# 3693 Water Treatment and Distribution

Assignment on  A newly planned city wants to construct a drinking water treatment plant and distribution system. Use the information given at the end of the document to answer the following questions: Design coagulation, flocculation, sedimentation, rapid sand filtration, and disinfection facilities. Using the data on enhanced coagulation (Table 2) and TTHM and HAA5 yield data and propose modification to the design necessary if your treatment process cannot meet the new regulation that specifies a maximum 80 and 60 ppb of TTHM and HAA5, respectively. Calculate the CT value achieved by your disinfection and compare with the table of values given in the lecture notes to understand whether the CT value is met by your dosing for primary disinfection. Discuss other problems associated with dissolved organic carbon in water for primary disinfection and secondary disinfection. Why should bacterial regrowth be an issue in water distribution system and what parameters affect the regrowth? Compare the possibility of bacterial regrowth in chlorinated and chloraminated system. You will need to read journal articles on this. Conceptually design a water treatment process for water: The river water has to be treated to remove dissolved solids to very low level to avoid solids deposition in boilers; List possible contaminants in stormwater from a car park that has to be used for gardening; and recycled water from secondary effluent that has to be treated for cooling tower in power plant and compare the benefits (economic/social/environmental) you would derive from using the recycled water instead of tap reticulated water. DATA Design capacity of the treatment plant is 0.2+0.02*(last two digits of the student ID) m3/s, with an initial demand expected to be 40% of the design capacity. First customer is expected to receive water after 36 hr of disinfection and customer at the end of treatment system is expected to be approximately 10 days after the disinfection. Consider chlorine as the primary disinfectant and chloramine as a secondary disinfectant. Water is assumed to travel the whole journey through pipes.   Treatment process design should consist of calculations, figures and tables with some narrative. All calculations should be done by self and type on the document. Strictly no copy-paste from the Internet as I already got failed before for that. The last two digits of my student id are “64”.