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Brewers’ spent grain (BSG), a lignocellulosic waste material, was evaluated as a low-cost adsorbent for the removal of synthetic dyes methylene blue (MB) and Congo red (CR) from aqueous solutions in a batch process. Characterisation of the BSG was performed by chemical analysis, FTIR and SEM. The effects of contact time, initial dye concentration, adsorbent particle size, adsorbent concentration and pH on the adsorption process were investigated. High removal of both dyes ranging from 70 to over 90 % was achieved. It was shown that in both cases (MB and CR adsorption) the process could be interpreted in terms of Langmuir and Freundlich adsorption isotherms. The kinetics of the adsorption process was well described by the pseudo-second-order model. The results indicated the potential use of BSG as a low-cost adsorbent for MB and CR dye removal from aqueous solutions. This work is licensed under a Creative Commons Attribution 4.0 International License.

Brewers’ spent grain (BSG), a lignocellulosic waste material, was evaluated as a low-cost adsorbent for the removal of synthetic dyes methylene blue (MB) and Congo red (CR) from aqueous solutions in a batch process. Characterisation of the BSG was performed by chemical analysis, FTIR and SEM. The effects of contact time, initial dye concentration, adsorbent particle size, adsorbent concentration and pH on the adsorption process were investigated. High removal of both dyes ranging from 70 to over 90 % was achieved. It was shown that in both cases (MB and CR adsorption) the process could be interpreted in terms of Langmuir and Freundlich adsorption isotherms. The kinetics of the adsorption process was well described by the pseudo-second-order model. The results indicated the potential use of BSG as a low-cost adsorbent for MB and CR dye removal from aqueous solutions. This work is licensed under a Creative Commons Attribution 4.0 International License.

Groundwater in the Eastern Croatia, as well in the South-eastern Hungary, contains relatively high concentrations of arsenic that can cause chronic toxicity to humans. Therefore, the aim to find an ef-fective composite adsorbent that can be applied for arsenic water remediation by introducing it in the groundwater treatment is very important. The presented results were obtained using layered double hy¬droxide (LDH) as a sorbing system. MgAl LDH samples with a Mg:Al molar ratio of 2:1 were synthe¬sized. Adsorption of arsenic anions from groundwater samples from Eastern Croatia, as well as adsorption of model aquatic arsenic sample solutions, on MgAl layered double hydroxide was investigated. Induc¬tively coupled plasma atomic emission spectrometry (ICP-AES) was used for determination of arsenic concentration after adsorption. It was shown that in both cases the adsorption process could be interpreted in terms of Kroeker adsorption isotherm regardless to the presence of other ions in the groundwater. Addi¬tionally, the influence of phosphate concentration on adsorption of model arsenic samples was examined and it was shown that (at least in examined range of arsenic and phosphate concentration) there is no sig¬nificant influence of phosphate on adsorption of arsenic. (doi: 10.5562/cca2283)