Influence of Carbon Sorbent Quantity on Breakthrough Time in Absorbent Filters for Antismog Half Mask Application

Abstract

In this article, we present polymer non-woven fabrics with the addition of carbon sorbents being tested to estimate the breakthrough time and efficient protection against vapors present in smog. For this purpose, three substances were selected, which constitute an inhalation hazard and are smog components: cyclohexane, toluene, and sulfur dioxide. It was demonstrated that an increased quantity of carbon sorbent in polymeric filters significantly prolongs the breakthrough time. However, high sorbent quantities may increase the filter surface mass and air flow resistance. To optimize the protective parameters with functionality, a compromise between the two has to be found. By comparing the breakthrough times for different carbon sorbent quantities, the optimal filter composition was elaborated. The analyzed non-woven fabrics were manufactured by the melt-blown process and filled with ball-milled carbon sorbents supplied directly into the fabric blowing nozzle. Both protective performance and textural properties were analyzed for two commercially available carbon sorbents. Furthermore, it was proven that high values of sorbent-specific surface area translates directly into greater filter performance.

Effect of the Sorption Layer on the Protection Time Provided by Anti-Smog Half-Masks

“…In the case of half-mask 1, the first increment in the downstream concentration of sulfur dioxide vapors did not occur until 5 h of the experiment. These results are consistent with the study by Brochocka et al [ 9 ], who reported that a filtering material incorporating activated carbon particles offered protection against sulfur dioxide for 6 h.…”

“…z o.o., Warsaw, Poland) to which AG Pleisch 30180 PL MC 12 × 20 CBRN carbon sorbent (PLEISCH, Bäretswil, Switzerland) was added. It has been shown that the comminution of carbon sorbent in a planetary mill does not adversely affect its textural properties [ 9 ]. In addition, three commercially available FFP2 filtering half-masks with a carbon sorbent were included in the study for the purpose of comparing protection times and morphological structures.…”

“… Experimental station for testing the protection time of half-masks against chemical substances: 1 — inlet of dry compressed air; 2, 6 — air valves; 3, 7 — mass flow meters; 4 — humidifier, 5 — cooler; 8 — evaporator; 9 — test substance and air mixer; 10 — pneumatic mount; 11 — sample; 12, 14 — gas detectors; 13 — thermohygrometer; 15 — test substance outlet to the fume hood. Source: [ 9 ]. …”

“…However, whenever air pollution levels exceed the relevant standards, respiratory protection devices should be used. The simplest means of protection against smog are filtering half-masks conforming to the health requirements stipulated in Regulation (EU) 2016/425 of the European Parliament and of the Council of 9 March 2016 [ 9 ]. Air pollution also necessitates measures aimed at protecting the entire population.…”

“…It is a nonpolar and nonreactive substance, due to which it primarily needs to be removed by physical adsorption [ 17 ]. According to literature data, the breakthrough time for cyclohexane vapors increases in proportion with the quantity of carbon sorbent in the nonwoven [ 9 ]. Toluene irritates the eyes of exposed individuals, is oto- and neurotoxic, and adversely affects reproduction.…”