Operation of a new sewage treatment process with technologies of excess sludge reduction and phosphorus recovery.
This paper shows the potential application of a new sewage treatment process with technologies of excess sludge reduction and phosphorus recovery. The process incorporated ozonation for excess sludge reduction and crystallisation process for phosphorus recovery to a conventional anaerobic/oxic (A/O) phosphorus removal process. A lab-scale continuous operation experiment was conducted with the ratio of sludge flow rate to ozonation tank of 1.1% of sewage inflow under 30 to 40 mgO3/gSS of ozone consumption and with sludge wasting ratio of 0.34% (one-fifth of a conventional A/O process). Throughout the operational experiment, a 60% reduction of excess sludge production was achieved in the new process. A biomass concentration of 2300 mg/L was maintained, and the accumulation of inactive biomass was not observed. The new process was estimated to give a phosphorus recovery degree of more than 70% as an advantage of excess sludge reduction. The slight increase in effluent COD was observed, but the process performance was maintained at a satisfactory level. These facts demonstrate an effectiveness of the new process for excess sludge reduction as well as for phosphorus recovery.
Saktaywin
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Department of Urban and Environmental Engineering, Graduate School of Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan. hs-tsuno@water.media.kyoto-u.ac.jp
Tsuno
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H
Nagare
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H
Soyama
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T
D000332:Aerobiosis; D000693:Anaerobiosis; D018533:Biomass; D010126:Ozone / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis*; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods
D012722:Sewage; D010758:Phosphorus; D010126:Ozone