초록 ▼

A method and apparatus for determining the oxygen uptake rate of bacteria in a body of liquid incorporates withdrawing a sample of the liquid into a chamber where a dissolved oxygen probe is located, the probe outputting a signal which is a function of the amount of dissolved oxygen in the sample. T

A method and apparatus for determining the oxygen uptake rate of bacteria in a body of liquid incorporates withdrawing a sample of the liquid into a chamber where a dissolved oxygen probe is located, the probe outputting a signal which is a function of the amount of dissolved oxygen in the sample. The sample is aerated, and a computer is used to sample the signal at regular intervals to produce a series of time-separated values corresponding to the sampled signals, the values representing the dissolved oxygen in the sample at the timed intervals. Repeated samples can be taken, so that the O.U.R. can be monitored on a continuing basis. The O.U.R. information can be used to control the rate of aeration in a tank, or to control the rate of recycling of activated sludge from the downstream to the upstream end of the tank.

대표청구항 ▼

A method of controlling the aeration rate of an activated sludge wastewater treatment tank, comprising the steps: (a) withdrawing a sample of mixed liquor and suspended solids from the tank into a chamber in which is located a dissolved oxygen probe that outputs a signal which is a function of the a

A method of controlling the aeration rate of an activated sludge wastewater treatment tank, comprising the steps: (a) withdrawing a sample of mixed liquor and suspended solids from the tank into a chamber in which is located a dissolved oxygen probe that outputs a signal which is a function of the amount of dissolved oxygen in the liquid adjacent the probe, (b) aerating the sample, then arresting the aeration, (c) using a computer to sample the signal at regular intervals after aeration has ceased, and to produe a set of time-separated values corresponding to the sampled signals, which values represent the dissolved oxygen in the sample of liquid at timed intervals, (d) emptying the chamber of its contents, (e) repeating the steps (a) to (d) a plurality of times to generate a plurality of sets of said values, (f) using computer means to calculate, for each set of said values, the rate at which the oxygen content of the sample decreases with time, and (g) whenever, for any set, the rate of decrease of the oxygen content is below a predetermined value, decreasing the said aeration rate.