Synthesis of Magnetic Biochar for Efficient Removal of Cr(III) Cations from the Aqueous Medium

Abstract

Porous biochars obtained from coniferous woods, and magnetic biochars based on them, which showed high sorption properties when extracting Cr(III) from aqueous solutions (from 0.005 to 0.0125 mol/L), were studied. The adsorption properties of the magnetic biochar are compared with the initial biochar. It has been established that the preparation of materials by the method of pyrolysis and subsequent treatment in a plasma reactor makes it possible to bring the samples under study into a number of promising adsorbents for the extraction of chromium from aqueous solutions.

Recent Developments in Understanding Biochar’s Physical–Chemistry

“…In particular, either pyrolysis or hydrothermal carbonization can be applied on the biomass feedstock treated with ironcontaining solutions in alkaline conditions [145]. Alternatively, the magnetic nanoparticles can be synthesized in the presence of the biochar, thereby being deposited directly on its surface [146]. In all cases the reactions occurring in the system follow the co-precipitation scheme reported in Equations ( 5)-( 9) [147][148][149][150]: When metal-containing solutions are soaked in biochars, new composites are obtained [80].…”

“…In particular, either pyrolysis or hydrothermal carbonization can be applied on the biomass feedstock treated with iron-containing solutions in alkaline conditions [145]. Alternatively, the magnetic nanoparticles can be synthesized in the presence of the biochar, thereby being deposited directly on its surface [146]. In all cases the reactions occurring in the system follow the co-precipitation scheme reported in Equations ( 5)-( 9) [147][148][149][150]: The conditions used to produce magnetic biochars can lead not only to materials easily removable from soils and water, but also with improved physicochemical properties (that is surface area and porosity) that enable better sorption capacity for organic and inorganic contaminants as compared to non-functionalized biochars [141,145,146].…”

ХАРАКТЕРИСТИКА КОМПОЗИТНОГО ПОЛІМЕРНОГО МАТЕРІАЛУ ДІАТОМІТ-АЛЬГІНАТ-Fe3O4

“…Наприклад, синтез АВ відбувається за температури 800-1000 °С, а для відновлення сорбційної ємності АВ використовують обробку водяною парою з наступною регенерацією за температури близько 500 °С та реактивація за 800 °С. Виконана велика кількість робіт, що присвячені розробці і використанню недорогих і ефективних адсорбентів, наприклад, доменного шлаку [3], біовугілля [4], бентонітової глини [5], композитів на основі біовугілля, активного мулу [6], діатоміту [7]. Серед різноманітних адсорбентів глини є речовинами, які завдяки своїм численним перевагам, таким як висока хімічна стабільність у кислому середовищі та адсорбційна ємність, висока пористість та ефективність, привертають увагу дослідників впродовж багатьох років [8][9][10].…”

Sustainable synthesis of rose flower-like magnetic biochar from tea waste for environmental applications

“…Carbon rich feedstock such as bamboo, peanut shell, orange peel, pinewood, sludge, soybean Stover, switch grass, palm bark, corn straw and rice straw could be the idea precursors for development of biochar for different applications [8] , [9] , [13] , [22] , [23] . Increased production and consumption of food is connected with the production of food wastes that leads to many social and environmental challenges, however it can be considered as an inexpensive source of valuable components [24] , [25] , [26] , [27] , [28] including substrates and feedstock for biochar production.…”

“…Magnetization of biochar [18] , [22] , [28] , [29] can be obtained by various methods including i) impregnation-pyrolysis, ii) co-precipitation, iii) reductive co-deposition or iv) hydrothermal carbonization. The literature data on magnetization effect on biochar adsorption properties are indicating that different response can be noted both increased [18] or reduced [22] , [32] adsorption capacity.…”