Purify the Air Supply

Has your time spent indoors increased during the COVID-19 pandemic as a result of stay-at-home and shelter-in-place policies worldwide? Your challenge is to use the International Space Station (ISS) as inspiration and develop a system to monitor and/or purify indoor air. It is entirely up to you whether the system you design is able to be used on Earth (for example in homes, businesses, transportation, etc.) and/or in space.

Happy faces !

Summary

Real Time Gas Monitoring System:This system offers a method to monitor the real time gas levels of the rooms in a house. This system uses a collection of sensors connected over a wireless network.Our purification project is a hypothesis based on a few existing research observations. Our hypothesis assumes that using the present existing research observations we can create a novel solution for the same.

How We Addressed This Challenge

Exposure to high gas levels can be dangerous, and have long lasting if not fatal effects. Detecting potentially dangerous conditions before an incident occurs can save both time and money.

The system makes use of a combination of gas sensors and a wifi board to create a network through which data is transferred. These sensors will collect data related to the concentration of smoke, carbon monoxide, air quality and any flammable gases present in the air and relay this data to a web / android application. The user can use the application to view gas levels over time. This will allow him to make changes to the ventilation in rooms to help avoid hazardous regions.

The hypothesis aims on creating a purification apparatus that can be attached on the present air ventilation and conditioning system. It focuses on solving the drawbacks of the present existing filter systems.

The present drawbacks are as follows:

  • HEPA Filter: Cannot trap gaseous pollutants
  • Carbon Filter: Need regular filter replacement and do not remove particulate pollution
  • UV light: Cannot trap gaseous pollutants
  • Ionize : Produces high levels of ozone


How We Developed This Project

MONITORING SYSTEM

Sensors Used:

a) MQ-9 Sensor

This gas sensor is used to detect the presence of carbon monoxide and flammable gases in the air. If the concentration of either of these gases exceeds a certain threshold limit, then an alarm could be triggered on the user’s phone.

b) MQ-135 Sensor

This gas sensor measures the quality of air and also alerts the user if smoke levels exceed a safe limit.These will all be connected to a multiplexer which is then connected to a NodeMCU board. Multiple setups can be installed in different rooms as required.


PURIFICATION SYSTEM

Aerogels have high surface area due to their unique internal geometry. They can be reinforced in appropriate material for desired structural stability. They are light in weight, thus are a good standing candidate for space exploration missions where weight is a constraint.

HYPOTHESIS

The following can be achieved by using different layers of aerogels or reinforced aerogels as filtering layers.

1) Using a cellulose reinforced aerogel:

The following is hydrophilic in nature and can be used to trap the moisture content form the air. Then, it can be dried to evaporate the same thus providing an easy maintenance.
The following is based on the present data on the NASA website. According to the information provided, the ISS presently uses silica gel to trap moisture in air, which loses its capability to absorb moisture by 75% by one year of usage. Thus, the following aims to solve the stated issue.
Since cellulose is a biodegradable natural polymer, the following should be ecofriendly.

2) Purification using Graphene titanium oxide aerogel:

The following layer focuses on purifying air from the gaseous pollutants by providing a surface site for photocatalytic oxidation. Since the step has only gaseous residuals, the cleansing of the filter layer should not be necessary.

The following was inspired by the present technique that uses activated charcoals for purification at ISS.

3) Purification using silica aerogel:

As per one of the research papers on Research Gate (link enclosed), the silica gel immobilizes the microbes. The same concept is planned to be used over filtration as well. As per our hypothesis, the microbes will be trapped due to internal structure of the aerogel. Then, the following when exposed to UV light or sunlight should kill the bacteria.

These three layers together comprise of the purification apparatus. The dimensions of the layers haven’t been determined as they would need experimental observations.

PROS:

  • The apparatus is light weight as aerogels have 99.8% air.
  • The are good at thermal insulation thus can be used at extreme environmental conditions.
  • The concept in fresh thus has a large scope for development.

CONS:

  • The results mentioned in references above haven’t been made available as commercial products, thus we can’t predict the economic price of the development.
  • The following is just a hypothesis based on a few existing researches, the experimental trial might provide a variation in results.
Project Demo
  • As and when we get the data from the sensors we collect that data and post it onto the cloud (we are using thingspeak as the cloud here).
  • Once the data are posted on the cloud we by further adding the Matlab visualization view them in the graph format.
  • Then we have added and react to the maximum values that can be reached so suppose if any one of the four fields (that are Carbon monoxide levels, flammable gas levels(methane), Air Quality, and smoke concentration.) reaches a value which can be considered a threat or a problem in long exposure to that value we send a mail to the particular person on his registered mail-id notifying him about the danger level and telling him what could be done to reduce the level of a particular gas.

We did not possess any of the sensors on hand so we wrote a python script to send in sample values after certain intervals of time. This image shows the concentrations of gases over time: 

https://ibb.co/DQXpQJL 

The 4 different types of gases we are looking at receive real-time updates from the NodeMCU units.

In order to notify the user about high, dangerous levels of gases we use a system of webhooks and applets to send an email notification to the user. The first image shows the React on the Thinkspeak domain which activates at high levels of a particular gas and the second image shows the applets which were made on IFTTT which send an email when triggered. 

1) React

2) Applets 

For example, if the value of Carbon Monoxide exceeds 10ppm then the React is triggered sending an email to the user.


https://ibb.co/HdKgKLk (do note the time) 

in this, the level of Carbon monoxide has exceeded the limit so then there should be a mail which should be received notifying the same, here is the picture

https://ibb.co/C2THhfy


The above system can even be integrated with your phone number where you can get the message on your notifying the same and many more interactions with the users can be done.


The reason for uploading the data on this cloud (thingspeak ) was that we can further use this data for predicting the future using ML and AI wherein during any festival time(Diwali) we can notify the user beforehand that the air quality may not be good so keep there windows and doors closed so as to keep him safe.



Data & Resources

1) Reference for NASA Data:

https://www.nasa.gov/mission_pages/station/research/long_duration_sorbent_testbed

Clearing the Air in Space: Improving Life Support on International Space Station and For Deep Space Exploration

Reference for research observation taken under consideration:

Cellulose Aerogels: Synthesis, Applications, and Prospects by Lin-Yu Long , Yun-Xuan Weng , ID and Yu-Zhong Wang

2)Reference for NASA Data:

https://science.nasa.gov/science-news/science-at-nasa/2000/ast13nov_1

Breathing Easy on the Space Station

Reference for research observation taken under consideration:

https://www.sciencedirect.com/science/article/pii/S1877705815028908

Preparation Functionalized Graphene Aerogels as Air Cleaner Filter by XichengXiong, NaJI ChunfengSong, QinglingLiu

3) Reference for research observation taken under consideration:

https://www.researchgate.net/publication/228440592_Aerogels_as_biosensors_Viral_particle_detection_by_bacteria_immobilized_on_large_pore_aerogel

Aerogels as biosensors: Viral particle detection by bacteria immobilized on large pore aerogel - Article in Journal of Non-Crystalline Solids

Tags
#air quality #hardware
Global Judging
This project was submitted for consideration during the Space Apps Global Judging process.