Cleaning waste water with algae: Strange brew

Bloomin' algae... ALGAL blooms happen when waste water from farms, factories and dwellings carries large amounts of normally scarce nutrients like nitrogen, potassium and phosphorous into rivers, lakes and seas. Algae, often unicellular ones, lap these nutrients up and breed like billy-o. These blooms are occasionally dangerous, if the algae involved are toxic, and are generally regarded as undesirable. But what if it were possible to control an algal bloom, and use it to absorb such nutrients b...