Development and Investigation of Hydrogen Sulfide Adsorbents From Natural Materials

Adsorption materials based on natural minerals are considered in the world literature as inexpensive hydrogen sulfide adsorbents capable of completely replacing commercial products such as synthetic zeolites. The global demand for inexpensive, accessible, safe materials is growing, including in the field of cleaning industrial and agricultural gas emissions from hydrogen sulfide. The article presents an analysis of literary data on natural clays, activated sludge and other materials and methods of their use for hydrogen sulfide adsorption. Data on the composition of activated sludge, clays and limestone rocks are provided. The composition studies were carried out on an infrared spectrophotometer. The inorganic component of activated sludge includes iron oxide, aluminum, calcium, magnesium compounds, and silicates. Limestone consists of carbonates, iron oxide, silicates, and when calcined at high temperatures, it mainly forms calcium oxide. Various clays contain aluminosilicates, iron oxides, copper, cobalt, and manganese. Due to the content of metal oxides, natural materials have a chemisorption mechanism, and due to the content of aluminum and silicon compounds, they have a physical sorption mechanism. 17 compositions of composite materials from natural minerals were developed and their sulfur content was studied. A study was also conducted on the absorption capacity of activated sludge in a liquid state. It was shown that all natural materials have a high potential for use as adsorbents with minimal preparation (dehydration, calcination). Compositions that do not contain expensive additives, consisting mainly of сalcined limestone rock and clays, showed sulfur capacity from 10 to 40 %.