# Practical Approach for Smart and Circular Cities: Chatbots Used in Waste Recycling
## 4 An Analysis of Five Representative Chatbots That Support the CE
### Tracking of Consumption and Recycling  
At the level of a (smart) city, it is essential to track the consumption of products (what and how much is consumed) and their recycling. The process of becoming aware of the consumption of products, by which each person should buy only as much as he needs, is necessary and mandatory in this society due to the current excessive consumption. Most people buy products that they only sometimes use or buy much more than what is required for living. In this field, consumer education must focus on product quality, price, responsible use, rational purchase of products, and their recycling. During the holidays, most problems arise in relation to the excessive consumption of products. In this way, the population buys more products than they can consume, which leads to the throwing away of many purchases made initially, especially food [25]. Figure 6: The role of a chatbot in the circular economy. A chatbot implemented in the circular economy can help the human city/community and the individual who chaotically consumes products. Based on certain graphs and reports, statistics can be gathered both at the city level and at the person level. When we refer to the city level, we want to see the following:  
* What is the quantity of products and the category of products consumed in a month of everyday shopping and a month of excess shopping;
* Which are the periods when more is consumed;
* What is the percentage of citizens in the community who follow correct recycling procedures to protect the environment;
* What are the users' interests in the application;
* What is the trust of people in the chatbot;
* What effects does product recycling have on the community's economy and the environment. When referring to the person level, it is essential to consider the following:  
* How the monthly consumption of products evolves;
* Offering personalized help (advice, recommendations, a shopping schedule, and making a shopping list that includes only the necessary products and following this list) to reduce the number of products that are unnecessarily consumed [26];
* Whether or not the person recycles products and how we can influence this;
* The person's knowledge about the need to recycle products;
* The person's awareness of the excessive consumption of products;
* What are the amounts of money spent on purchases that are not necessary;
* What can this money be invested in. In accordance with the recommendations, we advocate the subsequent implementation methodology, articulated through a structured sequence of three fundamental steps (see Figure 7). Step 1: Track the products that a person buys  
It is necessary to create a database with a table for people, a table for products, and another table that shows the number of products consumed per month by a person. This can be achieved by identifying the person at the time of payment in the stores. A person can be identified by their bank account if they pay by card. After using the card and scanning all of the products, along with creating a tax receipt, a record can be made in the  
Figure 7: Consumption and recycling tracking process. consumption table where the products purchased by the person and the quantities for each purchased product will be entered. If the person pays in cash, they can be identified by other means, such as requesting an SSN or identification by a store shopping card [27,28]. Step 2: Tracking recycled products  
For this to be possible, the following is necessary:  
* The city should have waste collection points;
* A program (established by the city hall in collaboration with the company that has a contract with the city hall for waste recycling) of waste collection (by waste category) should be known to all citizens of the city;
* The city should be equipped with intelligent dumpsters. The intelligent dumpsters recognize products bought for recycling by different people, determine their quantities, and then record them in the database.