Aquatic weeds and their utilization 359rate of bacteria and plants. Temperature has a similar effect on the reproductive
rates of these organisms.
Figure 7.17 Ammonium nitrogen removal (Nr) as a function of reactor distance for three
hydraulic application rates (after Weber and Tchobanglous 1986; reproduced by the
permission of the Water Pollution Control Federation, USA)
Summer high temperatures may upset treatment by causing damage to some
plant species and/or by increasing bacterial metabolic activity, resulting in
altered balances between BOD 5 reduction rates and oxygen flux from the
atmosphere. Another potential problem is that the water may become
sufficiently warm to result in violations of discharge permit requirements on
water temperature or other factors affected by water temperature such as un-
ionized ammonia concentration.
Winter low temperatures will reduce the metabolic rate of bacteria and may
kill many plant species. A plant kill may, but not necessarily, result in loss of
bacterial structure and/or leakage of plant-contained compounds. Research in
this area is necessary. As water temperatures approaching 0°C metabolic
activity virtually ceases, thus, wastewater treatment would result only from
physical/chemical mechanisms. This reduced level of treatment may be
inadequate in some situations. In these cases aquatic treatment would have to be
considered a seasonal treatment process. Wastewater storage or some other form
Reactor distance (l), mAmmonium nitrogen removal (N), mg/L rHydraulic application rate
9.91 m^3 / (m^2 -day)
14.8 m^3 / (m^2 -day)
19.9 m^3 / (m^2 -day)