Calcium magnesium acetate, a non-corrosive road deicer is made with cells on rotating fibers. Salt causes millions of dollars damage to roads and bridges. Inexpensive raw material such as cheese whey and corn steep liquor can be used. When a rotary biological contactor is run half full and a light shone in the top, the light hits a thin moving film. In other photo reactors, colored solution blocks the light.
Light can degrade chlorine compounds and produce hydrogen, a non-polluting fuel.
Rapid increase of carbon dioxide threatens the very existence of mankind. Titania entrapped in the fiber increases the rate of the reaction. In a horizontal RBC, hydrogen has an easy exit, just like carbon dioxide has an easy exit when fermenting sugar to alcohol. The corrugations entrap air which is necessary for growth of the fungi when buried in soil.