Respirometry as a tool for rapid characterization of wastewater and activated sludge

Abstract

A procedure is presented to estimate biokinetic parameters for heterotrophic and autotrophic process models and to estimate wastewater characteristics in the context of the Activated Sludge Models No. 1 and No. 2. The procedure is based on respirometric measurements at low substrate to biomass ratio (S/X). The addition of nitrification inhibitor is avoided by applying a calibrated nitrification model to the respiration rate data resulting from both heterotrophic and autotrophic degradation. Furthermore, a new procedure is developed for simultaneous assessment of decay coefficients for heterotrophic and autotrophic biomass. The results show that, for a given wastewater/sludge combination S/X can be crucial in obtaining reliable parameter estimates: at a very low ratio not all parameters could be identified. A higher ratio caused problems because of nitrification inhibition.

Chemical oxygen demand fractions of municipal wastewater for modeling of wastewater treatment

“…Several methods have been developed for wastewater characterization, but the two most (Spanjers et al, 1995). This method needs experienced and skilled laboratory staff, specific experimental appliances and usually model-based interpretation.…”

Impact of optical indices on particle size distribution of activated sludge measured by laser diffraction method

“…Others investigate the relationship between the presence of protozoa in sludge and the structure and morphology of flocs on the course of the wastewater treatment process [9][10][11]. An important and currently commonly discussed tasks in wastewater treatment technology are the ways of description of physiological activity of activated [12,13] and fractioning of the substrate to build and calibrate computer models of sewage treatment systems [14][15][16][17][18]. An important aspect of investigation is also application of raw and treated sewage in agriculture [19][20][21].…”

Demanda bioquímica de oxígeno de efluentes con productos xenobióticos

“…En las condiciones de medida de la DBO con xenobióticos se puede necesitar hasta dos meses para llegar a anularse la absorción de oxígeno. Para la determinación de la Demanda Bioquímica de Oxigeno, la reacción A se lleva a cabo en una botella especial, de modo que se permita la medida del oxígeno consumido, ya por la medida de la disminución de presión, métodos manométricos (Jenkins, 1960) cuyos esquemas de medida se muestran en la Figura 2, ya por la medida de corriente electrolítica generadora del oxígeno utilizado por los microorganismos, métodos electrolíticos (Young, 1972y Sang, 1995 o por medida directa del oxígeno disuelto en la muestra con un electrodo de oxígeno (Spanjers, 1995 (Ellis, 1996) por ajuste de los datos experimentales. Como no existe una interpretación cuantitativa de la DBO con la materia orgánica, algunos laboratorios propusieron una disolución sintética como estándar de medida (Rehm, 1986) cuya composición por litro se presenta en la Tabla 2.…”