Anaerobic Digestion has gained popularity in recent years due to its significant contribution towards achieving waste management and renewable energy targets. One particular technology that has been widely used in the treatment of high strength organic wastewaters across a wide range of industries is upflow anaerobic sludge blankets (UASBs). A malt ingredients manufacturing factory has successfully applied this technology as a cost effective way to treat their high strength effluent, however unlike other industries there is a lack of research regarding the wastewater characterisation or UASB performance at either lab or full scale. This paper aims to address this gap in knowledge and provide information on both the wastewater composition and on the ability of a full-scale mesophilic UASB to treat it over a period of 638 days. Analysis of the wastewater revealed that the manufacture of malt ingredients produces a high strength effluent, which fits within the realms of previously documented wastewaters despite not sharing a similar characterisation profile. Mesophilic UASB has been show to be an effective and robust technology option for the treatment of this type of wastewater displaying steady operational performance even when conditions were in excess of the design limit. Due to the robust operational performance of the plant the main factor limiting total methane production was shown to be the organic loading rate.

With a greater push to achieve waste management and renewable energy targets technologies such as anaerobic digestion (AD) have increased in popularity. One such technology option is the Upflow Anaerobic Sludge Blanket (UASB) reactor, these have been shown to be a particularly robust option for high strength organic wastewaters, such as those generated by the malted ingredient manufacturing industry. Despite their effectiveness they are reported to have lengthy and complex start ups due to the range of physiochemical and biological interactions influencing sludge blanket stability. This process can be sped up by seeding the plant from sludge from similar plants, however this is not always possible. This paper aims to investigate the start up of a full-scale mesophilic UASB treating malted ingredient wastewater that was initially seeded with a granular sludge treating dairy wastewater. Operational performance during the first 75 days of start up was comparable to that of a fully established plant with a COD removal efficiency in excess of 81.89% and a biogas methane concentration greater than 57.24%. During this period the plant remained operationally robust with the Organic Loading Rates (OLR) exuding the greatest influence on plant performance. Similar to operations during stable conditions key operational parameters such as HRT times, temperatures and pH did not exert a strong influence on the plant.