Performance Evaluation of Compact RBC-Settling Tank System

Abstract

A laboratory study was conducted to investigate the performance of RBC-Settling tank system on wastewater treatment in comparison with conventional RBC. The same synthetic wastewater was fed parallel into four stage laboratory scale cascade-connected RBC-Settling tank and conventional RBC reactors at a fixed rotational speed and hydraulic loading. At three different organic loading rates of 6.14, 13.44 and 23.31 g SCOD/m2/day, the results of the systems are presented in terms of ammonia nitrogen (NH3-N), total kjeldahl nitrogen (TKN), organic and suspended solids (SS) loading and removal. Disk Biomass Index (DBI), Sludge Biomass Index (SBI) and Fractional Biomass Volatile Solids Destruction (FBVSD) were used to compare the disk active biomass and sludge stability of the RBC-Settling tank system with those of the conventional RBC. Removal efficiency of suspended solids, ammonia nitrogen and total Kjeldahl nitrogen was found to be much higher in the RBC-Settling tank system than the conventional RBC but organic removal in terms of SCOD removed g/m2/day of both reactors was not much different. Much better sludge stabilization was observed in the RBC-Settling tank system. The RBC-Settling tank system showed good performance on the suspended solids, NH3-N and TKN removal, and sludge stabilization as well as organic removal, which indicates that this is an effective and economical system for treating domestic wastewater in small and isolated communities.