Decomposition of Algae Sludge by Thermophilic Oxic Process

A laboratory scale study was undertaken to investigate the potential of decomposition of algae sludge by a thermophilic oxic process (TOP) . The characteristics of the thermophilic oxic process are that, a minute amount of excess sludge is formed, and organic materials are efficiently degraded, as well as all water is evaporated by the heat generated by bio-degradation.Feasibility of this study was assessed by determining the decomposition efficiency of added organic material, transference of organic carbon to CO2 and decrease efficiency of chlorophyll-a in media. By using cedar chips as media and waste food oil as an additional energy source, algae sludge could be decomposed by the thermophilic oxic process with the following conditions: total solid (TS) load of 1.5 kg⋅m-3⋅d-1, hydraulic volumetric load of 35l·m-3·d-1, waste food oil addition rate of 15% as added algae sludge and aeration rate of 200l⋅m-3⋅min-1.From above manipulation, more than 98% of chlorophyll-a in added algae sludge was decreased, more than 80% of total organic carbon was transferred into CO2, and due to it, low excess sludge production rate of 0.15 kg/kg-BOD treated has been certified in this process.