They don't talk about pollution, some pollution will drop off while coagulating microplastics can be much higher. The whole ocean is basically a fractionating column. Of course they are going to want to dump the salt in the bottom to complete the mass transfer loop of the upwelling water. This is going to mess up the whole thing.
Humans should be operating in closed water systems. We would have to do that anywhere else we go, we should be turning Earth into well run spaceship.
Filter it out already, problem solved. Look for solutions, not for problems. If microplastics do indeed concentrate in the depths this would offer a chance to take them out of the environment, the same goes for other pollutants.
> Here, inspired by a natural phenomenon, thermohaline convection, we demonstrate a solar-powered multistage membrane distillation with extreme salt-resisting performance. Using a confined saline layer as an evaporator, we initiate strong thermohaline convection to mitigate salt accumulation and enhance heat transfer.
The thermal difference between the deep sea water and surface water (or waste heat heated water, or solar heated water) can be used to generate electricity.
At 40-44% efficient given at least 1,435°C, Solid state thermoelectrics are more efficient than steam turbines at converting a thermal gradient to electricity.
Humans should be operating in closed water systems. We would have to do that anywhere else we go, we should be turning Earth into well run spaceship.