My graduation project – 1st June 2010

Five years after my graduation, would like to give my graduation project file for anyone who want or need.

Ha Noi Architectural University

Faculty of urban

2005-2010 school years graduation project

Design water sewer system of  Pho Chau town

Room U406

13h30 to 14h00, 1st June, 2010.

Content of graduation project celebration:

Fourth subcommittee  examiners including:

1. Head of subcommittee: Dr. Tran Thanh Son.

2. Dr. Vo Kim Long

3. Master. Nguyen Tien Dung

4. Proffessor.Science Dr. Nguyen Tai

5. Master. Vu Huu Thang

6. Clerk of subcommittee: Master. Nguyen My Hanh

7. Master. Tran Van Thuyet

Begin, clerk of subcommittee stated: “Student Tuong Thi Tu Khuyen. Class: 2005N1 with subject: Design sewer system of  Pho Chau town – Huong Son district – Ha Tinh province to year 2030”.

Presentation by student:

Thankful for the teachers and friends were present in my graduation project protect celebration today!

Before present about my subject, I want to give thanks to my guide teachers – Mr. Tran Thanh Son and Mr. Nguyen Tien Dung.

I want to give my thanks to my Family, my Relatives, my Friends, room 314 community, 05N1 class community, Cadviet forum and other individuals have helped me in this graduation project.

My research area is Pho Chau town belong to Huong Son district territory located in the northwestern of  Ha Tinh province.

Pho Chau town has steep terrain gradually in the direction from south to north, from east to west, surrounded by covered high mountains. Leveling elevations range from 8 metres to 18 metres compared to sea level.

There are two important transportation routes pass through Pho Chau town including Ho Chi Minh road in North – South axis and 8A Highway in East – West axis.

There is Ngan Pho river flows through Pho Chau town. This is a upstream tributary of  La river.

Pho Chau town has built the water supply system but hasn’t built the sewer system yet, so when construct the sewer system for Pho Chau we have begin from scratch.

I selected own sewer solution for Pho Chau, ie separate waste water system and storm water drainage system. And in my thesis, I only calculated waste water system, I didn’t calculate storm water system.

According to the forecast, by 2030, Pho Chau area is over 920 hectares with a population of more than 73,000 people.

With above conditions, I would suggest two solutions for design network and build waste water treatment plant.

Solution 1: The large region is conduct collection and biological waste water treatment in artificial condition. The small region is conduct collection and biological waste water treatment in natural condition.

Solution 2: Collect all waste water to the same station and treat by biological method in artificial condition.

After compared the advantages and disadvantages of  both solutions, I selected solution 2 to design.

There by I propose two sewer system design options for Pho Chau. Both options had 139 sewarage pipe with 138 nodes, with treatment station located in Son Phu commune territory and capacity of 10,500 m3/day.

However, option 1 had only a main sewer pipe, from node 15 to node 7 in parallel with Ho Chi Minh road, from node 7 to node 1 paralleled with the 8B highway.

Option 2 had 2 main sewer pipes, route 1 follows 17 road and 8B highway to treatment station, route 2 follows town’s belt road to treatment station.

The next, I conducted surveyed of the longitudinal section of main sewer pipe line and check sewer pipeline as both options. With option 1, the final sewer pipe burial depth is 5.19 m, option 2 is 4.9 m.
After compared the advantages and disadvantages of  both options, I selected option 2 to design.

     About sewage pumping station, I selected build location in treatment plant. It uses 3 submersible pump, including 2 working pumps and a standby pump.

After measured the treatment’s level: 96.8% according to BOD5, 83.28% according to suspended matter, 90% according to the amount of oxygen dissolved in water, I selected biological completely wastewater treatment method in artificial condition.

I suggested 2 options to design treatment plant:

+ Option 1: Biological treatment facility is Biophin tank, other tanks had rectangular surface as horizontal sand settling tank, first horizontal settling tank, second horizontal settling tank.

+ Option 2: Biological treatment facility is SBR tank, other tanks had rounded surface as water round sand settling tank, first vertical settling tank.

Through comparative advantages and disadvantages of 2 options between Biophin and SBR, between rectangular surface tanks and circular surface tanks about structure, height, treatment effective, I selected option 2 to design.

Ensuing, I surveyed sludge – water longitudinal section as selected option to define the loss of sludge – water stream through facilities and elevation of facilities in treatment plant.

Through I define ground elevation at SBR position is 9.53 m and I selected SBR to design detail.

About water supply and drainage for construction work, I designed water supply and drainage system for 8-storey condominium. Due to external pressure meet the highest floor of the house, so I selected a simple water supply scheme. Due to I designed own drainage system and completely treatment for Pho Chau town, so house’s drainage system didn’t need septic tank. According to Standard 4513-1988, item 5 for a 6-storey condominium or over, we need design fire fighting water supply system. I calculate fire fighting water tank in 1 hour for the building and use 2 fire fighting pumps.

     According to Standard 4513:1988, item 4.5, 4.6, I chose design water supply network in the building is truncated and has 1 water pipe into the building. The selection of fire-fighting water column and flow of each column based on item 4.25, water supply pipes material is galvanized iron pipe because of diameter smaller than 50 mm.

Regarding the construction, I designed construction for sewer pipe from node 100 to node 101, with 500m long, DN 500, construction time is 30 days. I determined the average labour number is 28.53. Aperiodic coefficient is 1.56. Labor distribution coefficient is 0.194

The above I was presented about my project. Thank for your attention. Please give me your question!

Clerk of subcommittee read comments and question of  opponency teacher: “… Project’s format: 156 A4 description pages, 15 A1 drawings…”

Question of opponency teacher –  Master. Nghiem Van Khanh:

“ What are principles of operation and treatment efficiency of SBR tank?”

Question of  Dr. Vo Kim Long:

“ Please mention measures and facilities to treat waste water?”

Question of Professor. Science Dr. Nguyen Tai:

“ Please let me know, what are capacity which Aeroten tank and Biophin tank used?”

“ Why did you choose circular surface waste water pumping station?”

Firstly, I want to answer the question of Ms.Khanh: “ What are principles of operation and treatment efficiency of SBR tank?”

Dear teachers and friends, SBR tank is waste water biological treatment facility by activated sludge method in which the two-stage sedimentation and aeration occurred in the same structure. Different from normally Aeroten technological is sedimentation and aeration occurred in two different tanks (Aeroten tank and second settling tank).

SBR system can treat waste water with high organic matter content, even treat nitrogen. Effectiveness of the treatment depends on substrate characteristics and air supply condition.

Thus, in the SBR tank occurred 5 basic processes are: fill, aeration, sedimentation, water discharge and sludge discharge.

Filling process can operate by 3 modes: static filling, stir filling and aeration filling. In my project, I selected static filling, distribute water by free flowing from the bottom of tank. Filling time is 3 hours.

Reaction process: aeration to conduct nitrification, nitrite and decomposition of organic matter, we can use different aeration measures such as: bottom tank air distribution disc, surface air bubbling machine. In this project, I chose surface air bubbling machine DMTA – 4409 of ASTIM Enterprise, the smallest operating radius is 9 meters, the largest operating radius is 21m and the average operating radius is 15 meters, it is enough to provide air to every location in the SBR tank. Aeration time of SBR was calculated as Aeroten tank combined with second settling tank. And the result was 4 hours.

After reaction process is sedimentation process: it occurs in complete quiesce state, sedimentation time is not over 2 hours, in this project, I chose 2 hours.

This was followed by the water discharge process. I found out some measures to collect surface water as use Decanter water collection equipment, it’s like a lever arm, it can rotate around one axis and move up and down with water level. Another way is use hose and buoy, fixed by picket and associate with tank wall by the chain. Finally, I chose water collection measure by fixed pipe and floating pipe combine with buoy. This surface water collection equipment can describe by this pipe … When open the valve, water will enter floating pipe and melt out. Hose and floating pipe slowly lower as the water level, until the hose meet fixed pipe, it can’t move anymore. Finish water discharge process for 2.5 hours.

Sludge discharge process: sludge in the tank will be discharged by the sludge pump.

Effective treatment of SBR tank: These processes below occur in SBR tank:

Organic matter oxidation to create CO2 and water.

Nitritation was carried out by nitro somonas bacteria.

Nitrification was carried out by nitro bacter bacteria.

There are principles of operation and treatment efficiency of SBR tank.

About the question of Dr. Vo Kim Long: “Please mention measures and facilities to treat waste water?”, I would answer as follow:

There are 4 basic methods of wastewater treatment: mechanical method, biological method, chemical method and physical method.

Regarding the wastewater treatment facilities, as you know, wastewater treatment process is actually the process which cleanup little by little the contaminants in water from large stuff to small stuff. Firstly, trash rack keep big stuffs, sand settling tank keep smaller sediment, suspended sludge are retained in the first settling tank, the water-soluble substance, can’t keep by mechanical measures. They need biological treatment facilities to create sludge and would be retained in the second settling tank.

I chose cylinder wastewater pumping station because: cylinder pumping station hasn’t dead water corner, about structure circular stuff more stable than square stuff.

End of graduation project protect celebration, clerk of subcommittee stated average mark of student, guide teacher’s mark and opponency teacher’s mark.
I want give my thank to my family, my brother and sister of my Mom, my cousins, my close friend, forum.

Thanks the members of the Cadviet forum helped me a lot about Autolisp and VBA, including: Tue_NV, anhcos, thiep, NguyenHoanh, phamthanhbinh.

Thanks for the help of all members or room 314. Thank Linh and Phuong Anh gave me your computers for borrow when my computer unusable. Thank Ha cook for me when I was busy. Thank Huyen and Chi gave me your motorbike when I need.

And … many other names which I can’t tell all.

Some photos:

Thầy mới chính là thầy hiệu trưởng mà em mong ước….

One thought on “My graduation project – 1st June 2010

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