Contribution to the Development of Sustainable Sanitation in Emerging Countries - Resource-Oriented Sustainable Sanitation (ROSS) Module

Project year: 2016 • Samir Y. S. Alnahhal (private person)


To design, develop, realize, and monitor a sanitation prototype in the Gaza Strip based on the concept of resource-oriented sanitation


The activities of designing, developing, realizing, and monitoring two sanitation pilot units according to the concept of resource-oriented sanitation, include:
- Preparing the engineering design including:
a. Calculation means for the ROSS components, including solid-liquid separator, nutrient adsorption tank, constructed wetland, storage and disposal equipment, and lactic acid fermentation tanks;
b. Engineering drawings for unit components and equipment
c. Technical specifications of all materials, equipment, and tools for developing, constructing, operating, and maintaining the pilot units
d. Bill of materials and cost analysis for all proposed components and equipment.
- Conducting baseline survey and sanitation need assessment in the targeted area, which located in Al-Shoka area, Rafah Governorate, southern part of the Gaza Strip, where no sewer networks and wastewater services are provided.
- Sharing the ROSS concept and methodology with local community for seeking the willingness of housekeepers to participate and get benefited from the pilot units.
- Selecting two households as the project beneficiaries based on pre-prepared selection social, economic, and technical criteria.
- Redesigning the ROSS units based on existing local conditions, including topography, sanitation infrastructure, household connections, daily water uses per each household, number of persons per household, etc.
- Conducting a hygiene and environmental training course to the selected households about ROSS concept, purpose and methodology, as well as its operation and maintenance in safe and hygienic ways.
- Constructing the two on-site pilot units in the backyards of the two households by a local small enterprise under the supervision of the authors
- Connecting the household connections of sanitation facilities, e.g., toilets, showers and washbasins to the different components of ROSS units. The greywater stream was separated from the backwater stream and connected directly to the subsurface flow (SSF) wetland (reed bed), while the backwater stream was connected to the designed, developed and realized solid-liquid separator in order to separate the black water solids, e.g., feces and toilet papers, from black water liquid. The liquid is allowed to flows toward nutrient adsorption to adsorb some nutrients by charcoal. Then, the black water liquid is connected to the SSF wetland. The treated effluent can be stored in a storage tanks to be available for reuse in irrigation or flow to the groundwater recharge tanks by the access water quantities. The separated solids can be stored in filter bags, which are installed in multi-interceptor double jacketed tanks of the solid-liquid separator. The filter bags of backwater solids and activating charcoal bag are collected manually and stored in lactic-acid fermentation tanks. The backwater solids and charcoal are mixed with lactic acid bacteria to start the lactic acid fermentation process, which can be used for initial stabilization of bio-solid wastes for 28 days. Then the mixture is composted aerobically to produce a Terra Preta-like substrate that is a nutrient-rich soil conditioner.
- Monitoring the operation phase of units by conducting site visits and testing some quality parameters for the effluent of treated water and produced soil conditioner.


Image: Concept, schematic design and realization for components, equipment, and associated processes in the ROSS unit.


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The main focus of this project is to design, develop, realize, and monitor a sanitation prototype in the Gaza Strip based on the concept of resource-oriented sanitation. This prototype will aim to handle and manage domestic wastewater on-site in a safe and hygienic manner. The prototype shall be low-cost; low-tech; and easy to implement, operate, and maintain; as well as culturally adoptable for communities in semi urban and rural areas in emerging countries. This decentralized approach consists of Terra Preta sanitation (TPS) and constructed wetlands (CWs). TPS converts bio-solid wastes, including solids of blackwater and solid organic wastes, into a soil conditioner or Terra Preta-like substrate in a hygienic and sustainable manner. In addition, CWs treat liquid wastewater (i.e., greywater and liquid of blackwater) and offer a treated water for irrigation purposes in a safe and hygienic way.

Further information

Based on the ROSS design and development by the author, the project was implemented by the Palestinian Environmental friends Association (PEF) under the framework of mufti-sectorial project "WASH support to vulnerable and war affected Gaza population" number PTIB21/Appeal/PEF/01, which was supported also by Oxfam Great Britain (GB).

Contact information

Samir Y. S. Alnahhal
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Samir A. A. Afifi
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