Hello Analiza,

In this document it is mentioned that Lime is added above sand layer. i have few questions related to this as i am working on similar drying bed but instead of fecal sludge i am working with slurry from toilet linked biogas didgester. I would like to understand following,

1. quantity of lime used in this facility ?
2. dimension of drying bed ?
3. how the quality of lime is analyzed ? purity %
4. what is motive of using lime, dewatering or killing pathogens from pH & temp.
5. what is the depth of fecal sludge applied on this drying bed.

Thanks and Regards,
Apurva Sahu
MSc. Student (Sanitary Engineering)
Unesco-IHE

Unfortunately I cannot open the attached file but have some observations.
Bacteriologically effective sewer sludge treatment can be negatively affected by what people throw into the toilet and to waht extend people use strong cleaning agents and flush these through the system.
Medicine remains, chlorine cleaning agents and used condoms each give their own type of problems in the final cleaning or conversion process.
The above means that the project also needs to attend to general education of the people who's toilet systems and septic tanks are cleaned. As part of the programme you can set up a shop where you sell biologically suitable detergents and cleaning agents that can safely be used for cleaning the systems, alolowing full conversion to safe fertilizers.

Thanks Analiza. Decentralised STFs are not only suitable for emergency situations, but they might be the viable option for urban authorities that do not have sufficient funds to have large treatment facilities in place. Could you kindly give more details about your project; e.g., capacity (cubic meters), average haulage distance, costs (estimates), land acquisition procedure, etc. Such details could handy for practitioners that seek to replicate your model

Localized Sludge Treatment Facility: Drying Bed Treatment System in Cagayan de Oro

One of the major challenges especially during emergency situation due to natural or manmade disasters is proper sanitation. WHO defines sanitation as the safe management of human waste (excreta) – which includes urine and faeces -through provision of latrines and the promotion of personal hygiene. Safe disposal of human waste and excreta is a priority from the very beginning of a camp set-up. Particularly, in longer-term emergencies, adequate sanitation is as important as a sufficient supply of water. Human waste is a major source of pollution and water contamination, and is often responsible for various health problems and diseases such as diarrhoea, dysentery and cholera. Therefore, the provision of proper sanitation services needs to be seen as closely related to health care and of vital importance. Sanitation facilities should be as compatible as possible with traditional defecation and cleansing practices, preferred positioning of latrines or other cultural or religious norms

Over time, pit latrines will have to be emptied or decommissioned – a reality which must be considered when first they are planned. The most immediate solution would be either close the latrine or to desludge regularly especially during disasters where in commonal latrines are the feasible sanitation facility solution that could be provided to the disaster survivors, and most often solution when septic tanks are already full is, they are to be desludged.

The most common challenge is how to manage the sludge/septage properly that it does not harm the environment especially polluting the groundwater and air. Thus, in Xavier Ecoville Resettlement site, Sustainable Sanitation (SuSan) Center -a college based unit of the School of Medicine, Xavier University, managed the sludge (wastes from septic tanks) locally by constructing a localized sludge treatment facility (drying bed treatment system or DBTS) in order to address this challenge.

The drying bed treatment system is using lime, charcoal and sawdust plus a microbial organism in order to kill or reduce the pathogens since it is deemed that as Ecological Village, it is envisioned that waste streams accumulated by the Xavier Ecoville community shall either be recycled/reused, or treated locally in order to reduce negative external effects in the environment. However, to check the effectivity of the drying bed treatment system, microbiological test shall be conducted by the SuSan center together with the School of Medicine after six months period of drying the sludge in the DBTS to check the pathogen level in the dried sludge and then, later secondary treatment through vermicomplosting shall be conducted, then finally the vermicast will be use in agriculture.