KID’S PAGE

By Trish Penny

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There’s Magic in Manure

 

Have you ever seen cow patties the size of Frisbees, or the little droppings from chickens? Over time, this waste adds up.  In fact, if you could pile up all the livestock manure that is produced in the United States in a year, it would weigh about 350 BILLION pounds! 

 

What do we do with all of this poo?

 

Farmers can use manure to fertilize their fields.  Animal droppings might not look or smell pretty, but they contain important nutrients that plants need to grow.  Unfortunately, there are not enough fields for all the waste that is produced by animals.  In fact, if too much manure is plowed into the soil, it can slide from hillsides and trickle into streams.  This pollution can harm animals and people who depend on fresh, clean water.

 

Dr. Lima and Dr. Marshall from the USDA Agricultural Research Service decided to create something useful from manure.  They have a special oven that they put the chicken manure droppings in that can reach over 1,300 degrees Fahrenheit.  That is about three times hotter than your oven at home!  By adding all that heat, the waste becomes a big, dry sponge full of tiny holes or pores.  Dr. Lima discovered that their sponge-like material was especially great at mopping up “heavy metals” that can pollute water.  Heavy metals can include substances like lead, mercury, and arsenic.  Most of these heavy metals occur naturally in the world around us.  However, when large amounts of these metals or chemicals leak into water supplies, or into the soil, they can become harmful to people and wildlife.

 

There are not many materials that can filter out the tiny, dissolved molecules from these hard-to-grab metals.  That is why there was so much excitement when they discovered that super heated chicken droppings made such a great mop.  Scientists take the pellets of poultry manure and turn them into activated carbon pellets.  Then the carbon pellets are ground up into different sizes, depending on what the scientists want to filter out of the water.

 

The carbon pellets have a negative electrical charge, which enable it to cling to tiny molecules of positively charged metals.  The burned waste material owes its negative charge to phosphorus.  Phosphorus gets into the chicken droppings because the animal eats a special diet that contains this important nutrient.  Chickens do not digest all of the phosphorus in their meals, so some of it comes out in their waste.

 

When the negatively charged sponge material gets near metal molecules with a positive charge, the two are strongly attracted to each other.  Think of how two

 

continued on next page . . .