Abstract: An adsorbent system includes a passage and first and second adsorbents in the passage. The first adsorbent includes granules of non-impregnated activated carbon and the second adsorbent includes granules of acid- or metal salt-impregnated adsorbent. The granules of acid- or metal salt-impregnated adsorbent have, by weight, at least 20% acid or metal salt content. The granules of acid- or metal salt-impregnated adsorbent have, by weight, at least 35% acid or metal salt content. The granules of non-impregnated activated carbon and the granules of acid- or metal salt-impregnated adsorbent have a size of mesh 4 to mesh 40, and, by total combined weight of the granules of non-impregnated activated carbon and the granules of acid- or metal salt-impregnated adsorbent, the first adsorbent has 55%-75% of the granules of non-impregnated activated carbon and the second adsorbent has 45%-25% of the granules of acid- or metal salt-impregnated adsorbent.

Abstract: An adsorbent system includes a passage and first and second adsorbents arranged in series in the passage. The first adsorbent includes granules of non-impregnated charcoal and the second adsorbent includes granules of acid- or metal salt-impregnated adsorbent. The granules of acid- or metal salt-impregnated adsorbent have, by weight, at least 20% acid or metal salt content.