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Coagulation is a general treatment method to remove suspended fine particles, colour and other constituents from raw water, after adding chemicals (coagulants) and followed by further treatment. Coagulation is often applied in both conventional and advanced water treatment processes for the production of drinking water.

Theoretical calculation of the optimum coagulant dose is not possible. Therefore, for each raw water experiments are needed. In glass beakers the coagulation process (rapid mixing, flocculation and sedimentation) is performed as shown in Fiure. This bench scale test is the so called “Jar test”.

The overall aim of this project is to make an app which allows to analyze the google sheet data generated from the lab jar test experiments and calcualte the optimum coagulant dose. The app also allows the users to eneters the some plant operational data to calculate the total coagulant dose needed.

A live app can be found here.

1. About the coagulant calculaor app

2. User Expereince (UX) design

• User Goals:

3. Flow chart

4. Features

• Existing features
• future features

5.Technologies used

6.Testing

7.Bugs

8. Deployment

9. How does the app works?

10. Acknowledgement

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This app is designed to calcualte the optimum coagulant dose that need to be applied in a water treatment plant based on the raw water quality.The app determine the optimum dose based on the laboratory data from google sheet. The app also calcualte the total amount ot dose needed based on the type of coagulant used, optimum dose and user input (flow rate and storage time of the coagulant). The app can be used by the plant operator, students and water supply engineering professonals.

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Dosing of coagulant (chemical) i.e. FeCl3 is needed to remove the fine particles from drinking water treatment. Moreover, overdosing of the chemicals will support for the resuspension of partcles and is also an environmental issues. Therefore, optimization of the coagulant dose based on the water qaulity is rather important which save cost and environment. This project is aimed to design the app which allows to calcualte the optimum coagulant dose based on the experimental data provided in google sheet and ultimately calcualte the total dose required depending upon the type of coagulant used.

The following users types can be benifitted from the app:

• Drinking water treatment plant operators

• Professionals dealing with water treatment designs.

• Post graduate students in the field of water supply and environmental engineering.

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The main goal of this project is to develop a coagulant dose calcualtor app that allows to calcualte the optimum coagulant dose for diffent water types. This is of great useful for me to apply in my teaching for a demonstration in the laboratory session to my students.

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Flow chart was used to conceptualise the optimum coagulant dose calcualtor idea. It was drawn using Lucid Chart. The flow diagram is as shown below.

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• App calcualtion is linked to the google sheet data. The google sheet access is given using google API.
• Google sheet has four worksheet named phRAW, pHRAW2, pHRAW3, pHRAW4 where mainly the experimental data at differnt conditions are stored.The sheet also has worksheet name "dose" where mainly the data calcualted by app based on user input data will be stored (see in Figure below).
• App has a fature to validate the data provided in the google sheet.

• Has a short introduction about the app to the user
• App ask user to provide the input data mainly flow rate in m3/s and storage time in months.

• Users has to enter data input either in float or integer
• User cannot provide input zero or negative
• User should provide a data input i.e. a number

• App calcualte the optimum coagulant dose for all experimental conditions based on data input in google sheet
• Based on the optimum dose calculated and user's input data, app calcualte the coagulant dose needed for differnt types of coagulants used

• user's input data and app calcualted data is updated in the new row in the google sheet

In future i plan to update the app including more features such as;

• Allow users to select option for choosing differnt types of coagulants like FeCl3, NaOCl, Al2SO4 etc
• Provide users the basic dimension of the coagulation unit required for the given type of the water

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• Python3 was used as a scripting language for the app development in this project.

• Lucid Chart was used to flow diagram for the app.

• Github was used to create the repository and to store the cproject's code after pushed from Git.

• Gitpod was used as the Code Editor for the site

• PEP8 online tool was used for manual testing procedures for code validation.

• Ami was used to develop a Mockup screenshot generator

• Heroku was used to deploy a final version of the Python Essentials application code.

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I have tested this project manually by passing the code through PEP8 online validation tool and confirmed there are no errors. The screenshot is as shown below:

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• When i wrote the project, i had most frequently indentation error as i forget to provide a tab
• The data input by users and app calcualted results were overwritten in the google sheet with the previously recorded data. this was solved by writing a code to save the evry new data entry and app calcualtion in a new row.
• When i wrote if statement, i forget to add colon at the end of if statement, which gave me unexpected indentation error.
• I want to display the calcualted data in bullet points in the app but it took all the data from google sheet (including headings and data). This was solved by using pretty_array package.

No bugs remaining

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The proejct was deployed to Heroku using the following steps:

• Sign up to Heroku and give a unique name to the app
• Inside the Heroku app page, go to the setting first and in the section config vars, add CREDS and paste entire creds.json file
• Add buildpack python and node.js (python on top and node.js on bottom)
• Go to the diploy section and select github and click connect to github
• Search git hub repository name related to the project to be depoloyed and click connect
• Deploy to the branch (either mannual or automatic)

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The app has a credential to access google data sheet . The app validates the data input in the google sheet. If the data entry in google sheet is not correct the app gives a message"Google sheet data is not valid. Please check the data entry" (see figure below where data input is not valid in google sheet (highlighted)). Moreover the app users do not have to do anything to the google sheet.

When the users run the coagulant dose calcualtor Heroku app,

• It first display the what the app is about.
• Ask user to enter flow rate in m3/s and do the validation of the data.
• After validation of first input data, the user is asked to provide second input data i.e., storage time. The app does the validation of this second input as well.

App validate the user's input data both flow rate and storage time (is data integer, float, and greater than 0). If data is not correct it ask users multiple time to provide correct input.

If user's input data is validate, the program runs and calcualte the following:

• Optimum coagulant dose for all conditions.
• Total coagulant dose (for differnt type of coagulant used i.e. FeCl3) is calcualted based on the optimum coagulant dose and users input data of flow rate and storage time. This is calculated for all four types of conditions like pHRAW, pHRAW2, pHRAW3 and pHRAW4.

All the new calcualtion and user's input data are updated in the google sheet

• no overwritten with previous data entry is allowed,
• data should be entered in new row
• in each simualtion four rows will be added for four differnt types of experimental conditions (pHRAW, pHRAW2, pHRAW3 and pHRAW4)
• Experimental condition is also recored in the last column to understand which data belong to what experiemntal condtions

To run the programm again, user has to click again run the programme.

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• Inspired from love sandwitch project from the code institute course
• Thanks to my mentor Marcel Mulders for his constructive feedback