Question 8
What is the key difference between primary and secondary sewage treatment?
Answer
| Primary sewage treatment |
| Secondary sewage treatment |
1. | It is a mechanical process involving the removal of coarse solid materials. | 1. | It is a biological process involving the action of microbes. |
2. | It is inexpensive and relatively less complicated. | 2. | It is a very expensive and complicated process. |
