We were learning about rerouting Grey Water in our Chemistry class when we started wondering if RO machines balance water pH. Thus, we started experimenting with digital solutions to conquer this problem which led us to this project.

What it does

Our solution makes use of an Arduino hooked up with servos motors. The servos motors have 2 purposes, 1 of them is to mix the water, the other 4 acts as the valves. Along with that, there's a pH sensor (A gravity analogue pH sensor) to send signals to the Arduino with float values of the pH. The looping algorithm of the Arduino is very simple. First, it opens the entry valve for a fixed time frame to let water in, then it closes. Then the pH sensor retrieves the pH of the water. Following that, if the pH is below 6, it adds the basic solution, comprising of minerals like calcium, through opening the valve and closing it after a fixed amount of time. If the ph is above 7.5, then an acidic solution is added instead, comprising of liquids like lime juice, in the same manner as the basic solution. Then the motor with flaps mixes the water solution and repeats the process of checking the pH value. If the pH is in the acceptable range, the output valve is opened, letting the water out and closing once the module is emptied.

How we built it

We built our project using Arduino.

Challenges we ran into

Using our Arduino simulator on TinkerCad we couldn't simulate a pH sensor and the valves, we could instead only simulate them using servo motors. In the physical version which we may build in the future, we would wire up a Gravity Analogue pH Sensor in any of the remaining pins for the Arduino and with minimal adjustments to the code, we could make our project a reality. We would also 3D Print the valves that would be necessary and attach them to the servos.

Accomplishments that we're proud of

We were able to develop an algorithm to fix this problem, emulate a working solution in time and do all of this in a medium/language that we were unfamiliar with at the beginning of this Hackathon.

What we learned

We learned a lot about Arduino and programming Arduinos on the technical side, as well as the water purification process and about pre-existing solutions to rerouting greywater that we picked up during our research.

What's next for pH2O

We would like to make our project more affordable and extend its capabilities as a water purifier for not only drinking water, but for other purposes, too, such as irrigation.

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