1.4.4 Wastewater Treatment

1.4.4 Wastewater Treatment

By Yuzki Wang

The women’s house toilet system (see section 1.4.5) is designed to protect and preserve the environment by collecting urine and faeces separately. This dry composting system allows sustainable operation of safe disposal on human excrement, wastewater management, ordo control and devotes human excreta for a productive purpose. The entire toilet structure is built above the earth with solid protection of concrete slab at the bottom of the infrastructure. Such construction can highly prevent potential groundwater and soil contamination towards the local community.

The system consists of two disposing chambers. The first chamber is in operation for a year then the alternative chamber will be in use for the following year. In the second year, the stocked faces in the first chamber will become dehydrated and compostable. Once the hydration is completed, centre staff can open up the chamber and manually extract the dried human disposal. The clean pit will then be ready for the third year of operation. The alternative design allows a sufficient timeline for the dehydration process. It is crucial to ensure the dried faeces contain no to absolutely low pathogen content, to eliminate health risks when handling the excrement. According to studies, composite faeces is rich in versatile micro-organisms (Malkki, n.d) and constitute a substantial source of nutrients (Moya et al, 2019). Composite faces not only consist of important plant nutrients such as Nitrogen, Phosphorus, and Potassium, it is also rich in organic matter in enhancing soil health (Moya et al, 2019). Therefore, the dried excrement will later be used as a soil conditioner in the vegetable garden. On the other hand, urine will be stored in urine tanks located outside of the toilet. Unlike wet faeces, urine poses a very little risk due to it being almost sterile and already consist of high nutrient content (World Health Organisation, 2018). Therefore, the Urine collected will later use directly for agriculture purposes as a liquid soil fertilizer.

Figure 13 Dry compost toilet waste management plan

World Health Organisation, (2018).

To ensure effectiveness of the toilet wastewater management system, it is very important to ensure two practices: The separation of urine and faeces must be efficient, and there must be a constant supply of ash, soil, or sawdust to cover faeces in the chamber. Accordingly, the Centre will offer classes and workshops on toilet waste management, excrement reuse and sustainable agriculture practice. Such toilet waste management education will allow the local community to understand the importance of wastewater treatment and gain knowledge on household wastewater management practice. Education on Excrement reuse will promote safe and sustainable toilet practice to the local community and in such a way that improves local community sanitation practice. Agriculture workshop will benefit the local women community by promoting a safe, low-cost and sustainable agriculture practice.

Figure 14 Wastewater management system concept at the Baghere Women’s House

Drawn by Y.Wang, (2021).