Treatment of marine sewage pumpout and RV park pumpout wastewater containing high strength concentrations of formaldehyde

'Full text:' A consortium of companies has developed an integrated 'on-site' wastewater treatment technology that is capable of handling and degrading RV Park and Marine Sewage Pumpout Wastes which contain formaldehyde [35 - 80 mg/L]. Boat and RV owners add formaldehyde to their toilets to eliminate odors. When these materials are pumped out they are high in solids content and have high concentrations of HCHO, which makes them difficult to degrade at POTWs. At the heart of this process is 1. An aeration tank with a Venturi Aerator totally external to the tank and 2. The addition of a blend of cultured bacteria that have selected for their ability to degrade formaldehyde. For a complete 'on-site' treatment system Bioclere Trickling Filters can follow this aeration/bacterial treatment system. This is an ideal system configuration for remote locations (RV Parks) or for fresh water lake Marinas looking to reduce their disposal costs and for groundwater discharge with no adverse effect on water quality. Until the development of the formaldehyde degrading bacteria for an industrial wastewater process there were no cultures commercially available specifically for degrading formaldehyde. The most commonly used bacteria were pseudomonas strains for carbohydrate or hydrocarbon wastewater extracted from activated sludge plants. And since formaldehyde is infinitely soluble in a liquid it is difficult to degrade or mineralize. The process in an activated sludge WWTP plant took over 72 hours. With the newly selected consortia of cultures, HCHO can be degraded in 12-14 hours on a batch basis. This is accomplished in a uniquely configured aeration tank where the 'environment' of the tank is constantly conditioned by a Venturi Aerator which strips carbon dioxide generated by the aerobes to maintain a neutral pH, and provide high levels of DO (>5.0 mg/L) to keep the process aerobic. (author)