which is enhancing the treatment performance. Cess-to-fit systems which were three types of configuration of actual-scale were conducted on hydraulic evaluation by tracer study under intermittent feeding and HRTs values of 24 h, 36 h, and 48 h with the conditions of tanks without media and tanks with media. The results indicated that the dispersion number were in range between 0.264 and 0.681 which indicating high amount of dispersion degree. The simple tank was the highest dispersion as compared to horizontal flow tank and vertical flow tank. However, the statistic analysis indicated that there were not significantly different. The results showed that trends of non-ideal reactor were complete-mixed pattern. The results were found that the dispersion number is inversely proportional to actual hydraulic retention time (HRT), which used to indicate dead space in reactor. The dead spaces were varying from 11 to 28 %. The effect of HRTs on dispersion number was found that typically the longer HRTs can increase in dispersion number, and the effect of media bed on hydraulic characteristics as compared to tanks without media was found that, the actual HRTs were significantly increased in the range of 4 to 19 %. The results of treatment performance indicated that the major mechanism for organic removal in cess-to-fit system is sedimentation, which mainly depended on HRT. The efficiency results of HRT 12 h were found that TCOD, TS, TVS, TSS, and TKN removal efficiencies were in ranges of 68-78%, 60-72%, 63-76%, 73-85%, and 40-47% respectively. For the HRT 24 h and 48 h, the removal efficiencies were in ranges of 79-89%, 73-78%, 74-82%, 85-94%, and 45-52% respectively. The statistic analysis indicated that the removal efficiencies of HRT 24 h and 48 h were significant better than the HRT 12 h. Mass balance in term of TSS was considered which was indicated that the HRT 12 h had the transfer coefficient of effluent between 0.16 and 0.33, while the HRT 24 h and 48 h were in range 0.06 to 0.14. Kinetic models for TCOD removal of cess-to-fit system were reported that the kinetic trend of cess-to-fit system was the complete-mixed reactor with 1st order reaction. The constant rates were found in ranges of 6.51 to 7.84 d-1. However, SCOD removal was not shown significantly reduction that could be from sludge solubilization which was disturbed by flushing hydraulic that leads soluble part from the bottom to be dispersed and mixed with the effluent. Cess-to-fit is the new technology which could be more interesting points to study and develop. This study recommended to redesign and improve the configuration by considering the dispersion characteristics which should be low that can get reducing in short-circuit and increasing in actual HRT. |
| Year | 2015 |
| 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) | Annachhatre, Ajit P.;Nguyen, Thi Kim Oanh;Nawatch Surinkul; |
| Scholarship Donor(s) | Royal Thai Government;Asian Institute of Technology Fellowship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2015 |