Bacteria are important in sewage disposal becuase they

Bc it eats the waste that is inside of the sewer pipes

Here is my answer below : 

The bacteria is very important because when bacteria is on a substance it begins to eat the product of deposition , so my answer again is is is important because it eats the sewage disposal.   

I hope this helps

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass