1. (a) Write a short motivation as to why some countries prefer the BODs as a measure of (4 pts) organic pollution from wastewater instead of COD. (b) Explain why it is important to include at the minimum screening and grit removal in all (6 pts) rudimentary treatment processes such as stabilisation lagoons and wetlands. (c) Explain why most of the times wetlands are not suitable for nitrogen removal from wastewater streams high in urine content. order to (6 pts) (d) For biological nutrient removal processes, which of the following statements is true (4 pts) (Choose TWO). A. The Standard UCT Process is a direct result of the modification of the Modified Phoredox (A2/0) Process by introducing the internal recycle from the anoxic to anaerobic chamber and returning secondary sludge into the anoxic zone. B. The Dephanox process is achieved by upgrading the Johannesburg Process by replacing the first anoxic zone with a trickling filter system. 400 C. The Four Stage Bardenpho Process achieves high levels of phosphorous removal. D. Nitrosifiers are responsible for the biological conversion of nitrite to nitrate. 116 E. Phosphate removal can be achieved in a Modified Ludzack-Ettinger Process by overloading the anoxic zone with COD. 156.