Valorisation of Waste Wood Biomass as Biosorbent for the Removal of Synthetic Dye Methylene Blue from Aqueous Solutions

Abstract

Background and purpose: Wood and wood processing industries are generators of a substantial amount of waste wood biomass, such as wood chips, shavings and sawdust. Such waste is often unused and its disposal can be a serious environmental problem. Different lignocellulosic waste materials have been successfully used as low-cost adsorbents (biosorbents) for the removal of synthetic dyes, as well as other contaminants, from wastewater. The aim of this study was to valorise the waste wood biomass of ten tree species, out of which seven are the most represented species of the Croatian growing stock, as biosorbents for the removal of synthetic dye methylene blue (MB) from model solutions. Materials and Methods: The waste wood biomasses (shavings or sawdust) of ten tree species, namely common beech, pedunculate oak, sessile oak, common hornbeam, narrow-leafed ash, poplar, European silver fir, Norway spruce, European larch and Douglas fir, were dried and milled prior to characterisation and adsorption experiments. Characterisation of the biosorbents was performed by chemical analysis and Fourier transform Fourier transform infrared spectroscopy (FTIR). Upon characterisation, batch adsorption experiments were conducted in order to survey waste wood biomass as potential adsorbents for the removal of synthetic dye MB. The colour removal was monitored spectrophotometrically at predetermined time intervals. Further adsorption experiments were performed using poplar sawdust. The effects of contact time, biosorbent concentration, initial dye concentration, and pH on the adsorption process were investigated. The experimental data obtained by batch adsorption experiments were analysed using adsorption isotherm models (Freundlich and Langmuir). Results: All the tested biosorbents were found to be very effective for the removal of MB from model dye solution, achieving high removal percentages ranging from 93.25 to 98.50%. Poplar sawdust proved to be the most effective. It was shown that MB adsorption process onto poplar sawdust could be interpreted in terms of Langmuir and Freundlich adsorption isotherm models. conclusions: Taken together, these results suggest that waste wood biomass has the potential to be used as a low-cost biosorbent for MB removal from aqueous solutions.

From Waste to Biosorbent: Removal of Congo Red from Water by Waste Wood Biomass

“…Furthermore, out of the tested samples, poplars are characterized by the smallest specific density and (thus) the highest internal porosity [26,27], which could be the reason for the highest biosorption efficiency. The same 10 biosorbents were screened for cationic dye Methylene Blue (MB) removal under similar experimental conditions (different contact time, t = 120 min) and showed exceptional biosorptive capability with over 90% MB removal in all runs [15]. These results are consistent with the research by Nacu [28] who reported that adsorption capacity of sawdust for cationic dyes is much higher than that for anionic dyes (such as CR).…”

“…Pine bark 1.6 100 [9] Lemon-scented gum sawdust 0.523 >80 [10] Fir (Abies nordmanniana) sawdust 28.1 86 [11] Chir pine (Pinus roxburghii) sawdust 5.8 72 [12] Eucalyptus (Eucalyptus globulus) sawdust ->80 [13] Methylene Blue White cedar sawdust 55.15 - [14] Poplar waste biomass 21.9 98.50 [15] Pine sawdust (Pinus strobus) 10.3 99.94 [16] Cedar tree sawdust 142.36 - [17] Basic Violet 1 Chir pine (Pinus roxburghii) sawdust 11.3 96 [12] Disperse Orange 30 Poplar sawdust 0.089 83.4 [18] Eriochrome Black T Sawdust unspecified 40.96 80 [19] Allura Red AS Sawdust unspecified 50.98 - [20] Safranine O Sawdust unspecified -98 [21] Compared to activated carbon and biochar, native lignocellulosic materials as biosorbents are mostly inferior, i.e., adsorption capacities of native materials are lower. Therefore, attempts have been made to improve the adsorption capacities of such materials by phys-ical and/or chemical methods, including the production of biochar.…”

“…Characterization of all investigated biosorbents, namely elemental composition (CHN analysis), contents of ash, extractives, proteins and cellulose, point of zero charge (pH pzc ), and determination of surface functional groups (by Fourier transform infrared spectroscopy, FTIR) was given previously [15].…”

“…Douglas fir the least efficient with 13.1% CR removal and biosorption capacity of 0.5 mg g −1 . A ported previously [15], all the tested samples are characterized by high cellulose con and probably also by considerable hemicellulose and lignin contents [8]. The presen many specific functional groups of these polymers usually favors the biosorptive rem of dyes.…”

“…The slight shifting of the peaks (frequency and intensity change) in the FTIR spectrum of CR loaded EP compared to that of EP could be assigned to the biosorption of CR on the surface of biosorbent. As reported previously [15], EP used in this study is comprised of a large portion of cellulose (40.53%). The presence of cellulose, hemicellulose, and lignin, with a substantial number of functional groups present at the biosorbent surface, favorably affects the removal of dyes.…”