Define the following terms, unit operation, unit process, hardness, assignment help

How do we select the type of water treatment technologies we will use?
What does the degree of water treatment depend on?
What does a conventional surface water treatment plant flow diagram look like?
How does coagulation/ flocculation work?
What can be used as coagulant?
What are coagulant aids? What are they used for? How do we know how much to add?
What causes water to be hard?
What types of problems are associated with Hard water?
What is water softening? How is it achieved?
How does Sedimentation reactor work?
How does filtration work?
Why do filters need to be backwashed?
What are the categories of human enteric pathogens?
What is the common disinfectant used for water treatment?
What are alternative water disinfectants?
What are the pros and cons of alternative water disinfectants?
How do water disinfectants work, what are the mechanisms?
What is Chlorine Residual? How much chlorine residual is provided at the furthest tap in the system?
What are disinfection by products (DBPs)? How do they form?