United Utilities Plc

Son Le

Duc Do

A method of treating bio waste including the steps of (1) fermenting substantially raw biowaste in a pathogen reduction stage under anaerobic conditions for a predetermined period at a temperature in the mesophillic temperature range and (2) subsequently separating the solid and liquid phases to produce a fermented cake and fermented liquor. The fermented cake has at least 15% solids on dry basis and contains over 500 mg/L ammonia, over 1,000 mg/L total Volatile Fatty Acids (tVFA) andless than 100,000 cfu per g dry solids. The fermented liquor contains over 10,000 mg/L COD, over 500 mg/L ammonia, over 1,000 mg/L tVFA and less than 5,000 mg/L of suspended solids.

Biowaste treatment

A method of treating putrescible cakes to reduce theand odor present in the cake and prevent further odor generation comprising the step of maintaining the cake under substantially anoxic condition in the presence of ammonium and/or nitrate moieties at pH 7.5 to pH 10.5 for a period of more than 1 day, the cake having a solids content of between 20% to 75% by weight.

Treatment of putrescrible cakes

A method of treating sewage sludge comprises a pathogen reduction stage in which raw sludge is incubated for a predetermined incubation period at a temperature in the mesophilic temperature range. The sludge is incubated in a plurality of sequential vessels () comprising an upstream vessel () which receives the raw sludge to be incubated and a downstream vessel () which discharges the incubated sludge. The sludge is fed from the upstream vessel () to the downstream vessel (), via any intermediate vessels (), and subsequently discharged after spending a predetermined residence time in each vessel, the total residence time being said predetermined incubation period.

Growing community of inventors

Warrington, United Kingdom

Son Le