Operational Problems and Solutions Coupled to Anaerobic Sludge Digesters

Anaerobic digestion has been the most important biological treatment process used in a wide scale from sluage to biomass, municipal to industrial wastewaters with different reactor configurations since the times of its application to waste and sludge stabilization. It is the only biological treatment and stabilization process that gives a product with higher energy level than its substrate. It provides full-capacity operation to municipal wastewater treatment (WWTP) with conventional activated sludge process with the energy produced at a high recovery ratio. The need for operational amelioration requires further correlation and adaptation of operational measures to design characteristics. Investment and operational costs are high for anaerobic systems as strictly insulated reactors are built. In case of maintenance or break-down, loss of time and money reach severely high levels. Operational burdens, problems and out-of-design situations can originate from several dominant factors produced during the process due to products, equipment sensitivity and wastewater characteristics. This study summarizes experience obtained in municipal WWTP investigation on operational problems in anaerobic digestion in Turkey. Operational problems such as H2S control, foaming, sludge management and break-down incidences related design and solution suggestions are presented with support from ongoing research in the international literature.