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8752112 
Journal Article 
Principles of activated sludge treatment 
Ramalho, RS 
1978 
No 
Hydrocarbon Processing
ISSN: 0887-0284
EISSN: 0018-8190 
57 
10 Sect 1 
112-118 
English 
A rational design concept for activated sludge plants has been developed based on fundamentals of operation, laboratory tests and engineering parameters. These are combined in a concise approach for integrating the activated sludge plant into the overall treatment scheme. The activated sludge process has been developed as a continuous operation by recycling biological sludge. Important process variables are indicated and defined. Composition of the different streams are characterized by three types of concentration. Soluble BOD comprises mainly carbonaceous materials in solution. It is a measure of required oxygen for aerobic biochemical reaction of biodegradable organic matter in the wastewater. Volatile suspended solids (VSS) correspond to biological sludge, constituted by heterogeneous population of microorganisms. Nonvolatile suspended solids (NVSS). Concentrations of soluble BOD and suspended solids for the different streams in the process flow are discussed. The author portrays these processes by mathematical model and determines parameters utilized in mathematical equations from experimental data obtained utilizing a series of bench scale laboratory reactors. Relationships pertinent to development of a model fall into three groups: kinetics; material balances; and optimum sludge settling conditions. Each of these aspects is discussed. A well designed activated sludge plant is needed in most HPI plants to reduce contaminants in wastewater to required levels. Stringent regulation of BOD and COD in wastewater effluent places a great emphasis on the treatment plant performance and demands good activated sludge plant design and operation. Thus, a clear understanding of activated sludge plants is essential. A rational design concept for activated sludge plants has been developed based on fundamentals of operation, laboratory tests and engineering parameters. These are combined in a concise approach for integrating the activated sludge plant into the overall treatment scheme. Design details of the plant together with necessary calculations are given.