. Removal of nitrate by an algal system. Water; Nitrates; Water; Algae. mechanism was not entirely algal was provided in a study in which a sample of the soil, water, and organxsms was en- closed in a darkened bottle and floated jn tht pond. At the end of one week, the original 21 mg/l of total dissolved nitrogen had been reduced to 1^.5 mg/l ( JO3-N, 12 mg/l; NO2-N, 2 mg/l; and NH3+0rganic-N, mg/l). Because light was not available during the incubation period, the nitrogen reduction was assumed to be the result of anaerobic bacterial decomposition. The dissolved oxygen content of water in
. Removal of nitrate by an algal system. Water; Nitrates; Water; Algae. mechanism was not entirely algal was provided in a study in which a sample of the soil, water, and organxsms was en- closed in a darkened bottle and floated jn tht pond. At the end of one week, the original 21 mg/l of total dissolved nitrogen had been reduced to 1^.5 mg/l ( JO3-N, 12 mg/l; NO2-N, 2 mg/l; and NH3+0rganic-N, mg/l). Because light was not available during the incubation period, the nitrogen reduction was assumed to be the result of anaerobic bacterial decomposition. The dissolved oxygen content of water in the bottle decreased from about an initial 12 mg/l to a non- detectable amount at the end of the test period. The organic carbon source was presumably the product of algal and bac- terial decomposition, as well as extracellular organic products of algal metabolism. A comparison of nitrogen removal data from one of the soil ponds with a minlpond of comparable depth and de- tention is shown in Figure 36. The remaining soil pond followed essentially the same pattern as the one shown and was omitted for graphical clarity. Also included in the figure are the removal data for the best 12-inch depth non- soil pond in each minlpond run. These data support the fol- lowing conclusions: soil pond cultures consistently removed more nitrogen than did a mixed minlpond at a similar deten- tion time, and the removals in the soil ponds were often higher than in the best routinely operated minlE>ond,. /STANDARD MINIPQND WITH <~^HIGHEST NITROGEN ASSIMILATION il DEC JAN FEB MAR APR MAY JUN JUL AUG MONTHS FIGURE 36-COMPARlSON OF TOTAL NITROGEN ASSIMILATION IN ONE SOIL POND WITH A COMPARABLY OPERATED MINIPOND AND STANDARD MINIPOND WITH HIGHEST NITROGEN ASSIMILATION -65-. 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 Cali
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Keywords: ., bookcentury1900, booksubje, booksubjectalgae, booksubjectnitrates
