In the "diluted" water there were approximately half as many organisms as in the "concentrated" water, while the dissolved oxygen was also approximately half.
DiscussionIn dealing with the pollution of a stream the role of reaeration by green organisms must be properly evaluated. If the pollution is not excessive so that the production of oxygen is overbalanced by the consumption, a marked increase in dissolved oxygen will result. With a more heavily polluted stream the dissolved oxygen might show from day to day, when samples are taken in the afternoon, complete saturation leading to erroneous conclusions because the temporary condition in the afternoon is by no means the daily average condition. Moreover, these erroneous results are usually obtained in the spring and especially in Vol. 23,No. 1 were undertaken to lay the foundation for the design of such a furnace.