Salinity gradient solar ponds - Solar Energy Sciences and Engineering Applications - page 204

Figure 7.3.2 Diffuser used to setup gradient.
Figure 7.3.3 Passive salt replenishment and surface washing.
salinity profile of the pond becoming unstable (Tabor, 1980). To maintain the stability
of the pond one should monitor and limit the stability margin number within the
predetermined safety limit. The use of a scanning injection diffuser system allows local
instabilities in the gradient layer to be eliminated.
7.3.2 Turbidity control
Turbidity is a measure of the clarity of water or in other words the degree of trans-
parency; its unit of measurement is nephelometric turbidity units (NTU). Desired values
of turbidity are less than 0.5 NTUs.
Dust, live or dead organic material and any other suspended material reduces the
clarity of the water and hence reduces the thermal efficiency of a solar pond. Heavy
dust particles would sink to the bottom of the pond and will not affect the pond
clarity, while the dead organic material like leaves, pollen etc. if not removed on time
can reduce the thermal performance of the pond and also help the growth of algae in
the pond. All dead organic material acts as food material for the growth of algae. So