Posts in this project
AquaFlow - Blog #1 - Introduction
AquaFlow - Blog #2 - The coarse filter
AquaFlow - Blog #3 - The sedimentation tank
AquaFlow - Blog #4 - The reed bed
AquaFlow - Blog #5 - The storage tank
AquaFlow - Blog #6 - Conclusions
The storage tank
The storage tank just stores clear water before it is sent to the irrigation system. This tank is simpler that the first sedimentation tank
1.1 The tank
The storage tank is just a 60 litres tank where an electrical pump is submersed. The pump is controlled by the electronic board and sends water to the irrigation system in the evening (when the evaporation rate is lower and the use of water is more effective) or when the tank is full. Pump is installed on a floating (see my previous post for more details)
1.2 The electronic board
Here is the schematic of the control board, which resembles the schematic for the sedimentation tank
The Seeduino XIAO is equipped with two sensors
- An LDR (Light Dependent Resistor). This sensor allows the Seeduino XIAO to have a coarse notion of time. In particular, this sensor let the Seeduino XIAO see the dawns and the dusks, and so can have a rough idea of when water is ready to be pumped to the next stage of the treatment system. As I mentioned, greywater should not be stored for more than 24 hours. As I already explained, I chose to use a board with a digital output that reports where the ambient brightness is above or below a threshold a threshold that can be adjusted with a simple trimmer. This makes adjustments easier, because I just need a screw driver to adjust the threshold, instead of re-flashing the Arduino sketch. This is the board I used
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- A sonar to detect the level of the water in the tank. The Seeduino XIAO can check if the tank is full or empty, or when water is being flushed into the tank. Sonar sensor I chose is the Grove Ultrasonic Ranger
The Seeduino XIAO controls a relay to switch on the pump
1.3 The control logic
The control logic for the storage tank is easier than the control logic of the sedimentation tank. The control logic performs two basic functions
- at dusk (when light sensor output switches from high to low), the water tank is emptied
- when water level reaches the maximum threshold, the pump is activated until water level reaches a safe level
These functions are shown in the following flowchart
