| abstract |
A method for controlling and/or optimising a process in which an aqueous system comprising biodegradable material, one or more biogenic fluorophores and optionally other soluble and/or insoluble and/or suspended substances is subjected to one or several separation processes and/or to chemical reactions and to biological treatment using mixed cultures of microorganisms so as to obtain as a final product purified water which has a substantially lower content of biodegradable matter than said aqueous system, which method comprises monitoring the microbiological activity of said biological system and/or fluctuations thereof by on-line measurement of fluorescent emission and/or variations therein for at least one characteristic biogenic fluorophore, e.g. NADH or NAD(P)H2, present in the mixed culture of microorganisms in the system when irradiated with light, and controlling one or several parameters of said process by using results from said measurement as measured variable(s) in an on-line automation system. By using the method, large fluctuations in the content of biodegradable material present in inlet waste water to the biological treatment step(s) of a waste water or sewage purification plant can be minimized, and accordingly, the overall performance of the purification plant can be improved. |