On the 48th page of the UN Desk Study of the Environment in the Occupied Palestinian Territories there is a discussion of a lake of sewage and its damage to the environment resulting from overflow from a sewage treatment plant. See link to un.
The lake is visible from space, worldwind://goto/world=Earth&
lat=31.55793&lon=34.51555&alt=2793 because it covers an area of 40 hectares. See link to world wind.
The report indicates the plant is processing some 12000 cubic meters of waste water a day. Which is well above its design limits.
The UN wants any ideas on how to deal with the sewage. I was thinking that as Gaza is essentially a desert area, it shouldnt be difficult to turn the lake into a thermal pond. If the waste water can be brought to a sufficiently high temperature then it should pasteurize the sewage.
If it were possible to retain around 500 watts per square meter for 8 hours a day over 40 hectares one would collect a lot of energy to heat the sewage. A simple analysis indicates enough energy to heat the 12000 cubic meters to a delta t of 114 degrees. Since the delta T is greater than 100 the influx of water should be brought to near boiling. Even with only 30 percent of the solar influx retained the water should be pasteurized. The extra heat should help to heat the existing water and the ground it is infiltrating. With sufficient time the whole lake and area around it should be sterilized.
My half baked idea is to cover the lake with an inflatable cover. Imagine the inflatable pool floats one can buy that are several parallel tubes. Make the tubes about twenty meters long and make the float about ten meters wide. Imbed a net of strong fiber into the plastic and sew that fiber into a woven tape to border the float. Grommets would be attached to the tape so that the floats can be tied together and spaced such that a second layer of floats at right angles to the first can be easily tied to the first. The contact between the floats should be minimal and the heat flow too small to support Hegg style convection currents within the tubes. Hopefully, the float would reflect only a minimal amount of light and allow only minimal amounts of heat to pass.
The heated water could be drawn off at the end of the day and pumped into another pond to allow for evaporative and other cooling at night. With two cooling ponds one could even use the hot and cool water to generate a little power. The cooled water could then be pumped into an artificially created wetland for bioremediation. (But thats another half baked invention.)