Sorption properties of materials based on residual biomass

Abstract

In this paper, we consider the possibility of using inexpensive and effective sorption materials based on plant raw materials, such as fruit rind, vegetable waste, fallen leaves, and the use of phytosorbents for the purification of sewage containing heavy metals and petroleum products. The use of vegetable waste for the manufacture of sorbents is a priority for solving environmental problems. It is suggested to use residual biomass as a sorption material, which is formed after extraction of lipids from C. sorokiniana microalgae and duckweed Lemna minor. To increase the sorption capacity, it was proposed to thermally modify the residual biomass. The optimum heat treatment conditions were 450 °C for 20 minutes with limited access to oxygen. The obtained biomass allows one to extract ions of heavy metals with efficiency of 91-93% for ions of lead, cadmium, zinc and copper. To increase the sorption capacity (A, mg/g) of the residual biomass, heat treated waste from the agro-industrial complex and chitosan were proposed as additives. The addition of chitosan makes it possible to obtain a sorption material in the form of granules, which is convenient to use. For the sorption materials obtained, microstructural studies were carried out, which allowed us to substantiate the sorption properties of the materials. The physical and mechanical properties of sorbents, such as abrasion, grindability, allow us to offer new materials for use on an industrial scale. In the article, a technological scheme for obtaining sorption materials from residual biomass is given.

Research of pH influence on sorption properties of sorbents on a basis of residual biomass of microalgae Chlorella sorokiniana and duckweed Lemna minor

“…For completing the process and final forming a shape of granules they were kept into alkali solution NaOH during 24 hours and after that these sorption materials were rinsed in distilled water to get pH ratio 7.0-7.5. The wet granules were dried at room temperature [1,14].…”

“…Therefore, research aimed to the search of new resources for sorption materials obtaining on their basis are current and perspective. Much attention is payed to the materials of the natural origin, for example to microalgae, to the higher water plants, because they are non-toxic initially and have a biosorption activity to the various kinds of the contamination [1][2][3][4][5].…”

“…On the final stage of valuable components extraction, a residual biomass is formed. It contains cellulose, lignin, hemicelluloses, which determine its sorption properties, therefore residual biomass can be used as a sorbent for water purification from heavy metal ions [1]. Applying of residual biomass is the one of stages of a complex use of microalgae and duckweed which consists of cultivation, extraction of useful substances, obtaining of sorbents for water purification, their regeneration after sorption process, and then biogas production by fermentation the residual biomass and fulfilled sorption materials.…”