. Removal of nitrate by an algal system. Water; Nitrates; Water; Algae. and then, as the nitrate decreased, nitrite followed the same trend. This pattern is illustrated in Figure 44, which shows a minipond with a high percentage of total nitrogen removal. The ponds with low effluent nitrate usually also had a low nitrite concentration. On several occasions, effluent nitrate-nitrogen concentrations were determined at two- or three-hour inter- vals for a 36-hour period. The variations in concentration were beyond the limits of the accuracy of the analysis; thus, a diurnal change in the concentra
. Removal of nitrate by an algal system. Water; Nitrates; Water; Algae. and then, as the nitrate decreased, nitrite followed the same trend. This pattern is illustrated in Figure 44, which shows a minipond with a high percentage of total nitrogen removal. The ponds with low effluent nitrate usually also had a low nitrite concentration. On several occasions, effluent nitrate-nitrogen concentrations were determined at two- or three-hour inter- vals for a 36-hour period. The variations in concentration were beyond the limits of the accuracy of the analysis; thus, a diurnal change in the concentration of this constituent could not be demonstrated. Dissolved Oxygen, This parameter was not routinely monitored, although determination of dissolved oxygen con- centration was a part of most diurnal studies. An example of the diurnal fluctuations in dissolved oxygen in four mini- ponds (data from September 10-11, I968) are shown in Figure 45. Ponds 1, 4, and 22 each showed approximately 75 percent total nitrogen assimilation, whereas pond 10 showed only about 40 percent. The greatest fluctuation was noted in pond 22, an unmixed soil pond. Undoubtedly this change occurred because the afternoon mixing tended to deoxygenate the pond water in the remaining ponds. The 5 mg/l minima noted in ponds 1, 4, and 22 were near the minimum concentra- tions recorded in any of the overnight studies. It is Interesting to note that the deoxygenation factor for the ponds is on the order of 1,25 mg/l/hr, whereas the oxygenation factor is a net of 2,5 mg/l/hr, or a gross of. DAYS OF RUN FIGURE 44-CHANGE IN NITROGEN FORMS DURING MINIPOND RUN -75-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original California. Dept. of Water Resources; Brown, Randall L. Sacramento]; For sale by the Supt. of Docs. , U. S. Govt. Print. Off. , Washingt
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Keywords: ., bookcentury1900, booksubje, booksubjectalgae, booksubjectnitrates
