FOG Waste receiving and processing facility design considerations

摘要

Fats, Oils, and Grease (FOG) wastes and high-strength wastes (HSW) are frequently received at municipal waterrnresource recovery facilities (WRRFs) as trucked-in wastes. These wastes offer significant benefits in terms of revenuernfrom tipping fees and feedstock for co-digestion in anaerobic digesters that produce biogas, which can bernbeneficially used as fuel. The number of treatment plants receiving and beneficially using trucked-in wastes currentlyrnin operation or under investigation is increasing rapidly across the North America as utilities strive tornremove this material from normal wastewater to avoid sewer system clogging, maintenance and backups,rnavoid the oxygen demand of these wastes in secondary treatment systems, and to capture and beneficiallyrnreuse the energy that is contained within the material.rnHistorically, trucked-in wastes have been discharged to the head end of treatment plants or to an upstreamrnmanhole in the incoming interceptor sewer to enable the material to be mixed with raw wastewater prior to treatmentrnthrough the liquid stream of the WRRF. However, this approach results in loss of material and degradation ofrnthe energy value of the FOG wastes and HSW and also creates collection and maintenance issues in the preliminaryrnand primary treatment systems. To prevent degradation of the material and retain maximum energy for thernCHP system, receiving stations are being constructed for direct off-loading of the wastes to processing and storagernfacilities prior to their transfer to anaerobic digesters at a relatively uniform rate to minimize the potential forrndigester upsets while at the same time to increase biogas production. This paper presents the key componentsrnand considerations in the design and operation of modern FOG waste receiving and processing facilities.