Over recent years the anaerobic digestion (AD) industry has rapidly expanded due to the Government Incentives introduced to support its vital role in providing a sustainable route to recycle organic wastes, produce renewable energy in the form of biogas and reduce greenhouse gas emissions.   The application of AD to treat materials such as sewage sludge, food waste and agricultural wastes is well publicised with the main technologies being simplistic and generally well understood.However the technologies for industrial effluent AD treatment are quite different from those for organic wastes with these being characterised by short retention times (as low as 12 hours) and a necessity to retain biomass within the system. Rising energy prices and Government incentives mean that the potential benefit of AD effluent treatment systems can be great and where this is coupled with trade effluent (Mogden charge) reductions or reduced OPEX of existing treatment systems then the payback periods can be as little as 1-2 years. Given the scale of opportunity, the interest in AD for effluent treatment has expanded from the more traditional applications (brewing, sugar refining, food & drink industries) to include more complex effluents (textiles, pharmaceuticals and chemical processing).