Fecal sludge dewatering unit for application with pyrolysis omniprocessor

Purpose

To design and develop an efficient fecal sludge dewatering system that minimizes energy requirements

Activities

Natural Synergies Limited is a stage development company aiming to provide an integrated solution within current difficult agricultural wastes and faecal matter to produce a sustainable energy source while maintaining local environment integrity.

Natural Synergies previous trial findings have shown both positives and limitations. The current approach has shown that it was important to remove not only free water, but also to make available interstitial and cell water for dewatering by utilising ultrasound cell disruption, in combination with electrokinetic (bags) that utilise electro-osmosis to drive water from the treated sludge. The integration of ultrasound cell disruption and electrokinetics is a valid dewatering methodology. However, although high % DM was achieved, the system was slow, potentially due the static nature of the original dewatering process design. Furthermore, the electrokinetic process is dependent on the use of electrodes that are sacrificial and lose effectiveness with time.

A number of technical hurdles has been overcome with regards to system design and material issues. Natural Synergies new developments includes the design of non-sacrificial electrodes; operation adaptability to OP or OI (batch and continuous process); through put optimisation to meet OP feed demands in terms of flow rate and solids content; and new reactors design.

Countries of activity

Location of main activity

Objectives

The primary goal of the project is to develop and efficient, low energy faecal sludge dewatering system which would increase faecal sludge solid concentration to >40 %DM, without the use of polymers, thereby enabling the dewatered solids to be utilised as an energy source using a thermal system such as a pyrolyser or gasifier. Dewatering without flocculants has been an extremely difficult issue to solve and is a key component for both the Omni-processor (OP) and Omni-ingestor (OI) strategies.

Further information

Natural Synergies has been developing a dewatering system that operates without the use of flocculants. The system uses ultrasound and electrostatic bags to separate out the solids. To date they have demonstrated refining secondary activated solids (SAS) with 0.5% TS to 35% - 45% TS using their system.

Dewatering without flocculants has been an extremely difficult issue to solve and is a key component for both the Omniprocessor (OP) and Omni-ingestor (OI) strategies. The current design by Natural Synergies is a batch process that is best suited for OP technologies, but if promising modifications to this technology could potentially be made to help it work with OI dewatering.

Developing country where the research is being or will be tested: India

Filter tags

Bill & Melinda Gates Foundation East Asia & Pacific Europe & Central Asia Faecal sludge treatment processes Global Private sector, including social enterprises Product design and engineering Treatment of faecal sludge

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