Contact-Adsorption-Regeneration-Stabilization Process for the Treatment of Municipal Wastewater

Abstract

In this work, the application of the contact-adsorption-regeneration-stabilization activated sludge process for the municipal wastewater treatment was investigated by using continuous experiments coupled with adsorption batch experiments. The process optimization for performance evaluation was studied. The obtained appropriate operational parameters of recycle ratio, hydraulic retention time (HRT) of the regeneration tank, HRT of the adsorption tank and solids retention time (SRT) of the system were 40%, 2 h, 30 min, and 6 d, respectively. Adsorptive kinetics and equilibrium were investigated with batch experiments of adsorption. The results showed that the activated sludge concentration was in a positive proportion to its adsorptive capability, but that temperature was in an inverse proportion to the adsorptive capability. Adsorptive equilibrium was reached within 15 min. In addition, the equilibrium data fitted well to both the Freundlich and Langmuir adsorption models.

Approaches to energy and resource recovery from municipal wastewater

“…By contrast, in the contact stabilization process (Figure 2.2a), wastewater is mixed with activated sludge in the contact tank operated at a short HRT of 15-60 min under limited DO concentration (Liu et al, 2009), where COD is mainly removed by biological adsorption and storage under the dynamic conditions in the contact tank. After clarification, the concentrated sludge is returned to an aerated stabilizer where adsorbed COD is biologically oxidized.…”

Assessment and optimization of environmental systems using data analysis and simulation.

“…In this study, the mixed liquor dissolved oxygen (DO) and the percentage of return sludge (RS) from the settling tank to the stabilization tank, were selected as key operational parameters affecting the total sludge production and overall removal efficiency of the system. The dissolved oxygen in the contact tank affects the physical, chemical and biological potential synergic functions of microorganisms in the mixed liquor to adsorb pollutants (Liu et al 2009). The return sludge parameter impacts the growth rate of organisms from the stabilization tank to maintain a specific level of food to microorganism ratio in the contact tank (Greene and DeLorenzo 2005).…”