Abstract:
This study was intended to enhance efficiency of sludge settling in activated sludge with two types of ballasting agent, purified fine talc and powder activated carbon (PAC). The settling efficiency was demonstrated by initial settling velocity. This experiment was performed in 4 reactors of conventional activated sludge (CAS). In each reactor, concentrations of ballasting agent are varied, i.e. 0%, 20%, 50%, and 80% (W/W). The affect of several parameters such as COD, MLSS, MLVSS, pH, SV30, and SVI were studied. Moreover, the floc formation between sludge and ballasting agent were studied by microscope and electron microscope. In addition, the ISV from this experiment can be use as a new way to design sedimentation tanks. The results showed that both ballasting agent could improve settling efficiency, which indicated from high ISV, 17.7 m/h from the condition of 80% (W/W) talc concentration. However, talc was a better ballasting agent rather than PAC on overy conditions. Also, this study illustrated the floc formation between sludge and the ballasting agents from electron microscope that ballasting agent was covered and enameled by sludge. Furthermore from the study with microscope and other parameters, Talc and PAC shown no interfere with bacterial activities. As a result, the ISV from this experiment can be used design sedimentation tank with decreased surface area on the appropriate condition.