Abstract |
In a plant scale study at Lebanon, Ohio, the improvement of the treatment and phosphorus removal were undertaken. On the basis on an economic analysis, it was proposed to treat the raw sludge by lime addition to a pH 11.5 This raw sludge was produced by clarification of raw wastewater that has been coagulated with either aluminum sulfate or ferric chloride. The limed sludge was then drained on sand drying beds, and the cake either given to local farmers or placed in a sanitary landfill. This process replaces the need for biological digestion. Two factors, that of a voluminous and dilute sludge, complicates the handling requirements. Cost savings are discussed. |