How are the terms Non biodegradable, Landfill, Runoff and Incinerator related to the disposal of chemical wastes?

The four terms you have given are related to chemical
wastes in the following way:

Chemical wastes are generally
non biodegradable. They either cannot be converted by organisms in nature into
substances that are not harmful or the process takes a very long time during which the
chemical wastes pose a lot of danger to all organisms that come in contact with
them.

Landfills cannot be used to dispose chemical wastes.
Doing so would lead to toxins entering the environment as harmful gases or into the
underground water table. To dispose chemical wastes special storage facilities are
required or landfills have to be altered to prevent the waste from spilling into the air
or water.

Chemical waste left in the open can easily runoff
and mix with the water supply when rain falls on it. They have to be kept secure from
agents that can lead to their uncontrolled spread.

Chemical
wastes usually cannot be incinerated as the gases produced contain very harmful
chemicals. If they are being burnt, the gases also have to be treated in an appropriate
manner.