PDX - Pursuit dynamics pre-treatment for sludge
| Date/Time: | 24 May 2012
14:00-14:15 |
Seminar Details
Anaerobic digestion (AD) is commonly used for sewage sludge treatment to produce energy and reduce the amount of material for final disposal. Bacteria break down the organic material, converting it into a methane rich biogas. The ability to break down secondary activated sludge (SAS) is limited as the organic material is largely contained within cellular structures that are not broken down by conventional mesophilic AD. Consequently biogas yields from SAS are significantly lower than from primary sludge.
PDX is a novel patented reactor design with the ability to inject high-velocity steam into a fluid to create a supersonic 'zone'. This mechanism has benefits for sludge pre-treatment, prior to AD. A study was undertaken at Cranfield University and a six month trial is underway with Isle Utilities to understand the benefits of the PDX pre-treatment process. This paper discusses the benefits of using PDX, which include:
-Breaking up large particulates and reducing viscosity, thus making pumping more efficient;
-Pathogen kill;
-Cell lysis, thus making organic material contained within the cells available in the AD process, resulting in increased solids destruction and an associated increase in gas production.
PDX has the potential to provide a cost effective alternative for sludge pre-treatment, potentially enabling water companies to produce an enhanced treated sludge (in accordance with the Safe Sludge Matrix) at a dramatically reduced cost. This paper is of interest to individuals or organisations engaged in the design, operation and optimisation of AD processes.
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