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Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Example pictures of some of the prepared samples: (a) sample from disaggregated non-used cigarette butts; (b) sample from disaggregated used cigarette butts; (c) sample from used cigarette butts before the cleaning treatment.