An empirical model for primary sedimentation of sewage

Model of Suspended Solids Removal in the Primary Sedimentation Tanks for the Treatment of Urban Wastewater

“…Physical settling operations are widely used in the treatment of wastewater. Primary settling tanks have been extensively used for the removal of suspended solids (SS) by gravitational settling that are not removed by preliminary treatment [1], and are also used as an integral part of the biological wastewater and sludge treatment process [2]. The removal of SS also results in a significant decrease of organic load, usually expressed in terms of biochemical oxygen demand (BOD) or chemical oxygen demand (COD).…”

“…In order to optimize the design and assessment of PSTs, it is necessary to determine their pollutant removal efficiency as a function of the geometric and operating characteristics of the settling tank and the solids concentration of the fed suspension. Some surveys [1,3,6,18,[32][33][34][35] showed the effects of SS concentration in raw wastewater, temperature, and some operating characteristics, such as HRT or q, on the performance of PSTs. These studies provided simplified the empirical mathematical models to describe the average removal of wastewater pollutants that are helpful in the design of sedimentation tanks or to predict the behavior of sedimentation tanks under certain operating conditions.…”

Optimization of A2O BNR Processes Using ASM and EAWAG Bio‐P Models: Model Performance

“…Temperature of the infiuent has often been reported to have significant effects on both sedimentation (Christoulas et al, 1998) and biological treatment (e.g., Choi et al, 1998;Carrera et al, 2003;Metcalf & Eddy, 1991). Values of the temperature-affected kinetic parameters in the model were derived using Henze et al (2000):…”

“…For the primary clarifier, the empirical model of Christoulas et al (1998) was selected to relate effluent total suspended solids (TSS) to influent TSS whereas the underflow solids concentration is calculated according to the solids flux theory from Cho et al (1996). A reduced version of ASM3 was adopted with four simplifying assumptions: (1) sufficient dissolved oxygen is available in the aerobic compartment (> 2.0 mg/L), (2) pure anoxic conditions, i.e., dissolved oxygen is zero, (3) nitrogen gas is neglected and the denitrification process is traced through nitrate and nitrite nitrogen (SNOX).…”

Analyzing the design criteria of primary settlers for small sewage treatment systems: A national survey in Taiwan

“…All the values in the parenthesis were typical values from literature [13,[15][16]. Three r s values (30%, 40%, and 50%) were used to estimate V s and the corresponding HDT.…”