STEM in practice: clean water for everyone

Project objective, problem to be solved, and main actions

The main objective of the project was to develop a water treatment system stored in cisterns using a hybrid electronically controlled water heating system.

The use of cisterns to collect and store rainwater is a reality in almost every country in the world. In Brazil, the presence of cisterns can be evidenced by the P1MC program. Studies point to the presence of microbiological contaminants in this stored water that are a potential risk to the health of people who consume it. Access to clean water is still one of the main causes of public health problems and school absenteeism. In several regions of the country, water for human consumption is stored in cisterns. Thus, the proposal is to have a system that performs the treatment and makes it suitable for human consumption.

The students participated in a marathon of challenges at a science fair FBJC, and it was when the group got to know the “AquaLuz” project. The equipment consisted of a water potabilization system that used solar radiation to disinfect water for human consumption in the rural semiarid region.

Although the device worked well, it had problems such as the amount of water treated per cycle and the difficulty of making it clean during periods with little sunlight. Given the difficulties presented, the problem of lack of potable water in the rural region of the Northeast and the dropout rate in schools in this region, the team proposed STEAM in practice: treated water for all, which is a device of a social nature similar to the project presented . However, this new equipment will have a superior potabilization capacity to implement it beyond residences; that is, in schools in the region. In addition, it will have a hybrid heating system – it will be able to run on electricity or energy from burning coal. The project brings a proposal following the UN SDGs, specifically objectives 4 and 6. In addition, the prototype will monitor water purification data in the cloud, fitting into an IoT proposal.

The initiative was the student´s idea, who then came to me. At school, we work with integrative projects, where we look for real demands and so we encourage students to look around them, looking for problems and solutions. In this way, students bring to the classroom proposals where teachers along with them look for solutions to these problems. At the beginning of the year, we always present the proposal to the students on how the discipline will be conducted.

https://www.youtube.com/watch?v=ybI4v0A7124

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Deepening into the issue and involvement of the school and local community

With the results of previous years and the dissemination of results to the school community, parents and students very much accept the proposal of mobilizing students in the development of projects, which in large part is an introduction to Scientific Initiation.

When the students decided to start the project, the research phases began, which is properly the scientific initiation, better identifying the problem, its scope, and possible solutions for water treatment. The engineering methodology was used, where after identifying the problem, a technical solution is proposed.

The research was conducted on sites such as ASA Brasil – responsible for the P1MC program (Project one million cisterns), verifying the dimension of the proposal, the scope of the solution, and which locations could benefit. With the problem defined, it was discussed what would be the best technique for developing the solution, and the thermal process was chosen for the treatment of water.
For water heating, two ways were proposed: one with electrical resistance and the other with coal burning, thus achieving a greater scope of application, since in some regions of the country there is no electrification.

An Organization Chart was prepared to define the functions of each member and a Schedule to list activities and deadlines. With the block diagram, it was possible to verify how each component is interconnected. The electrical schematic, programming, process flowchart, and prototype assembly were developed.

Tests of the prototype and analysis of the results began. With the improvements implemented in the prototype, the validation phase began.

It is expected to be able to treat water stored in cisterns, water from wells and weirs, for example. As additional features, we can use this IoT device to monitor the volumes of treated water and data storage in the cloud, since there is already a microcontroller and this device has this processing capacity.

The development of the solution

This is a STEAM project, in which it was necessary to deepen the theoretical concepts of some curricular components of Natural and Exact Sciences; all integrated with the area of ​​the electronics course since this project has the differential of automation that guarantees the efficiency of the potabilization process.

In an integrated way, the following curricular components that are part of our curriculum were worked on: Integrating Project, Electronic Automation, Analog, and Digital Electronics, Physics, Chemistry, Biology, Mathematics, and Portuguese.

The following areas of knowledge were listed:

• Biology: Study of microbiology and study of criteria for potability of water. Analysis of the parameters that guarantee the potability of the water (extra);
• Physics: Study of thermometry and heat transfer with water heating – specific and latent heat, the study of unit conversion units. Calculation of the energy needed to heat water. Calculate the Joule and Calorie equivalent. Calculation of electrical power and electrical energy consumed.
• Arts: External prototype design;
• Mathematics: Calculation in spreadsheets for equipment sizing;
• Electronics: Automation and prototype development. Algorithm development to control actuators and data storage in the cloud;
• Chemistry: Study of the calorific value of coal and firewood. Integration of the discipline with the Physics discipline;
• Portuguese Language: Text development and technical writing.
• Integrating Project: In the structuring of the project with the use of time management tools, resources, and project risk, simulation, and prototyping of the project.

The construction of the prototype

 

We finished the prototype and it is operational. Field implementation was not conducted.

Evaluation of the process and the developed solution

The evaluations were necessary to have quality control of the project. A practice that we used was the weekly meetings with the validation of the items to be presented by the group and analysis of the improvements to be implemented in the project. This dynamic favors the progress of the project and the group acquires autonomy.

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