Design of Dual Reticulation System for Greywater Reuse in Residential Premises

Project Design:

 

After excluding the high rise building apartment option in the preliminary evaluation that has been done in graduation project 1 since it has the largest cost and the lowest performance, we proceed with just two alternatives (individual house and residential compound having several houses). These two options were designed based on hydraulic design principles and plumbing codes used in Abu Dhabi.

 

First alternative (individual house):

For design and evaluation of a piping system for the individual house alternative, a scheme of house having two floors was used and a family size of 12 capita is considered. Designing a pipe includes estimation of waste flow rate for the design data and evaluation of any local conditions, which may affect the hydraulic operation of the system. Also select the hydraulic design equation, select pipe material, determine minimum and maximum sizes (diameter), determine minimum and maximum velocities and slopes are very important tasks to do. Besides that determining the volume of excavation is must in order to construct the piping system underground.

 

Hints:

1) The flow is determined based on the average greywater generation=192 Lpcd.

2) The used equation: Manning’s equation is commonly used to design the sewer pipe.

 

 

3) Assumption of full flow condition

4) The used material:UPVC.

5) Pipes sizes (diameter)

        For collecting the greywater: pipes with 200mm diameter. 

        For redistributing the treated greywater: pipes with 25mm, 50mm, 65mm and 100mm diameter.

6) Based on AD pluming code, the assumed slope of the pipes should maintain the velocity to be between 0.6-2.4 m/s.

7) The volume of excavation is determined based on slope and length of the pipes.

8) This alternative requires: 2 pumps, 3 storage tanks and 1 treatment plant. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Second alternative (residential compound having several houses):

The results obtained from analysis of the first alternative were then generalized to design and evaluate the second alternative. Since we assumed that the residential compound is having 14 houses, so we just multiply the results by 14. The following drawing shows the designed pipes for collecting and redistributing the greywater to the 14 houses. This alternative requires: 28 pumps (the total of the pumps for 14 houses if each one have 2), 2 main storage tanks and 1 treatment plant.