b. Sustainable wastewater engineering involves application of the principles of science and engineering for the treatment of wastewater to remove pollutants or reduce them to an acceptable level prior to discharge to a water body or other environment, without compromising the self-purification capacity of that environment. Draw a flow diagram for a process to treat a municipal wastewater that has a high concentration of suspended solids, organic matter, and pathogens. Also, illustrate a sludge treatment option. (17 marks) c. A number of different methods can be used to measure the organic content of wastewater. The commonly used techniques include (1) biochemical oxygen demand (BOD), (2) chemical oxygen demand (COD), and (3) total organic carbon (TOC). (i). Define the terms (BOD, COD and TOC). ( 6 marks) (ii). Describe graphically the mechanism for BOD measurement obtained after 5 days. (6 marks) d. Table 1 presents common wastewater unit processes. Relate the unit process with a typical pollutant. (10 marks) Table 1: Common wastewater unit processes e. Wastewater contains a wide variety of microorganisms, some of which are pathogens, while others play a significant role in degradation of organic matter. Table 2 presents some significant groups of bacteria. Complete the Table below and list their genus and their functions. (14 marks) Table 2: Significant types of bacteria a. Explore the legislation covering waste management in South Africa. (15 marks) b. Explain the fundamental principles of processing solid wastes. (10 marks) c. A landfill site is one of waste management technologies. Sketch a completed landfill design and elaborate on the biochemical processes (gases produced/mechanism) with organic material (by the activity of micro-organisms). (15 marks)