In other modules we've introduced you to treatment objectives for fecal sludge and markets for treatment products. In this module we will provide you with an overview of treatment technologies to meet these objectives and market demands. Following this module you'll be able to explain different levels of technology development, list technology based on the level of technology development and group technologies by treatment objectives. Many technologies exist for the treatment of fecal sludge such as planted drying beds, co-composting, fly larvae composting pyrolysis, or lime treatment. These different technologies have different levels of research, design, operating and maintenance experience. For example, unplanted drying beds have been extensively researched and implemented for fecal sludge treatment in the past twenty years. This slide shows our pilot scale research facility in Dar es Salaam, Tanzania. Such research has produced knowledge for treatment design and operation for example, on the influence of sand filter diameter and filter depth on the treatment performance. Here's an example of a full scale construction operation on drying beds for fecal sludge treatment in Kampala. Examples like this provide further information for example how to best remove sludge from drying beds or dewatering and drying times. Such information can then improve further treatment designs and operations. We call technologies with this level of development and operating experience established technologies. Other established technologies include planted drying beds co-composting, settling-thickening tanks and deep row entrenchment. In contrast to established technologies, technologies that are available that are established for the treatment of other waste, such as waste water and solid waste. We call these technologies transferring technologies as information on operation is currently still being transferred and adapted for fecal sludge. These technologies include anaerobic digestion, incineration vermi-composting, lime treatment and mechanical dewatering, as shown here for a fecal sludge treatment plant in Manila. These technologies can be used for treatment but less reliable information is available on their design and operation with fecal sludge compared to the established technologies. Fecal sludge management is a really dynamic field and many innovative technologies are also being developed. For example pyrolysis, ammonia treatment fly larvae composting, or pelletizing, as shown here on the fecal sludge treatment plant in Durban. These technologies are currently in their research stage in preparation for scaling up. So why do we distinguish technologies as established, transferring and innovative? The level of technology development is an important indicator in selecting an appropriate technology based on the level of adaption, research, innovation, as well as design, operation and maintenance that will be required for successful implementation of this technology. Established technologies can be more reliably implemented, but much less information's available for the transferring and innovative technologies. Therefore, established technologies should selected when limited capacity for this adaption, innovation and research and development are available. For transferring technologies and innovative technologies the increased risk, due to the lower level of technology development needs to be considered and managed. This could be, for example done through public private partnerships or research collaboration with a university. This could pay off as transferring innovative technologies have the potential to be more efficient. For example, in space requirements, and they can also produce products that have a higher revenue potential that could off-set treatment costs. You might be overwhelmed by the large number of treatment technologies presented here, and you just want to know what technology do I need for drying out sludge or to inactivate pathogens. To answer this question, it is best to group technology based on treatment objectives: Solid-liquid separation sludge stabilization, nutrient management and pathogen inactivation. Technologies for solid-liquid separation include drying beds, mechanical dewatering technologies and settling-thickening tanks. These technologies are designed to separate solids and liquid material in fecal sludge. For example, on this planted drying bed in Thailand sludge is loaded on the surface of the sand filter layer. Solids and fecal sludge remain on the surface of this filter layer while the liquid passes through the filter layer and is collected at the bottom of the filter in a drainage network for further treatment. Treatment technologies typically achieve several treatment objectives. For example, with planted drying beds sludge can remain on the surface for up to ten years and also become stabilized as you can see with the stabilized sludge on the surface of this planted drying bed. Other treatment technologies of sludge stabilization include co-composting, anaerobic digestion fly larvae and vermi-composting and incineration and pyrolysis. Technologies for nutrient management can include co-composting deep row entrenchment, and fly larvae and vermi-composting. As always, the appropriate level of inactivation of pathogens for the intended use of treatment products must be a priority to protect public health. Co-composting, storage of dried sludge, lime and ammonia treatment and incineration and pyrolysis are technologies that achieve high levels of pathogen inactivation. Frequently fecal sludge is mostly comprised of water. So all technologies for solid-liquid separation and also for example, anaerobic digestion produce liquid effluents that require further treatment. Technologies for effluent treatment include infiltration planted drying beds, waste stabilization ponds anaerobic baffled reactors and filters and constructed wetlands. if treatment is located adjacent to the waste water treatment plant you can also include co-treatment with waste stabilization ponds or even technologies based on activated sludge process. Treatment that adequately protects public and environmental health requires combinations of different treatment technologies with different treatment objectives. Let's look at one example. This picture shows the Dumaguete treatment plant in the Philippines. It has the capacity to treat 80 cubic meter of fecal sludge from septic tanks per day. At Dumaguete, the sludge discharges into an anaerobic waste stabilization pond. Following the effluent from this anaerobic waste stabilization pond is further treated in facultative and maturation waste stabilization ponds and constructed wet lands. The solids that settle in anaerobic waste stabilization ponds are dewatered and dried on dying beds. In separate modules you will learn more about these treatment technologies. This will enable you to select technologies for a complete fecal sludge treatment plant and know important design considerations. You now have a good overview of treatment technologies for fecal sludge, but remember technology is only a part of the solution next to the level of technology development and treatment objectives presented in this module, consideration like capital operation and maintenance cost, the existing institution arrangements and capacity, the enabling environment and socio-economic characteristics need to be considered and will be discussed in separate modules. In this module, you were introduced to different treatment technologies for fecal sludge. Technologies have different levels of technology development based on existing level of knowledge from research, design, and operation and maintenance. This should be considered when selecting treatment technologies. Knowing the treatment objectives for treatment technologies so for example, solid-liquid separation from unplanted drying bed or sludge stabilization, nutrient management and pathogen inactivation for co-composting are important to select and combine fecal sludge treatment technologies for a complete fecal sludge treatment plant.
