- Volume 19 Issue 3
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Hydraulic Evaluation and Performance of On-Site Sanitation Systems in Central Thailand
- Koottatep, Thammarat ;
- Eamrat, Rawintra ;
- Pussayanavin, Tatchai ;
- Polprasert, Chongrak
- Received : 2014.05.27
- Accepted : 2014.08.26
- Published : 2014.09.30
On-site sanitation systems are typically installed to treat grey and toilet wastewaters in areas without sewer and centralized treatment systems. It is well known that, due to inappropriate design and operation, treatment performance of these systems in developing countries is not satisfactory in the removal of pathogens and organic matters. This research aimed to investigate the hydraulic conditions occurring in some on-site sanitation systems and the effects of hydraulic retention times (HRTs) on the system performance. The experiments were conducted with a laboratory-scale septic tank (40L in size) and an actual septic tank (600L in size), to test the hydraulic conditions by using tracer study with HRTs varying at 12, 24 and 48 hr. The experimental results showed the dispersion numbers to be in the range of 0.017-0.320 and the short-circuit ratios in the range of 0.014-0.031, indicating the reactors having a high level of sort-circuiting and approaching complete-mix conditions. The removal efficiency of
Hydraulic conditions;Hydraulic retention time;On-site sanitation;Septic tanks;Treatment performance
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