The influence of amination of sorbent based on buckwheat (Fagopyrum esculentum) husks on the sorption effectiveness of Reactive Black 5 dye

The Effect of Modifying Canadian Goldenrod (Solidago canadensis) Biomass with Ammonia and Epichlorohydrin on the Sorption Efficiency of Anionic Dyes from Water Solutions

“…The positive impact of low pH on the sorption efficiency of anionic dyes was also observed in studies addressing RB5 sorption onto activated carbon [ 34 ], carbon nanotubes [ 35 ], buckwheat husks [ 23 ], and chitin-based sorbents [ 36 ]. The same tendency was also noted in research investigating RY84 sorption onto coconut shells [ 37 ], sunflower husks [ 22 ], compost [ 38 ], and chitosan-based sorbents [ 39 , 40 ].…”

“…The shorter equilibrium times of dye sorption onto GB-EA compared with GB, GB-A, and GB-E stemmed from a high concentration of -NH 2 groups on the sorbent’s surface. The amine functional groups of GB-EA, protonated at pH 3, were responsible for a strong positive charge on the sorbent’s surface, which intensified and accelerated the dyes’ binding from the solution [ 20 , 21 , 23 ]. No similar effect was observed in the case of GB-A ( Figure 4 ), due to a substantially lower content of primary amine functional groups.…”

“…An ammonia water bath offers the simplest but least effective method for biomass amination. However, the efficiency of material amination can be boosted by its preliminary chemical activation, e.g., with epichlorohydrin [ 23 ].…”

Aminated Rapeseed Husks (Brassica napus) as an Effective Sorbent for Removing Anionic Dyes from Aqueous Solutions

“…The sorption effectiveness of rapeseed husks modified with epichlorohydrin and then aminated with ammonia (RH-EA) is much greater than that of non-modified lignocellulosic biosorbents, such as seed husks, plant stalks or sawdust ( Table 5 ). The process of biomass amination that had earlier been pre-activated with epichlorohydrin effectively increases the sorption capacity of other lignocellulosic materials, like sunflower seeds and buckwheat sed husks, wheat straw or Canadian goldenrod biomass, as described in our previous works [ 19 , 34 , 39 , 40 ].…”

“…However, the plant biomass amination upon the direct reaction of ammonia with the polysaccharides and lignin contained in the sorbent is deemed to be little effective. In order to increase its effectiveness, the material may be pre-activated by, e.g., reaction with epichlorohydrin [ 19 ]. It is assumed that plant biomass enriched in amine functional groups can gain high sorption capacity towards anionic dyes.…”