第三章单元测试
The idealized biofilm having the following properties except ( ).
The following description of the fundamental “law” of the steady-state biofilm is correct. ( )
- The model of a steady-state biofilm requires simultaneous solution of ( ).
The following figures shows that ( ).
- The result of mass-transport resistance is that the substrate concentrations at any position in the biofilm usually are lower than in the bulk liquid. ( )
Two biofilms having the same physical thickness, should have similar
values. ( )The fundamental understanding of a steady-state biofilm is that the biomass per unit surface area (XfLf) is constant in time, and the biomass at any one location is at steady state.
S*min represents the growth potential in the steady-state-biofilm model, and S*min much less than 1.0 indicates the net positive growth is much greater than the loss. ( )
- K* compares external mass transport to the maximum utilization rate. K* less than 1 means that the substrate utilization is controlled by external mass transport. ( )
- For deep biofilm, it has the maximum flux into the biofilm. ( )
A:Mass-transport resistance is not important to the biofilm.
B:
An effective diffusion layer of thickness L represents external mass-transport resistance.
C:Has a locally uniform thickness of Lf.D:The biofilm has a uniform biomass density.
答案:Mass-transport resistance is not important to the biofilm.
A:The growth of new biomass per unit area per hour (YJ T) is just balanced by the losses. B:
The growth of new biomass (YJ ) is just balanced by the losses per unit area b’XfLf.
C:The growth of new biomass per unit area per hour (YJ T) is just balanced by the losses per unit area b’XfLf. D:The growth of new biomass per unit area (YJ ) is just balanced by the losses per unit area b’XfLf.A:mass-balance for active biomass in the biofilm
B:mass-balance for substrate in the biofilm.
C:mass-balance for substrate transport to the biofilm.
D:boundary and continuity conditions.
A:
J and XfLf increases very sharply as S increases slightly above Smin.
B:At some value of S>Smin, the slope of J versus S declines from near infinity and approaches 1.0. C:For very large S, the slope of J versus S declines gradually and eventually approaches the limiting case of one-half-order kinetics, or J=k1/2S1/2 . D:For S large enough, J (and XfLf) increases for larger S, because the substrate concentrations inside the biofilm rise in response to a higher S.
A:错 B:对
A:错 B:对
A:错 B:对
A:对 B:错
A:对 B:错
A:错 B:对
