Question

justify that the surface of Earth is an effective filter

Answer 1

Filter of uv rays is done by ozone layer in stratosphere.

Answer 2

the soil is the earths largest filter which is found to be natural. this can be justified by looking at the water which flows downwards can be found for instance in wells and the same water is found to be so clean that it can be used again with little or with at all no treatment added to it. the filtration of water by the soil is made possible through several physical, chemical or biological processes.