GPS-X Technical Reference

Suspended Growth Models 134
Hydrolysis
The hydrolysis of particulate COD to soluble material suitable for growth is a critical step
in the COD cycle. The general model modelled hydrolysis as an aerobic process only,
but newgeneral includes hydrolysis under anoxic and anaerobic conditions and uses
these processes as a sink for COD 'loss.
Fermentation
Whereas the fermentation of SS to SLF was a non-growth related process in the general
model, in newgeneral, this process is associated with the growth of heterotrophic
organisms and hence, a portion of the fermented COD winds up as new biomass;
however, equally important is the stoichiometry of this process because, like hydrolysis,
this process includes a COD 'loss' component.
The Model Matrix for the newgeneral model is found in Appendix A.
COMPREHENSIVE MODEL (MANTIS2)
Introduction
A new comprehensive model incorporating the most commonly observed biological,
physical, and chemical processes in wastewater treatment plants was developed and
implemented in GPS-X. MANTIS2 is the outcome of Hydromantis’ commitment to
provide state of the art models to its clients through research and development. The
MANTIS2 model incorporates a large amount of information which has become
available in technical literature in the last decade. The motivation behind the
development of a comprehensive model arises from the fact that after the publications of
ASM2d and ADM1, there has been growing interest in extending the capabilities of
models to incorporate the side stream treatment processes like struvite precipitation,
nitrification-anammox for nitrogen removal, and other precipitation processes. Although
state variable interfaces between ASM2d and ADM1 are well defined, the state variable
mapping between two models present practical challenges in model implementation and
limits the versatility in modelling.
MANTIS2 Model Components
The key features of the MANTIS2 model are:
Carbon, Nitrogen, and Phosphorus removal with integrated anaerobic digestion
processes.
Mass balance for COD, C, N, P, Ca, Mg, K, and charge
GPS-X Technical Reference