The Kinetic Model of the Uptake and Release of Pollutants by Tubificidae in Sludge Reduction System

Abstract

Tubificidae is often used in the wastewater treatment systems to minimize the sludge production. A two-compartment kinetic model was applied to simulate the uptake and release of C, N and P-bearing pollutants by Tubificidae in a sludge reduction system. The nonlinear fitting method was used to calculate the uptake rate constantK1and the release rate constantK2for TOC, TN and TP, which were 4.983, 25.764, 10.154 and 3.671, 23.683, 9.023, respectively. The model fitted quite well with the collected data, suggesting that the model was applicable. The results showed that Tubificidae activity would increase the C, N and P concentrations in the system, and the specific release rates of C, N and P-bearing pollutants were 4.31 mg COD/gL. hoffmeisteri· d, 0.722 mg TN/gL. hoffmeisteri· d, and 0.14 mg TP/gL. hoffmeisteri· d,respectively. Ammonia nitrogen contributed up to 70.42% of the released nitrogen.