Modelling techniques for biological reaction systems: 1 Mathematical description and model representation

This paper is the first in a series of three which deals with modelling and numeric techniques for biological reaction systems. A matrix for­ ma rov1des a usef\11. method for model presentation. The matrix ensures clarity as to the compounds, processes, reaction terms and s01chio.metry compnsmg the model. It allows ready comparison of different models and facilitates incorporating the model in a computer slffiulauon program

Design and control of equalization tanks.

Includes bibliography.The objective of this investigation was to develop a control strategy for the operation of an equalization tank upstream of a waste water treatment plant which utilizes the available equalization hold-up volume in such a manner that it reduces, optimally, diurnal fluctuations in both influent flow and load rates. The influent to a wastewater treatment plant generally exhibits wide diurnal variations in both flow rate and concentration, and consequently in load rate (defined as the product of flow rate and concentration). Deviations of these parameters from steady state cause plant operating problems in areas such as aeration control (due to load rate fluctuations) settling tank overloading due to flow rate fluctuations) and/or over- or under-aeration which affects settling properties, and others